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Stock-Based Compensation Plans and Arrangements (Tables)

12 Months Ended

Dec. 31, 2019

Black-Scholes Model Assumptions for Calculating Stock Option Fair Values

There were no stock options granted in 2019. The fair values of the options granted in 2018 and 2017 were estimated as of the grant date using a Black-Scholes option pricing model with the following weighted average assumptions:

	Years Ended December 31,
	2018			2017
Expected life of the option	3.2 years			3.0 years
Expected volatility		36	%		34	%
Risk-free interest rate		2.27	%		1.44	%
Expected dividend rate		4.70	%		4.13	%
Weighted average fair value of options granted	$	2.59		$	2.69

Stock Option Activity

The following table summarizes Navient’s stock option activity in 2019.

(Dollars in millions, except per share data)	Number of Options			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value⁽¹⁾
Outstanding at December 31, 2018		11,174,890		$	12.97
Granted		—			—
Exercised⁽²⁾		(2,826,673	)		7.79
Canceled		(2,046,287	)		18.15
Outstanding at December 31, 2019⁽³⁾		6,301,930		$	13.61	1.6 yrs.	$	12
Exercisable at December 31, 2019		4,887,506		$	13.44	1.2 yrs.	$	12

⁽¹⁾

The aggregate intrinsic value represents the total intrinsic value (the aggregate difference between our closing stock price on December 31, 2019 and the exercise price of in-the-money options) that would have been received by the option holders if all in-the-money options had been exercised on December 31, 2019.

⁽²⁾

The total intrinsic value of Navient stock options exercised was $11 million, $12 million and $9 million for 2019, 2018 and 2017, respectively.

⁽³⁾

As of December 31, 2019, there was $.3 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted average period of 1.1 years.

Restricted Stock Activity

The following table summarizes Navient’s restricted stock activity in 2019.

	Number of Shares			Weighted Average Grant Date Fair Value
Non-vested at December 31, 2018		—		$	—
Granted		78,835			11.72
Vested⁽¹⁾		(78,835	)		11.72
Canceled		—			—
Non-vested at December 31, 2019⁽²⁾		—		$	—

⁽¹⁾

The total fair value of Navient shares that vested was $1 million, $1 million and $1 million for 2019, 2018 and 2017, respectively.

⁽²⁾

As of December 31, 2019, there was no unrecognized compensation cost related to restricted stock.

Restricted Stock Unit and Performance Stock Unit Activity

The following table summarizes Navient’s RSU and PSU activity in 2019.

	Number of RSUs/PSUs			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2018		4,259,771		$	12.55
Granted		2,096,830			10.95
Vested and converted to common stock⁽¹⁾		(2,336,927	)		11.14
Canceled		(80,053	)		12.96
Outstanding at December 31, 2019⁽²⁾		3,939,621		$	12.52

⁽¹⁾

The total fair value of Navient RSUs and PSUs that vested and converted to common stock was $26 million, $22 million and $23 million for 2019, 2018 and 2017, respectively.

⁽²⁾

As of December 31, 2019, there was $10 million of unrecognized compensation cost related to RSUs and PSUs, which is expected to be recognized over a weighted average period of 1.8 years.

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets
Loans, net	$ 86,820	$ 94,498
Investments
Held-to-maturity	19
Other	192	226
Total investments	211	226
Cash and cash equivalents	1,233	1,286
Restricted cash and cash equivalents	2,548	3,976
Goodwill and acquired intangible assets, net	757	786
Other assets	3,334	3,404
Total assets	94,903	104,176
Liabilities
Short-term borrowings	8,483	5,422
Long-term borrowings	81,715	93,519
Other liabilities	1,356	1,688
Total liabilities	91,554	100,629
Commitments and contingencies
Equity
Common stock, par value $0.01 per share; 1.125 billion shares authorized: 451 million and 445 million shares issued, respectively	4	4
Additional paid-in capital	3,198	3,145
Accumulated other comprehensive income (net of tax (benefit) expense of $(30) and $35, respectively)	(91)	113
Retained earnings	3,664	3,218
Total Navient Corporation stockholders’ equity before treasury stock	6,775	6,480
Less: Common stock held in treasury at cost: 236 million and 198 million shares, respectively	(3,439)	(2,961)
Total Navient Corporation stockholders’ equity	3,336	3,519
Noncontrolling interest	13	28
Total equity	3,349	3,547
Total liabilities and equity	94,903	104,176
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Assets
Loans, net	83,864	91,619
Investments
Total assets	87,459	96,503
Investments
Restricted cash	2,506	3,928
Other assets, net	1,089	956
Liabilities
Short-term borrowings	7,089	4,341
Long-term borrowings	72,856	82,738
Net assets of consolidated variable interest entities	7,514	9,424
FFELP Loans [Member]
Assets
Loans, net	64,575	72,253
FFELP Loans [Member] \| Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Assets
Loans, net	64,255	71,921
Private Education Loans [Member]
Assets
Loans, net	22,245	22,245
Private Education Loans [Member] \| Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Assets
Loans, net	$ 19,609	$ 19,698

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 597	$ 395	$ 292
Net changes in cash flow hedges, net of taxes	(204)	39	55
Total comprehensive income	$ 393	$ 434	$ 347

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
-Paragraph 1B
-Subparagraph (a)
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 6: http://www.xbrl.org/2003/role/exampleRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3000-108585

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
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-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=116874947&loc=SL4591552-111686

+ Details

Allowance for Loan Losses - Receivable for Partially Charged-Off Private Education Loans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Charge-offs	$ (429)	$ (459)	$ (499)
Private Education Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Charge-offs	(385)	(403)	(443)
Private Education Loans [Member] \| Loans Receivable For Partially Charged Off Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Receivable at beginning of period	674	760	815
Expected future recoveries of current period defaults	74	89	110
Recoveries	(126)	(139)	(155)
Charge-offs	(34)	(36)	(10)
Receivable at end of period	$ 588	$ 674	$ 760

Derivative Financial Instruments - Carrying Value and Related Fair Value Hedging Adjustments of Liabilities (Detail) - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Short-term borrowings [Member]
Derivatives Fair Value [Line Items]
Carrying Value	$ 1,001	$ 664
Hedge Basis Adjustments	4	(3)
Long-term borrowings [Member]
Derivatives Fair Value [Line Items]
Carrying Value	11,488	13,657
Hedge Basis Adjustments	$ (58)	$ (368)

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income	$ 597	$ 395	$ 292
Adjustments to reconcile net income to net cash provided by operating activities:
(Gains) on sale of education loans	(16)		(3)
(Gains) losses on debt repurchases	(45)	(19)	3
Goodwill and acquired intangible asset impairment and amortization expense	30	47	23
Stock-based compensation expense	25	25	35
Mark-to-market (gains)/losses on derivative and hedging activities, net	130	37	(83)
Provisions for loan losses	258	370	426
Decrease (increase) in accrued interest receivable	78	(125)	(29)
(Decrease) increase in accrued interest payable	(96)	58	11
Decrease in other assets	191	321	485
(Decrease) increase in other liabilities	(133)	31	(5)
Total adjustments	422	745	866
Total net cash provided by operating activities	1,019	1,140	1,158
Investing activities
Education loans acquired	(5,411)	(3,652)	(7,371)
Principal payments on education loans	12,472	13,973	14,738
Proceeds from sales of education loans	408
Other investing activities, net	9	(76)	(88)
Proceeds from sales and maturities of other securities	7	115	23
Purchase of subsidiaries, net of cash and restricted cash acquired			(184)
Total net cash provided by investing activities	7,485	10,360	7,118
Financing activities
Borrowings collateralized by loans in trust - issued	7,919	9,006	8,440
Borrowings collateralized by loans in trust - repaid	(14,271)	(14,057)	(13,919)
Long-term notes issued		495	1,613
Long-term notes repaid	(1,950)	(2,947)	(1,464)
Other financing activities, net	(189)	(162)	(33)
Common stock repurchased	(440)	(220)	(440)
Common dividends paid	(147)	(166)	(176)
Total net cash used in financing activities	(9,985)	(10,884)	(8,342)
Net (decrease) increase in cash, cash equivalents, restricted cash and restricted cash equivalents	(1,481)	616	(66)
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of period	5,262	4,646	4,712
Cash, cash equivalents, restricted cash and restricted cash equivalents at end of period	3,781	5,262	4,646
Cash disbursements made (refunds received) for:
Interest	3,479	3,460	2,872
Income taxes paid	93	57	157
Income taxes received	(4)	(6)	(1)
Reconciliation of the Consolidated Statements of Cash Flows to the Consolidated Balance Sheets:
Total cash, cash equivalents, restricted cash and restricted cash equivalents at end of period	5,262	5,262	4,646
Non-cash activities
Investing activity - Education loans			1,746
Investing activity - Held-to-maturity asset backed securities retained related to sales of education loans	22
Operating activity - Other assets acquired and other liabilities assumed, net			137
Operating activity - Servicing assets recognized upon sales of education loans	3
Financing activity - Borrowings assumed in acquisition of education loans			1,883
Asset-backed Securities, Securitized Loans and Receivables [Member]
Financing activities
Asset-backed commercial paper conduits, net	$ (907)	$ (2,833)	$ (2,363)

Borrowings - Financing VIEs (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Securities Financing Transaction [Line Items]
Short-term borrowings	$ 8,483	$ 5,422
Long-term borrowings	81,715	93,519
Total	90,198	98,941
Loans	86,820	94,498
Total assets	94,903	104,176
Total Before Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	8,479	5,425
Long-term borrowings	81,756	93,868
Total	90,235	99,293
Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	4	(3)
Long-term borrowings	(41)	(349)
Total	(37)	(352)
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	7,089	4,341
Long-term borrowings	72,856	82,738
Total	79,945	87,079
Loans	83,864	91,619
Cash	2,506	3,928
Other assets, Net	1,089	956
Total assets	87,459	96,503
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| FFELP Loan Securitizations [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	72
Long-term borrowings	59,735	66,318
Total	59,807	66,318
Loans	60,834	66,266
Cash	1,833	3,181
Other assets, Net	1,400	1,211
Total assets	64,067	70,658
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Private Education Loan Securitizations [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	2,120	300
Long-term borrowings	11,430	12,985
Total	13,550	13,285
Loans	15,412	16,336
Cash	509	536
Other assets, Net	152	198
Total assets	16,073	17,070
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| FFELP Loan ABCP Facilities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	2,783	2,927
Long-term borrowings	617	2,625
Total	3,400	5,552
Loans	3,421	5,656
Cash	63	132
Other assets, Net	102	162
Total assets	3,586	5,950
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Private Education Loan ABCP Facilities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	2,114	1,114
Long-term borrowings	1,513	1,266
Total	3,627	2,380
Loans	4,197	3,361
Cash	101	79
Other assets, Net	28	27
Total assets	4,326	3,467
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Total Before Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	7,089	4,341
Long-term borrowings	73,295	83,194
Total	80,384	87,535
Loans	83,864	91,619
Cash	2,506	3,928
Other assets, Net	1,682	1,598
Total assets	88,052	97,145
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Long-term borrowings	(439)	(456)
Total	(439)	(456)
Other assets, Net	(593)	(642)
Total assets	$ (593)	$ (642)

Derivative Financial Instruments - Collateral Held and Pledged (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Collateral held:
Cash (obligation to return cash collateral is recorded in short-term borrowings)	$ 337	$ 266
Securities at fair value - on-balance sheet securitization derivatives (not recorded in financial statements)	69	90
Total collateral held	406	356
Derivative asset at fair value including accrued interest	282	210
Collateral pledged to others:
Cash (right to receive return of cash collateral is recorded in investments)	155	188
Total collateral pledged	155	188
Derivative liability at fair value including accrued interest and premium receivable	$ 658	$ 752

Allowance for Loan Losses - Age Analysis of Past Due Loans Delinquencies (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans in repayment and percentage of each status:
Total loans in repayment	$ 86,820	$ 94,498
Loans allowance for losses	(1,112)	(1,286)	$ (1,367)	$ (1,433)
FFELP Loans [Member]
Loans in repayment and percentage of each status:
Total loans in repayment	64,575	72,253
Loans allowance for losses	(64)	(76)	(60)	$ (67)
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans current	7,557	7,890	8,333
Total loans in repayment	8,442	9,025	9,378
Total loans, gross	9,270	9,969	10,536
Loans unamortized premium (discount)	(203)	(212)	(225)
Total loans	9,067	9,757	10,311
Loans receivable for partially charged-off loans	347	367	385
Loans allowance for losses	(941)	(1,100)	(1,171)
Loans, net	$ 8,473	$ 9,024	$ 9,525
Dimensions of concentration risk	100.00%	100.00%	100.00%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Total loans in repayment	$ 13,647	$ 13,012	$ 13,546
Total loans, gross	14,052	13,562	14,344
Loans unamortized premium (discount)	(414)	(547)	(699)
Total loans	13,638	13,015	13,645
Loans receivable for partially charged-off loans	241	307	375
Loans allowance for losses	(107)	(101)	(126)
Loans, net	$ 13,772	$ 13,221	$ 13,894
Dimensions of concentration risk	100.00%	100.00%	100.00%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| School/Grace/Deferment [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Total loans, gross	$ 349	$ 426	$ 477
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| School/Grace/Deferment [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Total loans, gross	280	392	584
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Forbearance [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Total loans, gross	479	518	681
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Forbearance [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Total loans, gross	125	158	214
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Loans current	47,255	53,500	59,264
Total loans in repayment	53,538	59,551	67,853
Total loans, gross	64,094	71,730	81,097
Loans unamortized premium (discount)	545	599	666
Total loans	64,639	72,329	81,763
Loans allowance for losses	(64)	(76)	(60)
Loans, net	$ 64,575	$ 72,253	$ 81,703
Dimensions of concentration risk	100.00%	100.00%	100.00%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| FFELP Loans [Member] \| School/Grace/Deferment [Member]
Loans in repayment and percentage of each status:
Total loans, gross	$ 3,114	$ 3,793	$ 4,711
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| FFELP Loans [Member] \| Forbearance [Member]
Loans in repayment and percentage of each status:
Total loans, gross	7,442	8,386	8,533
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 31 to 60 Days Past Due [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 296	$ 344	$ 351
Loans delinquent, percentage	3.50%	3.80%	3.70%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 31 to 60 Days Past Due [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 53	$ 71	$ 120
Loans delinquent, percentage	0.40%	0.50%	0.90%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 31 to 60 Days Past Due [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 2,094	$ 1,964	$ 2,638
Loans delinquent, percentage	3.90%	3.40%	3.90%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 61 to 90 Days Past Due [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 191	$ 235	$ 207
Loans delinquent, percentage	2.30%	2.60%	2.20%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 61 to 90 Days Past Due [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 27	$ 32	$ 59
Loans delinquent, percentage	0.20%	0.30%	0.40%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 61 to 90 Days Past Due [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 1,082	$ 910	$ 1,763
Loans delinquent, percentage	2.00%	1.50%	2.60%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 90 Days Past Due [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 398	$ 556	$ 487
Loans delinquent, percentage	4.70%	6.20%	5.20%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 90 Days Past Due [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 41	$ 58	$ 110
Loans delinquent, percentage	0.30%	0.40%	0.80%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, 90 Days Past Due [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 3,107	$ 3,177	$ 4,188
Loans delinquent, percentage	5.80%	5.30%	6.20%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Current [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	89.50%	87.40%	88.90%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Current [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans current	$ 13,526	$ 12,851	$ 13,257
Dimensions of concentration risk	99.10%	98.80%	97.90%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Current [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	88.30%	89.80%	87.30%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Loans In Repayment [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	91.10%	90.50%	89.00%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Loans In Repayment [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	97.10%	95.90%	94.40%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Loans In Repayment [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	83.50%	83.00%	83.70%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Delinquent Loans in Repayment [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	10.50%	12.60%	11.10%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Delinquent Loans in Repayment [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	0.90%	1.20%	2.10%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Delinquent Loans in Repayment [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	11.70%	10.20%	12.70%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Forbearance, Loans In Repayment [Member] \| Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	5.40%	5.40%	6.80%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Forbearance, Loans In Repayment [Member] \| Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	0.90%	1.20%	1.60%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Financing Receivables, Forbearance, Loans In Repayment [Member] \| FFELP Loans [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	12.20%	12.30%	11.20%

Derivative Financial Instruments

12 Months Ended

Dec. 31, 2019

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Derivative Financial Instruments

7. Derivative Financial Instruments

Risk Management Strategy

We maintain an overall interest rate risk management strategy that incorporates the use of derivative instruments to minimize the economic effect of interest rate changes. Our goal is to manage interest rate sensitivity by modifying the repricing frequency and underlying index characteristics of certain balance sheet assets and liabilities so the net interest margin is not, on a material basis, adversely affected by movements in interest rates. We do not use derivative instruments to hedge credit risk. As a result of interest rate fluctuations, hedged assets and liabilities will appreciate or depreciate in market value. Income or loss on the derivative instruments that are linked to the hedged assets and liabilities will generally offset the effect of this unrealized appreciation or depreciation for the period the item is being hedged. We view this strategy as a prudent management of interest rate sensitivity. In addition, we utilize derivative contracts to minimize the economic impact of changes in foreign currency exchange rates on certain debt obligations that are denominated in foreign currencies. As foreign currency exchange rates fluctuate, these liabilities will appreciate and depreciate in value. These fluctuations, to the extent the hedge relationship is effective, are offset by changes in the value of the cross-currency interest rate swaps executed to hedge these instruments. Management believes certain derivative transactions entered into as hedges, primarily Floor Income Contracts and basis swaps, are economically effective; however, those transactions generally do not qualify for hedge accounting under GAAP (as discussed below) and thus may adversely impact earnings.

Although we use derivatives to minimize the risk of interest rate and foreign currency changes, the use of derivatives does expose us to both market and credit risk. Market risk is the chance of financial loss resulting from changes in interest rates, foreign exchange rates and market liquidity. Credit risk is the risk that a counterparty will not perform its obligations under a contract and it is limited to the loss of the fair value gain in a derivative that the counterparty owes us. When the fair value of a derivative contract is negative, we owe the counterparty and, therefore, have no credit risk exposure to the counterparty; however, the counterparty has exposure to us. We minimize the credit risk in derivative instruments by entering into transactions with highly rated counterparties that are reviewed regularly by our Credit Department. We also maintain a policy of requiring that all derivative contracts be governed by an International Swaps and Derivative Association Master Agreement. Depending on the nature of the derivative transaction, bilateral collateral arrangements related to Navient Corporation contracts generally are required as well. When we have more than one outstanding derivative transaction with the counterparty, and there exists legally enforceable netting provisions with the counterparty (i.e., a legal right to offset receivable and payable derivative contracts), the “net” mark-to-market exposure, less collateral the counterparty has posted to us, represents exposure with the counterparty. When there is a net negative exposure, we consider our exposure to the counterparty to be zero. At December 31, 2019 and 2018, we had a net positive exposure (derivative gain positions to us less collateral which has been posted by counterparties to us) related to Navient Corporation derivatives of $12 million and $19 million, respectively.

Our on-balance sheet securitization trusts have $4.0 billion of Euro and British Pound Sterling denominated bonds outstanding as of December 31, 2019. To convert these non-U.S. dollar denominated bonds into U.S. dollar liabilities, the trusts have entered into foreign-currency swaps with highly-rated counterparties. In addition, the trusts have entered into $3.7 billion notional of interest rates swaps which are primarily used to convert Prime received on securitized education loans to LIBOR paid on the bonds. Our securitization trusts with swaps have ISDA documentation with protections against counterparty risk. The collateral calculations contemplated in the ISDA documentation of our securitization trusts require collateral based on the fair value of the derivative which may be adjusted for additional collateral based on rating agency criteria requirements considered within the collateral agreement. The trusts are not required to post collateral to the counterparties. At December 31, 2019 and 2018, the net positive exposure on swaps in securitization trusts was $0 and $7 million, respectively.

Accounting for Derivative Instruments

Derivative instruments that are used as part of our interest rate and foreign currency risk management strategy include interest rate swaps, cross-currency interest rate swaps, and interest rate floor contracts with indices that relate to the pricing of specific balance sheet assets and liabilities. The accounting for derivative instruments requires that every derivative instrument, including certain derivative instruments embedded in other contracts, be recorded on the balance sheet as either an asset or liability measured at its fair value. As more fully described below, if certain criteria are met, derivative instruments are classified and accounted for by us as either fair value or cash flow hedges. If these criteria are not met, the derivative financial instruments are accounted for as trading.

7. Derivative Financial Instruments (Continued)

Fair Value Hedges

Fair value hedges are generally used by us to hedge the exposure to changes in fair value of a recognized fixed rate asset or liability. We enter into interest rate swaps to economically convert fixed rate assets into variable rate assets and fixed rate debt into variable rate debt. We also enter into cross-currency interest rate swaps to economically convert foreign currency denominated fixed and floating debt to U.S. dollar denominated variable debt. For fair value hedges, we generally consider all components of the derivative’s gain and/or loss when assessing hedge effectiveness and generally hedge changes in fair values due to interest rates or interest rates and foreign currency exchange rates.

Cash Flow Hedges

We use cash flow hedges to hedge the exposure to variability in cash flows for a forecasted debt issuance and for exposure to variability in cash flows of floating rate debt. This strategy is used primarily to minimize the exposure to volatility from future changes in interest rates. Gains and losses on qualifying hedges are recorded in accumulated other comprehensive income. In the case of a forecasted debt issuance, gains and losses are reclassified to earnings over the period which the stated hedged transaction affects earnings. If we determine it is not probable that the anticipated transaction will occur, gains and losses are reclassified immediately to earnings. In assessing hedge effectiveness, generally all components of each derivative’s gains or losses are included in the assessment. We generally hedge exposure to changes in cash flows due to changes in interest rates or total changes in cash flow.

Trading Activities

When derivative instruments do not qualify as hedges, they are accounted for as trading instruments where all changes in fair value are recorded through earnings. We sell interest rate floors (Floor Income Contracts) to hedge the embedded Floor Income options in education loan assets. The Floor Income Contracts are written options which have a more stringent hedge effectiveness hurdle to meet. Specifically, our Floor Income Contracts do not qualify for hedge accounting treatment because the pay down of principal of the education loans underlying the Floor Income embedded in those education loans does not exactly match the change in the notional amount of our written Floor Income Contracts. Additionally, the term, the interest rate index and the interest rate index reset frequency of the Floor Income Contracts can be different from that of the education loans. Therefore, Floor Income Contracts do not qualify for hedge accounting treatment and are recorded as trading instruments. Regardless of the accounting treatment, we consider these contracts to be economic hedges for risk management purposes. We use this strategy to minimize our exposure to changes in interest rates.

We use basis swaps to minimize earnings variability caused by having different reset characteristics on our interest-earning assets and interest-bearing liabilities. The specific terms and notional amounts of the swaps are determined based on a review of our asset/liability structure, our assessment of future interest rate relationships, and on other factors such as short-term strategic initiatives. Hedge accounting requires that when using basis swaps, the change in the cash flows of the hedge effectively offset both the change in the cash flows of the asset and the change in the cash flows of the liability. Our basis swaps hedge variable interest rate risk; however, they generally do not meet this effectiveness criterion because the index of the swap does not exactly match the index of the hedged assets. Additionally, some of our FFELP Loans can earn at either a variable or a fixed interest rate depending on market interest rates and, therefore, swaps economically hedging these FFELP Loans do not meet the criteria for hedge accounting treatment. As a result, these swaps are recorded at fair value with changes in fair value reflected currently in the statement of income.

7. Derivative Financial Instruments (Continued)

Summary of Derivative Financial Statement Impact

The following tables summarize the fair values and notional amounts or number of contracts of all derivative instruments at December 31, 2019 and 2018, and their impact on other comprehensive income and earnings for 2019, 2018 and 2017.

Impact of Derivatives on Consolidated Balance Sheet

		Cash Flow				Fair Value⁽⁴⁾						Trading						Total
(Dollars in millions)	Hedged Risk Exposure	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019			Dec. 31, 2018			Dec. 31, 2019			Dec. 31, 2018			Dec. 31, 2019			Dec. 31, 2018
Fair Values⁽¹⁾
Derivative Assets:
Interest rate swaps	Interest rate	$	—	$	—	$	226		$	170		$	4		$	3		$	230		$	173
Cross-currency interest rate swaps	Foreign currency and interest rate		—		—		—			6			—			—			—			6
Total derivative assets⁽²⁾			—		—		226			176			4			3			230			179
Derivative Liabilities:
Interest rate swaps	Interest rate		—		—		—			(34	)		(20	)		(45	)		(20	)		(79	)
Floor Income Contracts	Interest rate		—		—		—			—			(68	)		(53	)		(68	)		(53	)
Cross-currency interest rate swaps	Foreign currency and interest rate		—		—		(575	)		(639	)		—			(26	)		(575	)		(665	)
Other⁽³⁾	Interest rate		—		—		—			—			(1	)		(4	)		(1	)		(4	)
Total derivative liabilities⁽²⁾			—		—		(575	)		(673	)		(89	)		(128	)		(664	)		(801	)
Net total derivatives		$	—	$	—	$	(349	)	$	(497	)	$	(85	)	$	(125	)	$	(434	)	$	(622	)

⁽¹⁾

Fair values reported are exclusive of collateral held and pledged and accrued interest. Assets and liabilities are presented without consideration of master netting agreements. Derivatives are carried on the balance sheet based on net position by counterparty under master netting agreements, and classified in other assets or other liabilities depending on whether in a net positive or negative position.

⁽²⁾	The following table reconciles gross positions without the impact of master netting agreements to the balance sheet classification:

	Other Assets						Other Liabilities
(Dollar in millions)	December 31, 2019			December 31, 2018			December 31, 2019			December 31, 2018
Gross position	$	230		$	179		$	(664	)	$	(801	)
Impact of master netting agreements		(18	)		(22	)		18			22
Derivative values with impact of master netting agreements (as carried on balance sheet)		212			157			(646	)		(779	)
Cash collateral (held) pledged		(337	)		(266	)		155			188
Net position	$	(125	)	$	(109	)	$	(491	)	$	(591	)

⁽³⁾	^{“Other” includes derivatives related to our Total Return Swap Facility.}

⁽⁴⁾	^{The following table shows the carrying value of liabilities in fair value hedges and the related fair value hedging adjustments to these liabilities:}

	As of December 31, 2019					As of December 31, 2018
(Dollar in millions)	Carrying Value		Hedge Basis Adjustments			Carrying Value		Hedge Basis Adjustments
Short-term borrowings	$	1,001	$	4		$	664	$	(3	)
Long-term borrowings	$	11,488	$	(58	)	$	13,657	$	(368	)

7. Derivative Financial Instruments (Continued)

The above fair values include adjustments when necessary for counterparty credit risk for both when we are exposed to the counterparty, net of collateral postings, and when the counterparty is exposed to us, net of collateral postings. The net adjustments decreased the asset position at December 31, 2019 and December 31, 2018 by $11 million and $26 million, respectively. In addition, the above fair values reflect adjustments for illiquid derivatives as indicated by a wide bid/ask spread in the interest rate indices to which the derivatives are indexed. These adjustments decreased the overall net asset positions at December 31, 2019 and December 31, 2018 by $12 million and $19 million, respectively.

	Cash Flow				Fair Value				Trading				Total
(Dollars in billions)	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018
Notional Values:
Interest rate swaps	$	19.1	$	21.4	$	8.6	$	10.3	$	51.5	$	66.9	$	79.2	$	98.6
Floor Income Contracts		—		—		—		—		21.2		27.9		21.2		27.9
Cross-currency interest rate swaps		—		—		4.0		4.5		—		.2		4.0		4.7
Other⁽¹⁾		—		—		—		—		—		.2		—		.2
Total derivatives	$	19.1	$	21.4	$	12.6	$	14.8	$	72.7	$	95.2	$	104.4	$	131.4

⁽¹⁾	“Other” includes derivatives related to our Total Return Swap Facility.

Mark-to-Market Impact of Derivatives on Consolidated Statements of Income

	Total Gains (Losses)
	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Fair Value Hedges⁽²⁾:
Interest Rate Swaps
Gains (losses) recognized in net income on derivatives	$	281		$	(137	)	$	(214	)
Gains (losses) recognized in net income on hedged items		(299	)		162			193
Net fair value hedge ineffectiveness gains (losses)		(18	)		25			(21	)
Cross currency interest rate swaps
Gains (losses) recognized in net income on derivatives		57			(311	)		921
Gains (losses) recognized in net income on hedged items		(18	)		210			(954	)
Net fair value hedge ineffectiveness gains (losses)		39			(101	)		(33	)
Total fair value hedges⁽¹⁾⁽²⁾		21			(76	)		(54	)
Cash Flow Hedges:
Total cash flow hedges⁽²⁾		—			—			—
Trading
Interest rate swaps		44			22			8
Floor income contracts		(22	)		15			81
Cross currency interest rate swaps		(2	)		(3	)		2
Other		2			4			(15	)
Total trading derivatives⁽³⁾		22			38			76
Mark-to-market gains (losses) recognized	$	43		$	(38	)	$	22

⁽¹⁾	Recorded in interest expense in the consolidated statements of income for 2019 with the adoption of ASU No. 2017-12. Recorded in “gains (losses) on derivatives and hedging activities, net” in the consolidated statements of income for 2018 and 2017.

⁽²⁾	The accrued interest income (expense) on fair value hedges and cash flow hedges is recorded in interest expense and is excluded from this table.

⁽³⁾	Recorded in “gains (losses) on derivative and hedging activities, net” in the consolidated statements of income.

7. Derivative Financial Instruments (Continued)

Impact of Derivatives on Consolidated Statements of Changes in Stockholders’ Equity (net of tax)

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Total gains (losses) on cash flow hedges	$	(165	)	$	50		$	25
Reclassification adjustments for derivative (gains) losses included in net income (interest expense)⁽¹⁾⁽²⁾		(39	)		(11	)		30
Total change in stockholders’ equity for unrealized gains (losses) on derivatives	$	(204	)	$	39		$	55

⁽¹⁾

Includes net settlement income/expense.

⁽²⁾

We expect to reclassify $2 million of after-tax net losses from accumulated other comprehensive income to earnings during the next 12 months related to amortization of terminated hedge relationships.

Collateral

The following table details collateral held and pledged related to derivative exposure between us and our derivative counterparties.

(Dollars in millions)	December 31, 2019		December 31, 2018
Collateral held:
Cash (obligation to return cash collateral is recorded in short-term borrowings)	$	337	$	266
Securities at fair value — corporate derivatives (not recorded in financial statements)⁽¹⁾		—		—
Securities at fair value — on-balance sheet securitization derivatives (not recorded in financial statements)⁽²⁾		69		90
Total collateral held	$	406	$	356
Derivative asset at fair value including accrued interest	$	282	$	210
Collateral pledged to others:
Cash (right to receive return of cash collateral is recorded in investments)	$	155	$	188
Total collateral pledged	$	155	$	188
Derivative liability at fair value including accrued interest and premium receivable	$	658	$	752

⁽¹⁾	The Company has the ability to sell or re-pledge securities it holds as collateral.

⁽²⁾	The trusts do not have the ability to sell or re-pledge securities they hold as collateral.

Our corporate derivatives contain credit contingent features. At our current unsecured credit rating, we have fully collateralized our corporate derivative liability position (including accrued interest and net of premiums receivable) of $53 million with our counterparties. Downgrades in our unsecured credit rating would not result in any additional collateral requirements. Trust related derivatives do not contain credit contingent features related to our or the trusts’ credit ratings.

Borrowings - Expected Maturities of Long-term Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
2020	$ 6,800
2021	10,200
2022	8,000
2023	7,600
2024	7,300
2025-2043	42,500
Total	81,715	$ 93,519
Fixed Maturities [Member]
Debt Instrument [Line Items]
2020	6,768
2021	10,158
2022	7,953
2023	7,515
2024	7,211
2025-2043	42,151
Long term debt maturities total	81,756
Hedge accounting adjustments	(41)
Total	81,715
Fixed Maturities [Member] \| Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
2021	1,439
2022	1,741
2023	1,501
2024	1,352
2025-2043	2,428
Long term debt maturities total	8,461
Hedge accounting adjustments	398
Total	8,859
Fixed Maturities [Member] \| Secured Borrowings [Member]
Debt Instrument [Line Items]
2020	6,768
2021	8,719
2022	6,212
2023	6,014
2024	5,859
2025-2043	39,723
Long term debt maturities total	73,295
Hedge accounting adjustments	(439)
Total	$ 72,856

Stock-Based Compensation Plans and Arrangements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 25	$ 25	$ 35
Unrecognized compensation cost	$ 11
Weighted average period for total unrecognized compensation cost	1 year 9 months 18 days
Stock options granted	0
Time Vested Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	Most stock options are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date.
Restricted Stock Units, RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	RSUs generally are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date
Performance Stock Units, PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	PSUs vest based on achieving certain corporate performance goals over a three-year performance period
Navient Corporation 2014 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effective date	Apr. 07, 2014
Shares authorized to be issued under plan	55,000,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effective date	May 01, 2014
Shares authorized to be issued under plan	3,000,000
Grants Made since 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term for stock options (in years)	5 years
Grants Made Prior to 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term for stock options (in years)	10 years

Stock-Based Compensation Plans and Arrangements - Restricted Stock and Performance Stock Unit Activity (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 11
Weighted average period for total unrecognized compensation cost	1 year 9 months 18 days
Restricted Stock Units and Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of restricted stock that vested	$ 26	$ 22	$ 23
Unrecognized compensation cost	$ 10
Weighted average period for total unrecognized compensation cost	1 year 9 months 18 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of restricted stock that vested	$ 1	$ 1	$ 1
Unrecognized compensation cost	$ 0

Stockholders' Equity - Common Share Repurchases and Issuances (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity, Class of Treasury Stock [Line Items]
Average purchase price per share	$ 12.76	$ 12.64	$ 14.85
Shares repurchased related to employee stock-based compensation plans	3,226,301	3,829,629	1,847,651
Average purchase price per share	$ 11.62	$ 13.71	$ 15.40
Common shares issued	5,717,053	5,659,681	3,680,479
Common Stock Shares Outstanding [Member]
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased	34,491,342	17,443,351	29,646,374
Shares repurchased related to employee stock-based compensation plans	3,226,301	3,829,629	1,847,651
Common shares issued	5,717,053	5,659,681	3,680,479

Allowance for Loan Losses - Receivable for Partially Charged-Off Private Education Loans (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate			$ (21)	$ (32)
Private Education Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate			$ (21)	$ (32)
Private Education Loans [Member] \| Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	80.50%	79.00%	80.50%	79.00%
Private Education Loans [Member] \| Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	81.00%	80.50%	81.00%	80.50%
Private Education Loans [Member] \| Loans Receivable For Partially Charged Off Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate	$ (21)	$ (32)	$ (21)	$ (32)

Borrowings - Gains (Losses) on Debt Repurchases (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt principal repurchased	$ 1,184	$ 2,809	$ 513
Gains (losses) on debt repurchases	$ 45	$ 19	$ (3)

Segment Reporting

12 Months Ended

Dec. 31, 2019

Segment Reporting [Abstract]

Segment Reporting

16. Segment Reporting

We monitor and assess our ongoing operations and results based on the following four reportable operating segments: Federal Education Loans, Consumer Lending, Business Processing and Other.

These segments meet the quantitative thresholds for reportable operating segments. Accordingly, the results of operations of these reportable operating segments are presented separately. The underlying operating segments are used by the Company’s chief operating decision maker to manage the business, review operating performance and allocate resources, and qualify to be aggregated as part of the primary reportable operating segments. As discussed further below, we measure the profitability of our operating segments based on Core Earnings net income. Accordingly, information regarding our reportable operating segments is provided on a Core Earnings basis.

Federal Education Loans Segment

In this segment, Navient holds and acquires FFELP Loans and performs servicing and asset recovery services on its own loan portfolio, federal education loans owned by ED and other institutions. Although FFELP Loans are no longer originated, we continue to pursue acquisitions of FFELP Loan portfolios as well as servicing and asset recovery services contracts. These acquisitions leverage our servicing scale and generate incremental earnings and cash flow. In this segment, we generate revenue primarily through net interest income on the FFELP Loan portfolio (after provision for loan losses) as well as servicing and asset recovery services revenue. This segment is expected to generate significant amounts of earnings and cash flow over the remaining life of the portfolio.

The following table includes GAAP-basis asset information for our Federal Education Loans segment.

	December 31,
(Dollars in millions)	2019		2018
FFELP Loans, net	$	64,575	$	72,253
Cash and investments⁽¹⁾		2,043		3,368
Other		2,202		2,100
Total assets	$	68,820	$	77,721

⁽¹⁾

^{Includes restricted cash and investments.}

16. Segment Reporting (Continued)

Consumer Lending Segment

In this segment, Navient holds, originates and acquires consumer loans and performs servicing activities on its own education loan portfolio. Originations and acquisitions leverage our servicing scale and generate incremental earnings and cash flow. In this segment, we generate revenue primarily through net interest income on the Private Education Loan portfolio (after provision for loan losses). This segment is expected to generate significant amounts of earnings and cash flow over the remaining life of the portfolio.

The following table includes GAAP-basis asset information for our Consumer Lending segment.

	December 31,
Dollars in millions)	2019		2018
Private Education Loans, net	$	22,245	$	22,245
Cash and investments⁽¹⁾		927		732
Other		931		1,076
Total assets	$	24,103	$	24,053

⁽¹⁾

^{Includes restricted cash and investments.}

Business Processing Segment

In this segment, Navient performs revenue cycle management and business processing services for over 500 non-education related government and healthcare clients. Our integrated solutions technology and superior data driven approach allows state governments, agencies, court systems, municipalities, and toll authorities (Government Services) to reduce their operating expenses while maximizing revenue opportunities. Healthcare services include revenue cycle outsourcing, accounts receivable management, extended business office support and consulting engagements. We offer customizable solutions for our clients that include hospitals, hospital systems, medical centers, large physician groups and other healthcare providers.

At December 31, 2019 and 2018, the Business Processing segment had total assets of $423 million and $448 million, respectively, on a GAAP basis.

Other Segment

Our Other segment primarily consists of our corporate liquidity portfolio and the repurchase of debt, unallocated expenses of shared services, restructuring/other reorganization expenses, and the deferred tax asset remeasurement loss recognized due to the enactment of the TCJA in the fourth quarter of 2017.

Unallocated expenses of shared services are comprised of costs primarily related to certain executive management, the board of directors, accounting, finance, legal, human resources, compliance and risk management, regulatory-related costs, stock-based compensation expense, and information technology costs related to infrastructure and operations. Regulatory-related costs include actual settlement amounts as well as third-party professional fees we incur in connection with regulatory matters and are presented net of any insurance reimbursements for covered costs related to such matters.

At December 31, 2019 and 2018, the Other segment had total assets of $1.6 billion and $2.0 billion, respectively, on a GAAP basis.

16. Segment Reporting (Continued)

Measure of Profitability

We prepare financial statements and present financial results in accordance with GAAP. However, we also evaluate our business segments and present financial results on a basis that differs from GAAP. We refer to this different basis of presentation as Core Earnings. We provide this Core Earnings basis of presentation on a consolidated basis and for each business segment because this is what we review internally when making management decisions regarding our performance and how we allocate resources. We also refer to this information in our presentations with credit rating agencies, lenders and investors. Because our Core Earnings basis of presentation corresponds to our segment financial presentations, we are required by GAAP to provide Core Earnings disclosure in the notes to our consolidated financial statements for our business segments.

Core Earnings are not a substitute for reported results under GAAP. We use Core Earnings to manage our business segments because Core Earnings reflect adjustments to GAAP financial results for two items, discussed below, that are mostly due to timing factors generally beyond the control of management. Accordingly, we believe that Core Earnings provide management with a useful basis from which to better evaluate results from ongoing operations against the business plan or against results from prior periods. Consequently, we disclose this information because we believe it provides investors with additional information regarding the operational and performance indicators that are most closely assessed by management. When compared to GAAP results, the two items we remove to result in our Core Earnings presentations are:

Mark-to-market gains/losses resulting from our use of derivative instruments to hedge our economic risks that do not qualify for hedge accounting treatment or do qualify for hedge accounting treatment but result in ineffectiveness; and

The accounting for goodwill and acquired intangible assets.

While GAAP provides a uniform, comprehensive basis of accounting, for the reasons described above, our Core Earnings basis of presentation does not. Core Earnings are subject to certain general and specific limitations that investors should carefully consider. For example, there is no comprehensive, authoritative guidance for management reporting. Our Core Earnings are not defined terms within GAAP and may not be comparable to similarly titled measures reported by other companies. Accordingly, our Core Earnings presentation does not represent a comprehensive basis of accounting. Investors, therefore, may not be able to compare our performance with that of other financial services companies based upon Core Earnings. Core Earnings results are only meant to supplement GAAP results by providing additional information regarding the operational and performance indicators that are most closely used by management, our board of directors, credit rating agencies, lenders and investors to assess performance.

16. Segment Reporting (Continued)

Segment Results and Reconciliations to GAAP

	Year Ended December 31, 2019
												Adjustments
(Dollars in millions)	Federal Education Loans		Consumer Lending		Business Processing		Other			Total Core Earnings		Reclassi- fications			Additions/ (Subtractions)			Total Adjustments⁽¹⁾			Total GAAP
Interest income:
Education loans	$	2,907	$	1,731	$	—	$	—		$	4,638	$	8		$	(68	)	$	(60	)	$	4,578
Other loans		1		1		—		—			2		—			—			—			2
Cash and investments		50		16		—		27			93		—			—			—			93
Total interest income		2,958		1,748		—		27			4,733		8			(68	)		(60	)		4,673
Total interest expense		2,376		980		—		161			3,517		6			(35	)		(29	)		3,488
Net interest income (loss)		582		768		—		(134	)		1,216		2			(33	)		(31	)		1,185
Less: provisions for loan losses		30		228		—		—			258		—			—			—			258
Net interest income (loss) after provisions for loan losses		552		540		—		(134	)		958		2			(33	)		(31	)		927
Other income (loss):
Servicing revenue		229		11		—		—			240		—			—			—			240
Asset recovery and business processing revenue		230		—		258		—			488		—			—			—			488
Other income (loss)		28		1		—		14			43		(41	)		65			24			67
Gains on sales of loans		—		16		—		—			16		—			—			—			16
Gains on debt repurchases		—		—		—		33			33		39			(27	)		12			45
Total other income (loss)		487		28		258		47			820		(2	)		38			36			856
Expenses:
Direct operating expenses		359		156		215		—			730		—			—			—			730
Unallocated shared services expenses		—		—		—		254			254		—			—			—			254
Operating expenses		359		156		215		254			984		—			—			—			984
Goodwill and acquired intangible asset impairment and amortization		—		—		—		—			—		—			30			30			30
Restructuring/other reorganization expenses		—		—		—		6			6		—			—			—			6
Total expenses		359		156		215		260			990		—			30			30			1,020
Income (loss) before income tax expense (benefit)		680		412		43		(347	)		788		—			(25	)		(25	)		763
Income tax expense (benefit)⁽²⁾		155		96		10		(80	)		181		—			(15	)		(15	)		166
Net income (loss)	$	525	$	316	$	33	$	(267	)	$	607	$	—		$	(10	)	$	(10	)	$	597

⁽¹⁾	Core Earnings adjustments to GAAP:

	Year Ended December 31, 2019
(Dollars in millions)	Net Impact of Derivative Accounting			Net Impact of Acquired Intangibles			Total
Net interest income (loss) after provisions for loan losses	$	(31	)	$	—		$	(31	)
Total other income (loss)		36			—			36
Goodwill and acquired intangible asset impairment and amortization		—			30			30
Total Core Earnings adjustments to GAAP	$	5		$	(30	)		(25	)
Income tax expense (benefit)								(15	)
Net income (loss)							$	(10	)

⁽²⁾	Income taxes are based on a percentage of net income before tax for the individual reportable segment.

16. Segment Reporting (Continued)

	Year Ended December 31, 2018
												Adjustments
(Dollars in millions)	Federal Education Loans		Consumer Lending		Business Processing		Other			Total Core Earnings		Reclassi- fications			Additions/ (Subtractions)			Total Adjustments⁽¹⁾			Total GAAP
Interest income:
Education loans	$	3,080	$	1,778	$	—	$	—		$	4,858	$	17		$	(70	)	$	(53	)	$	4,805
Other loans		4		2		—		—			6		—			—			—			6
Cash and investments		46		13		—		38			97		—			—			—			97
Total interest income		3,130		1,793		—		38			4,961		17			(70	)		(53	)		4,908
Total interest expense		2,467		1,013		—		192			3,672		8			(12	)		(4	)		3,668
Net interest income (loss)		663		780		—		(154	)		1,289		9			(58	)		(49	)		1,240
Less: provisions for loan losses		70		300		—		—			370		—			—			—			370
Net interest income (loss) after provisions for loan losses		593		480		—		(154	)		919		9			(58	)		(49	)		870
Other income (loss):
Servicing revenue		262		12		—		—			274		—			—			—			274
Asset recovery and business processing revenue		163		—		267		—			430		—			—			—			430
Other income (loss)		24		—		—		6			30		(22	)		(29	)		(51	)		(21	)
Gains on debt repurchases		—		—		—		9			9		13			(3	)		10			19
Total other income (loss)		449		12		267		15			743		(9	)		(32	)		(41	)		702
Expenses:
Direct operating expenses		298		169		229		—			696		—			—			—			696
Unallocated shared services expenses		—		—		—		288			288		—			—			—			288
Operating expenses		298		169		229		288			984		—			—			—			984
Goodwill and acquired intangible asset impairment and amortization		—		—		—		—			—		—			47			47			47
Restructuring/other reorganization expenses		—		—		—		13			13		—			—			—			13
Total expenses		298		169		229		301			997		—			47			47			1,044
Income (loss) before income tax expense (benefit)		744		323		38		(440	)		665		—			(137	)		(137	)		528
Income tax expense (benefit)⁽²⁾		164		71		8		(97	)		146		—			(13	)		(13	)		133
Net income (loss)	$	580	$	252	$	30	$	(343	)	$	519	$	—		$	(124	)	$	(124	)	$	395

⁽¹⁾	Core Earnings adjustments to GAAP:

	Year Ended December 31, 2018
(Dollars in millions)	Net Impact of Derivative Accounting			Net Impact of Acquired Intangibles			Total
Net interest income after provisions for loan losses	$	(49	)	$	—		$	(49	)
Total other income (loss)		(41	)		—			(41	)
Goodwill and acquired intangible asset impairment and amortization		—			47			47
Total Core Earnings adjustments to GAAP	$	(90	)	$	(47	)		(137	)
Income tax expense (benefit)								(13	)
Net income (loss)							$	(124	)

⁽²⁾	Income taxes are based on a percentage of net income before tax for the individual reportable segment.

16. Segment Reporting (Continued)

	Year Ended December 31, 2017
													Adjustments
(Dollars in millions)	Federal Education Loans		Consumer Lending		Business Processing		Other			Total Core Earnings			Reclassi- fications			Additions/ (Subtractions)			Total Adjustments⁽¹⁾			Total GAAP
Interest income:
Education loans	$	2,679	$	1,634	$	—	$	—		$	4,313		$	69		$	(55	)	$	14		$	4,327
Other loans		13		—		—		—			13			—			—			—			13
Cash and investments		29		5		—		9			43			—			—			—			43
Total interest income		2,721		1,639		—		9			4,369			69			(55	)		14			4,383
Total interest expense		2,022		825		—		143			2,990			(8	)		(11	)		(19	)		2,971
Net interest income (loss)		699		814		—		(134	)		1,379			77			(44	)		33			1,412
Less: provisions for loan losses		44		382		—		—			426			—			—			—			426
Net interest income (loss) after provisions for loan losses		655		432		—		(134	)		953			77			(44	)		33			986
Other income (loss):
Servicing revenue		280		10		—		—			290			—			—			—			290
Asset recovery and business processing revenue		263		—		212		—			475			—			—			—			475
Other income (loss)		3		—		—		16			19			(77	)		89			12			31
Gains on sales of loans		3		—		—		—			3			—			—			—			3
Losses on debt repurchases		—		—		—		(3	)		(3	)		—			—			—			(3	)
Total other income (loss)		549		10		212		13			784			(77	)		89			12			796
Expenses:
Direct operating expenses		316		156		187		—			659			—			—			—			659
Unallocated shared services expenses		—		—		—		307			307			—			—			—			307
Operating expenses		316		156		187		307			966			—			—			—			966
Goodwill and acquired intangible asset impairment and amortization		—		—		—		—			—			—			23			23			23
Restructuring/other reorganization expenses		—		—		—		29			29			—			—			—			29
Total expenses		316		156		187		336			995			—			23			23			1,018
Income (loss) before income tax expense (benefit)		888		286		25		(457	)		742			—			22			22			764
Income tax expense (benefit)⁽²⁾		321		103		9		58			491			—			(19	)		(19	)		472
Net income (loss)	$	567	$	183	$	16	$	(515	)	$	251		$	—		$	41		$	41		$	292

⁽¹⁾	Core Earnings adjustments to GAAP:

	Year Ended December 31, 2017
(Dollars in millions)	Net Impact of Derivative Accounting		Net Impact of Acquired Intangibles			Total
Net interest income after provisions for loan losses	$	33	$	—		$	33
Total other income (loss)		12		—			12
Goodwill and acquired intangible asset impairment and amortization		—		23			23
Total Core Earnings adjustments to GAAP	$	45	$	(23	)		22
Income tax expense (benefit)							(19	)
Net income (loss)						$	41

⁽²⁾	Income taxes are based on a percentage of net income before tax for the individual reportable segment with the impact of the DTA Remeasurement Loss included in the Other segment.

16. Segment Reporting (Continued)

Summary of Core Earnings Adjustments to GAAP

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Core Earnings net income	$	607		$	519		$	251
Core Earnings adjustments to GAAP:
Net impact of derivative accounting⁽¹⁾		5			(90	)		45
Net impact of goodwill and acquired intangible assets⁽²⁾		(30	)		(47	)		(23	)
Net income tax effect⁽³⁾		15			13			19
Total Core Earnings adjustments to GAAP		(10	)		(124	)		41
GAAP net income	$	597		$	395		$	292

⁽¹⁾

Derivative accounting: Core Earnings exclude periodic gains and losses that are caused by the mark-to-market valuations on derivatives that do not qualify for hedge accounting treatment under GAAP as well as the periodic mark-to-market gains and losses that are a result of ineffectiveness recognized related to effective hedges under GAAP. These gains and losses occur in our Federal Education Loans, Consumer Lending and Other reportable segments. Under GAAP, for our derivatives that are held to maturity, the mark-to-market gain or loss over the life of the contract will equal $0 except for Floor Income Contracts where the mark-to-market gain will equal the amount for which we sold the contract. In our Core Earnings presentation, we recognize the economic effect of these hedges, which generally results in any net settlement cash paid or received being recognized ratably as an interest expense or revenue over the hedged item’s life.

⁽²⁾

Goodwill and acquired intangible assets: Our Core Earnings exclude goodwill and intangible asset impairment and amortization of acquired intangible assets.

⁽³⁾

Net tax effect: Such tax effect is based upon our Core Earnings effective tax rate for the year.

Education Loans - Education Loan Portfolio by Program (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Ending Balance of education loans	$ 86,820	$ 94,498
Percentage to total education loans	100.00%	100.00%
Average Balance education loans	$ 90,783	$ 100,252
Average Effective Interest Rate of education loans	5.04%	4.79%
FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Ending Balance of education loans	$ 64,575	$ 72,253
Stafford And Other Education Loans [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Ending Balance of education loans	$ 21,723	$ 24,641
Percentage to total education loans	25.00%	26.00%
Average Balance education loans	$ 23,198	$ 26,612
Average Effective Interest Rate of education loans	4.24%	3.98%
Consolidation Loans Member \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Ending Balance of education loans	$ 42,852	$ 47,612
Percentage to total education loans	49.00%	50.00%
Average Balance education loans	$ 45,073	$ 50,359
Average Effective Interest Rate of education loans	4.13%	3.91%
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Ending Balance of education loans	$ 22,245	$ 22,245
Percentage to total education loans	26.00%	24.00%
Average Balance education loans	$ 22,512	$ 23,281
Average Effective Interest Rate of education loans	7.69%	7.64%

Borrowings - Expected Maturities of Long-term Borrowings (Parenthetical) (Detail) $ in Billions	Dec. 31, 2019 USD ($)
Debt Disclosure [Abstract]
On-balance sheet securitization trust debt included in projected principal paydowns in 2020	$ 6.8
Aggregate principal amount of debt maturing in 2020	6.8
Aggregate principal amount of debt maturing in 2021	10.2
Aggregate principal amount of debt maturing in 2022	8.0
Aggregate principal amount of debt maturing in 2023	7.6
Aggregate principal amount of debt maturing in 2024	7.3
Aggregate principal amount of debt maturing in 2025-2043	$ 42.5

Revenue from Contracts with Customers Accounted for in Accordance with ASC 606

12 Months Ended

Dec. 31, 2019

Revenue From Contract With Customer [Abstract]

Revenue from Contracts with Customers Accounted for in Accordance with ASC 606

15. Revenue from Contracts with Customers Accounted for in Accordance with ASC 606

The following tables illustrate the disaggregation of revenue from contracts accounted for under ASC 606 with customers according to service type and client type by reportable operating segment.

Revenue by Service Type

	Years Ended December 31,
	2019						2018
(Dollars in millions)	Federal Education Loans		Business Processing		Total Revenue		Federal Education Loans		Business Processing		Total Revenue
Federal Education Loan asset recovery services	$	133	$	—	$	133	$	91	$	—	$	91
Government services		—		154		154		—		175		175
Healthcare services		—		104		104		—		93		93
Total	$	133	$	258	$	391	$	91	$	268	$	359

Revenue by Client Type

	Years Ended December 31,
	2019						2018
(Dollars in millions)	Federal Education Loans		Business Processing		Total Revenue		Federal Education Loans		Business Processing		Total Revenue
Federal government	$	74	$	17	$	91	$	21	$	7	$	28
Guarantor agencies		52		—		52		58		—		58
Other institutions		7		—		7		12		—		12
State and local government		—		83		83		—		92		92
Tolling authorities		—		54		54		—		76		76
Hospitals and other healthcare providers		—		104		104		—		93		93
Total	$	133	$	258	$	391	$	91	$	268	$	359

As of December 31, 2019 and 2018, there was $67 million and $74 million, respectively, of net accounts receivable related to these contracts. Navient had no material contract assets or contract liabilities.

Allowance for Loan Losses - Average Recorded Investment and Interest Income Recognized for TDR (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Impaired financing receivable, Average recorded investment	$ 9,965	$ 10,637	$ 10,989
Impaired financing receivable, Interest income recognized	$ 770	$ 764	$ 708

Fair Value Measurements - Unobservable Data Used in Recurring Valuations of Level 3 (Detail) $ in Millions	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Interest Rate Swaps [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	$ 210	$ 94
Cross-Currency Interest Rate Swaps [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	(575)	(659)
Other [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	(1)	$ (4)
Level 3 [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	(593)
Level 3 [Member] \| Cross-Currency Interest Rate Swaps [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	$ (575)
Derivative Asset (Liability) Net, Valuation Technique [Extensible List]	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Derivatives	0.04
Derivative Asset (Liability) Net, Measurement Input [Extensible List]	us-gaap:MeasurementInputConstantPrepaymentRateMember
Level 3 [Member] \| Other [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	$ (1)
Level 3 [Member] \| Prime/LIBOR Basis Swaps [Member] \| Interest Rate Swaps [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	$ (17)
Derivative Asset (Liability) Net, Valuation Technique [Extensible List]	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Level 3 [Member] \| Prime/LIBOR Basis Swaps [Member] \| Interest Rate Swaps [Member] \| Constant Prepayment Rate [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivatives	0.08
Level 3 [Member] \| Prime/LIBOR Basis Swaps [Member] \| Interest Rate Swaps [Member] \| Bid/ask adjustment to discount rate [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivatives	0.0008

Allowance for Loan Losses - Loans Modified Accounts for TDR (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Modified loans	$ 475	$ 596	$ 816
Charge-offs	324	343	346
Payment-default	$ 109	$ 142	$ 181

Allowance for Loan Losses - Allowance for Credit Losses and Recorded Investments in Loans (Detail) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) SecurityLoan	Dec. 31, 2018 USD ($) SecurityLoan	Dec. 31, 2017 USD ($) SecurityLoan
Allowance for Loan Losses
Beginning balance				$ 1,286				$ 1,367	$ 1,286	$ 1,367	$ 1,433
Total provision	$ 50	$ 64	$ 68	76	$ 85	$ 85	$ 112	87	258	370	426
Net adjustment resulting from the change in the charge-off rate									(21)	(32)
Net charge-offs remaining									(408)	(427)
Total net charge-offs									(429)	(459)	(499)
Reclassification of interest reserve									7	8	7
Loan sales									(9)
Ending balance	1,112				1,286				1,112	1,286	1,367
Allowance Ending Balance:
Ending balance: individually evaluated for impairment - TDR	941				1,108				941	1,108	1,180
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	171				178				171	178	187
Ending balance	1,112				1,286				1,112	1,286	1,367
Loans Ending Balance:
Ending balance: individually evaluated for impairment - TDR	9,617				10,364				9,617	10,364	10,951
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	73,884				80,395				73,884	80,395	89,761
Purchased Non-Credit Impaired Loans acquired at a discount	4,311				5,030				4,311	5,030	5,847
Purchased Credit Impaired Loans	201				225				201	225	248
Ending total loans	88,013				96,014				88,013	96,014	106,807
FFELP Loans [Member]
Allowance for Loan Losses
Beginning balance				76				60	76	60	67
Total provision									30	70	42
Net charge-offs remaining									(42)	(54)
Total net charge-offs									(42)	(54)	(49)
Ending balance	64				76				64	76	60
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	64				76				64	76	60
Ending balance	64				76				64	76	60
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	61,589				68,880				61,589	68,880	77,860
Purchased Non-Credit Impaired Loans acquired at a discount	2,505				2,850				2,505	2,850	3,237
Ending total loans	64,094				71,730				$ 64,094	$ 71,730	$ 81,097
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate									0.07%	0.09%
Charge-offs as a percentage of average loans in repayment											0.07%
Allowance coverage of charge-offs \| SecurityLoan									1.5	1.4	1.2
Allowance as a percentage of the ending total loan balance									0.10%	0.11%	0.07%
Allowance as a percentage of the ending loans in repayment									0.12%	0.13%	0.09%
Average loans in repayment									$ 55,978	$ 62,927	$ 68,318
Ending loans in repayment	53,538				59,551				53,538	59,551	67,853
Private Education Loans [Member]
Allowance for Loan Losses
Beginning balance				1,201				1,297	1,201	1,297	1,351
Total provision									226	299	382
Net adjustment resulting from the change in the charge-off rate									(21)	(32)
Net charge-offs remaining									(364)	(371)
Total net charge-offs									(385)	(403)	(443)
Reclassification of interest reserve									7	8	7
Loan sales									(1)
Ending balance	1,048				1,201				1,048	1,201	1,297
Allowance Ending Balance:
Ending balance: individually evaluated for impairment - TDR	941				1,100				941	1,100	1,171
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	107				101				107	101	126
Ending balance	1,048				1,201				1,048	1,201	1,297
Loans Ending Balance:
Ending balance: individually evaluated for impairment - TDR	9,617				10,336				9,617	10,336	10,921
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	12,286				11,464				12,286	11,464	11,861
Purchased Non-Credit Impaired Loans acquired at a discount	1,806				2,180				1,806	2,180	2,610
Purchased Credit Impaired Loans	201				225				201	225	248
Ending total loans	23,910				24,205				$ 23,910	$ 24,205	$ 25,640
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate									1.67%	1.66%
Charge-offs as a percentage of average loans in repayment											1.98%
Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment									0.10%	0.14%
Allowance coverage of charge-offs \| SecurityLoan									2.7	3.0	2.9
Allowance as a percentage of the ending total loan balance									4.38%	4.96%	5.06%
Allowance as a percentage of the ending loans in repayment									4.74%	5.45%	5.66%
Average loans in repayment									$ 21,859	$ 22,312	$ 22,342
Ending loans in repayment	22,089				22,037				22,089	22,037	22,924
Other Loans [Member]
Allowance for Loan Losses
Beginning balance				$ 9				$ 10	9	10	15
Total provision									1	1	2
Net charge-offs remaining									(2)	(2)
Total net charge-offs									(2)	(2)	(7)
Loan sales									(8)
Ending balance					9					9	10
Allowance Ending Balance:
Ending balance: individually evaluated for impairment - TDR					8					8	9
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans					1					1	1
Ending balance					9					9	10
Loans Ending Balance:
Ending balance: individually evaluated for impairment - TDR					28					28	30
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	9				51				9	51	40
Ending total loans	9				79				9	$ 79	$ 70
Charge-offs as a percentage of average loans in repayment											5.39%
Allowance coverage of charge-offs \| SecurityLoan											1.5
Allowance as a percentage of the ending total loan balance										11.52%	14.32%
Allowance as a percentage of the ending loans in repayment										11.52%	14.32%
Average loans in repayment									29	$ 75	$ 130
Ending loans in repayment	$ 9				$ 79				$ 9	$ 79	$ 70

Borrowings - Company's Borrowings (Parenthetical) (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Short-term Debt	$ 8,483,000,000	$ 5,422,000,000
Long-term debt	81,715,000,000	93,519,000,000
Total Before Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Short-term Debt	8,479,000,000	5,425,000,000
Long-term debt	81,756,000,000	93,868,000,000
Total Before Hedge Accounting Adjustments [Member] \| FFELP Loan Securitizations ABS Repurchase Facilities [Member]
Debt Instrument [Line Items]
Short-term Debt	72,000,000	0
Long-term debt	231,000,000	244,000,000
Total Before Hedge Accounting Adjustments [Member] \| Private Education Loan ABS Repurchase Facilities [Member]
Debt Instrument [Line Items]
Short-term Debt	2,100,000,000	300,000,000
Long-term debt	194,000,000	2,000,000,000.0
Total Before Hedge Accounting Adjustments [Member] \| Short Term Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt principal amount	1,100,000,000	817,000,000
Total Before Hedge Accounting Adjustments [Member] \| Long Term Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt principal amount	$ 8,500,000,000	$ 10,800,000,000

Derivative Financial Instruments - Gross Positions without Impact of Master Netting Agreements (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives Fair Value [Line Items]
Derivative assets	$ 230	$ 179
Derivative values with impact of master netting agreements (as carried on balance sheet), Assets	212	157
Cash collateral (held) pledged, Assets	(337)	(266)
Derivative liabilities	(664)	(801)
Cash collateral (held) pledged, Liabilities	155	188
Other Assets [Member]
Derivatives Fair Value [Line Items]
Derivative assets	230	179
Impact of master netting agreements, Assets	(18)	(22)
Derivative values with impact of master netting agreements (as carried on balance sheet), Assets	212	157
Cash collateral (held) pledged, Assets	(337)	(266)
Net position, Assets	(125)	(109)
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivative liabilities	(664)	(801)
Impact of master netting agreements, Liabilities	18	22
Derivative values with impact of master netting agreements (as carried on balance sheet), Liabilities	(646)	(779)
Cash collateral (held) pledged, Liabilities	155	188
Net position, Liabilities	$ (491)	$ (591)

Income Taxes - Summary of Changes in Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Unrecognized tax benefits at beginning of year	$ 65.7	$ 57.4	$ 73.0
Increases resulting from tax positions taken during a prior period	4.0	8.0	0.7
Decreases resulting from tax positions taken during a prior period	(3.8)	(0.3)	(1.8)
Increases resulting from tax positions taken during the current period	1.9	3.8	4.4
Decreases related to settlements with taxing authorities	(11.1)	(1.4)	(5.1)
Reductions related to the lapse of statute of limitations	(3.1)	(1.8)	(13.8)
Unrecognized tax benefits at end of year	$ 53.6	$ 65.7	$ 57.4

Earnings (Loss) per Common Share

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Earnings (Loss) per Common Share

10. Earnings (Loss) per Common Share

Basic earnings (loss) per common share (“EPS”) are calculated using the weighted average number of shares of common stock outstanding during each period. A reconciliation of the numerators and denominators of the basic and diluted EPS calculations follows.

	Years Ended December 31,
(In millions, except per share data)	2019		2018		2017
Numerator:
Net income	$	597	$	395	$	292
Denominator:
Weighted average shares used to compute basic EPS		230		260		275
Effect of dilutive securities:
Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units and Employee Stock Purchase Plan (“ESPP”)⁽¹⁾		3		4		6
Dilutive potential common shares⁽²⁾		3		4		6
Weighted average shares used to compute diluted EPS		233		264		281
Basic earnings per common share	$	2.59	$	1.52	$	1.06
Diluted earnings per common share	$	2.56	$	1.49	$	1.04

⁽¹⁾

Includes the potential dilutive effect of additional common shares that are issuable upon exercise of outstanding stock options, restricted stock, restricted stock units, performance stock units and the outstanding commitment to issue shares under applicable ESPPs, determined by the treasury stock method.

⁽²⁾	For the years ended December 31, 2019, 2018 and 2017, securities covering approximately 4 million, 6 million and 5 million shares, respectively, were outstanding but not included in the computation of diluted earnings per share because they were anti-dilutive.

Earnings (Loss) per Common Share - Schedule of Earnings (Loss) per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income	$ 171	$ 145	$ 153	$ 128	$ 72	$ 114	$ 83	$ 126	$ 597	$ 395	$ 292
Denominator:
Weighted average shares used to compute basic EPS									230	260	275
Effect of dilutive securities:
Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units and Employee Stock Purchase Plan (“ESPP”)									3	4	6
Dilutive potential common shares									3	4	6
Weighted average shares used to compute diluted EPS									233	264	281
Basic earnings per common share	$ 0.79	$ 0.64	$ 0.65	$ 0.52	$ 0.28	$ 0.44	$ 0.31	$ 0.48	$ 2.59	$ 1.52	$ 1.06
Diluted earnings per common share	$ 0.78	$ 0.63	$ 0.64	$ 0.52	$ 0.28	$ 0.43	$ 0.31	$ 0.47	$ 2.56	$ 1.49	$ 1.04

Segment Reporting - Asset Information for Loans Segment (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Loans, net	$ 86,820	$ 94,498
Other	3,334	3,404
Total assets	94,903	104,176
Federal Education Loans [Member]
Segment Reporting Information [Line Items]
Loans, net	64,575	72,253
Cash and investments	2,043	3,368
Other	2,202	2,100
Total assets	68,820	77,721
Consumer Lending [Member]
Segment Reporting Information [Line Items]
Loans, net	22,245	22,245
Cash and investments	927	732
Other	931	1,076
Total assets	$ 24,103	$ 24,053

Allowance for Loan Losses - Allowance for Credit Losses and Recorded Investments in Loans (Parenthetical) (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 01, 2017
Accounts Notes And Loans Receivable [Line Items]
Net adjustment resulting from the change in the charge-off rate			$ (21,000,000)	$ (32,000,000)
FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance for loans acquired			0	0	$ 0
Loans receivable, discount	$ 33,000,000	$ 37,000,000	33,000,000	37,000,000	43,000,000	$ 47,000,000
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Net adjustment resulting from the change in the charge-off rate			(21,000,000)	(32,000,000)
Allowance for loans acquired			0	0	0
Loans receivable, discount	268,000,000	326,000,000	268,000,000	326,000,000	$ 392,000,000	$ 424,000,000
Private Education Loans [Member] \| Loans Receivable For Partially Charged Off Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Net adjustment resulting from the change in the charge-off rate	$ (21,000,000)	$ (32,000,000)	$ (21,000,000)	$ (32,000,000)
Private Education Loans [Member] \| Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Portion of loan amount charged off at default	80.50%	79.00%	80.50%	79.00%
Private Education Loans [Member] \| Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Portion of loan amount charged off at default	81.00%	80.50%	81.00%	80.50%

Stock-Based Compensation Plans and Arrangements - Stock Option Activity (Detail) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options, Outstanding, beginning balance	11,174,890
Granted, Options	0
Exercised, Options	(2,826,673)
Canceled, Options	(2,046,287)
Number of Options, Outstanding, ending balance	6,301,930
Number of Options, Exercisable, ending balance	4,887,506
Weighted Average Exercise Price per Share, Outstanding, beginning balance \| $ / shares	$ 12.97
Exercised, Weighted Average Exercise Price per Share \| $ / shares	7.79
Canceled, Weighted Average Exercise Price per Share \| $ / shares	18.15
Weighted Average Exercise Price per Share, Outstanding, ending balance \| $ / shares	13.61
Weighted Average Exercise Price per Share, Exercisable, ending balance \| $ / shares	$ 13.44
Weighted Average Remaining Contractual Term, Outstanding, ending balance	1 year 7 months 6 days
Weighted Average Remaining Contractual Term, Exercisable, ending balance	1 year 2 months 12 days
Aggregate Intrinsic Value, Outstanding, ending balance \| $	$ 12
Aggregate Intrinsic Value, Exercisable, ending balance \| $	$ 12

Fair Value Measurements - Included in Earnings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Gains (losses) on derivative and hedging activities, net	$ (50)	$ (414)	$ 788
Gain (Losses) on Derivative Instruments [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Gains (losses) on derivative and hedging activities, net	10	(292)	906
Interest Expense [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Gains (losses) on derivative and hedging activities, net	$ (60)	$ (122)	$ (118)

Business Combinations, Goodwill and Acquired Intangible Assets

12 Months Ended

Dec. 31, 2019

Business Combinations [Abstract]

Business Combinations, Goodwill and Acquired Intangible Assets

5. Business Combinations, Goodwill and Acquired Intangible Assets

Business Combinations

Acquisitions are accounted for under the acquisition method of accounting as defined in ASC 805, “Business Combinations.” The Company allocates the purchase price to the fair value of the acquired tangible assets, liabilities and identifiable intangible assets as of the acquisition date as determined by an independent appraiser.

Acquisition of Earnest

In November 2017, Navient acquired a 95% majority controlling interest in Earnest for approximately $149 million in cash. Earnest is a leading financial technology and education finance company that originates Private Education Refinance Loans. We engaged an independent appraiser to assist in the valuation of the assets acquired and liabilities assumed including identifiable intangible assets and the determination of the fair value of the non-controlling interest. In November 2018, the Company finalized its purchase price allocation for Earnest, which resulted in an excess purchase price over fair value of net assets acquired, or goodwill, of $77 million. The results of operations of Earnest have been included in Navient’s consolidated financial statements since the acquisition date and are reflected in Navient’s Consumer Lending segment and its Private Education Refinance Loans reporting unit. Navient has not disclosed the pro forma impact of this acquisition to the results of operations for the year ended December 31, 2017, as the pro forma impact was deemed immaterial.

Identifiable intangible assets at the acquisition date included definite life intangible assets with an aggregate fair value of approximately $20 million primarily including the Earnest trade name and developed technology. The intangible assets are being amortized over a period of 5 to 10 years based on the estimated economic benefit derived from each of the underlying assets.

Acquisition of Duncan Solutions

In July 2017, Navient acquired a 100% controlling interest in Duncan Solutions for approximately $86 million in cash. Duncan Solutions is a leading transportation revenue management company serving municipalities and toll authorities, offering a range of technology-enabled products and services to support its clients’ parking and tolling operations. We engaged an independent appraiser to assist in the valuation of the assets acquired and liabilities assumed including identifiable intangible assets. In July 2018, the Company finalized its purchase price allocation for Duncan Solutions, which resulted in an excess purchase price over the fair value of net assets acquired, or goodwill, of $39 million. The results of operations of Duncan Solutions have been included in Navient’s consolidated financial statements since the acquisition date and are reflected in Navient’s Business Processing segment and its Government Services reporting unit. Navient has not disclosed the pro forma impact of this acquisition to the results of operations for the year ended December 31, 2017, as the pro forma impact was deemed immaterial.

Identifiable intangible assets at the acquisition date include definite life intangible assets with an aggregate fair value of approximately $33 million primarily including customer relationships, developed technology and the Duncan Solutions trade name. The intangible assets are being amortized over a period of 2 to 10 years based on the estimated economic benefit derived from each of the underlying assets.

5. Business Combinations, Goodwill and Acquired Intangible Assets (Continued)

Goodwill

The following table summarizes our goodwill for our reporting units and reportable segments as of December 31, 2019 and 2018.

(Dollars in millions)	Goodwill
Federal Education Loans reportable segment:
FFELP Loans	$	227
Federal Education Loan Servicing		13
Total Federal Education Loans reportable segment		240
Consumer Lending reportable segment:
Private Education Loans		106
Private Education Refinance Loans		77
Total Consumer Lending reportable segment		183
Business Processing reportable segment:
Government Services		136
Healthcare Services		106
Total Business Processing reportable segment		242
Total	$	665

Annual Goodwill Impairment Testing – October 1, 2019

We perform our goodwill impairment testing annually in the fourth quarter as of October 1. As part of the 2019 annual impairment testing, we retained a third-party appraisal firm to assist in the valuations required to perform Step 1 impairment testing of goodwill associated with our FFELP Loans, Federal Education Loan Servicing, Private Education Loans, Private Education Refinance Loans, Government Services, and Healthcare Services reporting units as of October 1, 2019. No goodwill was deemed impaired in conjunction with these reporting units as a result of Step 1 impairment testing as the fair values of the reporting units were substantially greater than their respective carry values.

The income approach was the primary approach used to estimate the fair value of each reporting unit. The income approach measures the value of each reporting unit’s future economic benefit determined by its discounted cash flows derived from our projections plus an assumed terminal growth rate consistent with what we believe a market participant would assume in an acquisition. These projections are generally five-year projections that reflect the anticipated cash flow fluctuations of the respective reporting units. If a component of a reporting unit is winding down or is assumed to wind down, the projections extend through the anticipated wind-down period and no residual value is ascribed.

Under our guidance, the third-party appraisal firm developed the discount rate for each reporting unit incorporating such factors as the risk free rate, a market rate of return, a measure of volatility (Beta) and a company-specific and capital markets risk premium, as appropriate, to adjust for volatility and uncertainty in the economy and to capture specific risk related to the respective reporting units. We considered whether an asset sale or an equity sale would be the most likely sale structure for each reporting unit and valued each reporting unit based on the more likely hypothetical scenario. The discount rates reflect market-based estimates of capital costs and are adjusted for our assessment of a market participant’s view with respect to execution, source concentration and other risks associated with the projected cash flows of individual reporting units. We reviewed and approved the discount rates provided by the third-party appraiser including the factors incorporated to develop the discount rates for each reporting unit.

5. Business Combinations, Goodwill and Acquired Intangible Assets (Continued)

We and the third-party appraisal firm also considered a market approach for the Government Services and Healthcare Services reporting units. Market-based multiples related primarily to revenue and EBITDA for comparable publicly traded companies and similar transactions were evaluated as an indicator of the value of the reporting units to assess the reasonableness of the estimated fair value derived from the income approach.

We also considered the current regulatory and legislative environment, the current economic environment, our 2019 earnings, 2020 expected earnings, market expectations regarding our stock price, and our market capitalization in relation to book equity. Although our market capitalization was less than our book equity during 2019, it was concluded that our market capitalization in relation to our book equity does not indicate impairment of our reporting units’ respective goodwill at December 31, 2019.

Acquired Intangible Assets

Acquired intangible assets include the following:

	As of December 31, 2019							As of December 31, 2018
(Dollars in millions)	Cost Basis⁽¹⁾		Accumulated Impairment and Amortization⁽¹⁾			Net		Cost Basis⁽¹⁾		Accumulated Impairment and Amortization⁽¹⁾			Net
Customer, services and lending relationships	$	262	$	(220	)	$	42	$	284	$	(226	)	$	58
Favorable lease		1		(1	)		—		1		—			1
Non-competes		3		(3	)		—		3		(3	)		—
Software and technology		114		(96	)		18		115		(90	)		25
Trade names and trademarks		52		(20	)		32		61		(24	)		37
Total acquired intangible assets	$	432	$	(340	)	$	92	$	464	$	(343	)	$	121

⁽¹⁾

Accumulated impairment and amortization include impairment amounts only if the acquired intangible asset has been deemed partially impaired. When an acquired intangible asset is considered fully impaired and no longer in use, the cost basis and any accumulated amortization related to the asset is written off.

We recorded amortization of acquired intangible assets from continuing operations totaling $25 million, $31 million and $23 million in 2019, 2018 and 2017, respectively. We will continue to amortize our intangible assets with definite useful lives over their remaining estimated useful lives. We estimate amortization expense associated with these intangible assets will be $21 million, $19 million, $15 million, $13 million and $23 million in 2020, 2021, 2022, 2023 and after 2023, respectively.

In our Government Services reporting unit, we wrote off a $16 million toll services relationship acquired intangible asset in 2018 due to the termination of a significant toll services contract.

Stock-Based Compensation Plans and Arrangements - Stock Option Activity (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 11.0
Weighted average period for total unrecognized compensation cost	1 year 9 months 18 days
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised	$ 11.0	$ 12.0	$ 9.0
Unrecognized compensation cost	$ 0.3
Weighted average period for total unrecognized compensation cost	1 year 1 month 6 days

Stockholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 31, 2019	Sep. 30, 2018
Class of Stock [Line Items]
Common stock, shares authorized	1,125,000,000	1,125,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares issued	451,000,000	445,000,000
Common shares unissued but encumbered	24,000,000
Dividends per common share	$ 0.64	$ 0.64	$ 0.64
Common stock dividends paid	$ 147,000,000	$ 166,000,000	$ 176,000,000
Authorized share repurchased program amount				$ 1,000,000,000	$ 500,000,000
Common Stock Shares Outstanding [Member]
Class of Stock [Line Items]
Common stock, shares issued	215,000,000
Common stock repurchased	34,491,342	17,443,351	29,646,374
Purchase price of common stock repurchased on open market	$ 440,000,000	$ 220,000,000	$ 440,000,000
Common Stock [Member]
Class of Stock [Line Items]
Authorized common share repurchased program remaining available amount	$ 1,000,000,000
Closing price of common stock	$ 13.68

Commitments, Contingencies and Guarantees

12 Months Ended

Dec. 31, 2019

Commitments And Contingencies Disclosure [Abstract]

Commitments, Contingencies and Guarantees

13. Commitments, Contingencies and Guarantees

Legal Proceedings

The Company has been named as defendant in a number of putative class action cases alleging violations of various state and federal consumer protection laws including the Telephone Consumer Protection Act (“TCPA”), the Consumer Financial Protection Act of 2010 (“CFPA”), the Fair Credit Reporting Act (“FCRA”), the Fair Debt Collection Practices Act (“FDCPA”) and various other state consumer protection laws.

In January 2017, the Consumer Financial Protection Bureau (the “CFPB”) and Attorneys General for the State of Illinois and the State of Washington initiated civil actions naming Navient Corporation and several of its subsidiaries as defendants alleging violations of certain Federal and State consumer protection statutes, including the CFPA, FCRA, FDCPA and various state consumer protection laws. In October 2017, the Attorney General for the Commonwealth of Pennsylvania initiated a civil action against Navient Corporation and Navient Solutions, LLC (“Solutions”), containing similar alleged violations of the CFPA and the Pennsylvania Unfair Trade Practices and Consumer Protection Law. Additionally, in 2018 the Attorneys General for the States of California and Mississippi initiated similar actions against the Company and certain subsidiaries alleging violations of various state and federal consumer protection laws. We refer to the Illinois, Pennsylvania, Washington, California, and Mississippi Attorneys General collectively as the “State Attorneys General.” In addition to these matters, a number of lawsuits have been filed by nongovernmental parties or, in the future, may be filed by additional governmental or nongovernmental parties seeking damages or other remedies related to similar issues raised by the CFPB and the State Attorneys General. As the Company has previously stated, we believe the suits improperly seek to impose penalties on Navient based on new, unannounced servicing standards applied retroactively only against one servicer, and that the allegations are false. We therefore have denied these allegations and intend to vigorously defend against the allegations in each of these cases. For additional information on these civil actions, please refer to section entitled “Regulatory Matters” below.

At this point in time, the Company is unable to anticipate the timing of a resolution or the impact that these legal proceedings may have on the Company’s consolidated financial position, liquidity, results of operation or cash flows. As a result, it is not possible at this time to estimate a range of potential exposure, if any, for amounts that may be payable in connection with these matters and reserves have not been established. It is possible that an adverse ruling or rulings may have a material adverse impact on the Company.

Regulatory Matters

In addition, Navient and its subsidiaries are subject to examination or regulation by the SEC, CFPB, FFIEC, ED and various state agencies as part of its ordinary course of business. Items or matters similar to or different from those described above may arise during the course of those examinations. We also routinely receive inquiries or requests from various regulatory entities or bodies or government agencies concerning our business or our assets. Generally, the Company endeavors to cooperate with each such inquiry or request.

As previously disclosed, the Company and various of its subsidiaries have been subject to the following investigations and inquiries:

•

In December 2013, Navient received Civil Investigative Demands (“CIDs”) issued by the Illinois Attorney General, the Washington Attorney General and multiple other state Attorneys General. According to the CIDs, the investigations were initiated to ascertain whether any practices declared to be unlawful under the Consumer Fraud and Deceptive Business Practices Act have occurred or are about to occur. The Company subsequently received separate but similar CIDs or subpoenas from the Attorneys General for the District of Columbia, Kansas, Oregon, Colorado, New Jersey and New York. We have and in the future may receive additional CIDs or subpoenas and other inquiries from these or other Attorneys General with respect to similar or different matters.

•

In April 2014, Solutions received a CID from the CFPB as part of the CFPB’s separate investigation regarding allegations relating to Navient’s disclosures and assessment of late fees and other matters. Navient has received a series of supplemental CIDs on these matters. In August 2015, Solutions received a letter from the CFPB notifying Solutions that, in accordance with the CFPB’s discretionary Notice and Opportunity to Respond and Advise (“NORA”) process, the CFPB’s Office of Enforcement was considering recommending that the CFPB take legal action against Solutions. The NORA letter related to a previously disclosed investigation into Solutions’ disclosures and assessment of late fees and other matters and states that, in connection with any action, the CFPB may seek restitution, civil monetary penalties and corrective action against Solutions. The Company responded to the NORA letter in September 2015.

13. Commitments, Contingencies and Guarantees (Continued)

•

In November 2014, Navient’s subsidiary, Pioneer Credit Recovery, Inc. (“Pioneer”), received a CID from the CFPB as part of an investigation regarding Pioneer’s activities relating to rehabilitation loans and collection of defaulted student debt. In May 2019, Pioneer received a similar CID from the New York Department of Financial Services (the “NY DFS”).

•

In December 2014, Solutions received a subpoena from the NY DFS as part of its inquiry with regard to whether persons or entities have engaged in fraud or misconduct with respect to a financial product or service under New York Financial Services Law or other laws.

Under the terms of the Separation and Distribution Agreement between the Company and SLM BankCo, Navient has agreed to indemnify SLM BankCo for all claims, actions, damages, losses or expenses that may arise from the conduct of activities of pre-Spin-Off SLM BankCo occurring prior to the Spin-Off other than those specifically excluded in the Separation and Distribution Agreement. As a result, subject to the terms, conditions and limitations set forth in the Separation and Distribution Agreement, Navient has agreed to indemnify and hold harmless Sallie Mae and its subsidiaries, including Sallie Mae Bank from liabilities arising out of the regulatory matters and CFPB and State Attorneys General lawsuits mentioned above. Navient has asserted various claims for indemnification against Sallie Mae and Sallie Mae Bank for these specifically excluded items arising out of the CFPB and the State Attorneys General lawsuits if and to the extent any indemnified liabilities exist now or in the future. We expect these various indemnification claims to be resolved at a future date as the cases move toward conclusion. Navient has no reserves related to indemnification matters with SLM BankCo as of December 31, 2019.

OIG Audit

The Office of the Inspector General (the “OIG”) of ED commenced an audit regarding Special Allowance Payments (“SAP”) on September 10, 2007. In September 2013, we received the final audit determination of Federal Student Aid (the “Final Audit Determination”) on the final audit report issued by the OIG in August 2009 related to this audit. The Final Audit Determination concurred with the final audit report issued by the OIG and instructed us to make adjustment to our government billing to reflect the policy determination. In August 2016, we filed our notice of appeal to the Administrative Actions and Appeals Service Group of ED, and a hearing was held in April 2017. In March 2019, the administrative law judge hearing the appeal affirmed the audit’s findings, holding the then-existing Dear Colleague letter relied upon by the Company and other industry participants was inconsistent with the statutory framework creating the SAP rules applicable to loans funded by certain types of debt obligations at issue. We have appealed the administrative law judge’s decision to the Secretary of Education given Navient’s adherence to ED-issued guidance and the potential impact on participants in any ED program student loan servicers if such guidance is deemed unreliable and may not be relied upon. We continue to believe that our SAP billing practices were proper, considering then-existing ED guidance and lack of applicable regulations. The Company established a reserve for this matter in 2014 and does not believe, at this time, that an adverse ruling would have a material effect on the Company as a whole.

Contingencies

In the ordinary course of business, we and our subsidiaries are defendants in or parties to pending and threatened legal actions and proceedings including actions brought on behalf of various classes of claimants. These actions and proceedings may be based on alleged violations of consumer protection, securities, employment and other laws. In certain of these actions and proceedings, claims for substantial monetary damage are asserted against us and our subsidiaries. We and our subsidiaries are also subject to potential unasserted claims by third parties.

In the ordinary course of business, we and our subsidiaries are subject to regulatory examinations, information gathering requests, inquiries and investigations. In connection with formal and informal inquiries in these cases, we and our subsidiaries receive requests, subpoenas and orders for documents, testimony and information in connection with various aspects of our regulated activities.

We are required to establish reserves for litigation and regulatory matters where those matters present loss contingencies that are both probable and estimable. When loss contingencies are not both probable and estimable, we do not establish reserves.

In view of the inherent difficulty of predicting the outcome of such litigation and regulatory matters, we cannot predict what the eventual outcome of the pending matters will be, what the timing or the ultimate resolution of these matters will be, or what the eventual loss, fines or penalties, if any, related to each pending matter may be.

13. Commitments, Contingencies and Guarantees (Continued)

Based on current knowledge, reserves have been established for certain litigation, regulatory matters, and unasserted contract claims where the loss is both probable and estimable. Based on current knowledge, management does not believe that loss contingencies, if any, arising from pending investigations, litigation or regulatory matters will have a material adverse effect on our consolidated financial position, liquidity, results of operations or cash flows, except as otherwise disclosed.

As of June 30, 2018, we concluded that a contingency loss was no longer probable of occurring. Accordingly, the related $40 million contingency reserve was released as a reduction of operating expenses in the second quarter of 2018.

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Maximum remaining term for investment purchased for estimating at cost	90 days
Decrease in valuation due to net credit risk adjustments	$ 11	$ 26
Decrease in valuation due to liquidity adjustments	$ 12	$ 19

Borrowings

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Borrowings

6. Borrowings

Borrowings consist of secured borrowings issued through our securitization program, borrowings through secured facilities, unsecured notes issued by us, and other interest-bearing liabilities related primarily to obligations to return cash collateral held.

The following table summarizes our borrowings.

	December 31, 2019								December 31, 2018
(Dollars in millions)	Short Term		Long Term			Total			Short Term			Long Term			Total
Unsecured borrowings:
Senior unsecured debt⁽¹⁾	$	1,052	$	8,461		$	9,513		$	817		$	10,674		$	11,491
Total unsecured borrowings		1,052		8,461			9,513			817			10,674			11,491
Secured borrowings:
FFELP Loan securitizations⁽²⁾		72		59,735			59,807			—			66,318			66,318
Private Education Loan securitizations⁽³⁾		2,120		11,430			13,550			300			12,985			13,285
FFELP Loan ABCP facilities		2,783		617			3,400			2,927			2,625			5,552
Private Education Loan ABCP facilities		2,114		1,513			3,627			1,114			1,266			2,380
Other⁽⁴⁾		338		—			338			267			—			267
Total secured borrowings		7,427		73,295			80,722			4,608			83,194			87,802
Total before hedge accounting adjustments		8,479		81,756			90,235			5,425			93,868			99,293
Hedge accounting adjustments		4		(41	)		(37	)		(3	)		(349	)		(352	)
Total	$	8,483	$	81,715		$	90,198		$	5,422		$	93,519		$	98,941

⁽¹⁾	Includes principal amount of $1.1 billion and $817 million of short-term debt as of December 31, 2019 and 2018, respectively. Includes principal amount of $8.5 billion and $10.8 billion of long-term debt as of December 31, 2019 and 2018, respectively.

⁽²⁾

Includes $72 million and $0 of short-term debt related to the FFELP Loan ABS repurchase facilities (“FFELP Loan Repurchase Facilities”) as of December 31, 2019 and 2018, respectively. Includes $231 million and $244 million of long-term debt related to the FFELP Loan Repurchase Facilities as of December 31, 2019 and 2018, respectively.

⁽³⁾

Includes $2.1 billion and $300 million of short-term debt related to the Private Education Loan ABS repurchase facilities (“Private Education Loan Repurchase Facilities”) as of December 31, 2019 and 2018, respectively. Includes $194 million and $2.0 billion of long-term debt related to the Private Education Loan Repurchase Facilities as of December 31, 2019 and 2018, respectively.

⁽⁴⁾	“Other” primarily includes the obligation to return cash collateral held related to derivative exposures.

6. Borrowings (Continued)

Short-term Borrowings

Short-term borrowings have a remaining term to maturity of one year or less. The following tables summarize outstanding short-term borrowings (secured and unsecured), the weighted average interest rates at the end of each period, and the related average balances and weighted average interest rates during the periods.

	December 31, 2019					Year Ended December 31, 2019
(Dollars in millions)	Ending Balance		Weighted Average Interest Rate			Average Balance		Weighted Average Interest Rate
FFELP Loan securitizations	$	72		3.16	%	$	49		3.18	%
Private Education Loan securitizations		2,120		4.14			1,672		4.57
FFELP Loan ABCP facilities		2,783		2.46			2,371		3.11
Private Education Loan ABCP facilities		2,114		2.76			1,053		3.20
Senior unsecured debt		1,056		6.42			1,492		7.05
Other interest-bearing liabilities		338		1.55			307		2.16
Total short-term borrowings	$	8,483		3.42	%	$	6,944		4.28	%
Maximum outstanding at any month end	$	8,564

	December 31, 2018					Year Ended December 31, 2018
(Dollars in millions)	Ending Balance		Weighted Average Interest Rate			Average Balance		Weighted Average Interest Rate
Private Education Loan securitizations	$	300		5.23	%	$	536		4.72	%
FFELP Loan ABCP facilities		2,927		3.10			1,137		2.79
Private Education Loan ABCP facilities		1,114		3.63			847		3.40
Senior unsecured debt		814		4.92			2,021		5.90
Other interest-bearing liabilities		267		2.39			292		1.73
Total short-term borrowings	$	5,422		3.56	%	$	4,833		4.35	%
Maximum outstanding at any month end	$	6,363

6. Borrowings (Continued)

Long-term Borrowings

The following tables summarize outstanding long-term borrowings, the weighted average interest rates at the end of the periods, and the related average balances during the periods.

	December 31, 2019
			Weighted Average			Year Ended December 31, 2019
(Dollars in millions)	Ending Balance⁽¹⁾		Interest Rate⁽²⁾			Average Balance
Floating rate notes:
U.S. dollar-denominated:
Interest bearing, due 2021-2083	$	63,731		2.66	%	$	68,664
Non-U.S. dollar-denominated:
Interest bearing, due 2023-2040		3,577		.61			4,262
Total floating rate notes		67,308		2.55			72,926
Fixed rate notes:
U.S. dollar-denominated:
Interest bearing, due 2021-2068		14,407		4.88			13,941
Non-U.S.-dollar denominated:		—		—			57
Total fixed rate notes		14,407		4.88			13,998
Total long-term borrowings	$	81,715		2.96	%	$	86,924

	December 31, 2018
			Weighted Average			Year Ended December 31, 2018
(Dollars in millions)	Ending Balance⁽¹⁾		Interest Rate⁽²⁾			Average Balance
Floating rate notes:
U.S. dollar-denominated:
Interest bearing, due 2019-2083	$	74,842		3.38	%	$	80,189
Non-U.S. dollar-denominated:
Interest bearing, due 2023-2040		4,064		.66			4,919
Total floating rate notes		78,906		3.24			85,108
Fixed rate notes:
U.S. dollar-denominated:
Interest bearing, due 2020-2059		14,431		5.57			13,814
Non-U.S.-dollar denominated:
Interest bearing, due 2034		182		2.49			273
Total fixed rate notes		14,613		5.53			14,087
Total long-term borrowings	$	93,519		3.60	%	$	99,195

⁽¹⁾

Ending balance is expressed in U.S. dollars using the spot currency exchange rate. Includes fair value adjustments under hedge accounting for notes designated as the hedged item in a fair value hedge.

⁽²⁾

Weighted average interest rate is stated rate relative to currency denomination of debt.

6. Borrowings (Continued)

As of December 31, 2019, the expected maturities of our long-term borrowings are shown in the following table.

	Expected Maturity
(Dollars in millions)	Senior Unsecured Debt		Secured Borrowings⁽¹⁾			Total⁽²⁾
Year of Maturity
2020	$	—	$	6,768		$	6,768
2021		1,439		8,719			10,158
2022		1,741		6,212			7,953
2023		1,501		6,014			7,515
2024		1,352		5,859			7,211
2025-2043		2,428		39,723			42,151
		8,461		73,295			81,756
Hedge accounting adjustments		398		(439	)		(41	)
Total	$	8,859	$	72,856		$	81,715

⁽¹⁾

We view our securitization trust debt as long-term based on the contractual maturity dates which range from 2021 to 2083. However, we have projected the expected principal paydowns based on our current estimates regarding the securitized loans’ prepayment speeds for purposes of this disclosure to better reflect how we expect this debt to be paid down over time. The projected principal paydowns in year 2020 include $6.8 billion related to the securitization trust debt.

⁽²⁾

The aggregate principal amount of debt that matures in each period is $6.8 billion in 2020, $10.2 billion in 2021, $8.0 billion in 2022, $7.6 billion in 2023, $7.3 billion in 2024 and $42.5 billion in 2025-2043.

6. Borrowings (Continued)

Variable Interest Entities

We consolidate the following financing VIEs as of December 31, 2019 and 2018, as we are the primary beneficiary. As a result, these VIEs are accounted for as secured borrowings.

	December 31, 2019
	Debt Outstanding								Carrying Amount of Assets Securing Debt Outstanding
(Dollars in millions)	Short Term		Long Term			Total			Loans		Cash		Other Assets, Net			Total
Secured Borrowings — VIEs:
FFELP Loan securitizations	$	72	$	59,735		$	59,807		$	60,834	$	1,833	$	1,400		$	64,067
Private Education Loan securitizations		2,120		11,430			13,550			15,412		509		152			16,073
FFELP Loan ABCP facilities		2,783		617			3,400			3,421		63		102			3,586
Private Education Loan ABCP facilities		2,114		1,513			3,627			4,197		101		28			4,326
Total before hedge accounting adjustments		7,089		73,295			80,384			83,864		2,506		1,682			88,052
Hedge accounting adjustments		—		(439	)		(439	)		—		—		(593	)		(593	)
Total	$	7,089	$	72,856		$	79,945		$	83,864	$	2,506	$	1,089		$	87,459

	December 31, 2018
	Debt Outstanding								Carrying Amount of Assets Securing Debt Outstanding
(Dollars in millions)	Short Term		Long Term			Total			Loans		Cash		Other Assets, Net			Total
Secured Borrowings — VIEs:
FFELP Loan securitizations	$	—	$	66,318		$	66,318		$	66,266	$	3,181	$	1,211		$	70,658
Private Education Loan securitizations		300		12,985			13,285			16,336		536		198			17,070
FFELP Loan ABCP facilities		2,927		2,625			5,552			5,656		132		162			5,950
Private Education Loan ABCP facilities		1,114		1,266			2,380			3,361		79		27			3,467
Total before hedge accounting adjustments		4,341		83,194			87,535			91,619		3,928		1,598			97,145
Hedge accounting adjustments		—		(456	)		(456	)		—		—		(642	)		(642	)
Total	$	4,341	$	82,738		$	87,079		$	91,619	$	3,928	$	956		$	96,503

6. Borrowings (Continued)

Secured Facilities and Unsecured Debt

FFELP Loan ABCP Facilities

We have various ABCP borrowing facilities that we use to finance our FFELP Loans. Liquidity is available under these secured credit facilities to the extent we have eligible collateral and available capacity. The maximum borrowing capacity under these facilities will vary and is subject to each agreement’s borrowing conditions. These include but are not limited to the facility’s size, current usage and the availability and fair value of qualifying unencumbered FFELP Loan collateral. Our borrowings under these facilities are non-recourse. The maturity dates on these facilities range from November 2020 to April 2021. The interest rate on certain facilities can increase under certain circumstances. The facilities are subject to termination under certain circumstances. As of December 31, 2019, there was approximately $3.4 billion outstanding under these facilities, with approximately $3.6 billion of assets securing these facilities. As of December 31, 2019, the maximum unused capacity under these facilities was $867 million. As of December 31, 2019, we had $319 million of unencumbered FFELP Loans.

FFELP Loan Repurchase Facilities

In 2018, we closed a $0.9 billion FFELP Loan Repurchase Facility that provides liquidity for the acquisition of certain Navient-sponsored auction rate securities. Borrowings under the facility are secured by the auction rate securities. The lenders also have unsecured recourse to Navient Corporation as guarantor for any shortfall in amounts payable. Because the facility is secured by Navient-sponsored instruments issued in previous securitizations, we show the debt as part of FFELP Loan securitizations in the various borrowing tables above. As of December 31, 2019, there was approximately $0.3 billion outstanding under this facility.

Private Education Loan ABCP Facilities

We have various ABCP borrowing facilities that we use to finance our Private Education Loans. Liquidity is available under these secured credit facilities to the extent we have eligible collateral and available capacity. The maximum borrowing capacity under these facilities will vary and is subject to each agreement’s borrowing conditions. These include but are not limited to the facility’s size, current usage and the availability and fair value of qualifying unencumbered Private Education Loan collateral. Our borrowings under these facilities are non-recourse. The maturity dates on these facilities range from June 2020 to December 2021. The interest rate on certain facilities can increase under certain circumstances. The facilities are subject to termination under certain circumstances. As of December 31, 2019, there was approximately $3.6 billion outstanding under these facilities, with approximately $4.3 billion of assets securing these facilities. As of December 31, 2019, the maximum unused capacity under these facilities was $384 million. As of December 31, 2019, we had $2.6 billion of unencumbered Private Education Loans.

Private Education Loan Repurchase Facilities

Since the fourth quarter of 2015, we have closed on $4.2 billion of Private Education Loan Repurchase Facilities. These repurchase facilities are collateralized by Residual Interests in previously issued Private Education Loan ABS trusts. The lenders also have unsecured recourse to Navient Corporation as guarantor for any shortfall in amounts payable. Because these facilities are secured by the Residual Interests in previous securitizations, we show the debt as part of Private Education Loan securitizations in the various borrowing tables above. As of December 31, 2019, there was approximately $2.3 billion outstanding under these facilities.

Senior Unsecured Debt

We issued $0, $500 million and $1.6 billion of unsecured debt in 2019, 2018 and 2017, respectively.

Debt Repurchases

The following table summarizes activity related to our senior unsecured debt and ABS repurchases. “Gains (losses) on debt repurchases” is shown net of hedging-related gains and losses.

	Years Ended December 31,
(Dollars in millions)	2019		2018		2017
Debt principal repurchased	$	1,184	$	2,809	$	513
Gains (losses) on debt repurchases	$	45	$	19	$	(3	)

Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Changes in Stockholders' Equity (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) on cash flow hedges	$ (165)	$ 50	$ 25
Total change in stockholders’ equity for unrealized gains (losses) on derivatives	(204)	39	55
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustments for derivative (gains) losses included in net income (interest expense)	$ (39)	$ (11)	$ 30

Segment Reporting - Segment Result and Reconciliations to GAAP - Core Earnings Adjustments (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses	$ 244	$ 248	$ 225	$ 209	$ 222	$ 221	$ 186	$ 242	$ 927	$ 870	$ 986
Total other income (loss)									856	702	796
Goodwill and acquired intangible asset impairment and amortization	6	6	11	7	8	23	6	9	30	47	23
Income tax expense (benefit)	49	40	41	36	34	33	30	36	166	133	472
Net income (loss)	$ 171	$ 145	$ 153	$ 128	$ 72	$ 114	$ 83	$ 126	597	395	292
Total Adjustments [Member] \| Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses									(31)	(49)	33
Total other income (loss)									36	(41)	12
Goodwill and acquired intangible asset impairment and amortization									30	47	23
Total Core Earnings adjustments to GAAP									(25)	(137)	22
Income tax expense (benefit)									(15)	(13)	(19)
Net income (loss)									(10)	(124)	41
Net Impact of Goodwill and Acquired Intangible Assets [Member] \| Total Adjustments [Member] \| Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Goodwill and acquired intangible asset impairment and amortization									30	47	23
Total Core Earnings adjustments to GAAP									(30)	(47)	(23)
Net Impact of Derivative Accounting [Member] \| Total Adjustments [Member] \| Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses									(31)	(49)	33
Total other income (loss)									36	(41)	12
Total Core Earnings adjustments to GAAP									$ 5	$ (90)	$ 45

Allowance for Loan Losses - Recorded Investment, Unpaid Principal Balance and Related Allowance for TDR Loans (Detail) - TDR [Member] - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable Impaired [Line Items]
Recorded investment	$ 9,594	$ 10,326
Total ending loans	9,617	10,336
Related allowance	$ 941	$ 1,100

Segment Reporting (Tables)

12 Months Ended

Dec. 31, 2019

Segment Results and Reconciliations to GAAP

	Year Ended December 31, 2019
												Adjustments
(Dollars in millions)	Federal Education Loans		Consumer Lending		Business Processing		Other			Total Core Earnings		Reclassi- fications			Additions/ (Subtractions)			Total Adjustments⁽¹⁾			Total GAAP
Interest income:
Education loans	$	2,907	$	1,731	$	—	$	—		$	4,638	$	8		$	(68	)	$	(60	)	$	4,578
Other loans		1		1		—		—			2		—			—			—			2
Cash and investments		50		16		—		27			93		—			—			—			93
Total interest income		2,958		1,748		—		27			4,733		8			(68	)		(60	)		4,673
Total interest expense		2,376		980		—		161			3,517		6			(35	)		(29	)		3,488
Net interest income (loss)		582		768		—		(134	)		1,216		2			(33	)		(31	)		1,185
Less: provisions for loan losses		30		228		—		—			258		—			—			—			258
Net interest income (loss) after provisions for loan losses		552		540		—		(134	)		958		2			(33	)		(31	)		927
Other income (loss):
Servicing revenue		229		11		—		—			240		—			—			—			240
Asset recovery and business processing revenue		230		—		258		—			488		—			—			—			488
Other income (loss)		28		1		—		14			43		(41	)		65			24			67
Gains on sales of loans		—		16		—		—			16		—			—			—			16
Gains on debt repurchases		—		—		—		33			33		39			(27	)		12			45
Total other income (loss)		487		28		258		47			820		(2	)		38			36			856
Expenses:
Direct operating expenses		359		156		215		—			730		—			—			—			730
Unallocated shared services expenses		—		—		—		254			254		—			—			—			254
Operating expenses		359		156		215		254			984		—			—			—			984
Goodwill and acquired intangible asset impairment and amortization		—		—		—		—			—		—			30			30			30
Restructuring/other reorganization expenses		—		—		—		6			6		—			—			—			6
Total expenses		359		156		215		260			990		—			30			30			1,020
Income (loss) before income tax expense (benefit)		680		412		43		(347	)		788		—			(25	)		(25	)		763
Income tax expense (benefit)⁽²⁾		155		96		10		(80	)		181		—			(15	)		(15	)		166
Net income (loss)	$	525	$	316	$	33	$	(267	)	$	607	$	—		$	(10	)	$	(10	)	$	597

⁽¹⁾	Core Earnings adjustments to GAAP:

	Year Ended December 31, 2019
(Dollars in millions)	Net Impact of Derivative Accounting			Net Impact of Acquired Intangibles			Total
Net interest income (loss) after provisions for loan losses	$	(31	)	$	—		$	(31	)
Total other income (loss)		36			—			36
Goodwill and acquired intangible asset impairment and amortization		—			30			30
Total Core Earnings adjustments to GAAP	$	5		$	(30	)		(25	)
Income tax expense (benefit)								(15	)
Net income (loss)							$	(10	)

⁽²⁾	Income taxes are based on a percentage of net income before tax for the individual reportable segment.

	Year Ended December 31, 2018
												Adjustments
(Dollars in millions)	Federal Education Loans		Consumer Lending		Business Processing		Other			Total Core Earnings		Reclassi- fications			Additions/ (Subtractions)			Total Adjustments⁽¹⁾			Total GAAP
Interest income:
Education loans	$	3,080	$	1,778	$	—	$	—		$	4,858	$	17		$	(70	)	$	(53	)	$	4,805
Other loans		4		2		—		—			6		—			—			—			6
Cash and investments		46		13		—		38			97		—			—			—			97
Total interest income		3,130		1,793		—		38			4,961		17			(70	)		(53	)		4,908
Total interest expense		2,467		1,013		—		192			3,672		8			(12	)		(4	)		3,668
Net interest income (loss)		663		780		—		(154	)		1,289		9			(58	)		(49	)		1,240
Less: provisions for loan losses		70		300		—		—			370		—			—			—			370
Net interest income (loss) after provisions for loan losses		593		480		—		(154	)		919		9			(58	)		(49	)		870
Other income (loss):
Servicing revenue		262		12		—		—			274		—			—			—			274
Asset recovery and business processing revenue		163		—		267		—			430		—			—			—			430
Other income (loss)		24		—		—		6			30		(22	)		(29	)		(51	)		(21	)
Gains on debt repurchases		—		—		—		9			9		13			(3	)		10			19
Total other income (loss)		449		12		267		15			743		(9	)		(32	)		(41	)		702
Expenses:
Direct operating expenses		298		169		229		—			696		—			—			—			696
Unallocated shared services expenses		—		—		—		288			288		—			—			—			288
Operating expenses		298		169		229		288			984		—			—			—			984
Goodwill and acquired intangible asset impairment and amortization		—		—		—		—			—		—			47			47			47
Restructuring/other reorganization expenses		—		—		—		13			13		—			—			—			13
Total expenses		298		169		229		301			997		—			47			47			1,044
Income (loss) before income tax expense (benefit)		744		323		38		(440	)		665		—			(137	)		(137	)		528
Income tax expense (benefit)⁽²⁾		164		71		8		(97	)		146		—			(13	)		(13	)		133
Net income (loss)	$	580	$	252	$	30	$	(343	)	$	519	$	—		$	(124	)	$	(124	)	$	395

⁽¹⁾	Core Earnings adjustments to GAAP:

	Year Ended December 31, 2018
(Dollars in millions)	Net Impact of Derivative Accounting			Net Impact of Acquired Intangibles			Total
Net interest income after provisions for loan losses	$	(49	)	$	—		$	(49	)
Total other income (loss)		(41	)		—			(41	)
Goodwill and acquired intangible asset impairment and amortization		—			47			47
Total Core Earnings adjustments to GAAP	$	(90	)	$	(47	)		(137	)
Income tax expense (benefit)								(13	)
Net income (loss)							$	(124	)

⁽²⁾	Income taxes are based on a percentage of net income before tax for the individual reportable segment.

	Year Ended December 31, 2017
													Adjustments
(Dollars in millions)	Federal Education Loans		Consumer Lending		Business Processing		Other			Total Core Earnings			Reclassi- fications			Additions/ (Subtractions)			Total Adjustments⁽¹⁾			Total GAAP
Interest income:
Education loans	$	2,679	$	1,634	$	—	$	—		$	4,313		$	69		$	(55	)	$	14		$	4,327
Other loans		13		—		—		—			13			—			—			—			13
Cash and investments		29		5		—		9			43			—			—			—			43
Total interest income		2,721		1,639		—		9			4,369			69			(55	)		14			4,383
Total interest expense		2,022		825		—		143			2,990			(8	)		(11	)		(19	)		2,971
Net interest income (loss)		699		814		—		(134	)		1,379			77			(44	)		33			1,412
Less: provisions for loan losses		44		382		—		—			426			—			—			—			426
Net interest income (loss) after provisions for loan losses		655		432		—		(134	)		953			77			(44	)		33			986
Other income (loss):
Servicing revenue		280		10		—		—			290			—			—			—			290
Asset recovery and business processing revenue		263		—		212		—			475			—			—			—			475
Other income (loss)		3		—		—		16			19			(77	)		89			12			31
Gains on sales of loans		3		—		—		—			3			—			—			—			3
Losses on debt repurchases		—		—		—		(3	)		(3	)		—			—			—			(3	)
Total other income (loss)		549		10		212		13			784			(77	)		89			12			796
Expenses:
Direct operating expenses		316		156		187		—			659			—			—			—			659
Unallocated shared services expenses		—		—		—		307			307			—			—			—			307
Operating expenses		316		156		187		307			966			—			—			—			966
Goodwill and acquired intangible asset impairment and amortization		—		—		—		—			—			—			23			23			23
Restructuring/other reorganization expenses		—		—		—		29			29			—			—			—			29
Total expenses		316		156		187		336			995			—			23			23			1,018
Income (loss) before income tax expense (benefit)		888		286		25		(457	)		742			—			22			22			764
Income tax expense (benefit)⁽²⁾		321		103		9		58			491			—			(19	)		(19	)		472
Net income (loss)	$	567	$	183	$	16	$	(515	)	$	251		$	—		$	41		$	41		$	292

⁽¹⁾	Core Earnings adjustments to GAAP:

	Year Ended December 31, 2017
(Dollars in millions)	Net Impact of Derivative Accounting		Net Impact of Acquired Intangibles			Total
Net interest income after provisions for loan losses	$	33	$	—		$	33
Total other income (loss)		12		—			12
Goodwill and acquired intangible asset impairment and amortization		—		23			23
Total Core Earnings adjustments to GAAP	$	45	$	(23	)		22
Income tax expense (benefit)							(19	)
Net income (loss)						$	41

⁽²⁾	Income taxes are based on a percentage of net income before tax for the individual reportable segment with the impact of the DTA Remeasurement Loss included in the Other segment.

Core Earnings Adjustments to GAAP

Summary of Core Earnings Adjustments to GAAP

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Core Earnings net income	$	607		$	519		$	251
Core Earnings adjustments to GAAP:
Net impact of derivative accounting⁽¹⁾		5			(90	)		45
Net impact of goodwill and acquired intangible assets⁽²⁾		(30	)		(47	)		(23	)
Net income tax effect⁽³⁾		15			13			19
Total Core Earnings adjustments to GAAP		(10	)		(124	)		41
GAAP net income	$	597		$	395		$	292

⁽¹⁾

⁽²⁾

Goodwill and acquired intangible assets: Our Core Earnings exclude goodwill and intangible asset impairment and amortization of acquired intangible assets.

⁽³⁾

Net tax effect: Such tax effect is based upon our Core Earnings effective tax rate for the year.

Federal Education Loans [Member]

Asset Information for Loans Segment

The following table includes GAAP-basis asset information for our Federal Education Loans segment.

	December 31,
(Dollars in millions)	2019		2018
FFELP Loans, net	$	64,575	$	72,253
Cash and investments⁽¹⁾		2,043		3,368
Other		2,202		2,100
Total assets	$	68,820	$	77,721

⁽¹⁾

^{Includes restricted cash and investments.}

Consumer Lending [Member]

Asset Information for Loans Segment

The following table includes GAAP-basis asset information for our Consumer Lending segment.

	December 31,
Dollars in millions)	2019		2018
Private Education Loans, net	$	22,245	$	22,245
Cash and investments⁽¹⁾		927		732
Other		931		1,076
Total assets	$	24,103	$	24,053

⁽¹⁾

^{Includes restricted cash and investments.}

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Valuation allowance, Operating loss and credit carryovers	$ 60.0	$ 43.0
Unrecognized tax benefits at end of year	53.6	$ 65.7	$ 57.4	$ 73.0
Unrecognized tax benefits recognition impact on effective tax rate	$ 42.4
Minimum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Statute of limitation period for open tax reviews	3 years
Maximum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Statute of limitation period for open tax reviews	4 years
State [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Valuation allowance, Operating loss and credit carryovers	$ 36.0
Operating loss carryforwards	$ 556.0
Operating loss carryforwards, expiration dates	2021
Tax-effected NOL	$ 39.0
Disallowed interest expense carryforwards	1,551.0
Tax effected disallowed interest expense	21.0
Disallowed interest expense carryforwards valuation allowance	21.0
Federal and State [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Capital loss carryforwards	$ 10.0
Capital loss carryforwards expiration date	2021
Tax effected Capital loss	$ 3.0
Capital loss carryforwards valuation allowance	3.0
Federal [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Valuation allowance, Operating loss and credit carryovers	0.0
Operating loss carryforwards	$ 66.0
Operating loss carryforwards, expiration dates	2031
Tax-effected NOL	$ 14.0

Earnings (Loss) per Common Share (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Schedule of Earnings (Loss) per Common Share

	Years Ended December 31,
(In millions, except per share data)	2019		2018		2017
Numerator:
Net income	$	597	$	395	$	292
Denominator:
Weighted average shares used to compute basic EPS		230		260		275
Effect of dilutive securities:
Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units and Employee Stock Purchase Plan (“ESPP”)⁽¹⁾		3		4		6
Dilutive potential common shares⁽²⁾		3		4		6
Weighted average shares used to compute diluted EPS		233		264		281
Basic earnings per common share	$	2.59	$	1.52	$	1.06
Diluted earnings per common share	$	2.56	$	1.49	$	1.04

⁽¹⁾

⁽²⁾	For the years ended December 31, 2019, 2018 and 2017, securities covering approximately 4 million, 6 million and 5 million shares, respectively, were outstanding but not included in the computation of diluted earnings per share because they were anti-dilutive.

Revenue from Contracts with Customers Accounted for in Accordance with ASC 606 - Summary of Disaggregation of Revenue from Contracts Accounted Under ASC 606 with Customers (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 391	$ 359
Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	91	28
Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	52	58
Other Institutions [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	7	12
State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	83	92
Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	54	76
Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	104	93
Federal Education Loan Asset Recovery Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	133	91
Government Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	154	175
Healthcare Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	104	93
Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	133	91
Federal Education Loans [Member] \| Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	74	21
Federal Education Loans [Member] \| Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	52	58
Federal Education Loans [Member] \| Other Institutions [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	7	12
Federal Education Loans [Member] \| Federal Education Loan Asset Recovery Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	133	91
Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	258	268
Business Processing [Member] \| Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	17	7
Business Processing [Member] \| State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	83	92
Business Processing [Member] \| Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	54	76
Business Processing [Member] \| Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	104	93
Business Processing [Member] \| Government Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	154	175
Business Processing [Member] \| Healthcare Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 104	$ 93

Earnings (Loss) per Common Share - Schedule of Earnings (Loss) per Common Share (Parenthetical) (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Securities not included in the computation of diluted earnings per share	4	6	5

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Loan reserves	$ 257	$ 292
Education loan premiums and discounts, net	44	48
Accrued expenses not currently deductible	16	14
Operating loss and credit carryovers	17	18
Stock-based compensation plans	10	16
Other	21	18
Total deferred tax assets	365	406
Deferred tax liabilities:
Market value adjustments on education loans, investments and derivatives	13	46
Acquired intangible assets	17	12
Original issue discount on borrowings	10	7
Other	18	19
Total deferred tax liabilities	58	84
Net deferred tax assets	$ 307	$ 322

Income Taxes - Reconciliations of Statutory U.S. Federal Income Tax Rates to Our Effective Tax Rate for Continuing Operations (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	35.00%
DTA remeasurement loss			$ 208

Organization and Business - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Loans, net	$ 86,820	$ 94,498

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Dec. 31, 2019	Jan. 31, 2020	Jun. 28, 2019
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	Navient Corporation
Entity Central Index Key	0001593538
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		193,333,131
Entity Public Float			$ 3.1
Entity File Number	001-36228
Entity Tax Identification Number	46-4054283
Entity Address, Address Line One	123 Justison Street
Entity Address, City or Town	Wilmington
Entity Address, State or Province	DE
Entity Address, Postal Zip Code	19801
City Area Code	(302)
Local Phone Number	283-8000
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference	Portions of the proxy statement (the “2020 Proxy Statement”) relating to the Registrant’s 2020 Annual Meeting of Stockholders, currently scheduled to be held on May 21, 2020, are incorporated by reference into Part III of this Annual Report on Form 10-K.
Common Stock Par Value. 01 Per Share [Member]
Document Information [Line Items]
Title of 12(b) Security	Common stock, par value $.01 per share
Trading Symbol	NAVI
Security Exchange Name	NASDAQ
Senior Notes Due December 15, 2043 [Member]
Document Information [Line Items]
Title of 12(b) Security	6% Senior Notes due December 15, 2043
Trading Symbol	JSM
Security Exchange Name	NASDAQ

Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Impact of Derivatives on Consolidated Balance Sheet

		Cash Flow				Fair Value⁽⁴⁾						Trading						Total
(Dollars in millions)	Hedged Risk Exposure	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019			Dec. 31, 2018			Dec. 31, 2019			Dec. 31, 2018			Dec. 31, 2019			Dec. 31, 2018
Fair Values⁽¹⁾
Derivative Assets:
Interest rate swaps	Interest rate	$	—	$	—	$	226		$	170		$	4		$	3		$	230		$	173
Cross-currency interest rate swaps	Foreign currency and interest rate		—		—		—			6			—			—			—			6
Total derivative assets⁽²⁾			—		—		226			176			4			3			230			179
Derivative Liabilities:
Interest rate swaps	Interest rate		—		—		—			(34	)		(20	)		(45	)		(20	)		(79	)
Floor Income Contracts	Interest rate		—		—		—			—			(68	)		(53	)		(68	)		(53	)
Cross-currency interest rate swaps	Foreign currency and interest rate		—		—		(575	)		(639	)		—			(26	)		(575	)		(665	)
Other⁽³⁾	Interest rate		—		—		—			—			(1	)		(4	)		(1	)		(4	)
Total derivative liabilities⁽²⁾			—		—		(575	)		(673	)		(89	)		(128	)		(664	)		(801	)
Net total derivatives		$	—	$	—	$	(349	)	$	(497	)	$	(85	)	$	(125	)	$	(434	)	$	(622	)

⁽¹⁾

⁽²⁾	The following table reconciles gross positions without the impact of master netting agreements to the balance sheet classification:

	Other Assets						Other Liabilities
(Dollar in millions)	December 31, 2019			December 31, 2018			December 31, 2019			December 31, 2018
Gross position	$	230		$	179		$	(664	)	$	(801	)
Impact of master netting agreements		(18	)		(22	)		18			22
Derivative values with impact of master netting agreements (as carried on balance sheet)		212			157			(646	)		(779	)
Cash collateral (held) pledged		(337	)		(266	)		155			188
Net position	$	(125	)	$	(109	)	$	(491	)	$	(591	)

⁽³⁾	^{“Other” includes derivatives related to our Total Return Swap Facility.}

⁽⁴⁾	^{The following table shows the carrying value of liabilities in fair value hedges and the related fair value hedging adjustments to these liabilities:}

	As of December 31, 2019					As of December 31, 2018
(Dollar in millions)	Carrying Value		Hedge Basis Adjustments			Carrying Value		Hedge Basis Adjustments
Short-term borrowings	$	1,001	$	4		$	664	$	(3	)
Long-term borrowings	$	11,488	$	(58	)	$	13,657	$	(368	)

Gross Positions with Impact of Master Netting Agreements

The following table reconciles gross positions without the impact of master netting agreements to the balance sheet classification:

	Other Assets						Other Liabilities
(Dollar in millions)	December 31, 2019			December 31, 2018			December 31, 2019			December 31, 2018
Gross position	$	230		$	179		$	(664	)	$	(801	)
Impact of master netting agreements		(18	)		(22	)		18			22
Derivative values with impact of master netting agreements (as carried on balance sheet)		212			157			(646	)		(779	)
Cash collateral (held) pledged		(337	)		(266	)		155			188
Net position	$	(125	)	$	(109	)	$	(491	)	$	(591	)

⁽³⁾	^{“Other” includes derivatives related to our Total Return Swap Facility.}

⁽⁴⁾	^{The following table shows the carrying value of liabilities in fair value hedges and the related fair value hedging adjustments to these liabilities:}

Carrying Value and Related Fair Value Hedging Adjustments of Liabilities

The following table shows the carrying value of liabilities in fair value hedges and the related fair value hedging adjustments to these liabilities:

	As of December 31, 2019					As of December 31, 2018
(Dollar in millions)	Carrying Value		Hedge Basis Adjustments			Carrying Value		Hedge Basis Adjustments
Short-term borrowings	$	1,001	$	4		$	664	$	(3	)
Long-term borrowings	$	11,488	$	(58	)	$	13,657	$	(368	)

Derivative Notional Values

	Cash Flow				Fair Value				Trading				Total
(Dollars in billions)	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018
Notional Values:
Interest rate swaps	$	19.1	$	21.4	$	8.6	$	10.3	$	51.5	$	66.9	$	79.2	$	98.6
Floor Income Contracts		—		—		—		—		21.2		27.9		21.2		27.9
Cross-currency interest rate swaps		—		—		4.0		4.5		—		.2		4.0		4.7
Other⁽¹⁾		—		—		—		—		—		.2		—		.2
Total derivatives	$	19.1	$	21.4	$	12.6	$	14.8	$	72.7	$	95.2	$	104.4	$	131.4

⁽¹⁾	“Other” includes derivatives related to our Total Return Swap Facility.

Mark-to-Market Impact of Derivatives on Consolidated Statements of Income

	Total Gains (Losses)
	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Fair Value Hedges⁽²⁾:
Interest Rate Swaps
Gains (losses) recognized in net income on derivatives	$	281		$	(137	)	$	(214	)
Gains (losses) recognized in net income on hedged items		(299	)		162			193
Net fair value hedge ineffectiveness gains (losses)		(18	)		25			(21	)
Cross currency interest rate swaps
Gains (losses) recognized in net income on derivatives		57			(311	)		921
Gains (losses) recognized in net income on hedged items		(18	)		210			(954	)
Net fair value hedge ineffectiveness gains (losses)		39			(101	)		(33	)
Total fair value hedges⁽¹⁾⁽²⁾		21			(76	)		(54	)
Cash Flow Hedges:
Total cash flow hedges⁽²⁾		—			—			—
Trading
Interest rate swaps		44			22			8
Floor income contracts		(22	)		15			81
Cross currency interest rate swaps		(2	)		(3	)		2
Other		2			4			(15	)
Total trading derivatives⁽³⁾		22			38			76
Mark-to-market gains (losses) recognized	$	43		$	(38	)	$	22

⁽¹⁾	Recorded in interest expense in the consolidated statements of income for 2019 with the adoption of ASU No. 2017-12. Recorded in “gains (losses) on derivatives and hedging activities, net” in the consolidated statements of income for 2018 and 2017.

⁽²⁾	The accrued interest income (expense) on fair value hedges and cash flow hedges is recorded in interest expense and is excluded from this table.

⁽³⁾	Recorded in “gains (losses) on derivative and hedging activities, net” in the consolidated statements of income.

Impact of Derivatives on Consolidated Statements of Changes in Stockholders' Equity

Impact of Derivatives on Consolidated Statements of Changes in Stockholders’ Equity (net of tax)

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Total gains (losses) on cash flow hedges	$	(165	)	$	50		$	25
Reclassification adjustments for derivative (gains) losses included in net income (interest expense)⁽¹⁾⁽²⁾		(39	)		(11	)		30
Total change in stockholders’ equity for unrealized gains (losses) on derivatives	$	(204	)	$	39		$	55

⁽¹⁾

Includes net settlement income/expense.

⁽²⁾

We expect to reclassify $2 million of after-tax net losses from accumulated other comprehensive income to earnings during the next 12 months related to amortization of terminated hedge relationships.

Collateral Held and Pledged

The following table details collateral held and pledged related to derivative exposure between us and our derivative counterparties.

(Dollars in millions)	December 31, 2019		December 31, 2018
Collateral held:
Cash (obligation to return cash collateral is recorded in short-term borrowings)	$	337	$	266
Securities at fair value — corporate derivatives (not recorded in financial statements)⁽¹⁾		—		—
Securities at fair value — on-balance sheet securitization derivatives (not recorded in financial statements)⁽²⁾		69		90
Total collateral held	$	406	$	356
Derivative asset at fair value including accrued interest	$	282	$	210
Collateral pledged to others:
Cash (right to receive return of cash collateral is recorded in investments)	$	155	$	188
Total collateral pledged	$	155	$	188
Derivative liability at fair value including accrued interest and premium receivable	$	658	$	752

⁽¹⁾	The Company has the ability to sell or re-pledge securities it holds as collateral.

⁽²⁾	The trusts do not have the ability to sell or re-pledge securities they hold as collateral.

Fair Value Measurements

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Fair Value Measurements

12. Fair Value Measurements

We use estimates of fair value in applying various accounting standards for our financial statements. We categorize our fair value estimates based on a hierarchical framework associated with three levels of price transparency utilized in measuring financial instruments at fair value.

Education Loans

Our FFELP Loans and Private Education Loans are accounted for at cost or at the lower of cost or market if the loan is held-for-sale. Fair values were determined by modeling loan cash flows using stated terms of the assets and internally developed assumptions.

FFELP Loans

The significant assumptions used to determine fair value of our FFELP Loans are prepayment speeds, default rates, cost of funds, discount rate, capital levels and expected Repayment Borrower Benefits to be earned. In addition, the Floor Income component of our FFELP Loan portfolio is valued with option models using both observable market inputs and internally developed inputs. A number of significant inputs into the models are internally derived and not observable in active markets. While the resulting fair value can be validated against market transactions where we are a participant, these markets are not considered active. As such, these are level 3 valuations.

Private Education Loans

The significant assumptions used to determine fair value of our Private Education Loans are prepayment speeds, default rates, recovery rates, cost of funds, discount rate and capital levels. A number of significant inputs into the models are internally derived and not observable in active markets. While the resulting fair value can be validated against market transactions where we are a participant, these markets are not considered active. As such, these are level 3 valuations.

Cash and Investments (Including “Restricted Cash and Investments”)

Cash and cash equivalents are carried at cost. Carrying value approximates fair value. The fair value of investments in commercial paper, ABCP, or demand deposits that have a remaining term of less than 90 days when purchased are estimated to equal their cost and, when needed, adjustments for liquidity and credit spreads are made depending on market conditions and counterparty credit risks. No additional adjustments were deemed necessary. These are level 2 valuations.

Borrowings

Borrowings are accounted for at cost in the financial statements except when denominated in a foreign currency or when designated as the hedged item in a fair value hedge relationship. When the hedged risk is the benchmark interest rate (which for us is LIBOR) and not full fair value, the cost basis is adjusted for changes in value due to benchmark interest rates only. Foreign currency-denominated borrowings are re-measured at current spot rates in the financial statements. The full fair value of all borrowings is disclosed. Fair value was determined through standard bond pricing models and option models (when applicable) using the stated terms of the borrowings, observable yield curves, foreign currency exchange rates, volatilities from active markets or from quotes from broker-dealers. Fair value adjustments for unsecured corporate debt are made based on indicative quotes from observable trades and spreads on credit default swaps specific to the Company. Fair value adjustments for secured borrowings are based on indicative quotes from broker-dealers. These adjustments for both secured and unsecured borrowings are material to the overall valuation of these items and, currently, are based on inputs from inactive markets. As such, these are level 3 valuations.

12. Fair Value Measurements (Continued)

Derivative Financial Instruments

All derivatives are accounted for at fair value in the financial statements. The fair value of a majority of derivative financial instruments was determined by standard derivative pricing and option models using the stated terms of the contracts and observable market inputs. In some cases, we utilized internally developed inputs that are not observable in the market, and as such, classified these instruments as level 3 fair values. Complex structured derivatives or derivatives that trade in less liquid markets require significant estimates and judgment in determining fair value that cannot be corroborated with market transactions.

When determining the fair value of derivatives, we take into account counterparty credit risk for positions where there is exposure to the counterparty on a net basis by assessing exposure net of collateral held. The net exposures for each counterparty are adjusted based on market information available for the specific counterparty, including spreads from credit default swaps. When the counterparty has exposure to us under derivatives with us, we fully collateralize the exposure, minimizing the adjustment necessary to the derivative valuations for our credit risk. While trusts that contain derivatives are not required to post collateral, when the counterparty is exposed to the trust the credit quality and securitized nature of the trusts minimizes any adjustments for the counterparty’s exposure to the trusts. The net credit risk adjustment (adjustments for our exposure to counterparties net of adjustments for the counterparties’ exposure to us) decreased the valuations at December 31, 2019 by $11 million.

Inputs specific to each class of derivatives disclosed in the table below are as follows:

•

Interest rate swaps — Derivatives are valued using standard derivative cash flow models. Derivatives that swap fixed interest payments for LIBOR interest payments (or vice versa) and derivatives swapping quarterly reset LIBOR for daily reset LIBOR or one-month LIBOR were valued using the LIBOR swap yield curve which is an observable input from an active market. These derivatives are level 2 fair value estimates in the hierarchy. Other derivatives swapping LIBOR interest payments for another variable interest payment (primarily Prime) are valued using the LIBOR swap yield curve and observable market spreads for the specified index. The markets for these swaps are generally illiquid as indicated by a wide bid/ask spread. The adjustment made for liquidity decreased the valuations by $12 million at December 31, 2019. These derivatives are level 3 fair value estimates.

•

Cross-currency interest rate swaps — Derivatives are valued using standard derivative cash flow models. Derivatives hedging foreign-denominated bonds are valued using the LIBOR swap yield curve (for both USD and the foreign-denominated currency), cross-currency basis spreads and forward foreign currency exchange rates. These inputs are observable inputs from active markets. Therefore, the resulting valuation is a level 2 fair value estimate. Amortizing notional derivatives (derivatives whose notional amounts change based on changes in the balance of, or pool of, assets or debt) hedging trust debt use internally derived assumptions for the trust assets’ prepayment speeds and default rates to model the notional amortization. Management makes assumptions concerning the extension features of derivatives hedging rate-reset notes denominated in a foreign currency. These inputs are not market observable; therefore, these derivatives are level 3 fair value estimates.

•

Floor Income Contracts — Derivatives are valued using an option pricing model. Inputs to the model include the LIBOR swap yield curve and LIBOR interest rate volatilities. The inputs are observable inputs in active markets and these derivatives are level 2 fair value estimates.

The carrying value of borrowings designated as the hedged item in a fair value hedge is adjusted for changes in fair value due to benchmark interest rates and foreign-currency exchange rates. These valuations are determined through standard bond pricing models and option models (when applicable) using the stated terms of the borrowings, and observable yield curves, foreign currency exchange rates and volatilities.

12. Fair Value Measurements (Continued)

The following table summarizes the valuation of our financial instruments that are marked-to-market on a recurring basis. During 2019 and 2018, there were no significant transfers of financial instruments between levels.

	Fair Value Measurements on a Recurring Basis
	December 31, 2019											December 31, 2018
(Dollars in millions)	Level 1		Level 2			Level 3			Total			Level 1		Level 2			Level 3			Total
Assets
Derivative instruments:⁽¹⁾
Interest rate swaps		—		227			3			230			—		171			2			173
Cross-currency interest rate swaps		—		—			—			—			—		—			6			6
Total derivative assets⁽²⁾		—		227			3			230			—		171			8			179
Total	$	—	$	227		$	3		$	230		$	—	$	171		$	8		$	179
Liabilities⁽³⁾
Derivative instruments⁽¹⁾
Interest rate swaps	$	—	$	—		$	(20	)	$	(20	)	$	—	$	(50	)	$	(29	)	$	(79	)
Floor Income Contracts		—		(68	)		—			(68	)		—		(53	)		—			(53	)
Cross-currency interest rate swaps		—		—			(575	)		(575	)		—		(26	)		(639	)		(665	)
Other		—		—			(1	)		(1	)		—		—			(4	)		(4	)
Total derivative liabilities⁽²⁾		—		(68	)		(596	)		(664	)		—		(129	)		(672	)		(801	)
Total	$	—	$	(68	)	$	(596	)	$	(664	)	$	—	$	(129	)	$	(672	)	$	(801	)

⁽¹⁾	Fair value of derivative instruments excludes accrued interest and the value of collateral.

⁽²⁾	See “Note 7 — Derivative Financial Instruments” for a reconciliation of gross positions without the impact of master netting agreements to the balance sheet classification.

⁽³⁾	Borrowings which are the hedged items in a fair value hedge relationship and which are adjusted for changes in value due to benchmark interest rates only are not carried at full fair value and are not reflected in this table.

12. Fair Value Measurements (Continued)

The following tables summarize the change in balance sheet carrying value associated with level 3 financial instruments carried at fair value on a recurring basis.

	Year Ended December 31, 2019
	Derivative Instruments
(Dollars in millions)	Interest Rate Swaps			Cross Currency Interest Rate Swaps			Other			Total Derivative Instruments
Balance, beginning of period	$	(27	)	$	(633	)	$	(4	)	$	(664	)
Total gains/(losses):
Included in earnings⁽¹⁾		8			(60	)		2			(50	)
Included in other comprehensive income		—			—			—			—
Settlements		2			118			1			121
Transfers in and/or out of level 3		—			—			—			—
Balance, end of period	$	(17	)	$	(575	)	$	(1	)	$	(593	)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date⁽²⁾	$	9		$	58		$	3		$	70

	Year Ended December 31, 2018
	Derivative Instruments
(Dollars in millions)	Interest Rate Swaps			Cross Currency Interest Rate Swaps			Other			Total Derivative Instruments
Balance, beginning of period	$	(41	)	$	(322	)	$	(18	)	$	(381	)
Total gains/(losses):
Included in earnings⁽¹⁾		11			(433	)		8			(414	)
Included in other comprehensive income		—			—			—			—
Settlements		3			122			6			131
Transfers in and/or out of level 3		—			—			—			—
Balance, end of period	$	(27	)	$	(633	)	$	(4	)	$	(664	)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date⁽²⁾	$	13		$	(284	)	$	14		$	(257	)

	Year Ended December 31, 2017
	Derivative Instruments
(Dollars in millions)	Interest Rate Swaps			Cross Currency Interest Rate Swaps			Other			Total Derivative Instruments
Balance, beginning of period	$	(46	)	$	(1,243	)	$	(13	)	$	(1,302	)
Total gains/(losses):
Included in earnings⁽¹⁾		—			803			(15	)		788
Included in other comprehensive income		—			—			—			—
Settlements		5			118			10			133
Transfers in and/or out of level 3		—			—			—			—
Balance, end of period	$	(41	)	$	(322	)	$	(18	)	$	(381	)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date⁽²⁾	$	5		$	795		$	(5	)	$	795

⁽¹⁾

“Included in earnings” is comprised of the following amounts recorded in the specified line item in the consolidated statements of income:

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Gains (losses) on derivative and hedging activities, net	$	10		$	(292	)	$	906
Interest expense		(60	)		(122	)		(118	)
Total	$	(50	)	$	(414	)	$	788

⁽²⁾

Recorded in “gains (losses) on derivative and hedging activities, net” in the consolidated statements of income.

12. Fair Value Measurements (Continued)

The following table presents the significant inputs that are unobservable or from inactive markets used in the recurring valuations of the level 3 financial instruments detailed above.

(Dollars in millions)	Fair Value at December 31, 2019			Valuation Technique	Input	Range
Derivatives
Prime/LIBOR basis swaps	$	(17	)	Discounted cash flow	Constant Prepayment Rate	8%
					Bid/ask adjustment to discount rate	.08%
Cross-currency interest rate swaps		(575	)	Discounted cash flow	Constant Prepayment Rate	4%
Other		(1	)
Total	$	(593	)

The significant inputs that are unobservable or from inactive markets related to our level 3 derivatives detailed in the table above would be expected to have the following impacts to the valuations:

•

Prime/LIBOR basis swaps — These swaps do not actively trade in the markets as indicated by a wide bid/ask spread. A wider bid/ask spread will result in a decrease in the overall valuation. In addition, the unobservable inputs include Constant Prepayment Rates of the underlying securitization trust the swap references. A decrease in this input will result in a longer weighted average life of the swap which will increase the value for swaps in a gain position and decrease the value for swaps in a loss position, everything else equal. The opposite is true for an increase in the input.

•

Cross-currency interest rate swaps — The unobservable inputs used in these valuations are Constant Prepayment Rates of the underlying securitization trust the swap references. A decrease in this input will result in a longer weighted average life of the swap. All else equal in a typical currency market, this will result in a decrease to the valuation due to the delay in the cash flows of the currency exchanges as well as diminished liquidity in the forward exchange markets as you increase the term. The opposite is true for an increase in the input.

The following table summarizes the fair values of our financial assets and liabilities, including derivative financial instruments.

	December 31, 2019									December 31, 2018
(Dollars in millions)	Fair Value			Carrying Value			Difference			Fair Value			Carrying Value			Difference
Earning assets
FFELP Loans	$	64,478		$	64,575		$	(97	)	$	72,074		$	72,253		$	(179	)
Private Education Loans		22,984			22,245			739			22,958			22,245			713
Cash and investments		3,992			3,992			—			5,488			5,488			—
Total earning assets		91,454			90,812			642			100,520			99,986			534
Interest-bearing liabilities
Short-term borrowings		8,498			8,483			(15	)		5,418			5,422			4
Long-term borrowings		81,317			81,715			398			92,173			93,519			1,346
Total interest-bearing liabilities		89,815			90,198			383			97,591			98,941			1,350
Derivative financial instruments
Floor Income Contracts		(68	)		(68	)		—			(53	)		(53	)		—
Interest rate swaps		210			210			—			94			94			—
Cross-currency interest rate swaps		(575	)		(575	)		—			(659	)		(659	)		—
Other		(1	)		(1	)		—			(4	)		(4	)		—
Excess of net asset fair value over carrying value							$	1,025								$	1,884

Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Derivative Gain Loss On Derivative Net [Abstract]
Amount of after-tax net losses to be reclassified from accumulated other comprehensive income to earnings in the next 12 months	$ 2

Income Taxes - Components of Provision for Income Tax Expense (Benefit) (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current provision/(benefit):
Federal									$ 78	$ 71	$ 77
State									11	13	(3)
Foreign										3	3
Total current provision/(benefit)									89	87	77
Deferred provision/(benefit):
Federal									73	33	385
State									3	13	11
Foreign									1		(1)
Total deferred provision/(benefit)									77	46	395
Provision for income tax expense/(benefit)	$ 49	$ 40	$ 41	$ 36	$ 34	$ 33	$ 30	$ 36	$ 166	$ 133	$ 472

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Allowance for loans losses	$ 1,112	$ 1,286
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,125,000,000	1,125,000,000
Common stock, shares issued	451,000,000	445,000,000
Tax (benefit) expense for accumulated other comprehensive income	$ (30)	$ 35
Common stock held in treasury	236,000,000	198,000,000
FFELP Loans [Member]
Allowance for loans losses	$ 64	$ 76
Private Education Loans [Member]
Allowance for loans losses	$ 1,048	$ 1,201

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Dividends per common share	$ 0.64	$ 0.64	$ 0.64
Retained Earnings [Member]
Dividends per common share	0.64	0.64	0.64
Total Stockholders' Equity [Member]
Dividends per common share	$ 0.64	$ 0.64	$ 0.64

Revenue from Contracts with Customers Accounted for in Accordance with ASC 606 (Tables)

12 Months Ended

Dec. 31, 2019

Revenue From Contract With Customer [Abstract]

Summary of Disaggregation of Revenue from Contracts Accounted Under ASC 606 with Customers

15. Revenue from Contracts with Customers Accounted for in Accordance with ASC 606

The following tables illustrate the disaggregation of revenue from contracts accounted for under ASC 606 with customers according to service type and client type by reportable operating segment.

Revenue by Service Type

	Years Ended December 31,
	2019						2018
(Dollars in millions)	Federal Education Loans		Business Processing		Total Revenue		Federal Education Loans		Business Processing		Total Revenue
Federal Education Loan asset recovery services	$	133	$	—	$	133	$	91	$	—	$	91
Government services		—		154		154		—		175		175
Healthcare services		—		104		104		—		93		93
Total	$	133	$	258	$	391	$	91	$	268	$	359

Revenue by Client Type

	Years Ended December 31,
	2019						2018
(Dollars in millions)	Federal Education Loans		Business Processing		Total Revenue		Federal Education Loans		Business Processing		Total Revenue
Federal government	$	74	$	17	$	91	$	21	$	7	$	28
Guarantor agencies		52		—		52		58		—		58
Other institutions		7		—		7		12		—		12
State and local government		—		83		83		—		92		92
Tolling authorities		—		54		54		—		76		76
Hospitals and other healthcare providers		—		104		104		—		93		93
Total	$	133	$	258	$	391	$	91	$	268	$	359

Quarterly Financial Information (unaudited)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information (unaudited)

17. Quarterly Financial Information (unaudited)

	2019
(Dollars in millions, except per share data)	First Quarter		Second Quarter			Third Quarter		Fourth Quarter
Net interest income	$	285	$	293		$	312	$	294
Less: provisions for loan losses		76		68			64		50
Net interest income after provisions for loan losses		209		225			248		244
Other income		212		254			192		176
Gains (losses) on derivative and hedging activities, net		7		(32	)		4		43
Operating expenses		256		241			251		235
Goodwill and acquired intangible asset impairment and amortization expense		7		11			6		6
Restructuring/other reorganization expenses		1		1			2		2
Income tax expense		36		41			40		49
Net income	$	128	$	153		$	145	$	171
Basic earnings per common share	$	.52	$	.65		$	.64	$	.79
Diluted earnings per common share	$	.52	$	.64		$	.63	$	.78

	2018
(Dollars in millions, except per share data)	First Quarter		Second Quarter			Third Quarter		Fourth Quarter
Net interest income	$	329	$	298		$	306	$	307
Less: provisions for loan losses		87		112			85		85
Net interest income after provisions for loan losses		242		186			221		222
Other income		163		176			203		196
Gains (losses) on derivative and hedging activities, net		48		(40	)		2		(48	)
Operating expenses		275		201			255		252
Goodwill and acquired intangible asset impairment and amortization expense		9		6			23		8
Restructuring/other reorganization expenses		7		2			1		4
Income tax expense		36		30			33		34
Net income	$	126	$	83		$	114	$	72
Basic earnings per common share	$	.48	$	.31		$	.44	$	.28
Diluted earnings per common share	$	.47	$	.31		$	.43	$	.28

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Equity [Abstract]

Common Share Repurchases and Issuances

The following table summarizes our common share repurchases and issuances.

	Years Ended December 31,
	2019		2018		2017
Common stock repurchased⁽¹⁾		34,491,342		17,443,351		29,646,374
Average purchase price per share	$	12.76	$	12.64	$	14.85
Shares repurchased related to employee stock-based compensation plans⁽²⁾		3,226,301		3,829,629		1,847,651
Average purchase price per share	$	11.62	$	13.71	$	15.40
Common shares issued⁽³⁾		5,717,053		5,659,681		3,680,479

⁽¹⁾

^{Common shares purchased under our share repurchase program.}

⁽²⁾

^{Comprises shares withheld from stock option exercises and vesting of restricted stock for employees’ tax withholding obligations and shares tendered by employees to satisfy option exercise costs.}

⁽³⁾

^{Common shares issued under our various compensation and benefit plans.}

Stockholders' Equity

12 Months Ended

Dec. 31, 2019

Equity [Abstract]

Stockholders' Equity

9. Stockholders’ Equity

Common Stock

Our shareholders have authorized the issuance of 1.125 billion shares of common stock. The par value of Navient common stock is $0.01 per share. At December 31, 2019, 215 million shares were issued and outstanding and 24 million shares were unissued but encumbered for outstanding stock options, restricted stock units, performance stock units and dividend equivalent units for employee compensation and remaining authority for stock-based compensation plans. The stock-based compensation plans are described in “Note 11 — Stock-Based Compensation Plans and Arrangements.”

Dividend and Share Repurchase Program

In 2019, 2018 and 2017, we paid $147 million ($0.64 per share), $166 million (0.64 per share) and $176 million ($0.64 per share), respectively, of common stock dividends.

In 2019, 2018 and 2017, we repurchased 34.5 million, 17.4 million and 29.6 million shares of common stock, respectively, for $440 million, $220 million and $440 million, respectively. Our board of directors authorized a $500 million share repurchase program in September 2018 which was fully utilized in 2019. In October 2019, our board of directors approved an additional $1 billion multi-year share repurchase program. As of December 31, 2019, the remaining common share repurchase authority was $1 billion.

The following table summarizes our common share repurchases and issuances.

	Years Ended December 31,
	2019		2018		2017
Common stock repurchased⁽¹⁾		34,491,342		17,443,351		29,646,374
Average purchase price per share	$	12.76	$	12.64	$	14.85
Shares repurchased related to employee stock-based compensation plans⁽²⁾		3,226,301		3,829,629		1,847,651
Average purchase price per share	$	11.62	$	13.71	$	15.40
Common shares issued⁽³⁾		5,717,053		5,659,681		3,680,479

⁽¹⁾

^{Common shares purchased under our share repurchase program.}

⁽²⁾

⁽³⁾

^{Common shares issued under our various compensation and benefit plans.}

The closing price of our common stock on December 31, 2019 was $13.68.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Use of Estimates

Our financial reporting and accounting policies conform to generally accepted accounting principles in the United States of America (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Uncertain and volatile market and economic conditions increase the risk and complexity of the judgments in these estimates and actual results could differ from estimates. Accounting policies that include the most significant judgments, estimates and assumptions include the allowance for loan losses, the amortization of loan premiums and discounts using the effective interest rate method, goodwill and intangible asset impairment assessment and fair value measurement.

Consolidation

The consolidated financial statements include the accounts of Navient Corporation and its majority-owned and controlled subsidiaries and those Variable Interest Entities (“VIEs”) for which we are the primary beneficiary, after eliminating the effects of intercompany accounts and transactions.

We consolidate any VIEs where we have determined we are the primary beneficiary. A VIE is a legal entity that does not have sufficient equity at risk to finance its own operations, or whose equity holders do not have the power to direct the activities that most significantly affect the economic performance of the entity, or whose equity holders do not share proportionately in the losses or benefits of the entity. The primary beneficiary of the VIE is the entity which has both: (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses or receive benefits of the entity that could potentially be significant to the VIE. As it relates to our securitizations and other secured borrowing facilities that are VIEs as of December 31, 2019 that we consolidate, we are the primary beneficiary as we are the servicer of the related education loan assets and own the Residual Interest of the securitization trusts and secured borrowing facilities.

Fair Value Measurement

We use estimates of fair value in applying various accounting standards for our financial statements. Fair value measurements are used in one of four ways:

•

In the consolidated balance sheet with changes in fair value recorded in the consolidated statement of income;

•

In the consolidated balance sheet with changes in fair value recorded in the accumulated other comprehensive income section of the consolidated statement of changes in stockholders’ equity;

•

In the consolidated balance sheet for instruments carried at lower of cost or fair value with impairment charges recorded in the consolidated statement of income; and

•

In the notes to the financial statements.

Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between willing and able market participants. In general, our policy in estimating fair value is to first look at observable market prices for identical assets and liabilities in active markets, where available. When these are not available, other inputs are used to model fair value such as prices of similar instruments, yield curves, volatilities, prepayment speeds, default rates and credit spreads, relying first on observable data from active markets. Depending on current market conditions, additional adjustments to fair value may be based on factors such as liquidity and credit spreads. Transaction costs are not included in the determination of fair value. When possible, we seek to validate the model’s output to market transactions. Depending on the availability of observable inputs and prices, different valuation models could produce materially different fair value estimates. The values presented may not represent future fair values and may not be realizable.

We categorize our fair value estimates based on a hierarchical framework associated with three levels of price transparency utilized in measuring financial instruments at fair value. Classification is based on the lowest level of input that is significant to the fair value of the instrument. The three levels are as follows:

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Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the measurement date. The types of financial instruments included in level 1 are highly liquid instruments with quoted prices.

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Level 2 — Inputs from active markets, other than quoted prices for identical instruments, are used to determine fair value. Significant inputs are directly observable from active markets for substantially the full term of the asset or liability being valued.

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Level 3 — Pricing inputs significant to the valuation are unobservable. Inputs are developed based on the best information available. However, significant judgment is required by us in developing the inputs.

Loans

Loans, consisting primarily of federally insured education loans and Private Education Loans, that we have the ability and intent to hold for the foreseeable future are classified as held-for-investment and are carried at amortized cost. Amortized cost includes the unamortized premiums, discounts, and capitalized origination costs and fees, all of which are amortized to interest income as further discussed below. Loans which are held-for-investment also have an allowance for loan loss as needed. Any loans we have not classified as held-for-investment are classified as held-for-sale and carried at the lower of cost or fair value. Loans are classified as held-for-sale when we have the intent and ability to sell such loans. Loans which are held-for-sale do not have the associated premium, discount, and capitalized origination costs and fees amortized into interest income. In addition, once a loan is classified as held-for-sale, there is no further adjustment to the loan’s allowance for loan losses that existed immediately prior to the reclassification to held-for-sale.

Allowance for Loan Losses

Purchased Credit Impaired (“PCI”) Loans

Loans acquired with evidence of deterioration of credit quality since origination for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable are PCI loans accounted for under Accounting Standard Codification (“ASC”) 310-30, “Loans and Debt Securities Acquired with Deteriorated Credit Quality.” When considering whether evidence of credit quality deterioration exists as of the purchase date, the Company considers loan guarantees and the following credit attributes: delinquency status, use of forbearance, recent borrower FICO scores, use of loan modification programs, and borrowers who have filed for bankruptcy.

The Company aggregates loans with common risk characteristics into pools and accounts for each pool as a single asset with a single composite interest rate and an aggregate expectation of cash flows. The pools are initially recorded at fair value. The Company recognizes interest income based on each pool’s effective interest rate which is based on our estimate of all cash flows expected to be received and includes an assumption about prepayment rates. The pools are tested quarterly for impairment by re-estimating the future cash flows to be received from the pools. If the new estimated cash flows result in a pool’s effective interest rate increasing, then this new yield is used prospectively over the remaining life of the pool. If the new estimated cash flows result in a pool’s effective interest rate decreasing, the pool is impaired and written down through a valuation allowance to maintain the effective interest rate. Loans classified as PCI do not have charge-offs reported nor are they reported as Trouble Debt Restructuring (“TDR”) loans.

Based on the credit attributes discussed above, we determined that $261 million principal amount of Private Education Loans acquired in 2017 are accounted for as PCI loans with a fair value and resulting carry value of $101 million as of the acquisition date. As of acquisition, this portfolio’s contractually required payments receivable (the total undiscounted amount of all uncollected contractual principal and interest payments both past due and scheduled for the future, adjusted for prepayments) was $411 million with an estimated accretable yield (income expected to be recognized in future periods) of $108 million. As of December 31, 2019, the carrying amount was $70 million with no valuation allowance recorded.

Purchased Non-Credit Impaired Loans

Loans acquired that do not have evidence of credit deterioration since origination are recorded at fair value with no allowance for loan losses established at the acquisition date. Loan premiums and discounts are amortized as a part of interest income using the interest method under ASC 310-20, “Nonrefundable Fees and Other Costs.” An allowance for loan losses would be established if incurred losses in the loans exceed the remaining unamortized discount recorded at the time of acquisition (i.e., the next two years of expected charge-offs as well as any additional TDR allowance required is greater than the remaining discount). As a result of this policy, to the extent that actual charge-offs exceed any related allowance for loan losses recognized post-acquisition, provision for loan losses is recorded when the loans are charged off. Charge-offs are recorded through the allowance for loan losses. In 2017, we acquired Private Education Loans with an unpaid principal balance of $2.8 billion at a discount of $424 million and FFELP Loans with an unpaid principal balance of $3.5 billion at a discount of $47 million, that are accounted for under this policy. No allowance for loan losses has been established for these loans as of December 31, 2019, as the remaining purchased discount associated with the Private Education Loans of $268 million and FFELP Loans of $33 million as of December 31, 2019 remains greater than the incurred losses.

Allowance for Private Education Loan Losses

We consider a loan to be impaired when, based on current information, a loss has been incurred and it is probable that we will not receive all contractual amounts due. When making our assessment as to whether a loan is impaired, we also take into account more than insignificant delays in payment. We generally evaluate impaired loans on an aggregate basis by grouping similar loans. Impaired loans also include those loans which are individually assessed for impairment at a loan level, such as in a troubled debt restructuring (“TDR”). We maintain an allowance for loan losses at an amount sufficient to absorb losses incurred in our portfolios at the reporting date based on a projection of estimated probable credit losses incurred in the portfolio.

2. Significant Accounting Policies (Continued)

Our Private Education Loan portfolio contains TDR and non-TDR loans. For customers experiencing financial difficulty, certain Private Education Loans for which we have granted a forbearance of greater than three months, an interest rate reduction or an extended repayment plan are classified as TDRs. The allowance requirements are different based on these designations. In determining the allowance for loan losses on our non-TDR portfolio, we estimate the principal amount of loans that will default over the next two years (two years being the expected period between a loss event and default) and how much we expect to recover over time related to the defaulted amount. Expected defaults less our expected recoveries equal the allowance related to this portfolio. Our historical experience indicates that, on average, the time between the date that a customer experiences a default causing event (i.e., the loss trigger event) and the date that we charge off the unrecoverable portion of that loan is two years. Separately, for our TDR portfolio, we estimate an allowance amount sufficient to cover life-of-loan expected losses through an impairment calculation based on the difference between the loan’s basis and the present value of expected future cash flows (which would include life-of-loan default and recovery assumptions) discounted at the loan’s original effective interest rate. Our TDR portfolio is comprised mostly of loans with forbearance usage greater than three months and interest rate reductions. The separate allowance estimates for our TDR and non-TDR portfolios are combined into our total allowance for Private Education Loan losses.

In estimating both the non-TDR and TDR allowance amounts, we start with historical experience of customer default behavior. We make judgments about which historical period to start with and then make further judgments about whether that historical experience is representative of future expectations and whether additional adjustments may be needed to those historical default rates. We also take the economic environment into consideration when calculating the allowance for loan losses. We analyze key economic statistics and the effect we expect them to have on future defaults. Key economic statistics analyzed as part of the allowance for loan losses are primarily unemployment rates. Our allowance for loan losses is estimated using an analysis of delinquent and current accounts. Our model is used to estimate the likelihood that a loan may progress through the various delinquency stages and ultimately charge off. The evaluation of the allowance for loan losses is inherently subjective, as it requires material estimates that may be susceptible to significant changes. The estimate for the allowance for loan losses is subject to a number of assumptions. If actual future performance in delinquency, charge-offs and recoveries are significantly different than estimated, this could materially affect our estimate of the allowance for loan losses and the related provision for loan losses on our income statement.

We determine the collectability of our Private Education Loan portfolio by evaluating certain risk characteristics. We consider school type, credit score (FICO), existence of a cosigner, loan status and loan seasoning as the key credit quality indicators because they have the most significant effect on our determination of the adequacy of our allowance for loan losses. The type of school customers attend can have an impact on their graduation rate and job prospects after graduation and therefore affects their ability to make payments. Credit scores are an indicator of the credit worthiness of a customer and the higher the credit score the more likely it is the customer will be able to make all of their contractual payments. Loan status affects the credit risk because a past due loan is more likely to result in a credit loss than an up-to-date loan. Additionally, loans in a deferred payment status have different credit risk profiles compared with those in current payment status. Of the portfolio in repayment, loan seasoning is an important factor. It affects credit risk because a loan with a history of making payments generally has a lower incidence of default than a loan with a history of making infrequent or no payments. The existence of a cosigner lowers the likelihood of default. We monitor and update these credit quality indicators in the analysis of the adequacy of our allowance for loan losses on a quarterly basis.

To estimate the probable credit losses incurred in the loan portfolio at the reporting date, we use historical experience of customer payment behavior in connection with the key credit quality indicators and incorporate management expectations regarding macroeconomic and collection performance factors. Our model is based upon the most recent twelve months of actual collection experience as the starting point for the non-TDR portfolio and the most recent approximate 15 years for the TDR portfolio and applies expected macroeconomic changes and collection procedure changes to estimate expected losses caused by loss events incurred as of the balance sheet date. Our model for the non-TDR portfolio places a greater emphasis on the more recent default experience rather than the default experience for older historical periods, as we believe the more recent default experience is more indicative of the probable losses incurred in the loan portfolio today that will default over the next two years. The TDR portfolio uses a longer historical default experience since we are projecting life of loan remaining losses. Similar to estimating defaults, we use historical customer payment behavior to estimate the timing and amount of future recoveries on charged-off loans. We use judgment in determining whether historical performance is

2. Significant Accounting Policies (Continued)

representative of what we expect to collect in the future. We then apply the default and collection rate projections to each category of loans. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. Additionally, we consider changes in laws and regulations that could potentially impact the allowance for loan losses.

Our collection policies allow for periods of nonpayment for customers requesting additional payment grace periods upon leaving school or experiencing temporary difficulty meeting payment obligations. This is referred to as forbearance status and is considered in our allowance for loan losses. The loss confirmation period is in alignment with our typical collection cycle and takes into account these periods of nonpayment.

Our allowance for Private Education Loan losses also provides for possible additional future charge-offs as they occur related to the receivable for partially charged-off Private Education Loans. At the end of each month, for loans that are 212 days past due, we charge off the estimated loss of a defaulted loan balance. Actual recoveries are applied against the remaining loan balance that was not charged off. We refer to this remaining loan balance as the “receivable for partially charged-off loans.” If actual periodic recoveries are less than expected, the difference is immediately charged off through the allowance for Private Education Loan losses with an offsetting reduction in the receivable for partially charged-off Private Education Loans. If actual periodic recoveries are greater than expected, they will be reflected as a recovery through the allowance for Private Education Loan losses once the cumulative recovery amount exceeds the cumulative amount originally expected to be recovered.

Allowance for FFELP Loan Losses

FFELP Loans are insured as to their principal and accrued interest in the event of default subject to a Risk Sharing level based on the date of loan disbursement. These insurance obligations are supported by contractual rights against the United States. For loans disbursed after October 1, 1993, and before July 1, 2006, we receive 98% reimbursement on all qualifying default claims. For loans disbursed on or after July 1, 2006, we receive 97% reimbursement. For loans disbursed prior to October 1, 1993, we receive 100% reimbursement.

Similar to the allowance for Private Education Loan losses, the allowance for FFELP Loan losses uses historical experience of customer default behavior and a two-year loss confirmation period to estimate the credit losses incurred in the loan portfolio at the reporting date. We apply the default rate projections, net of applicable Risk Sharing, to each category for the current period to perform our quantitative calculation. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. For FFELP Loans that have lost their government insurance and have been charged off, any subsequent cash recoveries benefit the allowance for loan losses when received.

Investments

Our available-for-sale investment portfolio consists of investments that are carried at fair value, with the temporary changes in fair value carried as a separate component of stockholders’ equity, net of taxes. The amortized cost of debt securities in this category is adjusted for the amortization of related premiums and discounts, which are amortized using the effective interest rate method. Other-than-temporary impairment is evaluated by considering several factors, including the length of time and extent to which the fair value has been less than the amortized cost basis, the financial condition and near-term prospects of the security (considering factors such as adverse conditions specific to the security and ratings agency actions), and the intent and ability to retain the investment to allow for an anticipated recovery in fair value. The entire fair value loss on a security that is other-than-temporary impairment is recorded in earnings if we intend to sell the security or if it is more likely than not that we will be required to sell the security before the expected recovery of the loss. However, if the impairment is other-than-temporary, and those two conditions do not exist, the portion of the impairment related to credit losses is recorded in earnings and the impairment related to other factors is recorded in other comprehensive income. Securities classified as trading are accounted for at fair value with unrealized gains and losses included in investment income. Securities that we have the intent and ability to hold to maturity are classified as held-to-maturity and are accounted for at amortized cost unless the security is determined to have an other-than-temporary impairment. In this case it is accounted for in the same manner described above.

2. Significant Accounting Policies (Continued)

We also have other investments, primarily a receivable for cash collateral posted to derivative counterparties.

Cash and Cash Equivalents

Cash and cash equivalents can include term federal funds, Eurodollar deposits, commercial paper, asset-backed commercial paper (“ABCP”), CDs, treasuries and money market funds with original terms to maturity of less than three months.

Restricted Cash and Investments

Restricted cash primarily includes amounts held in education loan securitization trusts and other secured borrowings. This cash must be used to make payments related to trust obligations. Amounts on deposit in these accounts are primarily the result of timing differences between when principal and interest is collected on the trust assets and when principal and interest is paid on trust liabilities.

Securities pledged as collateral related to our derivative portfolio, where the counterparty has rights to replace the securities, are classified as restricted. When the counterparty does not have these rights, the security is recorded in investments and disclosed as pledged collateral in the notes. Additionally, certain counterparties require cash collateral pledged to us to be segregated and held in restricted cash accounts.

Goodwill and Acquired Intangible Assets

Goodwill is not amortized but is tested periodically for impairment. We test goodwill for impairment annually as of October 1 at the reporting unit level, which is the same as or one level below a business segment. Goodwill is also tested at interim periods if an event occurs or circumstances change that would indicate the carrying amount may be impaired.

We complete a goodwill impairment analysis which may be a qualitative or a quantitative two-step analysis depending on the facts and circumstances associated with the reporting unit. In conjunction with a qualitative impairment analysis, we assess relevant qualitative factors to determine whether it is “more-likely-than-not” that the fair value of a reporting unit is less than its carrying amount. The “more-likely-than-not” threshold is defined as having a likelihood of more than 50%. In conjunction with a quantitative impairment analysis, we complete Step 1 of the goodwill impairment analysis. Step 1 consists of a comparison of the fair value of the reporting unit to the reporting unit’s carrying value, including goodwill. If the carrying value of the reporting unit exceeds the fair value, Step 2 in the goodwill impairment analysis is performed to measure the amount of impairment loss, if any. Step 2 of the goodwill impairment analysis compares the implied fair value of the reporting unit’s goodwill to the carrying value of the reporting unit’s goodwill. The implied fair value of goodwill is determined in a manner consistent with determining goodwill in a business combination. If the carrying amount of the reporting unit’s goodwill exceeds the implied fair value of the goodwill, an impairment loss is recognized in an amount equal to that excess. If, based on first assessing impairment utilizing a qualitative approach, we determine it is “more-likely-than-not” that the fair value of the reporting unit is less than its carrying amount, we will also complete a quantitative impairment analysis.

Acquired intangible assets include, but are not limited to, trade names, customer and other relationships, and non-compete agreements. Acquired intangible assets with finite lives are amortized over their estimated useful lives in proportion to their estimated economic benefit. Finite-lived acquired intangible assets are reviewed for impairment using an undiscounted cash flow analysis when an event occurs or circumstances change indicating the carrying amount of a finite-lived asset or asset group may not be recoverable. If the carrying amount of the asset or asset groups exceeds the undiscounted cash flows, the fair value of the asset or asset group is determined using an acceptable valuation technique. An impairment loss would be recognized if the carrying amount of the asset
(or asset group) exceeds the fair value of the asset or asset group. The impairment loss recognized would be the difference between the carrying amount and fair value.

Securitization Accounting

Our securitizations use a two-step structure with a special purpose entity that legally isolates the transferred assets from us, even in the event of bankruptcy. Transactions receiving sale treatment are also structured to ensure that the holders of the beneficial interests issued are not constrained from pledging or exchanging their interests, and that we do not maintain effective control over the transferred assets. If these criteria are not met, then the transaction is accounted for as an on-balance sheet secured borrowing. In all cases, irrespective of whether they qualify as accounting sales our securitizations are legally structured to be sales of assets that isolate the transferred assets from us. If a securitization qualifies as a sale, we then assess whether we are the primary beneficiary of the securitization trust (VIE) and are required to consolidate such trust. If we are the primary beneficiary, then no gain or loss is recognized. See “Consolidation” of this Note 2 for additional information regarding the accounting rules for consolidation when we are the primary beneficiary of these trusts.

Irrespective of whether a securitization receives sale or on-balance sheet treatment, our continuing involvement with our securitization trusts is generally limited to:

•	Owning equity certificates or other certificates of certain trusts and, in certain cases, securities retained for the purpose of complying with risk retention requirements under securities laws.

•	Lending to certain trusts, under a revolving credit, amounts necessary to cover temporary cash flow needs of the trust. These amounts are repaid to us on subordinated basis with interest at a market rate.

•	The servicing of the education loan assets within the securitization trusts, on both a pre- and post-default basis.

•	Our acting as administrator for the securitization transactions we sponsored, which includes remarketing certain bonds at future dates.

•	Our responsibilities relative to representation and warranty violations.

•	Temporarily advancing to the trust certain borrower benefits afforded the borrowers of education loans that have been securitized. These advances subsequently are returned to us in the next quarter.

•	Certain back-to-back derivatives entered into by us contemporaneously with the execution of derivatives by certain Private Education Loan securitization trusts.

•	The option held by us to buy certain delinquent loans from certain Private Education Loan securitization trusts.

•	The option to exercise the clean-up call and purchase the education loans from the trust when the asset balance is 10% or less of the original loan balance.

•	The option, on some trusts, to purchase education loans aggregating up to 10% of the trust’s initial pool balance.

•	The option (in certain trusts) to call rate reset notes in instances where the remarketing process has failed.

The investors of the securitization trusts have no recourse to our other assets should there be a failure of the trusts to pay when due. Generally, the only arrangements under which we have to provide financial support to the trusts are representation and warranty violations requiring the buyback of loans.

Under the terms of the transaction documents of certain trusts, we have, from time to time, exercised our options to purchase delinquent loans from Private Education Loan trusts, to purchase the remaining loans from trusts once the loan balance falls below 10% of the original amount, to purchase education loans up to 10% of the trust’s initial balance, or to call rate reset notes. Certain trusts maintain financial arrangements with third parties also typical of securitization transactions, such as derivative contracts (swaps) and bond insurance policies that, in the case of a counterparty failure, could adversely impact the value of any Residual Interest.

2. Significant Accounting Policies (Continued)

We do not record servicing assets or servicing liabilities when our securitization trusts are consolidated. As of December 31, 2019, we have $18 million of servicing assets on our balance sheet, recorded in connection with asset sales where we retained the servicing.

Education Loan Interest Income

For loans classified as held-for-investment, we recognize education loan interest income as earned, adjusted for the amortization of premiums (which includes purchased premiums and capitalized direct origination costs), discounts and Repayment Borrower Benefits. These adjustments result in income being recognized based upon the expected yield of the loan over its life after giving effect to expected prepayments. We amortize premium and discount on education loans using a Constant Prepayment Rate (“CPR”) which measures the rate at which loans in the portfolio pay down principal compared to their stated terms. In determining the CPR, we only consider payments made in excess of contractually required payments. This would include loan refinancing and consolidations and other early payoff activity. For Repayment Borrower Benefits, the estimates of their effect on education loan yield are based on analyses of historical payment behavior of customers who are eligible for the incentives and its effect on the ultimate qualification rate for these incentives. We regularly evaluate the assumptions used to estimate the prepayment speeds and the qualification rates used for Repayment Borrower Benefits. In instances where there are changes to the assumptions, amortization is adjusted on a cumulative basis to reflect the change since the acquisition of the loan. Additionally, interest earned on education loans reflects potential non-payment adjustments in accordance with our uncollectible interest recognition policy. We do not amortize any premiums, discounts or other adjustments to the basis of education loans when they are classified as held-for-sale. See “Allowance for Loan Losses – Purchased Credit Impaired (‘PCI’) Loans” and “–Purchased Non-Credit Impaired Loans” of this Note 2 for discussion of the interest income methodology related to those portfolios.

Interest Expense

Interest expense is based upon contractual interest rates adjusted for the amortization of debt issuance costs, premiums and discounts. Our interest expense may also be adjusted for net payments/receipts related to interest rate and foreign currency swap agreements that qualify and are designated as hedges, as well as the mark-to-market impact of derivatives and debt in fair value hedge relationships with the adoption of ASU No. 2017-12 in 2019. Interest expense also includes the amortization of deferred gains and losses on closed hedge transactions that qualified as hedges. Amortization of debt issuance costs, premiums, discounts and terminated hedge-basis adjustments are recognized using the effective interest rate method.

Servicing Revenue

We perform loan servicing functions for third-parties in return for a servicing fee. Our compensation is typically based on a per-unit fee arrangement or a percentage of the loans outstanding. We recognize servicing revenues associated with these activities based upon the contractual arrangements as the services are rendered. We recognize late fees on third-party serviced loans as well as on loans in our portfolio according to the contractual provisions of the promissory notes, as well as our expectation of collectability.

Asset Recovery And Business Processing Revenue

Asset Recovery and Business Processing Revenue

We account for certain asset recovery and business processing contract revenue (herein referred to as revenue from contracts with customers) in accordance with ASC 606, “Revenue from Contracts with Customers.” Revenue earned by our Federal Education Loans segment is derived from asset recovery activities related to the collection of delinquent education loans on behalf of ED, Guarantor agencies and other institutions, as well as certain other guarantor activities. Revenue earned by our Business Processing segment is derived from government services, which includes receivables management services and account processing solutions, and healthcare services, which includes revenue cycle management services.

Most of our revenue from contracts with customers is derived from long-term contracts, the duration of which is expected to span more than one year. These contracts are billable monthly, as services are rendered, based on a percentage of the balance collected or the transaction processed, a flat fee per transaction or a stated rate per the service performed. In accordance with ASC 606, the unit of account is a contractual performance obligation, a promise to provide a distinct good or service to a customer. The transaction price is allocated to each distinct performance obligation when or as the good or service is transferred to the customer and the obligation is satisfied. Distinct performance obligations are identified based on the services specified in the contract that are capable of being distinct such that the customer can benefit from the service on its own or together with other resources that are available from the Company or a third party, and are also distinct in the context of the contract such that the transfer of the services is separately identifiable from other services promised in the contract. Most of our contracts include integrated service offerings that include obligations that are not separately identifiable and distinct in the context of our contracts. Accordingly, our contracts generally have a single performance obligation. A limited number of full-service offerings include multiple performance obligations.

2. Significant Accounting Policies (Continued)

Substantially all our revenue is variable revenue which is recognized over time as our customers receive and consume the benefit of our services in an amount consistent with monthly billings. Accordingly, we do not disclose variable consideration associated with the remaining performance obligation as we have recognized revenue in the amount we have the right to invoice for services performed. Our fees correspond to the value the customer has realized from our performance of each increment of the service (for example, an individual transaction processed or collection of a past due balance).

Prior to the third quarter of 2018, we received fees from Guarantor agencies for performing default aversion services on delinquent loans prior to default. The fee was received when the loan was initially placed with us and we were obligated to provide such services for the remaining life of the loan for no additional fee. In the event that the loan defaults, in accordance with certain servicing contracts, we were obligated to rebate a portion of the fee to the Guarantor agency in proportion to the principal and interest outstanding when the loan defaulted. We deferred the fees received, net of an estimate of future rebates owed due to subsequent defaults, and recognized such fees over the service period, which was estimated to be the life of the loan.

In 2017, $47 million of previously deferred asset recovery revenue, net of a reserve, was recognized as revenue related to loans for which the Company performed these default aversion services. In 2017, the Company was notified that it would no longer perform these services after 2017 due to the termination of the related contract as of December 31, 2017. In accordance with GAAP, we recognized this previously deferred revenue in 2017 to reflect a shortened period over which it was expected to be earned.

Transfer of Financial Assets and Extinguishments of Liabilities

We account for loan sales and debt repurchases in accordance with the applicable accounting guidance. Our securitizations and other secured borrowings are generally accounted for as on-balance sheet secured borrowings. See “Securitization Accounting” of this Note 2 for further discussion on the criteria assessed to determine whether a transfer of financial assets is a sale or a secured borrowing. If a transfer of loans qualifies as a sale, we derecognize the loan and recognize a gain or loss as the difference between the carrying basis of the loan sold and liabilities retained and the compensation received.

We periodically repurchase our outstanding debt in the open market or through public tender offers. We record a gain or loss on the early extinguishment of debt based upon the difference between the carrying cost of the debt and the amount paid to the third party and net of hedging gains and losses when the debt is in a qualifying hedge relationship.

We recognize the results of a transfer of loans and the extinguishment of debt based upon the settlement date of the transaction.

Derivative Accounting

The accounting guidance for our derivative instruments, which primarily include interest rate swaps, cross-currency interest rate swaps and Floor Income Contracts, requires that every derivative instrument, including certain derivative instruments embedded in other contracts, be recorded at fair value on the balance sheet as either an asset or liability. Derivative positions are recorded as net positions by counterparty based on master netting arrangements exclusive of accrued interest and cash collateral held or pledged.

Many of our derivatives, mainly fixed to variable or variable to fixed interest rate swaps and cross-currency interest rate swaps, qualify as effective hedges. For these derivatives, the relationship between the hedging instrument and the hedged items (including the hedged risk and method for assessing effectiveness), as well as the risk management objective and strategy for undertaking various hedge transactions at the inception of the hedging relationship, is documented. Each derivative is designated to either a specific (or pool of) asset(s) or liability(ies) on the balance sheet or expected future cash flows and designated as either a “fair value” or a “cash flow” hedge. Fair value hedges are designed to hedge our exposure to changes in fair value of a fixed rate or foreign denominated asset or liability, while cash flow hedges are designed to hedge our exposure to variability of either a floating rate asset’s or liability’s cash flows or an expected fixed rate debt issuance. For effective fair value hedges, both the derivative and the hedged item (for the risk being hedged) are marked-to-market with any difference reflecting ineffectiveness and recorded immediately in the statement of income. For effective cash flow hedges, the change in the fair value of the derivative is recorded in other comprehensive income, net of tax, and recognized in earnings in the same period as the earnings effects of the hedged item. The assessment of the hedge’s effectiveness is performed at inception and on an ongoing basis, generally using regression testing. For hedges of a pool of assets or liabilities, tests are performed to demonstrate the similarity of individual instruments of the pool. When it is determined that a derivative is not currently an effective hedge, ineffectiveness is recognized for the full change in value of the derivative with no offsetting mark-to-market of the hedged item for the current period. If it is also determined the hedge will not be effective in the future, we discontinue the hedge accounting prospectively, cease recording changes in the fair value of the hedged item, and begin amortization of any basis adjustments that exist related to the hedged item.

2. Significant Accounting Policies (Continued)

We also have derivatives, primarily Floor Income Contracts and certain basis swaps, that we believe are effective economic hedges but do not qualify for hedge accounting treatment. These derivatives are classified as “trading” and as a result they are marked-to-market through earnings with no consideration for the fair value fluctuation of the economically hedged item.

The “gains (losses) on derivative and hedging activities, net” line item in the consolidated statements of income includes the mark-to-market gains and losses of our derivatives that do not qualify for hedge accounting, as well as the realized changes in fair value related to derivative net settlements and dispositions that do not qualify for hedge accounting. The mark-to-market gains and losses of cash flow hedges are recorded in other comprehensive income, while the mark-to market gains and losses of fair value hedges are recorded in interest expense. Net settlement income/expense on derivatives that qualify as hedges are included with the income or expense of the hedged item (mainly interest expense).

Accounting for Stock-Based Compensation

We recognize stock-based compensation cost in our consolidated statements of income using the fair value based method. Under this method we determine the fair value of the stock-based compensation at the time of the grant and recognize the resulting compensation expense over the grant’s vesting period. We record stock-based compensation expense net of estimated forfeitures and as such, only those stock-based awards that we expect to vest are recorded. We estimate the forfeiture rate based on historical forfeitures of equity awards and adjust the rate to reflect changes in facts and circumstances, if any. Ultimately, the total expense recognized over the vesting period will equal the fair value of awards that actually vest.

Restructuring and Other Reorganization Expenses

From time to time we implement plans to restructure our business. In conjunction with these restructuring plans, involuntary benefit arrangements, disposal costs (including contract termination costs and other exit costs), as well as certain other costs that are incremental and incurred as a direct result of our restructuring plans, are classified as restructuring expenses in the consolidated statements of income.

The Company administers the Navient Corporation Employee Severance Plan and the Navient Corporation Executive Severance Plan for Senior Officers (collectively, “the Severance Plan”). The Severance Plan provides severance benefits in the event of termination of the Company’s full-time employees and part-time employees who work at least 24 hours per week. The Severance Plan establishes specified benefits based on base salary, job level immediately preceding termination and years of service upon involuntary termination of employment. The benefits payable under the Severance Plan relate to past service, and they accumulate and vest. Accordingly, we recognize severance expenses to be paid pursuant to the Severance Plan when payment of such benefits is probable and can be reasonably estimated in accordance with ASC 712, “Compensation — Nonretirement Postemployment Benefits.” Such benefits include severance pay calculated based on the Severance Plan, medical and dental benefits, and outplacement services expenses.

Contract termination costs are expensed at the earlier of (1) the contract termination date or (2) the cease use date under the contract. Other exit costs are expensed as incurred and classified as restructuring expenses if (1) the cost is incremental to and incurred as a direct result of planned restructuring activities and (2) the cost is not associated with or incurred to generate revenues subsequent to our consummation of the related restructuring activities.

Other reorganization expenses include certain internal costs and third-party costs incurred in connection with our cost reduction initiatives.

During 2019 and 2018, the Company incurred $6 million and $13 million, respectively, of restructuring/other reorganization expense in connection with an effort that will reduce costs and improve operating efficiency. These charges were due primarily to severance-related costs.

Income Taxes

We account for income taxes under the asset and liability approach which requires the recognition of deferred tax liabilities and assets for the expected future tax consequences of temporary differences between the carrying amounts and tax basis of our assets and liabilities. To the extent tax laws change, deferred tax assets and liabilities are adjusted in the period that the tax change is enacted. See “Note 14 – Income Taxes” for a description of the impact of the “Tax Cuts and Jobs Act” (“TCJA”) on the net deferred tax asset as of December 31, 2017.

“Income tax expense/(benefit)” includes (i) deferred tax expense/(benefit), which represents the net change in the deferred tax asset or liability balance during the year plus any change in a valuation allowance and (ii) current tax expense/(benefit), which represents the amount of tax currently payable to or receivable from a tax authority plus amounts accrued for unrecognized tax benefits. Income tax expense/(benefit) excludes the tax effects related to adjustments recorded in equity.

If we have an uncertain tax position, then that tax position is recognized only if it is more likely than not to be sustained upon examination based on the technical merits of the position. The amount of tax benefit recognized in the financial statements is the largest amount of benefit that is more than 50% likely of being sustained upon ultimate settlement of the uncertain tax position. We recognize interest related to unrecognized tax benefits in income tax expense/(benefit) and penalties, if any, in operating expenses.

Earnings (Loss) per Common Share

We compute earnings (loss) per common share (“EPS”) by dividing net income allocated to common shareholders by the weighted average common shares outstanding. Net income allocated to common shareholders represents net income applicable to common shareholders. Diluted earnings per common share is computed by dividing income allocated to common shareholders by the weighted average common shares outstanding plus amounts representing the dilutive effect of stock options outstanding, restricted stock, restricted stock units, and the outstanding commitment to issue shares under the Employee Stock Purchase Plan. See “Note 10 — Earnings (Loss) per Common Share” for further discussion.

Reclassifications

Certain reclassifications have been made to the balances as of and for the years ended December 31, 2018 and 2017, to be consistent with classifications adopted for 2019, which had no effect on net income, total assets or total liabilities.

Recently Issued Accounting Pronouncements

Effective in 2019

Leases

In 2016, the FASB issued ASU No. 2016-02, “Leases,” which requires the identification of arrangements that should be accounted for as leases by lessees. In general, lease arrangements exceeding a twelve-month term must be recognized as assets and liabilities on the balance sheet of the lessee. Under previous GAAP, all operating leases were off-balance sheet, regardless of the term. A right-of-use asset and lease obligation is recorded for all leases with a term exceeding twelve months, whether operating or financing, while the income statement reflects lease expense for operating leases and amortization/interest expense for financing leases. The standard was adopted on January 1, 2019 and resulted in recording a $28 million asset and liability. There is no change to the Company’s income statement as a result of this ASU. The standard was adopted prospectively without adjustment to comparative periods.

2. Significant Accounting Policies (Continued)

Hedging Activities

In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging,” which is intended to better align risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. The new standard was adopted on January 1, 2019 and required the mark-to-market gains and losses from qualifying fair value hedge relationships to be recorded in the same line item on the income statement as the item being hedged. As a result, the mark-to-market gains and losses from fair value hedging activity, which were previously recorded in gains (losses) on derivative and hedging activities, net, are recorded in interest expense. This change in presentation is prospective only and resulted in $21 million of gains being recorded in interest expense in 2019.

Effective in 2020

Allowance for Loan Losses

In 2016, the FASB issued ASU No. 2016-13, “Financial Instruments — Credit Losses,” which requires measurement and recognition of an allowance for loan loss that estimates the remaining current expected credit losses (“CECL”) for financial assets measured at amortized cost held at the reporting date. Our current allowance for loan loss is an incurred loss model. As a result, the new guidance will result in an increase to our allowance for loan losses. The new standard will impact the allowance for loan losses related to our Private Education Loans and FFELP Loans.

The standard will be applied through a cumulative-effect adjustment to retained earnings (net of tax) as of January 1, 2020, the effective date, for the education loans on our balance sheet as of that date (except for the $70 million purchased credit impaired portfolio where such allowance is recorded as an increase to the basis of the loans). Subsequently, changes in the estimated remaining current expected credit losses, including estimated losses on newly originated education loans, will be recorded through provision (net income). This standard represents a significant change from existing GAAP and will result in material changes to the Company’s accounting for the allowance for loan losses.

Related to the new CECL standard:

•

We have determined that, for modeling current expected credit losses, we can reasonably estimate expected losses that incorporate current and forecasted economic conditions over a three- year period. After this “reasonable and supportable” period there is a two-year reversion period to Navient’s actual long-term historical loss experience over a full economic life cycle. The model used to project losses utilizes key credit quality indicators of the loan portfolio and predicts how those attributes are expected to perform in connection with the forecasted economic conditions. These losses are calculated on an undiscounted basis. We project losses at the loan level and make estimates regarding prepayments, recoveries on defaults and reasonably expected new Troubled Debt Restructurings (“TDRs”).

•

Separately, as it relates to interest rate concessions granted as part of our private education loan modification program, a discounted cash flow model is used to calculate the amount of interest forgiven for loans currently in the program. The present value of this interest rate concession is included in our CECL allowance for loan loss.

•

Charge-offs will include the discount or premium related to such defaulted loan.

•

CECL requires our expected future recoveries for charged-off loans to be presented within the allowance for loan loss whereas today, we account for our receivable for partially charged-off loans ($588 million as of December 31, 2019) as part of our Private Education Loan portfolio. This change is only a change in classification on the balance sheet and does not impact retained earnings at adoption of CECL or provision and net income post adoption.

2. Significant Accounting Policies (Continued)

We are currently finalizing our evaluation of the impact of adopting this accounting standard on our consolidated financial statements. We currently estimate that our total allowance for loan losses will increase by approximately $800 million upon adoption on January 1, 2020 (excluding the impact of the balance sheet reclassifications related to the expected future recoveries and purchased credit impaired portfolio discussed above). This would have a corresponding reduction to equity of approximately $615 million. Although we have completed the development of the credit loss models used for CECL this estimated impact is not final as it is dependent upon continuing review and refinement of models, methodology, policies, controls and judgments through the end of the first quarter of 2020. As a result, this estimated impact is subject to change.

Goodwill

In 2017, the FASB issued ASU No. 2017-04, "Intangibles – Goodwill and Other: Simplifying the Test for Goodwill Impairment,” which eliminates the requirement to perform step two of the goodwill impairment test, which requires completing a hypothetical purchase price allocation, when step one indicates impairment has occurred. The new standard simplifies the goodwill impairment test by comparing the fair value of a reporting unit to its carrying value. Impairment will be recognized for the amount by which the carrying value exceeds the reporting unit fair value, not to exceed the total allocated reporting unit goodwill. The standard, which will be applied prospectively, is effective for the Company as of January 1, 2020.

Other Assets

12 Months Ended

Dec. 31, 2019

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Other Assets

8. Other Assets

The following table provides the detail of our other assets.

(Dollars in millions)	December 31, 2019		December 31, 2018
Accrued interest receivable	$	1,952	$	1,999
Benefit and insurance-related investments		459		470
Income tax asset, net (current and deferred)		258		271
Derivatives at fair value		212		157
Fixed assets, net		135		136
Accounts receivable		119		95
Other		199		276
Total	$	3,334	$	3,404

Income Taxes

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Income Taxes

14. Income Taxes

Reconciliations of the statutory U.S. federal income tax rates to our effective tax rate for continuing operations follow:

	Years Ended December 31,
	2019			2018			2017
Statutory rate		21.0	%		21.0	%		35.0	%
DTA Remeasurement Loss⁽¹⁾		—			—			27.2
State tax, net of federal benefit		1.4			3.9			.7
Other, net		(.5	)		.3			(1.1	)
Effective tax rate		21.9	%		25.2	%		61.8	%

⁽¹⁾

^{The TCJA, enacted on December 22, 2017, made significant changes to all aspects of income taxation, including a reduction to the corporate federal statutory tax rate. GAAP requires the effects of the TCJA to be recognized in the period the law is enacted, even though the effective date of the law for most provisions is January 1, 2018. The primary impact to us is the reduction to the corporate federal statutory tax rate from 35% to 21% as of January 1, 2018. This rate reduction required us to remeasure our deferred tax asset at December 31, 2017, at the 21% corporate federal statutory tax rate and resulted in a DTA Remeasurement Loss of $208 million for GAAP, which is reflected as incremental income tax expense in the fourth quarter of 2017.}

Income tax expense consists of:

	December 31,
(Dollars in millions)	2019		2018		2017
Current provision/(benefit):
Federal	$	78	$	71	$	77
State		11		13		(3	)
Foreign		—		3		3
Total current provision/(benefit)		89		87		77
Deferred provision/(benefit):
Federal		73		33		385
State		3		13		11
Foreign		1		—		(1	)
Total deferred provision/(benefit)		77		46		395
Provision for income tax expense/(benefit)	$	166	$	133	$	472

14. Income Taxes (Continued)

The tax effect of temporary differences that give rise to deferred tax assets and liabilities include the following:

	December 31,
(Dollars in millions)	2019		2018
Deferred tax assets:
Loan reserves	$	257	$	292
Education loan premiums and discounts, net		44		48
Accrued expenses not currently deductible		16		14
Operating loss and credit carryovers		17		18
Stock-based compensation plans		10		16
Other		21		18
Total deferred tax assets		365		406
Deferred tax liabilities:
Market value adjustments on education loans, investments and derivatives		13		46
Acquired intangible assets		17		12
Original issue discount on borrowings		10		7
Other		18		19
Total deferred tax liabilities		58		84
Net deferred tax assets	$	307	$	322

Included in operating loss and credit carryovers is a valuation allowance of $60 million and $43 million as of December 31, 2019 and 2018, respectively, against a portion of the Company’s federal and state deferred tax assets. The valuation allowance is primarily attributable to deferred tax assets for federal and state net operating loss carryforwards and state IRC § 163(j) disallowed interest expense carryforwards that management believes it is more likely than not will expire prior to being realized. The ultimate realization of the deferred tax assets is dependent upon the generation of future taxable income of the appropriate character (i.e. capital or ordinary) during the period in which the temporary differences become deductible. Factors generally considered by management include (but are not limited to): any changes in economic conditions, the scheduled reversals of deferred tax liabilities, and the history of positive taxable income available for net operating loss carrybacks in evaluating the realizability of the deferred tax assets.

As of December 31, 2019, we have gross federal net operating loss (“NOL”) carryforwards of $66 million (which begin to expire in 2031) and gross state NOL carryforwards of $556 million (which begin to expire in 2021). Tax-effected NOL amounts of $14 million (federal) and $39 million (state) have corresponding valuation allowances of $0 (federal) and $36 million (state).

As of December 31, 2019, we have gross state IRC § 163(j) disallowed interest expense carryforwards of $1,551 million (which is indefinite). State tax-effected IRC § 163(j) disallowed interest expense carryforward amount of $21 million has a corresponding valuation allowance of $21 million.

As of December 31, 2019, we have gross federal and state capital loss carryforwards of $10 million (which begin to expire in 2021). Tax-effected capital loss amount of $3 million (federal and state) has a corresponding valuation allowance of $3 million (federal and state).

14. Income Taxes (Continued)

Accounting for Uncertainty in Income Taxes

The following table summarizes changes in unrecognized tax benefits:

	December 31,
(Dollars in millions)	2019			2018			2017
Unrecognized tax benefits at beginning of year	$	65.7		$	57.4		$	73.0
Increases resulting from tax positions taken during a prior period		4.0			8.0			.7
Decreases resulting from tax positions taken during a prior period		(3.8	)		(.3	)		(1.8	)
Increases resulting from tax positions taken during the current period		1.9			3.8			4.4
Decreases related to settlements with taxing authorities		(11.1	)		(1.4	)		(5.1	)
Increases related to settlements with taxing authorities		—			—			—
Reductions related to the lapse of statute of limitations		(3.1	)		(1.8	)		(13.8	)
Unrecognized tax benefits at end of year	$	53.6		$	65.7		$	57.4

As of December 31, 2019, the gross unrecognized tax benefits are $53.6 million. Included in the $53.6 million are $42.4 million of unrecognized tax benefits that, if recognized, would favorably impact the effective tax rate.

The Company or one of its subsidiaries files income tax returns at the U.S. federal level, in most U.S. states, and various foreign jurisdictions. All periods prior to 2016 are closed for federal examinations purposes. Various combinations of subsidiaries, tax years, and jurisdictions remain open for review, subject to statute of limitations periods (typically 3 to 4 prior years). We do not expect the resolution of open audits to have a material impact on our unrecognized tax benefits.

Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Cash and investments	$ 93	$ 97	$ 43
Total interest income	4,673	4,908	4,383
Total interest expense	3,488	3,668	2,971
Net interest income	1,185	1,240	1,412
Less: provisions for loan losses	258	370	426
Net interest income after provisions for loan losses	927	870	986
Other income (loss):
Servicing revenue	240	274	290
Asset recovery and business processing revenue	488	430	475
Other income	45	17	9
Gains on sales of loans	16		3
Gains (losses) on debt repurchases	45	19	(3)
Gains (losses) on derivative and hedging activities, net	22	(38)	22
Total other income	856	702	796
Expenses:
Salaries and benefits	488	507	519
Other operating expenses	496	477	447
Total operating expenses	984	984	966
Goodwill and acquired intangible asset impairment and amortization expense	30	47	23
Restructuring/other reorganization expenses	6	13	29
Total expenses	1,020	1,044	1,018
Income before income tax expense	763	528	764
Income tax expense	166	133	472
Net income (loss)	$ 597	$ 395	$ 292
Basic earnings per common share	$ 2.59	$ 1.52	$ 1.06
Average common shares outstanding	230	260	275
Diluted earnings per common share	$ 2.56	$ 1.49	$ 1.04
Average common and common equivalent shares outstanding	233	264	281
Dividends per common share	$ 0.64	$ 0.64	$ 0.64
FFELP Loans [Member]
Interest income:
Total interest income	$ 2,847	$ 3,027	$ 2,693
Less: provisions for loan losses	30	70	42
Private Education Loans [Member]
Interest income:
Total interest income	1,731	1,778	1,634
Less: provisions for loan losses	226	299	382
Other Loans [Member]
Interest income:
Total interest income	$ 2	$ 6	$ 13

Business Combinations, Goodwill and Acquired Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Nov. 30, 2017	Jul. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2018	Jul. 31, 2018
Business Acquisition [Line Items]
Goodwill			$ 665	$ 665
Amortization of acquired intangible assets			25	31	$ 23
2020			21
2021			19
2022			15
2023			13
After 2023			$ 23
Government Services [Member] \| Toll Services [Member]
Business Acquisition [Line Items]
Impairment of intangible assets				$ 16
Earnest [Member]
Business Acquisition [Line Items]
Controlling interest percentage	95.00%
Payments to acquire business, cash	$ 149
Business acquisition, effective date of acquisition			Nov. 30, 2017
Goodwill						$ 77
Business acquisition, definite life intangible assets	$ 20
Earnest [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Definite life intangible assets, amortization period			5 years
Earnest [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Definite life intangible assets, amortization period			10 years
Duncan Solutions [Member]
Business Acquisition [Line Items]
Controlling interest percentage		100.00%
Payments to acquire business, cash		$ 86
Business acquisition, effective date of acquisition			Jul. 31, 2017
Goodwill							$ 39
Business acquisition, definite life intangible assets		$ 33
Duncan Solutions [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Definite life intangible assets, amortization period			2 years
Duncan Solutions [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Definite life intangible assets, amortization period			10 years

Derivative Financial Instruments - Mark-to-Market Impact of Derivatives on Consolidated Statements of Income (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gains (losses) recognized	$ 43	$ 4	$ (32)	$ 7	$ (48)	$ 2	$ (40)	$ 48	$ 22	$ (38)	$ 22
Interest Expense and Derivative Instruments Hedging Activities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gains (losses) recognized									43	(38)	22
Designated as Hedging Instrument [Member] \| Fair Value [Member] \| Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in net income on derivatives									281	(137)	(214)
Gains (losses) recognized in net income on hedged items									(299)	162	193
Net fair value hedge ineffectiveness gains (losses)									(18)	25	(21)
Designated as Hedging Instrument [Member] \| Fair Value [Member] \| Cross-Currency Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in net income on derivatives									57	(311)	921
Gains (losses) recognized in net income on hedged items									(18)	210	(954)
Net fair value hedge ineffectiveness gains (losses)									39	(101)	(33)
Mark-to-market gains (losses) recognized									21	(76)	(54)
Trading [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gains (losses) recognized									22	38	76
Trading [Member] \| Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gains (losses) recognized									44	22	8
Trading [Member] \| Cross-Currency Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gains (losses) recognized									(2)	(3)	2
Trading [Member] \| Floor Income Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gains (losses) recognized									(22)	15	81
Trading [Member] \| Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Mark-to-market gains (losses) recognized									$ 2	$ 4	$ (15)

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Net positive exposure related to corporate derivatives	$ 12,000,000	$ 19,000,000
Euro and British Pound Sterling denominated bonds outstanding in securitization trusts	4,000,000,000.0
Notional of interest rate swaps entered into by the trusts to swap Prime to LIBOR	104,400,000,000	131,400,000,000
Net positive exposure on foreign currency swaps	0	7,000,000
Decrease in valuation due to net credit risk adjustments	11,000,000	26,000,000
Decrease in valuation due to liquidity adjustments	12,000,000	19,000,000
Derivative liability at fair value including accrued interest and premium receivable	658,000,000	752,000,000
Counterparty [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liability at fair value including accrued interest and premium receivable	53,000,000
Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional of interest rate swaps entered into by the trusts to swap Prime to LIBOR	79,200,000,000	$ 98,600,000,000
Interest Rate Swaps [Member] \| Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional of interest rate swaps entered into by the trusts to swap Prime to LIBOR	$ 3,700,000,000

Stock-Based Compensation Plans and Arrangements

12 Months Ended

Dec. 31, 2019

Postemployment Benefits [Abstract]

Stock-Based Compensation Plans and Arrangements

11. Stock-Based Compensation Plans and Arrangements

We have one active stock-based incentive plan that provides for grants of equity awards to our employees and non-employee directors in various forms including stock options, restricted stock awards, restricted stock units and performance stock units. We also maintain an ESPP. Shares issued under these plans may be either shares reacquired by us or shares that are authorized but unissued. Our Navient Corporation 2014 Omnibus Incentive Plan became effective on April 7, 2014, and 55 million shares are authorized to be issued from this plan as of December 31, 2019. Our Navient Corporation ESPP became effective on May 1, 2014, and 3 million shares are authorized to be issued from this plan as of December 31, 2019.

For most awards, expense generally is recognized ratably over the vesting period net of estimated forfeitures, unless the employee meets certain retirement eligibility criteria. For employee awards that meet retirement eligibility criteria, we record the expense generally upon grant and for employees that become retirement eligible during the vesting period, we recognize expense from the grant date to the date on which the employee becomes retirement eligible. The total stock-based compensation cost recognized in 2019, 2018 and 2017 was $25 million, $25 million and $35 million, respectively. As of December 31, 2019, there was $11 million of total unrecognized compensation expense related to unvested stock awards, which is expected to be recognized over a weighted average period of 1.8 years.

11. Stock-Based Compensation Plans and Arrangements (Continued)

Stock Options

The exercise price of stock options equals the fair market value of our common stock on the date of grant. The maximum contractual term for stock options is 5 years for grants made since 2012, and 10 years for grants made prior to 2012. Most stock options are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date.

	Years Ended December 31,
	2018			2017
Expected life of the option	3.2 years			3.0 years
Expected volatility		36	%		34	%
Risk-free interest rate		2.27	%		1.44	%
Expected dividend rate		4.70	%		4.13	%
Weighted average fair value of options granted	$	2.59		$	2.69

The expected life is based in general on observed historical exercise patterns of Navient’s employees. The expected volatility is based in general on implied volatility from publicly-traded options on our stock at the grant date and historical volatility of our stock consistent with the expected life of the option. The risk-free interest rate is based on the U.S. Treasury spot rate at the grant date consistent with the expected life of the option. The dividend yield is based on the projected annual dividend payment per share based on the dividend amount at the grant date, divided by the stock price at the grant date.

The following table summarizes Navient’s stock option activity in 2019.

(Dollars in millions, except per share data)	Number of Options			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value⁽¹⁾
Outstanding at December 31, 2018		11,174,890		$	12.97
Granted		—			—
Exercised⁽²⁾		(2,826,673	)		7.79
Canceled		(2,046,287	)		18.15
Outstanding at December 31, 2019⁽³⁾		6,301,930		$	13.61	1.6 yrs.	$	12
Exercisable at December 31, 2019		4,887,506		$	13.44	1.2 yrs.	$	12

⁽¹⁾

⁽²⁾

The total intrinsic value of Navient stock options exercised was $11 million, $12 million and $9 million for 2019, 2018 and 2017, respectively.

⁽³⁾

As of December 31, 2019, there was $.3 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted average period of 1.1 years.

11. Stock-Based Compensation Plans and Arrangements (Continued)

Restricted Stock

Restricted stock awards generally are granted to non-employee directors and generally vest upon the director’s election to the board. Outstanding restricted stock is entitled to dividend equivalent units that vest subject to the same vesting requirements or lapse of transfer restrictions, as applicable, as the underlying restricted stock award. The fair value of restricted stock awards is based on our stock price at the grant date.

The following table summarizes Navient’s restricted stock activity in 2019.

	Number of Shares			Weighted Average Grant Date Fair Value
Non-vested at December 31, 2018		—		$	—
Granted		78,835			11.72
Vested⁽¹⁾		(78,835	)		11.72
Canceled		—			—
Non-vested at December 31, 2019⁽²⁾		—		$	—

⁽¹⁾

The total fair value of Navient shares that vested was $1 million, $1 million and $1 million for 2019, 2018 and 2017, respectively.

⁽²⁾

As of December 31, 2019, there was no unrecognized compensation cost related to restricted stock.

Restricted Stock Units and Performance Stock Units

Restricted stock units (“RSUs”) and performance stock units (“PSUs”) are equity awards granted to employees that entitle the holder to shares of our common stock when the award vests. RSUs generally are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date, while PSUs vest based on achieving certain corporate performance goals over a three-year performance period. Outstanding RSUs and PSUs are entitled to dividend equivalent units that vest subject to the same vesting requirements as the underlying award. The fair value of RSUs and PSUs is based on our stock price at the grant date.

The following table summarizes Navient’s RSU and PSU activity in 2019.

	Number of RSUs/PSUs			Weighted Average Grant Date Fair Value
Outstanding at December 31, 2018		4,259,771		$	12.55
Granted		2,096,830			10.95
Vested and converted to common stock⁽¹⁾		(2,336,927	)		11.14
Canceled		(80,053	)		12.96
Outstanding at December 31, 2019⁽²⁾		3,939,621		$	12.52

⁽¹⁾

The total fair value of Navient RSUs and PSUs that vested and converted to common stock was $26 million, $22 million and $23 million for 2019, 2018 and 2017, respectively.

⁽²⁾

As of December 31, 2019, there was $10 million of unrecognized compensation cost related to RSUs and PSUs, which is expected to be recognized over a weighted average period of 1.8 years.

Business Combinations, Goodwill and Acquired Intangible Assets - Acquired Intangible Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	$ 432	$ 464
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(340)	(343)
Intangible assets subject to amortization, Net	92	121
Customer, Services and Lending Relationships [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	262	284
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(220)	(226)
Intangible assets subject to amortization, Net	42	58
Favorable Lease [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	1	1
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(1)
Intangible assets subject to amortization, Net		1
Non-competes [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	3	3
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(3)	(3)
Software and Technology [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	114	115
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(96)	(90)
Intangible assets subject to amortization, Net	18	25
Trade Names and Trademarks [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	52	61
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(20)	(24)
Intangible assets subject to amortization, Net	$ 32	$ 37

Allowance for Loan Losses (Tables)

12 Months Ended

Dec. 31, 2019

Allowance for Credit Losses and Recorded Investments in Loans

4. Allowance for Loan Losses (Continued)

Allowance for Loan Losses Metrics

	Year Ended December 31, 2019
(Dollars in millions)	FFELP Loans			Private Education Loans			Other Loans			Total
Allowance for Loan Losses
Beginning balance	$	76		$	1,201		$	9		$	1,286
Total provision		30			226			1			258
Net adjustment resulting from the change in the charge-off rate⁽¹⁾		—			(21	)		—			(21	)
Net charge-offs remaining⁽²⁾		(42	)		(364	)		(2	)		(408	)
Total net charge-offs		(42	)		(385	)		(2	)		(429	)
Reclassification of interest reserve⁽³⁾		—			7			—			7
Loan sales		—			(1	)		(8	)		(9	)
Ending balance	$	64		$	1,048		$	—		$	1,112
Allowance Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	941		$	—		$	941
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		64			107			—			171
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		—			—			—			—
Purchased Credit Impaired Loans⁽⁴⁾		—			—			—			—
Ending total allowance	$	64		$	1,048		$	—		$	1,112
Loans Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	9,617		$	—		$	9,617
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		61,589			12,286			9			73,884
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		2,505			1,806			—			4,311
Purchased Credit Impaired Loans⁽⁴⁾		—			201			—			201
Ending total loans⁽⁵⁾	$	64,094		$	23,910		$	9		$	88,013
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate⁽¹⁾		.07	%		1.67	%		—	%
Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment⁽¹⁾		—	%		.10	%		—	%
Allowance coverage of charge-offs		1.5			2.7			—
Allowance as a percentage of the ending total loan balance		.10	%		4.38	%		—	%
Allowance as a percentage of the ending loans in repayment		.12	%		4.74	%		—	%
Ending total loans⁽⁵⁾	$	64,094		$	23,910		$	9
Average loans in repayment	$	55,978		$	21,859		$	29
Ending loans in repayment	$	53,538		$	22,089		$	9

⁽¹⁾

In third-quarter 2019, the portion of the loan amount charged off at default on Private Education Loans increased from 80.5% to 81%. This charge resulted in a $21 million reduction to the balance of the receivable for partially charged-off loan balance.

⁽²⁾

Charge-offs are reported net of expected recoveries. For Private Education Loans, the expected recovery amount is transferred to the receivable for partially charged-off loan balance. Charge-offs include charge-offs against the receivable for partially charged-off loans which represents the difference between what was expected to be recovered and any shortfalls in what was actually recovered in the period. See “Receivable for Partially Charged-Off Private Education Loans” for further discussion.

⁽³⁾

Represents the additional allowance related to the amount of uncollectible interest reserved within interest income that is transferred in the period to the allowance for loan losses when interest is capitalized to a loan’s principal balance.

⁽⁴⁾

The Purchased Credit Impaired Loans’ losses are not provided for by the allowance for loan losses in the above table as these loans are separately reserved for, if needed. No allowance for loan losses has been established for these loans as of December 31, 2019. The losses of the Purchased Non-Credit Impaired Loans acquired at a discount are not provided for by the allowance for loan losses in the above table as the remaining purchased discount associated with the FFELP and Private Education Loans of $33 million and $268 million, respectively, as of December 31, 2019 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of December 31, 2019.

⁽⁵⁾

Ending total loans for Private Education Loans includes the receivable for partially charged-off loans.

	Year Ended December 31, 2018
(Dollars in millions)	FFELP Loans			Private Education Loans			Other Loans			Total
Allowance for Loan Losses
Beginning balance	$	60		$	1,297		$	10		$	1,367
Total provision		70			299			1			370
Net adjustment resulting from the change in the charge- off rate⁽¹⁾		—			(32	)		—			(32	)
Net charge-offs remaining⁽²⁾		(54	)		(371	)		(2	)		(427	)
Total net charge-offs		(54	)		(403	)		(2	)		(459	)
Reclassification of interest reserve⁽³⁾		—			8			—			8
Ending balance	$	76		$	1,201		$	9		$	1,286
Allowance Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	1,100		$	8		$	1,108
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		76			101			1			178
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		—			—			—			—
Purchased Credit Impaired Loans⁽⁴⁾		—			—			—			—
Ending total allowance	$	76		$	1,201		$	9		$	1,286
Loans Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	10,336		$	28		$	10,364
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		68,880			11,464			51			80,395
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		2,850			2,180			—			5,030
Purchased Credit Impaired Loans⁽⁴⁾		—			225			—			225
Ending total loans⁽⁵⁾	$	71,730		$	24,205		$	79		$	96,014
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate⁽¹⁾		.09	%		1.66	%		—	%
Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment⁽¹⁾		—	%		.14	%		—	%
Allowance coverage of charge-offs		1.4			3.0			—
Allowance as a percentage of the ending total loan balance		.11	%		4.96	%		11.52	%
Allowance as a percentage of the ending loans in repayment		.13	%		5.45	%		11.52	%
Ending total loans⁽⁵⁾	$	71,730		$	24,205		$	79
Average loans in repayment	$	62,927		$	22,312		$	75
Ending loans in repayment	$	59,551		$	22,037		$	79

⁽¹⁾

In third-quarter 2018, the portion of the loan amount charged off at default on Private Education Loans increased from 79% to 80.5%. This charge resulted in a $32 million reduction to the balance of the receivable for partially charged-off loan balance.

₍₂₎

⁽³⁾

⁽⁴⁾

The Purchased Credit Impaired Loans’ losses are not provided for by the allowance for loan losses in the above table as these loans are separately reserved for, if needed. No allowance for loan losses has been established for these loans as of December 31, 2018. The losses of the Purchased Non-Credit Impaired Loans acquired at a discount are not provided for by the allowance for loan losses in the above table as the remaining purchased discount associated with the FFELP and Private Education Loans of $37 million and $326 million respectively, as of December 31, 2018 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of December 31, 2018.

⁽⁵⁾

Ending total loans for Private Education Loans includes the receivable for partially charged-off loans.

	Year Ended December 31, 2017
(Dollars in millions)	FFELP Loans			Private Education Loans			Other Loans			Total
Allowance for Loan Losses
Beginning balance	$	67		$	1,351		$	15		$	1,433
Total provision		42			382			2			426
Charge-offs⁽¹⁾		(49	)		(443	)		(7	)		(499	)
Reclassification of interest reserve⁽²⁾		—			7			—			7
Ending balance	$	60		$	1,297		$	10		$	1,367
Allowance Ending Balance:
Individually evaluated for impairment - TDR	$	—		$	1,171		$	9		$	1,180
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		60			126			1			187
Purchased Non-Credit Impaired Loans acquired at a discount⁽³⁾		—			—			—			—
Purchased Credit Impaired Loans⁽³⁾		—			—			—			—
Ending total allowance	$	60		$	1,297		$	10		$	1,367
Loans Ending Balance:
Individually evaluated for impairment - TDR	$	—		$	10,921		$	30		$	10,951
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		77,860			11,861			40			89,761
Purchased Non-Credit Impaired Loans acquired at a discount⁽³⁾		3,237			2,610			—			5,847
Purchased Credit Impaired Loans⁽³⁾		—			248			—			248
Ending total loans⁽⁴⁾	$	81,097		$	25,640		$	70		$	106,807
Charge-offs as a percentage of average loans in repayment		.07	%		1.98	%		5.39	%
Allowance coverage of charge-offs		1.2			2.9			1.5
Allowance as a percentage of the ending total loan balance		.07	%		5.06	%		14.32	%
Allowance as a percentage of the ending loans in repayment		.09	%		5.66	%		14.32	%
Ending total loans⁽⁴⁾	$	81,097		$	25,640		$	70
Average loans in repayment	$	68,318		$	22,342		$	130
Ending loans in repayment	$	67,853		$	22,924		$	70

⁽¹⁾

⁽²⁾

⁽³⁾

The Purchased Credit Impaired Loans’ losses are not provided for by the allowance for loan losses in the above table as these loans are separately reserved for, if needed. No allowance for loan losses has been established for these loans as of December 31, 2017. The losses of the Purchased Non-Credit Impaired Loans acquired at a discount are not provided for by the allowance for loan losses in the above table as the remaining purchased discount associated with the FFELP and Private Education Loans of $43 million and $392 million, respectively, as of December 31, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of December 31, 2017.

⁽⁴⁾

Ending total loans for Private Education Loans includes the receivable for partially charged-off loans.

Age Analysis of Past Due Loans Delinquencies

	FFELP Loan Delinquencies
	December 31, 2019						December 31, 2018						December 31, 2017
(Dollars in millions)	Balance			%			Balance			%			Balance			%
Loans in-school/grace/deferment⁽¹⁾	$	3,114					$	3,793					$	4,711
Loans in forbearance⁽²⁾		7,442						8,386						8,533
Loans in repayment and percentage of each status:
Loans current		47,255			88.3	%		53,500			89.8	%		59,264			87.3	%
Loans delinquent 31-60 days⁽³⁾		2,094			3.9			1,964			3.4			2,638			3.9
Loans delinquent 61-90 days⁽³⁾		1,082			2.0			910			1.5			1,763			2.6
Loans delinquent greater than 90 days⁽³⁾		3,107			5.8			3,177			5.3			4,188			6.2
Total FFELP Loans in repayment		53,538			100	%		59,551			100	%		67,853			100	%
Total FFELP Loans, gross		64,094						71,730						81,097
FFELP Loan unamortized premium		545						599						666
Total FFELP Loans		64,639						72,329						81,763
FFELP Loan allowance for losses		(64	)					(76	)					(60	)
FFELP Loans, net	$	64,575					$	72,253					$	81,703
Percentage of FFELP Loans in repayment					83.5	%					83.0	%					83.7	%
Delinquencies as a percentage of FFELP Loans in repayment					11.7	%					10.2	%					12.7	%
FFELP Loans in forbearance as a percentage of loans in repayment and forbearance					12.2	%					12.3	%					11.2	%

⁽¹⁾

Loans for customers who may still be attending school or engaging in other permitted educational activities and are not yet required to make payments on their loans, e.g., residency periods for medical students or a grace period for bar exam preparation, as well as loans for customers who have requested and qualify for other permitted program deferments such as military, unemployment, or economic hardships.

⁽²⁾	Loans for customers who have used their allowable deferment time or do not qualify for deferment, that need additional time to obtain employment or who have temporarily ceased making full payments due to hardship or other factors such as disaster relief.

⁽³⁾	The period of delinquency is based on the number of days scheduled payments are contractually past due.

	Private Education Loan Delinquencies
	TDRs
	December 31, 2019						December 31, 2018						December 31, 2017
(Dollars in millions)	Balance			%			Balance			%			Balance			%
Loans in-school/grace/deferment⁽¹⁾	$	349					$	426					$	477
Loans in forbearance⁽²⁾		479						518						681
Loans in repayment and percentage of each status:
Loans current		7,557			89.5	%		7,890			87.4	%		8,333			88.9	%
Loans delinquent 31-60 days⁽³⁾		296			3.5			344			3.8			351			3.7
Loans delinquent 61-90 days⁽³⁾		191			2.3			235			2.6			207			2.2
Loans delinquent greater than 90 days⁽³⁾		398			4.7			556			6.2			487			5.2
Total TDR loans in repayment		8,442			100	%		9,025			100	%		9,378			100	%
Total TDR loans, gross		9,270						9,969						10,536
TDR loans unamortized discount		(203	)					(212	)					(225	)
Total TDR loans		9,067						9,757						10,311
TDR loans receivable for partially charged-off loans		347						367						385
TDR loans allowance for losses		(941	)					(1,100	)					(1,171	)
TDR loans, net	$	8,473					$	9,024					$	9,525
Percentage of TDR loans in repayment					91.1	%					90.5	%					89.0	%
Delinquencies as a percentage of TDR loans in repayment					10.5	%					12.6	%					11.1	%
Loans in forbearance as a percentage of TDR loans in repayment and forbearance					5.4	%					5.4	%					6.8	%

⁽¹⁾	Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not yet required to make payments on their loans, e.g., residency periods for medical students or a grace period for bar exam preparation.

⁽²⁾	Loans for customers who have requested extension of grace period generally during employment transition or who have temporarily ceased making full payments due to hardship or other factors such as disaster relief, consistent with established loan program servicing policies and procedures.

⁽³⁾	The period of delinquency is based on the number of days scheduled payments are contractually past due.

	Private Education Loan Delinquencies
	Non-TDRs
	December 31, 2019						December 31, 2018						December 31, 2017
(Dollars in millions)	Balance			%			Balance			%			Balance			%
Loans in-school/grace/deferment⁽¹⁾	$	280					$	392					$	584
Loans in forbearance⁽²⁾		125						158						214
Loans in repayment and percentage of each status:
Loans current		13,526			99.1	%		12,851			98.8	%		13,257			97.9	%
Loans delinquent 31-60 days⁽³⁾		53			.4			71			.5			120			.9
Loans delinquent 61-90 days⁽³⁾		27			.2			32			.3			59			.4
Loans delinquent greater than 90 days⁽³⁾		41			.3			58			.4			110			.8
Total non-TDR loans in repayment		13,647			100	%		13,012			100	%		13,546			100	%
Total non-TDR loans, gross		14,052						13,562						14,344
Non-TDR loans unamortized discount		(414	)					(547	)					(699	)
Total non-TDR loans		13,638						13,015						13,645
Non-TDR loans receivable for partially charged-off loans		241						307						375
Non-TDR loans allowance for losses		(107	)					(101	)					(126	)
Non-TDR loans, net	$	13,772					$	13,221					$	13,894
Percentage of non-TDR loans in repayment					97.1	%					95.9	%					94.4	%
Delinquencies as a percentage of non-TDR loans in repayment					.9	%					1.2	%					2.1	%
Loans in forbearance as a percentage of non- TDR loans in repayment and forbearance					.9	%					1.2	%					1.6	%

⁽¹⁾	Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not yet required to make payments on their loans, e.g., residency periods for medical students or a grace period for bar exam preparation.

⁽²⁾	Loans for customers who have requested extension of grace period generally during employment transition or who have temporarily ceased making full payments due to hardship or other factors such as disaster relief, consistent with established loan program servicing policies and procedures.

⁽³⁾	The period of delinquency is based on the number of days scheduled payments are contractually past due.

Loans Modified Accounts for TDR

The following table provides the recorded investment, unpaid principal balance and related allowance for our TDR loans.

	TDRs
(Dollars in millions)	December 31, 2019		December 31, 2018
Recorded investment⁽¹⁾	$	9,594	$	10,326
Total ending loans⁽²⁾	$	9,617	$	10,336
Related allowance	$	941	$	1,100

⁽¹⁾

Recorded investment is equal to the unpaid principal balance (which includes the receivable for partially charged-off loans), accrued interest and unamortized discount.

⁽²⁾

Total ending loans includes the receivable for partially charged-off loans.

Entity Loan Modification Program [Member]

Loans Modified Accounts for TDR

The following table provides the amount of loans modified in the periods presented that resulted in a TDR. Additionally, the table summarizes charge-offs occurring in the TDR portfolio, as well as TDRs for which a payment default occurred in the current period within 12 months of the loan first being designated as a TDR. We define payment default as 60 days past due for this disclosure.

	Years Ended December 31,
(Dollars in millions)	2019		2018		2017
Modified loans⁽¹⁾	$	475	$	596	$	816
Charge-offs⁽²⁾	$	324	$	343	$	346
Payment-default	$	109	$	142	$	181

⁽¹⁾	Represents period ending balance of loans that have been modified during the period and resulted in a TDR.

⁽²⁾	Represents loans that charged off that were classified as TDRs.

Troubled Debt Restructuring Loans [Member]

Average Recorded Investment and Interest Income Recognized for TDR

4. Allowance for Loan Losses (Continued)

The following table provides the average recorded investment and interest income recognized for our TDR loans.

	Years Ended December 31,
(Dollars in millions)	2019		2018		2017
Average recorded investment	$	9,965	$	10,637	$	10,989
Interest income recognized	$	770	$	764	$	708

Private Education Loans [Member]

Private Education Loan Portfolio Stratified by Key Credit Quality Indicators

The following table highlights the principal balance (excluding the receivable for partially charged-off loans) of our Private Education Loan portfolio stratified by the key credit quality indicators.

	Private Education Loans Credit Quality Indicators
	TDRs
	December 31, 2019					December 31, 2018
(Dollars in millions)	Balance⁽³⁾		% of Balance			Balance⁽³⁾		% of Balance
Credit Quality Indicators
Original Winning FICO Scores:
FICO 640 and above	$	8,493		92	%	$	9,133		92	%
FICO below 640		777		8			836		8
Total	$	9,270		100	%	$	9,969		100	%
School Type:
Not-for-profit	$	7,387		80	%	$	7,888		79	%
For-profit		1,883		20			2,081		21
Total	$	9,270		100	%	$	9,969		100	%
Cosigners:
With cosigner⁽¹⁾	$	5,792		62	%	$	6,172		62	%
Without cosigner		3,478		38			3,797		38
Total	$	9,270		100	%	$	9,969		100	%
Seasoning⁽²⁾:
1-12 payments	$	224		3	%	$	335		3	%
13-24 payments		301		3			436		4
25-36 payments		472		5			660		7
37-48 payments		662		7			934		10
More than 48 payments		7,262		78			7,178		72
Not yet in repayment		349		4			426		4
Total	$	9,270		100	%	$	9,969		100	%

⁽¹⁾

Excluding Private Education Refinance Loans, which do not have a cosigner, the cosigner rate was 63% and 62% at December 31, 2019 and 2018, respectively.

⁽²⁾

Number of months in active repayment for which a scheduled payment was received.

⁽³⁾

Balance equals the gross Private Education Loans.

	Private Education Loans Credit Quality Indicators
	Non-TDRs
	December 31, 2019					December 31, 2018
(Dollars in millions)	Balance⁽³⁾		% of Balance			Balance⁽³⁾		% of Balance
Credit Quality Indicators
Original Winning FICO Scores:
FICO 640 and above	$	13,687		97	%	$	13,087		96	%
FICO below 640		365		3			475		4
Total	$	14,052		100	%	$	13,562		100	%
School Type:
Not-for-profit	$	12,614		90	%	$	11,953		88	%
For-profit		1,438		10			1,609		12
Total	$	14,052		100	%	$	13,562		100	%
Cosigners:
With cosigner⁽¹⁾	$	5,184		37	%	$	6,961		51	%
Without cosigner		8,868		63			6,601		49
Total	$	14,052		100	%	$	13,562		100	%
Seasoning⁽²⁾:
1-12 payments	$	4,673		33	%	$	3,353		25	%
13-24 payments		1,570		11			486		3
25-36 payments		603		4			322		2
37-48 payments		251		2			383		3
More than 48 payments		6,675		48			8,626		64
Not yet in repayment		280		2			392		3
Total	$	14,052		100	%	$	13,562		100	%

⁽¹⁾

Excluding Private Education Refinance Loans, which do not have a cosigner, the cosigner rate was 67% at December 31, 2019 and 2018.

⁽²⁾

Number of months in active repayment for which a scheduled payment was received.

⁽³⁾

^{Balance equals the gross Private Education Loans.}

Receivable For Partially Charged Off Loans

4. Allowance for Loan Losses (Continued)

The following table summarizes the activity in the receivable for partially charged-off loans.

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Receivable at beginning of period	$	674		$	760		$	815
Expected future recoveries of current period defaults⁽¹⁾		74			89			110
Recoveries⁽²⁾		(126	)		(139	)		(155	)
Charge-offs⁽³⁾		(34	)		(36	)		(10	)
Receivable at end of period	$	588		$	674		$	760

⁽¹⁾

Represents our estimate of the amount to be collected in the future.

⁽²⁾

Current period cash collections.

⁽³⁾

Represents the current period recovery shortfall — the difference between what was expected to be collected and what was actually collected. Additionally, in third-quarters of 2019 and 2018, the portion of the loan amount charged off at default increased from 80.5% to 81% and from 79% to 80.5%, respectively. This change resulted in a $21 million and $32 million reduction to the balance of the receivable for partially charged-off loans in 2019 and 2018, respectively. These amounts are included in total charge-offs as reported in the “Allowance for Private Education Loan Losses” table.

Accrued Interest Receivable

The following table provides information regarding accrued interest receivable on our Private Education Loans.

(Dollars in millions)	Total		Greater Than 90 Days Past Due		Allowance for Uncollectible Interest
December 31, 2019
TDR	$	182	$	18	$	18
Non-TDR		115		2		4
Total	$	297	$	20	$	22
December 31, 2018
TDR	$	205	$	26	$	23
Non-TDR		149		3		4
Total	$	354	$	29	$	27
December 31, 2017
TDR	$	196	$	20	$	20
Non-TDR		187		4		6
Total	$	383	$	24	$	26

Organization and Business

12 Months Ended

Dec. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization and Business

1. Organization and Business

Navient’s Business

Navient is a leading provider of education loan management and business processing solutions for education, healthcare, and government clients at the federal, state, and local levels. We help our clients and millions of Americans achieve success through technology-enabled financing, services and support.

With a focus on data-driven insights, service, compliance and innovative support, Navient:

•

owns $86.8 billion of education loans;

•

originates Private Education Loans;

•

services and performs asset recovery activities on its own portfolio of education loans, as well as education loans owned by other institutions including the United States Department of Education (“ED”); and

•

provides revenue cycle management and business processing services to federal, state and municipal clients, public authorities and healthcare organizations.

Segment Reporting - Segment Results and Reconciliations to GAAP (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Cash and investments									$ 93	$ 97	$ 43
Total interest income									4,673	4,908	4,383
Total interest expense									3,488	3,668	2,971
Net interest income	$ 294	$ 312	$ 293	$ 285	$ 307	$ 306	$ 298	$ 329	1,185	1,240	1,412
Less: provisions for loan losses	50	64	68	76	85	85	112	87	258	370	426
Net interest income after provisions for loan losses	244	248	225	209	222	221	186	242	927	870	986
Other income (loss):
Servicing revenue									240	274	290
Asset recovery and business processing revenue									488	430	475
Other income (loss)									67	(21)	31
Gains on sales of loans									16		3
Gains (losses) on debt repurchases									45	19	(3)
Total other income									856	702	796
Expenses:
Direct operating expenses									730	696	659
Unallocated shared services expenses									254	288	307
Total operating expenses	235	251	241	256	252	255	201	275	984	984	966
Goodwill and acquired intangible asset impairment and amortization	6	6	11	7	8	23	6	9	30	47	23
Restructuring/other reorganization expenses	2	2	1	1	4	1	2	7	6	13	29
Total expenses									1,020	1,044	1,018
Income before income tax expense									763	528	764
Income tax expense (benefit)	49	40	41	36	34	33	30	36	166	133	472
Net income (loss)	$ 171	$ 145	$ 153	$ 128	$ 72	$ 114	$ 83	$ 126	597	395	292
Operating Segments [Member]
Interest income:
Cash and investments									93	97	43
Total interest income									4,733	4,961	4,369
Total interest expense									3,517	3,672	2,990
Net interest income									1,216	1,289	1,379
Less: provisions for loan losses									258	370	426
Net interest income after provisions for loan losses									958	919	953
Other income (loss):
Servicing revenue									240	274	290
Asset recovery and business processing revenue									488	430	475
Other income (loss)									43	30	19
Gains on sales of loans									16		3
Gains (losses) on debt repurchases									33	9	(3)
Total other income									820	743	784
Expenses:
Direct operating expenses									730	696	659
Unallocated shared services expenses									254	288	307
Total operating expenses									984	984	966
Restructuring/other reorganization expenses									6	13	29
Total expenses									990	997	995
Income before income tax expense									788	665	742
Income tax expense (benefit)									181	146	491
Net income (loss)									607	519	251
Operating Segments [Member] \| Federal Education Loans [Member]
Interest income:
Cash and investments									50	46	29
Total interest income									2,958	3,130	2,721
Total interest expense									2,376	2,467	2,022
Net interest income									582	663	699
Less: provisions for loan losses									30	70	44
Net interest income after provisions for loan losses									552	593	655
Other income (loss):
Servicing revenue									229	262	280
Asset recovery and business processing revenue									230	163	263
Other income (loss)									28	24	3
Gains on sales of loans											3
Total other income									487	449	549
Expenses:
Direct operating expenses									359	298	316
Total operating expenses									359	298	316
Total expenses									359	298	316
Income before income tax expense									680	744	888
Income tax expense (benefit)									155	164	321
Net income (loss)									525	580	567
Operating Segments [Member] \| Consumer Lending [Member]
Interest income:
Cash and investments									16	13	5
Total interest income									1,748	1,793	1,639
Total interest expense									980	1,013	825
Net interest income									768	780	814
Less: provisions for loan losses									228	300	382
Net interest income after provisions for loan losses									540	480	432
Other income (loss):
Servicing revenue									11	12	10
Other income (loss)									1
Gains on sales of loans									16
Total other income									28	12	10
Expenses:
Direct operating expenses									156	169	156
Total operating expenses									156	169	156
Total expenses									156	169	156
Income before income tax expense									412	323	286
Income tax expense (benefit)									96	71	103
Net income (loss)									316	252	183
Operating Segments [Member] \| Business Processing [Member]
Other income (loss):
Asset recovery and business processing revenue									258	267	212
Total other income									258	267	212
Expenses:
Direct operating expenses									215	229	187
Total operating expenses									215	229	187
Total expenses									215	229	187
Income before income tax expense									43	38	25
Income tax expense (benefit)									10	8	9
Net income (loss)									33	30	16
Operating Segments [Member] \| Other Segment [Member]
Interest income:
Cash and investments									27	38	9
Total interest income									27	38	9
Total interest expense									161	192	143
Net interest income									(134)	(154)	(134)
Net interest income after provisions for loan losses									(134)	(154)	(134)
Other income (loss):
Other income (loss)									14	6	16
Gains (losses) on debt repurchases									33	9	(3)
Total other income									47	15	13
Expenses:
Unallocated shared services expenses									254	288	307
Total operating expenses									254	288	307
Restructuring/other reorganization expenses									6	13	29
Total expenses									260	301	336
Income before income tax expense									(347)	(440)	(457)
Income tax expense (benefit)									(80)	(97)	58
Net income (loss)									(267)	(343)	(515)
Adjustments [Member] \| Reclassifications [Member]
Interest income:
Total interest income									8	17	69
Total interest expense									6	8	(8)
Net interest income									2	9	77
Net interest income after provisions for loan losses									2	9	77
Other income (loss):
Other income (loss)									(41)	(22)	(77)
Gains (losses) on debt repurchases									39	13
Total other income									(2)	(9)	(77)
Adjustments [Member] \| Additions (Subtractions) [Member]
Interest income:
Total interest income									(68)	(70)	(55)
Total interest expense									(35)	(12)	(11)
Net interest income									(33)	(58)	(44)
Net interest income after provisions for loan losses									(33)	(58)	(44)
Other income (loss):
Other income (loss)									65	(29)	89
Gains (losses) on debt repurchases									(27)	(3)
Total other income									38	(32)	89
Expenses:
Goodwill and acquired intangible asset impairment and amortization									30	47	23
Total expenses									30	47	23
Income before income tax expense									(25)	(137)	22
Income tax expense (benefit)									(15)	(13)	(19)
Net income (loss)									(10)	(124)	41
Adjustments [Member] \| Total Adjustments [Member]
Interest income:
Total interest income									(60)	(53)	14
Total interest expense									(29)	(4)	(19)
Net interest income									(31)	(49)	33
Net interest income after provisions for loan losses									(31)	(49)	33
Other income (loss):
Other income (loss)									24	(51)	12
Gains (losses) on debt repurchases									12	10
Total other income									36	(41)	12
Expenses:
Goodwill and acquired intangible asset impairment and amortization									30	47	23
Total expenses									30	47	23
Income before income tax expense									(25)	(137)	22
Income tax expense (benefit)									(15)	(13)	(19)
Net income (loss)									(10)	(124)	41
Education Loan Portfolio [Member]
Interest income:
Total interest income									4,578	4,805	4,327
Education Loan Portfolio [Member] \| Operating Segments [Member]
Interest income:
Total interest income									4,638	4,858	4,313
Education Loan Portfolio [Member] \| Operating Segments [Member] \| Federal Education Loans [Member]
Interest income:
Total interest income									2,907	3,080	2,679
Education Loan Portfolio [Member] \| Operating Segments [Member] \| Consumer Lending [Member]
Interest income:
Total interest income									1,731	1,778	1,634
Education Loan Portfolio [Member] \| Adjustments [Member] \| Reclassifications [Member]
Interest income:
Total interest income									8	17	69
Education Loan Portfolio [Member] \| Adjustments [Member] \| Additions (Subtractions) [Member]
Interest income:
Total interest income									(68)	(70)	(55)
Education Loan Portfolio [Member] \| Adjustments [Member] \| Total Adjustments [Member]
Interest income:
Total interest income									(60)	(53)	14
Other Loans [Member]
Interest income:
Total interest income									2	6	13
Other Loans [Member] \| Operating Segments [Member]
Interest income:
Total interest income									2	6	13
Other Loans [Member] \| Operating Segments [Member] \| Federal Education Loans [Member]
Interest income:
Total interest income									1	4	$ 13
Other Loans [Member] \| Operating Segments [Member] \| Consumer Lending [Member]
Interest income:
Total interest income									$ 1	$ 2

Education Loans

12 Months Ended

Dec. 31, 2019

Receivables [Abstract]

Education Loans

3. Education Loans

Education loans consist of FFELP and Private Education Loans.

There are three principal categories of FFELP Loans: Stafford, PLUS, and FFELP Consolidation Loans. Generally, Stafford and PLUS Loans have repayment periods of between 5 and 10 years. FFELP Consolidation Loans have repayment periods of 12 to 30 years. FFELP Loans do not require repayment, or have modified repayment plans, while the customer is in-school and during the grace period immediately upon leaving school. The customer may also be granted a deferment or forbearance for a period of time based on need, during which time the customer is not considered to be in repayment. Interest continues to accrue on loans in the in-school, deferment and forbearance period. FFELP Loans obligate the customer to pay interest at a stated fixed rate or a variable rate reset annually (subject to a cap) on July 1 of each year depending on when the loan was originated and the loan type. FFELP Loans disbursed before April 1, 2006 earn interest at the greater of the borrower’s rate or a floating rate based on the Special Allowance Payment (“SAP”) formula, with the interest earned on the floating rate that exceeds the interest earned from the customer being paid directly by ED. For loans disbursed after April 1, 2006, FFELP Loans effectively only earn at the SAP rate, as the excess interest earned when the borrower rate exceeds the SAP rate (Floor Income) is required to be rebated to ED.

FFELP Loans are insured as to their principal and accrued interest in the event of default subject to a Risk Sharing level based on the date of loan disbursement. These insurance obligations are supported by contractual rights against the United States. For loans disbursed after October 1, 1993 and before July 1, 2006, we receive 98% reimbursement on all qualifying default claims. For loans disbursed on or after July 1, 2006, we receive 97% reimbursement.

Private Education Loans bear the full credit risk of the customer. Private Education Refinance Loans generally have a fixed interest rate with the remaining Private Education Loans generally at a variable rate indexed to LIBOR or Prime indices. The majority of non-refinance loans in our portfolio are cosigned. Similar to FFELP loans, Private Education Loans are generally non-dischargeable in bankruptcy. Most loans have repayment terms of 10 to 15 years or more, and for loans made prior to 2009, payments are typically deferred until after graduation. However, since 2009 we began to encourage interest-only or fixed payment options while the customer is enrolled in school.

3. Education Loans (Continued)

The estimated weighted average life of education loans in our portfolio was approximately 6 years at December 31, 2019 and 2018. The following table reflects the distribution of our education loan portfolio by program.

	December 31, 2019					Year Ended December 31, 2019
(Dollars in millions)	Ending Balance		% of Balance			Average Balance		Average Effective Interest Rate
FFELP Stafford and Other Education Loans, net⁽¹⁾	$	21,723		25	%	$	23,198		4.24	%
FFELP Consolidation Loans, net		42,852		49			45,073		4.13
Private Education Loans, net		22,245		26			22,512		7.69
Total education loans, net	$	86,820		100	%	$	90,783		5.04	%

	December 31, 2018					Year Ended December 31, 2018
(Dollars in millions)	Ending Balance		% of Balance			Average Balance		Average Effective Interest Rate
FFELP Stafford and Other Education Loans, net⁽¹⁾	$	24,641		26	%	$	26,612		3.98	%
FFELP Consolidation Loans, net		47,612		50			50,359		3.91
Private Education Loans, net		22,245		24			23,281		7.64
Total education loans, net	$	94,498		100	%	$	100,252		4.79	%

⁽¹⁾	Primarily Stafford Loans, but also includes federally guaranteed PLUS and HEAL Loans.

As of December 31, 2019 and 2018, 87% and 86%, respectively, of our education loan portfolio was in repayment.

Business Combinations, Goodwill and Acquired Intangible Assets - Summary of Goodwill for Each Reporting Units and Reportable Segments (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill	$ 665	$ 665
Federal Education Loans [Member]
Goodwill [Line Items]
Goodwill	240	240
Federal Education Loans [Member] \| FFELP Loans [Member]
Goodwill [Line Items]
Goodwill	227	227
Federal Education Loans [Member] \| Federal Education Loan Servicing [Member]
Goodwill [Line Items]
Goodwill	13	13
Consumer Lending Segment [Member]
Goodwill [Line Items]
Goodwill	183	183
Consumer Lending Segment [Member] \| Private Education Loans [Member]
Goodwill [Line Items]
Goodwill	106	106
Consumer Lending Segment [Member] \| Private Education Refinance Loans [Member]
Goodwill [Line Items]
Goodwill	77	77
Business Processing [Member]
Goodwill [Line Items]
Goodwill	242	242
Business Processing [Member] \| Government Services [Member]
Goodwill [Line Items]
Goodwill	136	136
Business Processing [Member] \| Healthcare Services [Member]
Goodwill [Line Items]
Goodwill	$ 106	$ 106

Fair Value Measurements - Change in Balance Sheet Carrying Value Associated with Level 3 Financial Instruments Carried at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ (664)	$ (381)	$ (1,302)
Total gains/(losses):
Included in earnings	(50)	(414)	788
Included in other comprehensive income	0	0	0
Settlements	121	131	133
Transfers in and/or out of level 3	0	0	0
Balance, end of period	(593)	(664)	(381)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	70	(257)	795
Interest Rate Swaps [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	(27)	(41)	(46)
Total gains/(losses):
Included in earnings	8	11
Included in other comprehensive income	0	0	0
Settlements	2	3	5
Transfers in and/or out of level 3	0	0	0
Balance, end of period	(17)	(27)	(41)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	9	13	5
Cross-Currency Interest Rate Swaps [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	(633)	(322)	(1,243)
Total gains/(losses):
Included in earnings	(60)	(433)	803
Included in other comprehensive income	0	0	0
Settlements	118	122	118
Transfers in and/or out of level 3	0	0	0
Balance, end of period	(575)	(633)	(322)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	58	(284)	795
Other [Member]
Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	(4)	(18)	(13)
Total gains/(losses):
Included in earnings	2	8	(15)
Included in other comprehensive income	0	0	0
Settlements	1	6	10
Transfers in and/or out of level 3	0	0	0
Balance, end of period	(1)	(4)	(18)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	$ 3	$ 14	$ (5)

Allowance for Loan Losses - Additional Information (Detail) $ in Billions	12 Months Ended
	Dec. 31, 2019 USD ($) Loan	Dec. 31, 2018 USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Percentage of loans granted forbearance that migrated to TDR classification	69.00%	65.00%
Payment default period for TDRs	60 days past due
Interest Rate Reduction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
TDR loans, Unpaid Principal Balance \| $	$ 1.7	$ 1.8
Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Delinquency period (in days)	212 days
Private Education Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of classes of loans \| Loan	2

Business Combinations, Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Business Combinations [Abstract]

Summary of Goodwill for Each Reporting Units and Reportable Segments

The following table summarizes our goodwill for our reporting units and reportable segments as of December 31, 2019 and 2018.

(Dollars in millions)	Goodwill
Federal Education Loans reportable segment:
FFELP Loans	$	227
Federal Education Loan Servicing		13
Total Federal Education Loans reportable segment		240
Consumer Lending reportable segment:
Private Education Loans		106
Private Education Refinance Loans		77
Total Consumer Lending reportable segment		183
Business Processing reportable segment:
Government Services		136
Healthcare Services		106
Total Business Processing reportable segment		242
Total	$	665

Acquired Intangible Assets

Acquired intangible assets include the following:

	As of December 31, 2019							As of December 31, 2018
(Dollars in millions)	Cost Basis⁽¹⁾		Accumulated Impairment and Amortization⁽¹⁾			Net		Cost Basis⁽¹⁾		Accumulated Impairment and Amortization⁽¹⁾			Net
Customer, services and lending relationships	$	262	$	(220	)	$	42	$	284	$	(226	)	$	58
Favorable lease		1		(1	)		—		1		—			1
Non-competes		3		(3	)		—		3		(3	)		—
Software and technology		114		(96	)		18		115		(90	)		25
Trade names and trademarks		52		(20	)		32		61		(24	)		37
Total acquired intangible assets	$	432	$	(340	)	$	92	$	464	$	(343	)	$	121

⁽¹⁾

Segment Reporting - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) Segment Client	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable operating segments \| Segment	4
Total assets	$ 94,903	$ 104,176
Business Processing [Member]
Segment Reporting Information [Line Items]
Total assets	$ 423	448
Business Processing [Member] \| Minimum [Member]
Segment Reporting Information [Line Items]
Number of clients for business processing services \| Client	500
Other Segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 1,600	$ 2,000

Allowance for Loan Losses - Accrued Interest Receivable (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	$ 1,952	$ 1,999
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	297	354	$ 383
Accrued Interest Receivable, Allowance for Uncollectible Interest	22	27	26
Private Education Loans [Member] \| TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	182	205	196
Accrued Interest Receivable, Allowance for Uncollectible Interest	18	23	20
Private Education Loans [Member] \| Non-TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	115	149	187
Accrued Interest Receivable, Allowance for Uncollectible Interest	4	4	6
Accrued Interest Receivable, Greater Than 90 Days Past Due [Member] \| Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	20	29	24
Accrued Interest Receivable, Greater Than 90 Days Past Due [Member] \| Private Education Loans [Member] \| TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	18	26	20
Accrued Interest Receivable, Greater Than 90 Days Past Due [Member] \| Private Education Loans [Member] \| Non-TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	$ 2	$ 3	$ 4

Education Loans (Tables)

12 Months Ended

Dec. 31, 2019

Receivables [Abstract]

Education Loan Portfolio by Program

	December 31, 2019					Year Ended December 31, 2019
(Dollars in millions)	Ending Balance		% of Balance			Average Balance		Average Effective Interest Rate
FFELP Stafford and Other Education Loans, net⁽¹⁾	$	21,723		25	%	$	23,198		4.24	%
FFELP Consolidation Loans, net		42,852		49			45,073		4.13
Private Education Loans, net		22,245		26			22,512		7.69
Total education loans, net	$	86,820		100	%	$	90,783		5.04	%

	December 31, 2018					Year Ended December 31, 2018
(Dollars in millions)	Ending Balance		% of Balance			Average Balance		Average Effective Interest Rate
FFELP Stafford and Other Education Loans, net⁽¹⁾	$	24,641		26	%	$	26,612		3.98	%
FFELP Consolidation Loans, net		47,612		50			50,359		3.91
Private Education Loans, net		22,245		24			23,281		7.64
Total education loans, net	$	94,498		100	%	$	100,252		4.79	%

⁽¹⁾	Primarily Stafford Loans, but also includes federally guaranteed PLUS and HEAL Loans.

Commitments, Contingencies and Guarantees - Additional Information (Detail) - USD ($)	Dec. 31, 2019	Jun. 30, 2018
Unasserted Claim [Member]
Loss Contingencies [Line Items]
Contingency reserve		$ 40,000,000
SLM BankCo [Member] \| Indemnification Matters [Member]
Loss Contingencies [Line Items]
Reserve for estimated amounts and costs incurred	$ 0

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Open Market Repurchases [Member]	Derivative Contract Settlement [Member]	Common Stock [Member]	Treasury Stock [Member]	Treasury Stock [Member] Open Market Repurchases [Member]	Treasury Stock [Member] Derivative Contract Settlement [Member]	Common Stock Shares Outstanding [Member]	Common Stock Shares Outstanding [Member] Open Market Repurchases [Member]	Common Stock Shares Outstanding [Member] Derivative Contract Settlement [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total Stockholders' Equity [Member]	Total Stockholders' Equity [Member] Open Market Repurchases [Member]	Total Stockholders' Equity [Member] Derivative Contract Settlement [Member]	Noncontrolling Interest [Member]
Beginning Balance, Value at Dec. 31, 2016	$ 3,723			$ 4	$ (2,223)						$ 3,022	$ 6	$ 2,890	$ 3,699			$ 24
Beginning Balance, Shares at Dec. 31, 2016				436,037,666	(145,173,548)			290,864,118
Comprehensive income:
Net income	292												292	292
Other comprehensive income (loss), net of tax	55											55		55
Total comprehensive income	347													347
Cash dividends:
Common stock	(176)												(176)	(176)
Dividend equivalent units related to employee stock-based compensation plans	(2)												(2)	(2)
Issuance of common shares	$ 20										20			20
Issuance of common shares, Shares	3,680,479			3,680,479				3,680,479
Stock-based compensation expense	$ 35										35			35
Repurchase of common stock:
Common stock repurchased		$ (440)				$ (440)		$ (440)							$ (440)
Common stock repurchased, Shares						(29,646,374)		(29,646,374)	(29,646,374)
Shares repurchased related to employee stock-based compensation plans	$ (29)				$ (29)									(29)
Shares repurchased related to employee stock-based compensation plans, Shares	(1,847,651)				(1,847,651)			(1,847,651)
Noncontrolling interest in Earnest upon acquisition	$ 7																7
Ending Balance, Value at Dec. 31, 2017	3,485			$ 4	$ (2,692)						3,077	61	3,004	3,454			31
Ending Balance, Shares at Dec. 31, 2017				439,718,145	(176,667,573)			263,050,572
Comprehensive income:
Net income	395												395	395
Other comprehensive income (loss), net of tax	39											39		39
Total comprehensive income	434													434
Cash dividends:
Common stock	(166)												(166)	(166)
Dividend equivalent units related to employee stock-based compensation plans	(2)												(2)	(2)
Issuance of common shares	$ 43										43			43
Issuance of common shares, Shares	5,659,681			5,659,681				5,659,681
Stock-based compensation expense	$ 25										25			25
Repurchase of common stock:
Common stock repurchased		(160)	$ (60)			$ (160)	$ (60)	$ (220)							(160)	$ (60)
Common stock repurchased, Shares						(13,131,159)	(4,312,192)	(17,443,351)	(13,131,159)	(4,312,192)
(Gain)/loss on settlement	4				$ 4									4
Shares repurchased related to employee stock-based compensation plans	$ (53)				$ (53)									(53)
Shares repurchased related to employee stock-based compensation plans, Shares	(3,829,629)				(3,829,629)			(3,829,629)
Purchase of noncontrolling interest	$ (3)																(3)
Reclassification from adoption of ASU No. 2018-02												13	(13)
Ending Balance, Value at Dec. 31, 2018	3,547			$ 4	$ (2,961)						3,145	113	3,218	3,519			28
Ending Balance, Shares at Dec. 31, 2018				445,377,826	(197,940,553)			247,437,273
Comprehensive income:
Net income	597												597	597
Other comprehensive income (loss), net of tax	(204)											(204)		(204)
Total comprehensive income	393													393
Cash dividends:
Common stock	(147)												(147)	(147)
Dividend equivalent units related to employee stock-based compensation plans	(4)												(4)	(4)
Issuance of common shares	$ 28										28			28
Issuance of common shares, Shares	5,717,053			5,717,053				5,717,053
Stock-based compensation expense	$ 25										25			25
Repurchase of common stock:
Common stock repurchased		$ (440)				$ (440)		$ (440)							$ (440)
Common stock repurchased, Shares						(34,491,342)		(34,491,342)	(34,491,342)
Shares repurchased related to employee stock-based compensation plans	$ (38)				$ (38)									(38)
Shares repurchased related to employee stock-based compensation plans, Shares	(3,226,301)				(3,226,301)			(3,226,301)
Net activity in noncontrolling interest	$ (15)																(15)
Ending Balance, Value at Dec. 31, 2019	$ 3,349			$ 4	$ (3,439)						$ 3,198	$ (91)	$ 3,664	$ 3,336			$ 13
Ending Balance, Shares at Dec. 31, 2019				451,094,879	(235,658,196)			215,436,683

Quarterly Financial Information (unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

	2019
(Dollars in millions, except per share data)	First Quarter		Second Quarter			Third Quarter		Fourth Quarter
Net interest income	$	285	$	293		$	312	$	294
Less: provisions for loan losses		76		68			64		50
Net interest income after provisions for loan losses		209		225			248		244
Other income		212		254			192		176
Gains (losses) on derivative and hedging activities, net		7		(32	)		4		43
Operating expenses		256		241			251		235
Goodwill and acquired intangible asset impairment and amortization expense		7		11			6		6
Restructuring/other reorganization expenses		1		1			2		2
Income tax expense		36		41			40		49
Net income	$	128	$	153		$	145	$	171
Basic earnings per common share	$	.52	$	.65		$	.64	$	.79
Diluted earnings per common share	$	.52	$	.64		$	.63	$	.78

	2018
(Dollars in millions, except per share data)	First Quarter		Second Quarter			Third Quarter		Fourth Quarter
Net interest income	$	329	$	298		$	306	$	307
Less: provisions for loan losses		87		112			85		85
Net interest income after provisions for loan losses		242		186			221		222
Other income		163		176			203		196
Gains (losses) on derivative and hedging activities, net		48		(40	)		2		(48	)
Operating expenses		275		201			255		252
Goodwill and acquired intangible asset impairment and amortization expense		9		6			23		8
Restructuring/other reorganization expenses		7		2			1		4
Income tax expense		36		30			33		34
Net income	$	126	$	83		$	114	$	72
Basic earnings per common share	$	.48	$	.31		$	.44	$	.28
Diluted earnings per common share	$	.47	$	.31		$	.43	$	.28

Segment Reporting - Core Earnings Adjustments to GAAP (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Adjustments Required To Reconcile Core Earnings [Line Items]
Net income (loss)	$ 171	$ 145	$ 153	$ 128	$ 72	$ 114	$ 83	$ 126	$ 597	$ 395	$ 292
Net income tax effect	$ (49)	$ (40)	$ (41)	$ (36)	$ (34)	$ (33)	$ (30)	$ (36)	(166)	(133)	(472)
Operating Segments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Net income (loss)									607	519	251
Net income tax effect									(181)	(146)	(491)
Total Adjustments [Member] \| Adjustments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Net income (loss)									(10)	(124)	41
Core Earnings adjustments to GAAP									(25)	(137)	22
Net income tax effect									15	13	19
Net Impact of Derivative Accounting [Member] \| Total Adjustments [Member] \| Adjustments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Core Earnings adjustments to GAAP									5	(90)	45
Net Impact of Goodwill and Acquired Intangible Assets [Member] \| Total Adjustments [Member] \| Adjustments [Member]
Adjustments Required To Reconcile Core Earnings [Line Items]
Core Earnings adjustments to GAAP									$ (30)	$ (47)	$ (23)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Other Assets (Tables)

12 Months Ended

Dec. 31, 2019

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Schedule of Other Assets

The following table provides the detail of our other assets.

(Dollars in millions)	December 31, 2019		December 31, 2018
Accrued interest receivable	$	1,952	$	1,999
Benefit and insurance-related investments		459		470
Income tax asset, net (current and deferred)		258		271
Derivatives at fair value		212		157
Fixed assets, net		135		136
Accounts receivable		119		95
Other		199		276
Total	$	3,334	$	3,404

Revenue from Contracts with Customers Accounted for in Accordance with ASC 606 - Additional Information (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Accounts receivable	$ 119,000,000	$ 95,000,000
ASU 2014-09 [Member]
Disaggregation Of Revenue [Line Items]
Accounts receivable	67,000,000	$ 74,000,000
Contract assets	0
Contract liability	$ 0

Stock-Based Compensation Plans and Arrangements - Black-Scholes Model Assumptions for Calculating Stock Option and ESPP Fair Values (Detail) - Employee Stock Option [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of the option	3 years 2 months 12 days	3 years
Expected volatility	36.00%	34.00%
Risk-free interest rate	2.27%	1.44%
Expected dividend rate	4.70%	4.13%
Weighted average fair value of options granted and stock purchase rights	$ 2.59	$ 2.69

Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2020	Jun. 01, 2017	Dec. 31, 2016
Summary Of Significant Accounting Policies [Line Items]
Uncollected contractual principal and interest payments	$ 86,820,000,000				$ 94,498,000,000				$ 86,820,000,000	$ 94,498,000,000
Percentage of threshold									50.00%
Goodwill impaired method for fair value determination									We complete a goodwill impairment analysis which may be a qualitative or a quantitative two-step analysis depending on the facts and circumstances associated with the reporting unit. In conjunction with a qualitative impairment analysis, we assess relevant qualitative factors to determine whether it is “more-likely-than-not” that the fair value of a reporting unit is less than its carrying amount. The “more-likely-than-not” threshold is defined as having a likelihood of more than 50%. In conjunction with a quantitative impairment analysis, we complete Step 1 of the goodwill impairment analysis. Step 1 consists of a comparison of the fair value of the reporting unit to the reporting unit’s carrying value, including goodwill. If the carrying value of the reporting unit exceeds the fair value, Step 2 in the goodwill impairment analysis is performed to measure the amount of impairment loss, if any. Step 2 of the goodwill impairment analysis compares the implied fair value of the reporting unit’s goodwill to the carrying value of the reporting unit’s goodwill. The implied fair value of goodwill is determined in a manner consistent with determining goodwill in a business combination. If the carrying amount of the reporting unit’s goodwill exceeds the implied fair value of the goodwill, an impairment loss is recognized in an amount equal to that excess. If, based on first assessing impairment utilizing a qualitative approach, we determine it is “more-likely-than-not” that the fair value of the reporting unit is less than its carrying amount, we will also complete a quantitative impairment analysis.
Option to exercise clean-up call and purchase education loans from trust of original loan balance									10% or less of the original loan balance
Percentage of trust's asset balance needed to trigger clean-up call									10.00%
Option to purchase education loan of the trust's initial pool balance									up to 10% of the trust’s initial pool balance
Description of post employment benefits									The Company administers the Navient Corporation Employee Severance Plan and the Navient Corporation Executive Severance Plan for Senior Officers (collectively, “the Severance Plan”). The Severance Plan provides severance benefits in the event of termination of the Company’s full-time employees and part-time employees who work at least 24 hours per week.
Restructuring/other reorganization expenses	2,000,000	$ 2,000,000	$ 1,000,000	$ 1,000,000	4,000,000	$ 1,000,000	$ 2,000,000	$ 7,000,000	$ 6,000,000	13,000,000	$ 29,000,000
Gains (losses) on derivative and hedging activities, net	43,000,000	$ 4,000,000	$ (32,000,000)	$ 7,000,000	(48,000,000)	$ 2,000,000	$ (40,000,000)	$ 48,000,000	22,000,000	(38,000,000)	22,000,000
ASC 2016-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Lease assets and liabilities amount									28,000,000
ASU 2017-12 [Member] \| Interest Expense [Member]
Summary Of Significant Accounting Policies [Line Items]
Gains (losses) on derivative and hedging activities, net									21,000,000
Default Aversion Service [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred asset recovery revenue recognized											47,000,000
Securitization Trust [Member]
Summary Of Significant Accounting Policies [Line Items]
Assets	$ 18,000,000								$ 18,000,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Delinquency period (in days)	212 days								212 days
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of aggregate education loan to purchase									10.00%
FFELP Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, Fair Value	$ 64,478,000,000				72,074,000,000				$ 64,478,000,000	72,074,000,000
Uncollected contractual principal and interest payments	64,575,000,000				72,253,000,000				64,575,000,000	72,253,000,000
Loans receivable, discount	$ 33,000,000				37,000,000				33,000,000	37,000,000	43,000,000		$ 47,000,000
Allowance for loans acquired									$ 0	0	0
FFELP Loans [Member] \| After October 1 1993 and before July 1 2006 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage reimbursement on all qualifying default claims period	98.00%								98.00%
FFELP Loans [Member] \| On or After July 1 2006 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage reimbursement on all qualifying default claims period	97.00%								97.00%
FFELP Loans [Member] \| Prior to October 1 1993 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage reimbursement on all qualifying default claims period	100.00%								100.00%
Loans Acquired With Non-Deteriorated Credit Quality [Member] \| FFELP Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, principal amount											3,500,000,000
Private Education Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, Fair Value	$ 22,984,000,000				22,958,000,000				$ 22,984,000,000	22,958,000,000
Uncollected contractual principal and interest payments	22,245,000,000				22,245,000,000				22,245,000,000	22,245,000,000
Estimated accretable yield													108,000,000
Valuation allowance	0								0
Loans receivable, discount	268,000,000				326,000,000				268,000,000	326,000,000	392,000,000		424,000,000
Allowance for loans acquired									$ 0	0	0
Allowance for credit losses factors influenced managements judgment									Our model is based upon the most recent twelve months of actual collection experience as the starting point for the non-TDR portfolio and the most recent approximate 15 years for the TDR portfolio and applies expected macroeconomic changes and collection procedure changes to estimate expected losses caused by loss events incurred as of the balance sheet date. Our model for the non-TDR portfolio places a greater emphasis on the more recent default experience rather than the default experience for older historical periods, as we believe the more recent default experience is more indicative of the probable losses incurred in the loan portfolio today that will default over the next two years. The TDR portfolio uses a longer historical default experience since we are projecting life of loan remaining losses. Similar to estimating defaults, we use historical customer payment behavior to estimate the timing and amount of future recoveries on charged-off loans. We use judgment in determining whether historical performance is representative of what we expect to collect in the future. We then apply the default and collection rate projections to each category of loans. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. Additionally, we consider changes in laws and regulations that could potentially impact the allowance for loan losses.
Private Education Loans [Member] \| Loans Receivable For Partially Charged Off Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Receivable for partially charged-off loans	588,000,000				$ 674,000,000				$ 588,000,000	$ 674,000,000	760,000,000			$ 815,000,000
Private Education Loans [Member] \| FFELP Loans [Member] \| ASU 2016-13 [Member] \| Allowance for Loan Losses [Member] \| Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated changes in total allowance for loan losses and equity												$ 800,000,000
Private Education Loans [Member] \| FFELP Loans [Member] \| ASU 2016-13 [Member] \| Equity [Member] \| Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated changes in total allowance for loan losses and equity												$ 615,000,000
Private Education Loans [Member] \| Loans With Deteriorated Credit Quality [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, principal amount													261,000,000
Loans receivable, Fair Value													101,000,000
Uncollected contractual principal and interest payments													$ 411,000,000
Loans receivable, carrying amount	$ 70,000,000								$ 70,000,000
Private Education Loans [Member] \| Loans Acquired With Non-Deteriorated Credit Quality [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, principal amount											$ 2,800,000,000

Other Assets - Schedule of Other Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Offsetting [Abstract]
Accrued interest receivable	$ 1,952	$ 1,999
Benefit and insurance-related investments	459	470
Income tax asset, net (current and deferred)	258	271
Derivatives at fair value	212	157
Fixed assets, net	135	136
Accounts receivable	119	95
Other	199	276
Total	$ 3,334	$ 3,404

Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	$ 86,820	$ 94,498
Total earning assets, Carrying Value	90,812	99,986
Short-term borrowings, Carrying Value	8,483	5,422
Long-term borrowings, Carrying Value	81,715	93,519
Total	90,198	98,941
Total earning assets, Fair Value	91,454	100,520
Short-term borrowings, Fair Value	8,498	5,418
Long-term borrowings, Fair Value	81,317	92,173
Total interest-bearing liabilities, Fair Value	89,815	97,591
FFELP Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	64,575	72,253
Loans receivable, Fair Value	64,478	72,074
Floor Income Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(68)	(53)
Derivative financial instruments, Fair Value	(68)	(53)
Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	210	94
Derivative financial instruments, Fair Value	210	94
Cross-Currency Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(575)	(659)
Derivative financial instruments, Fair Value	(575)	(659)
Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(1)	(4)
Derivative financial instruments, Fair Value	(1)	(4)
Private Education Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	22,245	22,245
Loans receivable, Fair Value	22,984	22,958
Difference [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total earning assets, Fair Value	642	534
Short-term borrowings, Fair Value	(15)	4
Long-term borrowings, Fair Value	398	1,346
Total interest-bearing liabilities, Fair Value	383	1,350
Excess of net asset fair value over carrying value	1,025	1,884
Difference [Member] \| FFELP Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable, Fair Value	(97)	(179)
Difference [Member] \| Private Education Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable, Fair Value	739	713
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and investments	3,992	5,488
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and investments	$ 3,992	$ 5,488

Borrowings - Long-Term Borrowings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term borrowings	$ 81,715	$ 93,519
Weighted Average Interest Rate	2.96%	3.60%
Long-term borrowings, Average Balance	$ 86,924	$ 99,195
U.S Dollar Denominated Interest Bearing, Due 2021-2083 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 63,731
Weighted Average Interest Rate	2.66%
Long-term borrowings, Average Balance	$ 68,664
Non-U. S Dollar-Denominated Interest Bearing, Due 2023-2040 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 3,577	$ 4,064
Weighted Average Interest Rate	0.61%	0.66%
Long-term borrowings, Average Balance	$ 4,262	$ 4,919
Floating Rate Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 67,308	$ 78,906
Weighted Average Interest Rate	2.55%	3.24%
Long-term borrowings, Average Balance	$ 72,926	$ 85,108
U.S Dollar Denominated Interest Bearing, Due 2021-2068 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 14,407
Weighted Average Interest Rate	4.88%
Long-term borrowings, Average Balance	$ 13,941
Non Us Dollar Denominated Interest Bearing Fixed Rate Notes Due [Member]
Debt Instrument [Line Items]
Long-term borrowings, Average Balance	57
Fixed Rate Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 14,407	$ 14,613
Weighted Average Interest Rate	4.88%	5.53%
Long-term borrowings, Average Balance	$ 13,998	$ 14,087
U.S Dollar Denominated Interest Bearing, Due 2019-2083 [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 74,842
Weighted Average Interest Rate		3.38%
Long-term borrowings, Average Balance		$ 80,189
U.S Dollar Denominated Interest Bearing, Due 2020-2059 [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 14,431
Weighted Average Interest Rate		5.57%
Long-term borrowings, Average Balance		$ 13,814
Non-U. S Dollar Denominated Interest Bearing, Due 2034 [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 182
Weighted Average Interest Rate		2.49%
Long-term borrowings, Average Balance		$ 273

Income Taxes - Reconciliations of Statutory U.S. Federal Income Tax Rates to Our Effective Tax Rate for Continuing Operations (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	35.00%
DTA Remeasurement Loss			27.20%
State tax, net of federal benefit	1.40%	3.90%	0.70%
Other, net	(0.50%)	0.30%	(1.10%)
Effective tax rate	21.90%	25.20%	61.80%

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Valuation of Financial Instruments that are Marked-to-Market on Recurring Basis

12. Fair Value Measurements (Continued)

	Fair Value Measurements on a Recurring Basis
	December 31, 2019											December 31, 2018
(Dollars in millions)	Level 1		Level 2			Level 3			Total			Level 1		Level 2			Level 3			Total
Assets
Derivative instruments:⁽¹⁾
Interest rate swaps		—		227			3			230			—		171			2			173
Cross-currency interest rate swaps		—		—			—			—			—		—			6			6
Total derivative assets⁽²⁾		—		227			3			230			—		171			8			179
Total	$	—	$	227		$	3		$	230		$	—	$	171		$	8		$	179
Liabilities⁽³⁾
Derivative instruments⁽¹⁾
Interest rate swaps	$	—	$	—		$	(20	)	$	(20	)	$	—	$	(50	)	$	(29	)	$	(79	)
Floor Income Contracts		—		(68	)		—			(68	)		—		(53	)		—			(53	)
Cross-currency interest rate swaps		—		—			(575	)		(575	)		—		(26	)		(639	)		(665	)
Other		—		—			(1	)		(1	)		—		—			(4	)		(4	)
Total derivative liabilities⁽²⁾		—		(68	)		(596	)		(664	)		—		(129	)		(672	)		(801	)
Total	$	—	$	(68	)	$	(596	)	$	(664	)	$	—	$	(129	)	$	(672	)	$	(801	)

⁽¹⁾	Fair value of derivative instruments excludes accrued interest and the value of collateral.

⁽²⁾	See “Note 7 — Derivative Financial Instruments” for a reconciliation of gross positions without the impact of master netting agreements to the balance sheet classification.

⁽³⁾	Borrowings which are the hedged items in a fair value hedge relationship and which are adjusted for changes in value due to benchmark interest rates only are not carried at full fair value and are not reflected in this table.

Change in Balance Sheet Carrying Value Associated with Level 3 Financial Instruments Carried at Fair Value on Recurring Basis

12. Fair Value Measurements (Continued)

The following tables summarize the change in balance sheet carrying value associated with level 3 financial instruments carried at fair value on a recurring basis.

	Year Ended December 31, 2019
	Derivative Instruments
(Dollars in millions)	Interest Rate Swaps			Cross Currency Interest Rate Swaps			Other			Total Derivative Instruments
Balance, beginning of period	$	(27	)	$	(633	)	$	(4	)	$	(664	)
Total gains/(losses):
Included in earnings⁽¹⁾		8			(60	)		2			(50	)
Included in other comprehensive income		—			—			—			—
Settlements		2			118			1			121
Transfers in and/or out of level 3		—			—			—			—
Balance, end of period	$	(17	)	$	(575	)	$	(1	)	$	(593	)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date⁽²⁾	$	9		$	58		$	3		$	70

	Year Ended December 31, 2018
	Derivative Instruments
(Dollars in millions)	Interest Rate Swaps			Cross Currency Interest Rate Swaps			Other			Total Derivative Instruments
Balance, beginning of period	$	(41	)	$	(322	)	$	(18	)	$	(381	)
Total gains/(losses):
Included in earnings⁽¹⁾		11			(433	)		8			(414	)
Included in other comprehensive income		—			—			—			—
Settlements		3			122			6			131
Transfers in and/or out of level 3		—			—			—			—
Balance, end of period	$	(27	)	$	(633	)	$	(4	)	$	(664	)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date⁽²⁾	$	13		$	(284	)	$	14		$	(257	)

	Year Ended December 31, 2017
	Derivative Instruments
(Dollars in millions)	Interest Rate Swaps			Cross Currency Interest Rate Swaps			Other			Total Derivative Instruments
Balance, beginning of period	$	(46	)	$	(1,243	)	$	(13	)	$	(1,302	)
Total gains/(losses):
Included in earnings⁽¹⁾		—			803			(15	)		788
Included in other comprehensive income		—			—			—			—
Settlements		5			118			10			133
Transfers in and/or out of level 3		—			—			—			—
Balance, end of period	$	(41	)	$	(322	)	$	(18	)	$	(381	)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date⁽²⁾	$	5		$	795		$	(5	)	$	795

⁽¹⁾

“Included in earnings” is comprised of the following amounts recorded in the specified line item in the consolidated statements of income:

Included in Earnings

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Gains (losses) on derivative and hedging activities, net	$	10		$	(292	)	$	906
Interest expense		(60	)		(122	)		(118	)
Total	$	(50	)	$	(414	)	$	788

⁽²⁾

Recorded in “gains (losses) on derivative and hedging activities, net” in the consolidated statements of income.

Unobservable Data Used in Recurring Valuations of Level 3

12. Fair Value Measurements (Continued)

The following table presents the significant inputs that are unobservable or from inactive markets used in the recurring valuations of the level 3 financial instruments detailed above.

(Dollars in millions)	Fair Value at December 31, 2019			Valuation Technique	Input	Range
Derivatives
Prime/LIBOR basis swaps	$	(17	)	Discounted cash flow	Constant Prepayment Rate	8%
					Bid/ask adjustment to discount rate	.08%
Cross-currency interest rate swaps		(575	)	Discounted cash flow	Constant Prepayment Rate	4%
Other		(1	)
Total	$	(593	)

Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments

The following table summarizes the fair values of our financial assets and liabilities, including derivative financial instruments.

	December 31, 2019									December 31, 2018
(Dollars in millions)	Fair Value			Carrying Value			Difference			Fair Value			Carrying Value			Difference
Earning assets
FFELP Loans	$	64,478		$	64,575		$	(97	)	$	72,074		$	72,253		$	(179	)
Private Education Loans		22,984			22,245			739			22,958			22,245			713
Cash and investments		3,992			3,992			—			5,488			5,488			—
Total earning assets		91,454			90,812			642			100,520			99,986			534
Interest-bearing liabilities
Short-term borrowings		8,498			8,483			(15	)		5,418			5,422			4
Long-term borrowings		81,317			81,715			398			92,173			93,519			1,346
Total interest-bearing liabilities		89,815			90,198			383			97,591			98,941			1,350
Derivative financial instruments
Floor Income Contracts		(68	)		(68	)		—			(53	)		(53	)		—
Interest rate swaps		210			210			—			94			94			—
Cross-currency interest rate swaps		(575	)		(575	)		—			(659	)		(659	)		—
Other		(1	)		(1	)		—			(4	)		(4	)		—
Excess of net asset fair value over carrying value							$	1,025								$	1,884

Allowance for Loan Losses - Private Education Loan Portfolio Stratified by Key Credit Quality Indicators (Parenthetical) (Detail) - With Cosigner [Member]	Dec. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	67.00%	67.00%
Private Education Loans - TDRs [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	63.00%	62.00%

Borrowings - Company's Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Short-term borrowings	$ 8,483	$ 5,422
Long-term borrowings	81,715	93,519
Total	90,198	98,941
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,056	814
FFELP Loan Securitizations [Member]
Debt Instrument [Line Items]
Short-term borrowings	72
Private Education Loan Securitizations [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,120	300
FFELP Loan ABCP Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,783	2,927
Total	3,400
Private Education Loan ABCP Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,114	1,114
Total	3,600
Total Before Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Short-term borrowings	8,479	5,425
Long-term borrowings	81,756	93,868
Total	90,235	99,293
Total Before Hedge Accounting Adjustments [Member] \| Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,052	817
Long-term borrowings	8,461	10,674
Total	9,513	11,491
Total Before Hedge Accounting Adjustments [Member] \| Total Unsecured Borrowings [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,052	817
Long-term borrowings	8,461	10,674
Total	9,513	11,491
Total Before Hedge Accounting Adjustments [Member] \| FFELP Loan Securitizations [Member]
Debt Instrument [Line Items]
Short-term borrowings	72
Long-term borrowings	59,735	66,318
Total	59,807	66,318
Total Before Hedge Accounting Adjustments [Member] \| Private Education Loan Securitizations [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,120	300
Long-term borrowings	11,430	12,985
Total	13,550	13,285
Total Before Hedge Accounting Adjustments [Member] \| FFELP Loan ABCP Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,783	2,927
Long-term borrowings	617	2,625
Total	3,400	5,552
Total Before Hedge Accounting Adjustments [Member] \| Private Education Loan ABCP Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,114	1,114
Long-term borrowings	1,513	1,266
Total	3,627	2,380
Total Before Hedge Accounting Adjustments [Member] \| Other [Member]
Debt Instrument [Line Items]
Short-term borrowings	338	267
Total	338	267
Total Before Hedge Accounting Adjustments [Member] \| Secured Borrowings [Member]
Debt Instrument [Line Items]
Short-term borrowings	7,427	4,608
Long-term borrowings	73,295	83,194
Total	80,722	87,802
Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Short-term borrowings	4	(3)
Long-term borrowings	(41)	(349)
Total	$ (37)	$ (352)

Segment Reporting - Core Earnings Adjustments to GAAP (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($)
Segment Reporting [Abstract]
Amount that will be equal to mark-to-market gain or loss over the life of the contract	$ 0

Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Significant Accounting Policies

2. Significant Accounting Policies

Use of Estimates

Consolidation

2. Significant Accounting Policies (Continued)

Fair Value Measurement

We use estimates of fair value in applying various accounting standards for our financial statements. Fair value measurements are used in one of four ways:

•

In the consolidated balance sheet with changes in fair value recorded in the consolidated statement of income;

•

In the consolidated balance sheet with changes in fair value recorded in the accumulated other comprehensive income section of the consolidated statement of changes in stockholders’ equity;

•

In the consolidated balance sheet for instruments carried at lower of cost or fair value with impairment charges recorded in the consolidated statement of income; and

•

In the notes to the financial statements.

•

Loans

2. Significant Accounting Policies (Continued)

Allowance for Loan Losses

Purchased Credit Impaired (“PCI”) Loans

Purchased Non-Credit Impaired Loans

Allowance for Private Education Loan Losses

2. Significant Accounting Policies (Continued)

Allowance for FFELP Loan Losses

Investments

2. Significant Accounting Policies (Continued)

We also have other investments, primarily a receivable for cash collateral posted to derivative counterparties.

Cash and Cash Equivalents

Restricted Cash and Investments

Goodwill and Acquired Intangible Assets

2. Significant Accounting Policies (Continued)

Securitization Accounting

Irrespective of whether a securitization receives sale or on-balance sheet treatment, our continuing involvement with our securitization trusts is generally limited to:

•	Owning equity certificates or other certificates of certain trusts and, in certain cases, securities retained for the purpose of complying with risk retention requirements under securities laws.

•	Lending to certain trusts, under a revolving credit, amounts necessary to cover temporary cash flow needs of the trust. These amounts are repaid to us on subordinated basis with interest at a market rate.

•	The servicing of the education loan assets within the securitization trusts, on both a pre- and post-default basis.

•	Our acting as administrator for the securitization transactions we sponsored, which includes remarketing certain bonds at future dates.

•	Our responsibilities relative to representation and warranty violations.

•	Temporarily advancing to the trust certain borrower benefits afforded the borrowers of education loans that have been securitized. These advances subsequently are returned to us in the next quarter.

•	Certain back-to-back derivatives entered into by us contemporaneously with the execution of derivatives by certain Private Education Loan securitization trusts.

•	The option held by us to buy certain delinquent loans from certain Private Education Loan securitization trusts.

•	The option to exercise the clean-up call and purchase the education loans from the trust when the asset balance is 10% or less of the original loan balance.

•	The option, on some trusts, to purchase education loans aggregating up to 10% of the trust’s initial pool balance.

•	The option (in certain trusts) to call rate reset notes in instances where the remarketing process has failed.

2. Significant Accounting Policies (Continued)

Education Loan Interest Income

Interest Expense

Servicing Revenue

Asset Recovery and Business Processing Revenue

2. Significant Accounting Policies (Continued)

Transfer of Financial Assets and Extinguishments of Liabilities

We recognize the results of a transfer of loans and the extinguishment of debt based upon the settlement date of the transaction.

Derivative Accounting

2. Significant Accounting Policies (Continued)

Accounting for Stock-Based Compensation

Restructuring and Other Reorganization Expenses

Other reorganization expenses include certain internal costs and third-party costs incurred in connection with our cost reduction initiatives.

2. Significant Accounting Policies (Continued)

Income Taxes

Earnings (Loss) per Common Share

Reclassifications

Recently Issued Accounting Pronouncements

Effective in 2019

Leases

2. Significant Accounting Policies (Continued)

Hedging Activities

Effective in 2020

Allowance for Loan Losses

Related to the new CECL standard:

•

Charge-offs will include the discount or premium related to such defaulted loan.

•

2. Significant Accounting Policies (Continued)

Goodwill

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Reconciliations of Statutory U.S. Federal Income Tax Rates to Our Effective Tax Rate for Continuing Operations

Reconciliations of the statutory U.S. federal income tax rates to our effective tax rate for continuing operations follow:

	Years Ended December 31,
	2019			2018			2017
Statutory rate		21.0	%		21.0	%		35.0	%
DTA Remeasurement Loss⁽¹⁾		—			—			27.2
State tax, net of federal benefit		1.4			3.9			.7
Other, net		(.5	)		.3			(1.1	)
Effective tax rate		21.9	%		25.2	%		61.8	%

⁽¹⁾

Components of Provision for Income Tax Expense (Benefit)

Income tax expense consists of:

	December 31,
(Dollars in millions)	2019		2018		2017
Current provision/(benefit):
Federal	$	78	$	71	$	77
State		11		13		(3	)
Foreign		—		3		3
Total current provision/(benefit)		89		87		77
Deferred provision/(benefit):
Federal		73		33		385
State		3		13		11
Foreign		1		—		(1	)
Total deferred provision/(benefit)		77		46		395
Provision for income tax expense/(benefit)	$	166	$	133	$	472

Schedule of Deferred Tax Assets and Liabilities

The tax effect of temporary differences that give rise to deferred tax assets and liabilities include the following:

	December 31,
(Dollars in millions)	2019		2018
Deferred tax assets:
Loan reserves	$	257	$	292
Education loan premiums and discounts, net		44		48
Accrued expenses not currently deductible		16		14
Operating loss and credit carryovers		17		18
Stock-based compensation plans		10		16
Other		21		18
Total deferred tax assets		365		406
Deferred tax liabilities:
Market value adjustments on education loans, investments and derivatives		13		46
Acquired intangible assets		17		12
Original issue discount on borrowings		10		7
Other		18		19
Total deferred tax liabilities		58		84
Net deferred tax assets	$	307	$	322

Summary of Changes in Unrecognized Tax Benefits

The following table summarizes changes in unrecognized tax benefits:

	December 31,
(Dollars in millions)	2019			2018			2017
Unrecognized tax benefits at beginning of year	$	65.7		$	57.4		$	73.0
Increases resulting from tax positions taken during a prior period		4.0			8.0			.7
Decreases resulting from tax positions taken during a prior period		(3.8	)		(.3	)		(1.8	)
Increases resulting from tax positions taken during the current period		1.9			3.8			4.4
Decreases related to settlements with taxing authorities		(11.1	)		(1.4	)		(5.1	)
Increases related to settlements with taxing authorities		—			—			—
Reductions related to the lapse of statute of limitations		(3.1	)		(1.8	)		(13.8	)
Unrecognized tax benefits at end of year	$	53.6		$	65.7		$	57.4

Borrowings - Additional Information (Detail) - USD ($)	12 Months Ended
Borrowings - Additional Information (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2015
Debt Instrument [Line Items]
Outstanding borrowings under facility	$ 90,198,000,000	$ 98,941,000,000
Issuance of unsecured debt	0	500,000,000	$ 1,600,000,000
FFELP Loan ABCP Facilities [Member]
Debt Instrument [Line Items]
Outstanding borrowings under facility	3,400,000,000
Assets securing facility	3,600,000,000
Maximum unused capacity	867,000,000
Unencumbered Loans	$ 319,000,000
FFELP Loan ABCP Facilities [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Facility maturity date	2020-11
FFELP Loan ABCP Facilities [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Facility maturity date	2021-04
FFELP Loan \| Asset-backed Securities, Securitized Loans and Receivables [Member]
Debt Instrument [Line Items]
Outstanding borrowings under facility	$ 300,000,000
Amount of asset-backed securitization repurchase facility		$ 900,000,000
Private Education Loan ABCP Facilities [Member]
Debt Instrument [Line Items]
Outstanding borrowings under facility	3,600,000,000
Assets securing facility	4,300,000,000
Maximum unused capacity	384,000,000
Unencumbered Loans	$ 2,600,000,000
Private Education Loan ABCP Facilities [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Facility maturity date	2020-06
Private Education Loan ABCP Facilities [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Facility maturity date	2021-12
Private Education Loan Repurchase Facilities [Member] \| Asset-backed Securities, Securitized Loans and Receivables [Member]
Debt Instrument [Line Items]
Outstanding borrowings under facility	$ 2,300,000,000
Amount of asset-backed securitization repurchase facility				$ 4,200,000,000

Borrowings - Outstanding Short-Term Borrowings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 8,483	$ 5,422
Weighted Average Interest Rate	3.42%	3.56%
Short-term borrowings, Average Balance	$ 6,944	$ 4,833
Weighted Average Interest Rate, Average Balance	4.28%	4.35%
Maximum outstanding at any month end	$ 8,564	$ 6,363
FFELP Loan Securitizations [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 72
Weighted Average Interest Rate	3.16%
Short-term borrowings, Average Balance	$ 49
Weighted Average Interest Rate, Average Balance	3.18%
Private Education Loan Securitizations [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 2,120	$ 300
Weighted Average Interest Rate	4.14%	5.23%
Short-term borrowings, Average Balance	$ 1,672	$ 536
Weighted Average Interest Rate, Average Balance	4.57%	4.72%
FFELP Loan ABCP Facilities [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 2,783	$ 2,927
Weighted Average Interest Rate	2.46%	3.10%
Short-term borrowings, Average Balance	$ 2,371	$ 1,137
Weighted Average Interest Rate, Average Balance	3.11%	2.79%
Private Education Loan ABCP Facilities [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 2,114	$ 1,114
Weighted Average Interest Rate	2.76%	3.63%
Short-term borrowings, Average Balance	$ 1,053	$ 847
Weighted Average Interest Rate, Average Balance	3.20%	3.40%
Senior Unsecured Debt [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 1,056	$ 814
Weighted Average Interest Rate	6.42%	4.92%
Short-term borrowings, Average Balance	$ 1,492	$ 2,021
Weighted Average Interest Rate, Average Balance	7.05%	5.90%
Other Interest Bearing Liabilities [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 338	$ 267
Weighted Average Interest Rate	1.55%	2.39%
Short-term borrowings, Average Balance	$ 307	$ 292
Weighted Average Interest Rate, Average Balance	2.16%	1.73%

Borrowings (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Company's Borrowings

The following table summarizes our borrowings.

	December 31, 2019								December 31, 2018
(Dollars in millions)	Short Term		Long Term			Total			Short Term			Long Term			Total
Unsecured borrowings:
Senior unsecured debt⁽¹⁾	$	1,052	$	8,461		$	9,513		$	817		$	10,674		$	11,491
Total unsecured borrowings		1,052		8,461			9,513			817			10,674			11,491
Secured borrowings:
FFELP Loan securitizations⁽²⁾		72		59,735			59,807			—			66,318			66,318
Private Education Loan securitizations⁽³⁾		2,120		11,430			13,550			300			12,985			13,285
FFELP Loan ABCP facilities		2,783		617			3,400			2,927			2,625			5,552
Private Education Loan ABCP facilities		2,114		1,513			3,627			1,114			1,266			2,380
Other⁽⁴⁾		338		—			338			267			—			267
Total secured borrowings		7,427		73,295			80,722			4,608			83,194			87,802
Total before hedge accounting adjustments		8,479		81,756			90,235			5,425			93,868			99,293
Hedge accounting adjustments		4		(41	)		(37	)		(3	)		(349	)		(352	)
Total	$	8,483	$	81,715		$	90,198		$	5,422		$	93,519		$	98,941

⁽¹⁾	Includes principal amount of $1.1 billion and $817 million of short-term debt as of December 31, 2019 and 2018, respectively. Includes principal amount of $8.5 billion and $10.8 billion of long-term debt as of December 31, 2019 and 2018, respectively.

⁽²⁾

⁽³⁾

⁽⁴⁾	“Other” primarily includes the obligation to return cash collateral held related to derivative exposures.

Outstanding Short-Term Borrowings

The following tables summarize outstanding short-term borrowings (secured and unsecured), the weighted average interest rates at the end of each period, and the related average balances and weighted average interest rates during the periods.

	December 31, 2019					Year Ended December 31, 2019
(Dollars in millions)	Ending Balance		Weighted Average Interest Rate			Average Balance		Weighted Average Interest Rate
FFELP Loan securitizations	$	72		3.16	%	$	49		3.18	%
Private Education Loan securitizations		2,120		4.14			1,672		4.57
FFELP Loan ABCP facilities		2,783		2.46			2,371		3.11
Private Education Loan ABCP facilities		2,114		2.76			1,053		3.20
Senior unsecured debt		1,056		6.42			1,492		7.05
Other interest-bearing liabilities		338		1.55			307		2.16
Total short-term borrowings	$	8,483		3.42	%	$	6,944		4.28	%
Maximum outstanding at any month end	$	8,564

	December 31, 2018					Year Ended December 31, 2018
(Dollars in millions)	Ending Balance		Weighted Average Interest Rate			Average Balance		Weighted Average Interest Rate
Private Education Loan securitizations	$	300		5.23	%	$	536		4.72	%
FFELP Loan ABCP facilities		2,927		3.10			1,137		2.79
Private Education Loan ABCP facilities		1,114		3.63			847		3.40
Senior unsecured debt		814		4.92			2,021		5.90
Other interest-bearing liabilities		267		2.39			292		1.73
Total short-term borrowings	$	5,422		3.56	%	$	4,833		4.35	%
Maximum outstanding at any month end	$	6,363

Long-Term Borrowings

The following tables summarize outstanding long-term borrowings, the weighted average interest rates at the end of the periods, and the related average balances during the periods.

	December 31, 2019
			Weighted Average			Year Ended December 31, 2019
(Dollars in millions)	Ending Balance⁽¹⁾		Interest Rate⁽²⁾			Average Balance
Floating rate notes:
U.S. dollar-denominated:
Interest bearing, due 2021-2083	$	63,731		2.66	%	$	68,664
Non-U.S. dollar-denominated:
Interest bearing, due 2023-2040		3,577		.61			4,262
Total floating rate notes		67,308		2.55			72,926
Fixed rate notes:
U.S. dollar-denominated:
Interest bearing, due 2021-2068		14,407		4.88			13,941
Non-U.S.-dollar denominated:		—		—			57
Total fixed rate notes		14,407		4.88			13,998
Total long-term borrowings	$	81,715		2.96	%	$	86,924

	December 31, 2018
			Weighted Average			Year Ended December 31, 2018
(Dollars in millions)	Ending Balance⁽¹⁾		Interest Rate⁽²⁾			Average Balance
Floating rate notes:
U.S. dollar-denominated:
Interest bearing, due 2019-2083	$	74,842		3.38	%	$	80,189
Non-U.S. dollar-denominated:
Interest bearing, due 2023-2040		4,064		.66			4,919
Total floating rate notes		78,906		3.24			85,108
Fixed rate notes:
U.S. dollar-denominated:
Interest bearing, due 2020-2059		14,431		5.57			13,814
Non-U.S.-dollar denominated:
Interest bearing, due 2034		182		2.49			273
Total fixed rate notes		14,613		5.53			14,087
Total long-term borrowings	$	93,519		3.60	%	$	99,195

⁽¹⁾

⁽²⁾

Weighted average interest rate is stated rate relative to currency denomination of debt.

Expected Maturities of Long-term Borrowings

As of December 31, 2019, the expected maturities of our long-term borrowings are shown in the following table.

	Expected Maturity
(Dollars in millions)	Senior Unsecured Debt		Secured Borrowings⁽¹⁾			Total⁽²⁾
Year of Maturity
2020	$	—	$	6,768		$	6,768
2021		1,439		8,719			10,158
2022		1,741		6,212			7,953
2023		1,501		6,014			7,515
2024		1,352		5,859			7,211
2025-2043		2,428		39,723			42,151
		8,461		73,295			81,756
Hedge accounting adjustments		398		(439	)		(41	)
Total	$	8,859	$	72,856		$	81,715

⁽¹⁾

⁽²⁾

Financing VIEs

We consolidate the following financing VIEs as of December 31, 2019 and 2018, as we are the primary beneficiary. As a result, these VIEs are accounted for as secured borrowings.

	December 31, 2019
	Debt Outstanding								Carrying Amount of Assets Securing Debt Outstanding
(Dollars in millions)	Short Term		Long Term			Total			Loans		Cash		Other Assets, Net			Total
Secured Borrowings — VIEs:
FFELP Loan securitizations	$	72	$	59,735		$	59,807		$	60,834	$	1,833	$	1,400		$	64,067
Private Education Loan securitizations		2,120		11,430			13,550			15,412		509		152			16,073
FFELP Loan ABCP facilities		2,783		617			3,400			3,421		63		102			3,586
Private Education Loan ABCP facilities		2,114		1,513			3,627			4,197		101		28			4,326
Total before hedge accounting adjustments		7,089		73,295			80,384			83,864		2,506		1,682			88,052
Hedge accounting adjustments		—		(439	)		(439	)		—		—		(593	)		(593	)
Total	$	7,089	$	72,856		$	79,945		$	83,864	$	2,506	$	1,089		$	87,459

	December 31, 2018
	Debt Outstanding								Carrying Amount of Assets Securing Debt Outstanding
(Dollars in millions)	Short Term		Long Term			Total			Loans		Cash		Other Assets, Net			Total
Secured Borrowings — VIEs:
FFELP Loan securitizations	$	—	$	66,318		$	66,318		$	66,266	$	3,181	$	1,211		$	70,658
Private Education Loan securitizations		300		12,985			13,285			16,336		536		198			17,070
FFELP Loan ABCP facilities		2,927		2,625			5,552			5,656		132		162			5,950
Private Education Loan ABCP facilities		1,114		1,266			2,380			3,361		79		27			3,467
Total before hedge accounting adjustments		4,341		83,194			87,535			91,619		3,928		1,598			97,145
Hedge accounting adjustments		—		(456	)		(456	)		—		—		(642	)		(642	)
Total	$	4,341	$	82,738		$	87,079		$	91,619	$	3,928	$	956		$	96,503

Gains (Losses) on Debt Repurchases

The following table summarizes activity related to our senior unsecured debt and ABS repurchases. “Gains (losses) on debt repurchases” is shown net of hedging-related gains and losses.

	Years Ended December 31,
(Dollars in millions)	2019		2018		2017
Debt principal repurchased	$	1,184	$	2,809	$	513
Gains (losses) on debt repurchases	$	45	$	19	$	(3	)

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 10
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-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 505
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-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net interest income	$ 294	$ 312	$ 293	$ 285	$ 307	$ 306	$ 298	$ 329	$ 1,185	$ 1,240	$ 1,412
Less: provisions for loan losses	50	64	68	76	85	85	112	87	258	370	426
Net interest income after provisions for loan losses	244	248	225	209	222	221	186	242	927	870	986
Other income	176	192	254	212	196	203	176	163
Gains (losses) on derivative and hedging activities, net	43	4	(32)	7	(48)	2	(40)	48	22	(38)	22
Operating expenses	235	251	241	256	252	255	201	275	984	984	966
Goodwill and acquired intangible asset impairment and amortization expense	6	6	11	7	8	23	6	9	30	47	23
Restructuring/other reorganization expenses	2	2	1	1	4	1	2	7	6	13	29
Income tax expense	49	40	41	36	34	33	30	36	166	133	472
Net income (loss)	$ 171	$ 145	$ 153	$ 128	$ 72	$ 114	$ 83	$ 126	$ 597	$ 395	$ 292
Basic earnings per common share	$ 0.79	$ 0.64	$ 0.65	$ 0.52	$ 0.28	$ 0.44	$ 0.31	$ 0.48	$ 2.59	$ 1.52	$ 1.06
Diluted earnings per common share	$ 0.78	$ 0.63	$ 0.64	$ 0.52	$ 0.28	$ 0.43	$ 0.31	$ 0.47	$ 2.56	$ 1.49	$ 1.04

Allowance for Loan Losses

12 Months Ended

Dec. 31, 2019

Receivables [Abstract]

Allowance for Loan Losses

4. Allowance for Loan Losses

Our provisions for loan losses represent the periodic expense of maintaining an allowance sufficient to absorb incurred probable losses, net of expected recoveries, in the held-for-investment loan portfolios. The evaluation of the provisions for loan losses is inherently subjective, as it requires material estimates that may be susceptible to significant changes. We segregate our Private Education Loan portfolio in two classes of loans in monitoring and assessing credit risk — Troubled Debt Restructurings (“TDRs”) and Non-TDRs. We believe that the allowance for loan losses is appropriate to cover probable losses incurred in the loan portfolios.

4. Allowance for Loan Losses (Continued)

Allowance for Loan Losses Metrics

	Year Ended December 31, 2019
(Dollars in millions)	FFELP Loans			Private Education Loans			Other Loans			Total
Allowance for Loan Losses
Beginning balance	$	76		$	1,201		$	9		$	1,286
Total provision		30			226			1			258
Net adjustment resulting from the change in the charge-off rate⁽¹⁾		—			(21	)		—			(21	)
Net charge-offs remaining⁽²⁾		(42	)		(364	)		(2	)		(408	)
Total net charge-offs		(42	)		(385	)		(2	)		(429	)
Reclassification of interest reserve⁽³⁾		—			7			—			7
Loan sales		—			(1	)		(8	)		(9	)
Ending balance	$	64		$	1,048		$	—		$	1,112
Allowance Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	941		$	—		$	941
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		64			107			—			171
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		—			—			—			—
Purchased Credit Impaired Loans⁽⁴⁾		—			—			—			—
Ending total allowance	$	64		$	1,048		$	—		$	1,112
Loans Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	9,617		$	—		$	9,617
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		61,589			12,286			9			73,884
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		2,505			1,806			—			4,311
Purchased Credit Impaired Loans⁽⁴⁾		—			201			—			201
Ending total loans⁽⁵⁾	$	64,094		$	23,910		$	9		$	88,013
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate⁽¹⁾		.07	%		1.67	%		—	%
Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment⁽¹⁾		—	%		.10	%		—	%
Allowance coverage of charge-offs		1.5			2.7			—
Allowance as a percentage of the ending total loan balance		.10	%		4.38	%		—	%
Allowance as a percentage of the ending loans in repayment		.12	%		4.74	%		—	%
Ending total loans⁽⁵⁾	$	64,094		$	23,910		$	9
Average loans in repayment	$	55,978		$	21,859		$	29
Ending loans in repayment	$	53,538		$	22,089		$	9

⁽¹⁾

⁽²⁾

⁽³⁾

⁽⁴⁾

⁽⁵⁾

Ending total loans for Private Education Loans includes the receivable for partially charged-off loans.

4. Allowance for Loan Losses (Continued)

	Year Ended December 31, 2018
(Dollars in millions)	FFELP Loans			Private Education Loans			Other Loans			Total
Allowance for Loan Losses
Beginning balance	$	60		$	1,297		$	10		$	1,367
Total provision		70			299			1			370
Net adjustment resulting from the change in the charge- off rate⁽¹⁾		—			(32	)		—			(32	)
Net charge-offs remaining⁽²⁾		(54	)		(371	)		(2	)		(427	)
Total net charge-offs		(54	)		(403	)		(2	)		(459	)
Reclassification of interest reserve⁽³⁾		—			8			—			8
Ending balance	$	76		$	1,201		$	9		$	1,286
Allowance Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	1,100		$	8		$	1,108
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		76			101			1			178
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		—			—			—			—
Purchased Credit Impaired Loans⁽⁴⁾		—			—			—			—
Ending total allowance	$	76		$	1,201		$	9		$	1,286
Loans Ending Balance:
Individually evaluated for impairment — TDR	$	—		$	10,336		$	28		$	10,364
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		68,880			11,464			51			80,395
Purchased Non-Credit Impaired Loans acquired at a discount⁽⁴⁾		2,850			2,180			—			5,030
Purchased Credit Impaired Loans⁽⁴⁾		—			225			—			225
Ending total loans⁽⁵⁾	$	71,730		$	24,205		$	79		$	96,014
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate⁽¹⁾		.09	%		1.66	%		—	%
Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment⁽¹⁾		—	%		.14	%		—	%
Allowance coverage of charge-offs		1.4			3.0			—
Allowance as a percentage of the ending total loan balance		.11	%		4.96	%		11.52	%
Allowance as a percentage of the ending loans in repayment		.13	%		5.45	%		11.52	%
Ending total loans⁽⁵⁾	$	71,730		$	24,205		$	79
Average loans in repayment	$	62,927		$	22,312		$	75
Ending loans in repayment	$	59,551		$	22,037		$	79

⁽¹⁾

₍₂₎

⁽³⁾

⁽⁴⁾

The Purchased Credit Impaired Loans’ losses are not provided for by the allowance for loan losses in the above table as these loans are separately reserved for, if needed. No allowance for loan losses has been established for these loans as of December 31, 2018. The losses of the Purchased Non-Credit Impaired Loans acquired at a discount are not provided for by the allowance for loan losses in the above table as the remaining purchased discount associated with the FFELP and Private Education Loans of $37 million and $326 million respectively, as of December 31, 2018 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of December 31, 2018.

⁽⁵⁾

Ending total loans for Private Education Loans includes the receivable for partially charged-off loans.

4. Allowance for Loan Losses (Continued)

	Year Ended December 31, 2017
(Dollars in millions)	FFELP Loans			Private Education Loans			Other Loans			Total
Allowance for Loan Losses
Beginning balance	$	67		$	1,351		$	15		$	1,433
Total provision		42			382			2			426
Charge-offs⁽¹⁾		(49	)		(443	)		(7	)		(499	)
Reclassification of interest reserve⁽²⁾		—			7			—			7
Ending balance	$	60		$	1,297		$	10		$	1,367
Allowance Ending Balance:
Individually evaluated for impairment - TDR	$	—		$	1,171		$	9		$	1,180
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		60			126			1			187
Purchased Non-Credit Impaired Loans acquired at a discount⁽³⁾		—			—			—			—
Purchased Credit Impaired Loans⁽³⁾		—			—			—			—
Ending total allowance	$	60		$	1,297		$	10		$	1,367
Loans Ending Balance:
Individually evaluated for impairment - TDR	$	—		$	10,921		$	30		$	10,951
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans		77,860			11,861			40			89,761
Purchased Non-Credit Impaired Loans acquired at a discount⁽³⁾		3,237			2,610			—			5,847
Purchased Credit Impaired Loans⁽³⁾		—			248			—			248
Ending total loans⁽⁴⁾	$	81,097		$	25,640		$	70		$	106,807
Charge-offs as a percentage of average loans in repayment		.07	%		1.98	%		5.39	%
Allowance coverage of charge-offs		1.2			2.9			1.5
Allowance as a percentage of the ending total loan balance		.07	%		5.06	%		14.32	%
Allowance as a percentage of the ending loans in repayment		.09	%		5.66	%		14.32	%
Ending total loans⁽⁴⁾	$	81,097		$	25,640		$	70
Average loans in repayment	$	68,318		$	22,342		$	130
Ending loans in repayment	$	67,853		$	22,924		$	70

⁽¹⁾

⁽²⁾

⁽³⁾

The Purchased Credit Impaired Loans’ losses are not provided for by the allowance for loan losses in the above table as these loans are separately reserved for, if needed. No allowance for loan losses has been established for these loans as of December 31, 2017. The losses of the Purchased Non-Credit Impaired Loans acquired at a discount are not provided for by the allowance for loan losses in the above table as the remaining purchased discount associated with the FFELP and Private Education Loans of $43 million and $392 million, respectively, as of December 31, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of December 31, 2017.

⁽⁴⁾

Ending total loans for Private Education Loans includes the receivable for partially charged-off loans.

4. Allowance for Loan Losses (Continued)

Key Credit Quality Indicators

FFELP Loans are substantially insured and guaranteed as to their principal and accrued interest in the event of default. The key credit quality indicator for this portfolio is loan status. The impact of changes in loan status is incorporated quarterly into the allowance for loan losses calculation.

	FFELP Loan Delinquencies
	December 31, 2019						December 31, 2018						December 31, 2017
(Dollars in millions)	Balance			%			Balance			%			Balance			%
Loans in-school/grace/deferment⁽¹⁾	$	3,114					$	3,793					$	4,711
Loans in forbearance⁽²⁾		7,442						8,386						8,533
Loans in repayment and percentage of each status:
Loans current		47,255			88.3	%		53,500			89.8	%		59,264			87.3	%
Loans delinquent 31-60 days⁽³⁾		2,094			3.9			1,964			3.4			2,638			3.9
Loans delinquent 61-90 days⁽³⁾		1,082			2.0			910			1.5			1,763			2.6
Loans delinquent greater than 90 days⁽³⁾		3,107			5.8			3,177			5.3			4,188			6.2
Total FFELP Loans in repayment		53,538			100	%		59,551			100	%		67,853			100	%
Total FFELP Loans, gross		64,094						71,730						81,097
FFELP Loan unamortized premium		545						599						666
Total FFELP Loans		64,639						72,329						81,763
FFELP Loan allowance for losses		(64	)					(76	)					(60	)
FFELP Loans, net	$	64,575					$	72,253					$	81,703
Percentage of FFELP Loans in repayment					83.5	%					83.0	%					83.7	%
Delinquencies as a percentage of FFELP Loans in repayment					11.7	%					10.2	%					12.7	%
FFELP Loans in forbearance as a percentage of loans in repayment and forbearance					12.2	%					12.3	%					11.2	%

⁽¹⁾

⁽²⁾	Loans for customers who have used their allowable deferment time or do not qualify for deferment, that need additional time to obtain employment or who have temporarily ceased making full payments due to hardship or other factors such as disaster relief.

⁽³⁾	The period of delinquency is based on the number of days scheduled payments are contractually past due.

4. Allowance for Loan Losses (Continued)

For Private Education Loans, the key credit quality indicators are FICO scores, school type, the existence of a cosigner, the loan status and loan seasoning. The FICO scores and school type are assessed at origination. The other Private Education Loan key quality indicators can change and are incorporated quarterly into the allowance for loan losses calculation. The following table highlights the principal balance (excluding the receivable for partially charged-off loans) of our Private Education Loan portfolio stratified by the key credit quality indicators.

	Private Education Loans Credit Quality Indicators
	TDRs
	December 31, 2019					December 31, 2018
(Dollars in millions)	Balance⁽³⁾		% of Balance			Balance⁽³⁾		% of Balance
Credit Quality Indicators
Original Winning FICO Scores:
FICO 640 and above	$	8,493		92	%	$	9,133		92	%
FICO below 640		777		8			836		8
Total	$	9,270		100	%	$	9,969		100	%
School Type:
Not-for-profit	$	7,387		80	%	$	7,888		79	%
For-profit		1,883		20			2,081		21
Total	$	9,270		100	%	$	9,969		100	%
Cosigners:
With cosigner⁽¹⁾	$	5,792		62	%	$	6,172		62	%
Without cosigner		3,478		38			3,797		38
Total	$	9,270		100	%	$	9,969		100	%
Seasoning⁽²⁾:
1-12 payments	$	224		3	%	$	335		3	%
13-24 payments		301		3			436		4
25-36 payments		472		5			660		7
37-48 payments		662		7			934		10
More than 48 payments		7,262		78			7,178		72
Not yet in repayment		349		4			426		4
Total	$	9,270		100	%	$	9,969		100	%

⁽¹⁾

Excluding Private Education Refinance Loans, which do not have a cosigner, the cosigner rate was 63% and 62% at December 31, 2019 and 2018, respectively.

⁽²⁾

Number of months in active repayment for which a scheduled payment was received.

⁽³⁾

Balance equals the gross Private Education Loans.

4. Allowance for Loan Losses (Continued)

	Private Education Loans Credit Quality Indicators
	Non-TDRs
	December 31, 2019					December 31, 2018
(Dollars in millions)	Balance⁽³⁾		% of Balance			Balance⁽³⁾		% of Balance
Credit Quality Indicators
Original Winning FICO Scores:
FICO 640 and above	$	13,687		97	%	$	13,087		96	%
FICO below 640		365		3			475		4
Total	$	14,052		100	%	$	13,562		100	%
School Type:
Not-for-profit	$	12,614		90	%	$	11,953		88	%
For-profit		1,438		10			1,609		12
Total	$	14,052		100	%	$	13,562		100	%
Cosigners:
With cosigner⁽¹⁾	$	5,184		37	%	$	6,961		51	%
Without cosigner		8,868		63			6,601		49
Total	$	14,052		100	%	$	13,562		100	%
Seasoning⁽²⁾:
1-12 payments	$	4,673		33	%	$	3,353		25	%
13-24 payments		1,570		11			486		3
25-36 payments		603		4			322		2
37-48 payments		251		2			383		3
More than 48 payments		6,675		48			8,626		64
Not yet in repayment		280		2			392		3
Total	$	14,052		100	%	$	13,562		100	%

⁽¹⁾

Excluding Private Education Refinance Loans, which do not have a cosigner, the cosigner rate was 67% at December 31, 2019 and 2018.

⁽²⁾

Number of months in active repayment for which a scheduled payment was received.

⁽³⁾

^{Balance equals the gross Private Education Loans.}

4. Allowance for Loan Losses (Continued)

	Private Education Loan Delinquencies
	TDRs
	December 31, 2019						December 31, 2018						December 31, 2017
(Dollars in millions)	Balance			%			Balance			%			Balance			%
Loans in-school/grace/deferment⁽¹⁾	$	349					$	426					$	477
Loans in forbearance⁽²⁾		479						518						681
Loans in repayment and percentage of each status:
Loans current		7,557			89.5	%		7,890			87.4	%		8,333			88.9	%
Loans delinquent 31-60 days⁽³⁾		296			3.5			344			3.8			351			3.7
Loans delinquent 61-90 days⁽³⁾		191			2.3			235			2.6			207			2.2
Loans delinquent greater than 90 days⁽³⁾		398			4.7			556			6.2			487			5.2
Total TDR loans in repayment		8,442			100	%		9,025			100	%		9,378			100	%
Total TDR loans, gross		9,270						9,969						10,536
TDR loans unamortized discount		(203	)					(212	)					(225	)
Total TDR loans		9,067						9,757						10,311
TDR loans receivable for partially charged-off loans		347						367						385
TDR loans allowance for losses		(941	)					(1,100	)					(1,171	)
TDR loans, net	$	8,473					$	9,024					$	9,525
Percentage of TDR loans in repayment					91.1	%					90.5	%					89.0	%
Delinquencies as a percentage of TDR loans in repayment					10.5	%					12.6	%					11.1	%
Loans in forbearance as a percentage of TDR loans in repayment and forbearance					5.4	%					5.4	%					6.8	%

⁽¹⁾	Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not yet required to make payments on their loans, e.g., residency periods for medical students or a grace period for bar exam preparation.

⁽²⁾	Loans for customers who have requested extension of grace period generally during employment transition or who have temporarily ceased making full payments due to hardship or other factors such as disaster relief, consistent with established loan program servicing policies and procedures.

⁽³⁾	The period of delinquency is based on the number of days scheduled payments are contractually past due.

4. Allowance for Loan Losses (Continued)

	Private Education Loan Delinquencies
	Non-TDRs
	December 31, 2019						December 31, 2018						December 31, 2017
(Dollars in millions)	Balance			%			Balance			%			Balance			%
Loans in-school/grace/deferment⁽¹⁾	$	280					$	392					$	584
Loans in forbearance⁽²⁾		125						158						214
Loans in repayment and percentage of each status:
Loans current		13,526			99.1	%		12,851			98.8	%		13,257			97.9	%
Loans delinquent 31-60 days⁽³⁾		53			.4			71			.5			120			.9
Loans delinquent 61-90 days⁽³⁾		27			.2			32			.3			59			.4
Loans delinquent greater than 90 days⁽³⁾		41			.3			58			.4			110			.8
Total non-TDR loans in repayment		13,647			100	%		13,012			100	%		13,546			100	%
Total non-TDR loans, gross		14,052						13,562						14,344
Non-TDR loans unamortized discount		(414	)					(547	)					(699	)
Total non-TDR loans		13,638						13,015						13,645
Non-TDR loans receivable for partially charged-off loans		241						307						375
Non-TDR loans allowance for losses		(107	)					(101	)					(126	)
Non-TDR loans, net	$	13,772					$	13,221					$	13,894
Percentage of non-TDR loans in repayment					97.1	%					95.9	%					94.4	%
Delinquencies as a percentage of non-TDR loans in repayment					.9	%					1.2	%					2.1	%
Loans in forbearance as a percentage of non- TDR loans in repayment and forbearance					.9	%					1.2	%					1.6	%

⁽¹⁾	Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not yet required to make payments on their loans, e.g., residency periods for medical students or a grace period for bar exam preparation.

⁽²⁾	Loans for customers who have requested extension of grace period generally during employment transition or who have temporarily ceased making full payments due to hardship or other factors such as disaster relief, consistent with established loan program servicing policies and procedures.

⁽³⁾	The period of delinquency is based on the number of days scheduled payments are contractually past due.

Receivable for Partially Charged-Off Private Education Loans

At the end of each month, for loans that are 212 or more days past due, we charge off the estimated loss of a defaulted loan balance. Actual recoveries are applied against the remaining loan balance that was not charged off. We refer to this remaining loan balance as the “receivable for partially charged-off loans.” If actual periodic recoveries are less than expected, the difference is immediately charged off through the allowance for Private Education Loan losses with an offsetting reduction in the receivable for partially charged-off Private Education Loans. If actual periodic recoveries are greater than expected, they will be reflected as a recovery through the allowance for Private Education Loan losses once the cumulative recovery amount exceeds the cumulative amount originally expected to be recovered.

4. Allowance for Loan Losses (Continued)

The following table summarizes the activity in the receivable for partially charged-off loans.

	Years Ended December 31,
(Dollars in millions)	2019			2018			2017
Receivable at beginning of period	$	674		$	760		$	815
Expected future recoveries of current period defaults⁽¹⁾		74			89			110
Recoveries⁽²⁾		(126	)		(139	)		(155	)
Charge-offs⁽³⁾		(34	)		(36	)		(10	)
Receivable at end of period	$	588		$	674		$	760

⁽¹⁾

Represents our estimate of the amount to be collected in the future.

⁽²⁾

Current period cash collections.

⁽³⁾

Troubled Debt Restructurings (“TDRs”)

We sometimes modify the terms of loans for customers experiencing financial difficulty. Where we have granted either a forbearance of greater than three months, an interest rate reduction or an extended repayment plan, these are classified as TDRs. Approximately 69% and 65% of the loans granted forbearance have qualified as a TDR loan at December 31, 2019 and 2018, respectively. The unpaid principal balance of TDR loans that were in an interest rate reduction plan as of December 31, 2019 and 2018 was $1.7 billion and $1.8 billion, respectively.

At December 31, 2019 and 2018, all of our TDR loans had a related allowance recorded. The following table provides the recorded investment, unpaid principal balance and related allowance for our TDR loans.

	TDRs
(Dollars in millions)	December 31, 2019		December 31, 2018
Recorded investment⁽¹⁾	$	9,594	$	10,326
Total ending loans⁽²⁾	$	9,617	$	10,336
Related allowance	$	941	$	1,100

⁽¹⁾

Recorded investment is equal to the unpaid principal balance (which includes the receivable for partially charged-off loans), accrued interest and unamortized discount.

⁽²⁾

Total ending loans includes the receivable for partially charged-off loans.

4. Allowance for Loan Losses (Continued)

The following table provides the average recorded investment and interest income recognized for our TDR loans.

	Years Ended December 31,
(Dollars in millions)	2019		2018		2017
Average recorded investment	$	9,965	$	10,637	$	10,989
Interest income recognized	$	770	$	764	$	708

	Years Ended December 31,
(Dollars in millions)	2019		2018		2017
Modified loans⁽¹⁾	$	475	$	596	$	816
Charge-offs⁽²⁾	$	324	$	343	$	346
Payment-default	$	109	$	142	$	181

⁽¹⁾	Represents period ending balance of loans that have been modified during the period and resulted in a TDR.

⁽²⁾	Represents loans that charged off that were classified as TDRs.

Accrued Interest Receivable

The following table provides information regarding accrued interest receivable on our Private Education Loans.

(Dollars in millions)	Total		Greater Than 90 Days Past Due		Allowance for Uncollectible Interest
December 31, 2019
TDR	$	182	$	18	$	18
Non-TDR		115		2		4
Total	$	297	$	20	$	22
December 31, 2018
TDR	$	205	$	26	$	23
Non-TDR		149		3		4
Total	$	354	$	29	$	27
December 31, 2017
TDR	$	196	$	20	$	20
Non-TDR		187		4		6
Total	$	383	$	24	$	26

Education Loans - Additional Information (Detail)	12 Months Ended
Education Loans - Additional Information (Detail)	Dec. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Percentage of education loan portfolio in repayment	87.00%	86.00%
After October 1 1993 and before July 1 2006 [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Percentage reimbursement on all qualifying default claims period	98.00%
On or After July 1 2006 [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Percentage reimbursement on all qualifying default claims period	97.00%
Weighted Average [Member]
Accounts Notes And Loans Receivable [Line Items]
Estimated weighted average life of education loans	6 years	6 years
Stafford Loans [Member] \| Minimum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	5 years
Stafford Loans [Member] \| Maximum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	10 years
Plus Loans [Member] \| Minimum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	5 years
Plus Loans [Member] \| Maximum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	10 years
Consolidation Loans [Member] \| Minimum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	12 years
Consolidation Loans [Member] \| Maximum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	30 years
Private Education Loans [Member] \| Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	10 years
Private Education Loans [Member] \| Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term	15 years

Fair Value Measurements - Valuation of Financial Instruments that are Marked-to-Market on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 230	$ 179
Derivative liabilities	(664)	(801)
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	230	173
Derivative liabilities	(20)	(79)
Cross-Currency Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		6
Derivative liabilities	(575)	(665)
Floor Income Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(68)	(53)
Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(1)	(4)
Fair Value Measurements Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	230	179
Total	230	179
Derivative liabilities	(664)	(801)
Total	(664)	(801)
Fair Value Measurements Recurring [Member] \| Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	227	171
Total	227	171
Derivative liabilities	(68)	(129)
Total	(68)	(129)
Fair Value Measurements Recurring [Member] \| Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	3	8
Total	3	8
Derivative liabilities	(596)	(672)
Total	(596)	(672)
Fair Value Measurements Recurring [Member] \| Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	230	173
Derivative liabilities	(20)	(79)
Fair Value Measurements Recurring [Member] \| Interest Rate Swaps [Member] \| Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	227	171
Derivative liabilities		(50)
Fair Value Measurements Recurring [Member] \| Interest Rate Swaps [Member] \| Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	3	2
Derivative liabilities	(20)	(29)
Fair Value Measurements Recurring [Member] \| Cross-Currency Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		6
Derivative liabilities	(575)	(665)
Fair Value Measurements Recurring [Member] \| Cross-Currency Interest Rate Swaps [Member] \| Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		(26)
Fair Value Measurements Recurring [Member] \| Cross-Currency Interest Rate Swaps [Member] \| Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		6
Derivative liabilities	(575)	(639)
Fair Value Measurements Recurring [Member] \| Floor Income Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(68)	(53)
Fair Value Measurements Recurring [Member] \| Floor Income Contracts [Member] \| Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(68)	(53)
Fair Value Measurements Recurring [Member] \| Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(1)	(4)
Fair Value Measurements Recurring [Member] \| Other [Member] \| Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	$ (1)	$ (4)

Derivative Financial Instruments - Derivative Notional Values (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Total Derivative Notional Values	$ 104,400,000,000	$ 131,400,000,000
Designated as Hedging Instrument [Member] \| Cash Flow [Member]
Derivative [Line Items]
Total Derivative Notional Values	19,100,000,000	21,400,000,000
Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	12,600,000,000	14,800,000,000
Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	72,700,000,000	95,200,000,000
Interest Rate Swaps [Member]
Derivative [Line Items]
Total Derivative Notional Values	79,200,000,000	98,600,000,000
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow [Member]
Derivative [Line Items]
Total Derivative Notional Values	19,100,000,000	21,400,000,000
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	8,600,000,000	10,300,000,000
Interest Rate Swaps [Member] \| Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	51,500,000,000	66,900,000,000
Floor Income Contracts [Member]
Derivative [Line Items]
Total Derivative Notional Values	21,200,000,000	27,900,000,000
Floor Income Contracts [Member] \| Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	21,200,000,000	27,900,000,000
Cross-Currency Interest Rate Swaps [Member]
Derivative [Line Items]
Total Derivative Notional Values	4,000,000,000.0	4,700,000,000
Cross-Currency Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	$ 4,000,000,000.0	4,500,000,000
Cross-Currency Interest Rate Swaps [Member] \| Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values		200,000,000
Other [Member]
Derivative [Line Items]
Total Derivative Notional Values		200,000,000
Other [Member] \| Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values		$ 200,000,000

Stock-Based Compensation Plans and Arrangements - Restricted Stock and Performance Stock Unit Activity (Detail)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Restricted Stock Units and Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Non-vested, beginning balance \| shares	4,259,771
Granted, Shares \| shares	2,096,830
Vested, Shares \| shares	(2,336,927)
Canceled, Shares \| shares	(80,053)
Number of Shares, Non-vested, ending balance \| shares	3,939,621
Weighted Average Grant Date Fair Value, Non-vested, beginning balance \| $ / shares	$ 12.55
Granted, Weighted Average Grant Date Fair Value \| $ / shares	10.95
Vested, Weighted Average Grant Date Fair Value \| $ / shares	11.14
Canceled, Weighted Average Grant Date Fair Value \| $ / shares	12.96
Weighted Average Grant Date Fair Value, Non-vested, ending balance \| $ / shares	$ 12.52
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Shares \| shares	78,835
Vested, Shares \| shares	(78,835)
Granted, Weighted Average Grant Date Fair Value \| $ / shares	$ 11.72
Vested, Weighted Average Grant Date Fair Value \| $ / shares	$ 11.72

Derivative Financial Instruments - Impact of Derivatives on Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative Assets:
Derivative assets	$ 230	$ 179
Derivative Liabilities:
Derivative liabilities	(664)	(801)
Net total derivatives	(434)	(622)
Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative Assets:
Derivative assets	226	176
Derivative Liabilities:
Derivative liabilities	(575)	(673)
Net total derivatives	(349)	(497)
Trading [Member]
Derivative Assets:
Derivative assets	4	3
Derivative Liabilities:
Derivative liabilities	(89)	(128)
Net total derivatives	(85)	(125)
Interest Rate Swaps [Member]
Derivative Assets:
Derivative assets	230	173
Derivative Liabilities:
Derivative liabilities	(20)	(79)
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative Assets:
Derivative assets	226	170
Derivative Liabilities:
Derivative liabilities		(34)
Interest Rate Swaps [Member] \| Trading [Member]
Derivative Assets:
Derivative assets	4	3
Derivative Liabilities:
Derivative liabilities	(20)	(45)
Cross-Currency Interest Rate Swaps [Member]
Derivative Assets:
Derivative assets		6
Derivative Liabilities:
Derivative liabilities	(575)	(665)
Cross-Currency Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative Assets:
Derivative assets		6
Derivative Liabilities:
Derivative liabilities	(575)	(639)
Cross-Currency Interest Rate Swaps [Member] \| Trading [Member]
Derivative Liabilities:
Derivative liabilities		(26)
Floor Income Contracts [Member]
Derivative Liabilities:
Derivative liabilities	(68)	(53)
Floor Income Contracts [Member] \| Trading [Member]
Derivative Liabilities:
Derivative liabilities	(68)	(53)
Other [Member]
Derivative Liabilities:
Derivative liabilities	(1)	(4)
Other [Member] \| Trading [Member]
Derivative Liabilities:
Derivative liabilities	$ (1)	$ (4)

Allowance for Loan Losses - Private Education Loan Portfolio Stratified by Key Credit Quality Indicators (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
With Cosigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	67.00%	67.00%
Private Education Loans - TDRs [Member] \| With Cosigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	63.00%	62.00%
Private Education Loans - TDRs [Member] \| Original Winning FICO Scores [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 9,270	$ 9,969
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - TDRs [Member] \| Original Winning FICO Scores [Member] \| FICO 640 and Above [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 8,493	$ 9,133
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	92.00%	92.00%
Private Education Loans - TDRs [Member] \| Original Winning FICO Scores [Member] \| FICO Below 640 [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 777	$ 836
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	8.00%	8.00%
Private Education Loans - TDRs [Member] \| School Type [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 9,270	$ 9,969
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - TDRs [Member] \| School Type [Member] \| Not For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 7,387	$ 7,888
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	80.00%	79.00%
Private Education Loans - TDRs [Member] \| School Type [Member] \| For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 1,883	$ 2,081
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	20.00%	21.00%
Private Education Loans - TDRs [Member] \| Cosigners [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 9,270	$ 9,969
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - TDRs [Member] \| Cosigners [Member] \| With Cosigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 5,792	$ 6,172
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	62.00%	62.00%
Private Education Loans - TDRs [Member] \| Cosigners [Member] \| Without Consigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 3,478	$ 3,797
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	38.00%	38.00%
Private Education Loans - TDRs [Member] \| Seasoning [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 9,270	$ 9,969
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - TDRs [Member] \| Seasoning [Member] \| 1-12 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 224	$ 335
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	3.00%	3.00%
Private Education Loans - TDRs [Member] \| Seasoning [Member] \| 13-24 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 301	$ 436
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	3.00%	4.00%
Private Education Loans - TDRs [Member] \| Seasoning [Member] \| 25-36 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 472	$ 660
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	5.00%	7.00%
Private Education Loans - TDRs [Member] \| Seasoning [Member] \| 37-48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 662	$ 934
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	7.00%	10.00%
Private Education Loans - TDRs [Member] \| Seasoning [Member] \| More than 48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 7,262	$ 7,178
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	78.00%	72.00%
Private Education Loans - TDRs [Member] \| Seasoning [Member] \| Not Yet in Repayment [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 349	$ 426
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	4.00%	4.00%
Private Education Loans - Non-TDRs [Member] \| Original Winning FICO Scores [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,052	$ 13,562
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - Non-TDRs [Member] \| Original Winning FICO Scores [Member] \| FICO 640 and Above [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 13,687	$ 13,087
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	97.00%	96.00%
Private Education Loans - Non-TDRs [Member] \| Original Winning FICO Scores [Member] \| FICO Below 640 [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 365	$ 475
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	3.00%	4.00%
Private Education Loans - Non-TDRs [Member] \| School Type [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,052	$ 13,562
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - Non-TDRs [Member] \| School Type [Member] \| Not For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 12,614	$ 11,953
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	90.00%	88.00%
Private Education Loans - Non-TDRs [Member] \| School Type [Member] \| For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 1,438	$ 1,609
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	10.00%	12.00%
Private Education Loans - Non-TDRs [Member] \| Cosigners [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,052	$ 13,562
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - Non-TDRs [Member] \| Cosigners [Member] \| With Cosigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 5,184	$ 6,961
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	37.00%	51.00%
Private Education Loans - Non-TDRs [Member] \| Cosigners [Member] \| Without Consigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 8,868	$ 6,601
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	63.00%	49.00%
Private Education Loans - Non-TDRs [Member] \| Seasoning [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,052	$ 13,562
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	100.00%	100.00%
Private Education Loans - Non-TDRs [Member] \| Seasoning [Member] \| 1-12 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 4,673	$ 3,353
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	33.00%	25.00%
Private Education Loans - Non-TDRs [Member] \| Seasoning [Member] \| 13-24 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 1,570	$ 486
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	11.00%	3.00%
Private Education Loans - Non-TDRs [Member] \| Seasoning [Member] \| 25-36 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 603	$ 322
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	4.00%	2.00%
Private Education Loans - Non-TDRs [Member] \| Seasoning [Member] \| 37-48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 251	$ 383
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	2.00%	3.00%
Private Education Loans - Non-TDRs [Member] \| Seasoning [Member] \| More than 48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 6,675	$ 8,626
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	48.00%	64.00%
Private Education Loans - Non-TDRs [Member] \| Seasoning [Member] \| Not Yet in Repayment [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 280	$ 392
Total Private Education Loan Credit Quality Indicators, Excluding Refinance Loans, Percent	2.00%	3.00%