Navient (NAVI) 10-Q 2 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2018shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	NAVI
Entity Registrant Name	NAVIENT CORP
Entity Central Index Key	1,593,538
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	257,966,088

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Investments
Available-for-sale	$ 2	$ 2
Other	294	386
Total investments	296	388
Cash and cash equivalents	2,143	1,518
Restricted cash and cash equivalents	3,105	3,128
Goodwill and acquired intangible assets, net	792	810
Other assets	3,453	4,025
Total assets	106,493	114,991
Liabilities
Short-term borrowings	5,007	4,771
Long-term borrowings	96,089	105,012
Other liabilities	1,642	1,723
Total liabilities	102,738	111,506
Commitments and contingencies
Equity
Common stock, par value $0.01 per share, 1.125 billion shares authorized: 445 million and 440 million shares issued, respectively	4	4
Additional paid-in capital	3,142	3,077
Accumulated other comprehensive income (net of tax expense of $72 and $36, respectively)	227	61
Retained earnings	3,186	3,004
Total Navient Corporation stockholders’ equity before treasury stock	6,559	6,146
Less: Common stock held in treasury at cost: 187 million and 177 million shares, respectively	(2,835)	(2,692)
Total Navient Corporation stockholders’ equity	3,724	3,454
Noncontrolling interest	31	31
Total equity	3,755	3,485
Total liabilities and equity	106,493	114,991
FFELP Loans [Member]
Assets
Loans, net	74,257	81,703
Private Education Loans [Member]
Assets
Loans, net	22,447	23,419
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Assets
Loans, net	93,389	98,596
Investments
Restricted cash	3,054	3,091
Other assets, net	1,025	1,160
Liabilities
Short-term borrowings	2,648	2,906
Long-term borrowings	85,107	89,317
Net assets of consolidated variable interest entities	9,713	10,624
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | FFELP Loans [Member]
Assets
Loans, net	73,480	77,710
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | Private Education Loans [Member]
Assets
Loans, net	$ 19,909	$ 20,886

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Allowance for loans losses	$ 1,315	$ 1,367
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,125,000,000	1,125,000,000
Common stock, shares issued	445,000,000	440,000,000
Tax expense for accumulated other comprehensive income	$ 72	$ 36
Common stock held in treasury	187,000,000	177,000,000
FFELP Loans [Member]
Allowance for loans losses	$ 79	$ 60
Private Education Loans [Member]
Allowance for loans losses	$ 1,226	$ 1,297

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
Cash and investments	$ 26	$ 12	$ 66	$ 29
Total interest income	1,241	1,140	3,639	3,224
Total interest expense	935	785	2,707	2,178
Net interest income	306	355	932	1,046
Less: provisions for loan losses	85	105	284	317
Net interest income after provisions for loan losses	221	250	648	729
Other income (loss):
Servicing revenue	86		263
Asset recovery and business processing revenue	106	157	313	367
Other income (loss)	28	4	29	3
Gains on sales of loans and investments		3		3
Losses on debt repurchases	(1)	(1)	(9)	(1)
Gains (losses) on derivative and hedging activities, net	2	25	10	(16)
Total other income	205	263	553	577
Expenses:
Salaries and benefits	121	128	380	381
Other operating expenses	134	110	351	326
Total operating expenses	255	238	731	707
Goodwill and acquired intangible asset impairment and amortization expense	23	6	39	17
Restructuring/other reorganization expenses	1		10
Total expenses	279	244	780	724
Income before income tax expense	147	269	421	582
Income tax expense	33	93	98	206
Net income attributable to Navient Corporation	$ 114	$ 176	$ 323	$ 376
Basic earnings per common share attributable to Navient Corporation	$ 0.44	$ 0.65	$ 1.23	$ 1.35
Average common shares outstanding	260	269	263	279
Diluted earnings per common share attributable to Navient Corporation	$ 0.43	$ 0.64	$ 1.21	$ 1.32
Average common and common equivalent shares outstanding	264	274	267	285
Dividends per common share attributable to Navient Corporation	$ 0.16	$ 0.16	$ 0.48	$ 0.48
FFELP Loans [Member]
Interest income:
Total interest income	$ 759	$ 681	$ 2,242	$ 1,979
Less: provisions for loan losses	10	10	60	30
Private Education Loans [Member]
Interest income:
Total interest income	455	445	1,327	1,204
Less: provisions for loan losses	75	95	224	285
Other Loans [Member]
Interest income:
Total interest income	1	2	4	12
Servicing Revenue [Member]
Other income (loss):
Servicing revenue	$ 70	$ 75	$ 210	$ 221

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 114	$ 176	$ 323	$ 376
Other comprehensive income:
Gains on derivatives	32	15	205	16
Reclassification adjustments for derivative (gains) losses included in net income (interest expense)	(1)		(2)
Total gains on derivatives	31	15	203	16
Income tax expense	(7)	(6)	(50)	(6)
Other comprehensive income, net of tax expense	24	9	153	10
Total comprehensive income attributable to Navient Corporation	$ 138	$ 185	$ 476	$ 386

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - 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	376												376	376
Other comprehensive income (loss), net of tax	10											10		10
Total comprehensive income	386													386
Cash dividends:
Common stock	(133)												(133)	(133)
Dividend equivalent units related to employee stock-based compensation plans	(3)												(3)	(3)
Issuance of common shares	$ 19										19			19
Issuance of common shares, Shares	3,535,988			3,535,988				3,535,988
Stock-based compensation expense	$ 26										26			26
Repurchase of common stock:
Common stock repurchased	(440)				$ (440)			$ (440)						(440)
Common stock repurchased, Shares					(29,646,374)			(29,646,374)
Shares repurchased related to employee stock-based compensation plans	$ (28)				$ (28)									(28)
Shares repurchased related to employee stock-based compensation plans, Shares	(1,741,529)				(1,741,529)			(1,741,529)
Ending Balance, Value at Sep. 30, 2017	$ 3,550			$ 4	$ (2,691)						3,067	16	3,130	3,526			24
Ending Balance, Shares at Sep. 30, 2017				439,573,654	(176,561,451)			263,012,203
Beginning Balance, Value at Jun. 30, 2017	3,564			$ 4	$ (2,524)						3,056	7	2,997	3,540			24
Beginning Balance, Shares at Jun. 30, 2017				439,187,978	(165,083,710)			274,104,268
Comprehensive income:
Net income	176												176	176
Other comprehensive income (loss), net of tax	9											9		9
Total comprehensive income	185													185
Cash dividends:
Common stock	(43)												(43)	(43)
Issuance of common shares	$ 4										4			4
Issuance of common shares, Shares	385,676			385,676				385,676
Stock-based compensation expense	$ 7										7			7
Repurchase of common stock:
Common stock repurchased	(165)				$ (165)									(165)
Common stock repurchased, Shares					(11,346,367)			(11,346,367)
Shares repurchased related to employee stock-based compensation plans	$ (2)				$ (2)									(2)
Shares repurchased related to employee stock-based compensation plans, Shares	(131,374)				(131,374)			(131,374)
Ending Balance, Value at Sep. 30, 2017	$ 3,550			$ 4	$ (2,691)						3,067	16	3,130	3,526			24
Ending Balance, Shares at Sep. 30, 2017				439,573,654	(176,561,451)			263,012,203
Beginning Balance, Value at Dec. 31, 2017	3,485			$ 4	$ (2,692)						3,077	61	3,004	3,454			31
Beginning Balance, Shares at Dec. 31, 2017				439,718,145	(176,667,573)			263,050,572
Comprehensive income:
Net income	323												323	323
Other comprehensive income (loss), net of tax	153											153		153
Total comprehensive income	476													476
Cash dividends:
Common stock	(126)												(126)	(126)
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	5,529,853			5,529,853				5,529,853
Stock-based compensation expense	$ 22										22			22
Repurchase of common stock:
Common stock repurchased		$ (35)	$ (60)			$ (35)	$ (60)	$ (95)							$ (35)	$ (60)
Common stock repurchased, Shares						(2,569,400)	(4,312,192)	(6,881,592)	(2,569,400)	(4,312,192)
(Gain)/loss on settlement	4				$ 4									4
Shares repurchased related to employee stock-based compensation plans	$ (52)				$ (52)									(52)
Shares repurchased related to employee stock-based compensation plans, Shares	(3,732,745)				(3,732,745)			(3,732,745)
Reclassification from adoption of ASU No. 2018-02	$ (13)											13	(13)
Ending Balance, Value at Sep. 30, 2018	3,755			$ 4	$ (2,835)						3,142	227	3,186	3,724			31
Ending Balance, Shares at Sep. 30, 2018				445,247,998	(187,281,910)			257,966,088
Beginning Balance, Value at Jun. 30, 2018	3,745			$ 4	$ (2,741)						3,134	203	3,114	3,714			31
Beginning Balance, Shares at Jun. 30, 2018				444,852,383	(180,225,077)			264,627,306
Comprehensive income:
Net income	114												114	114
Other comprehensive income (loss), net of tax	24											24		24
Total comprehensive income	138													138
Cash dividends:
Common stock	(42)												(42)	(42)
Issuance of common shares	$ 4										4			4
Issuance of common shares, Shares	395,615			395,615				395,615
Stock-based compensation expense	$ 4										4			4
Repurchase of common stock:
Common stock repurchased		$ (35)	$ (60)			$ (35)	$ (60)	$ (95)							$ (35)	$ (60)
Common stock repurchased, Shares						(2,569,400)	(4,312,192)	(6,881,592)	(2,569,400)	(4,312,192)
(Gain)/loss on settlement	4				$ 4									4
Shares repurchased related to employee stock-based compensation plans	$ (3)				$ (3)									(3)
Shares repurchased related to employee stock-based compensation plans, Shares	(175,241)				(175,241)			(175,241)
Ending Balance, Value at Sep. 30, 2018	$ 3,755			$ 4	$ (2,835)						$ 3,142	$ 227	$ 3,186	$ 3,724			$ 31
Ending Balance, Shares at Sep. 30, 2018				445,247,998	(187,281,910)			257,966,088

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Dividends per common share attributable to Navient Corporation	$ 0.16	$ 0.16	$ 0.48	$ 0.48
Retained Earnings [Member]
Dividends per common share attributable to Navient Corporation	0.16	0.16	0.48	0.48
Total Stockholders' Equity [Member]
Dividends per common share attributable to Navient Corporation	$ 0.16	$ 0.16	$ 0.48	$ 0.48

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating activities
Net income	$ 114	$ 176	$ 323	$ 376
Adjustments to reconcile net income to net cash provided by operating activities:
(Gains) on sales of loans and investments		(3)		(3)
Losses on debt repurchases	1	1	9	1
Goodwill and acquired intangible asset impairment and amortization expense	23	6	39	17
Stock-based compensation expense			22	26
Mark-to-market (gains) on derivative and hedging activities, net			(104)	(25)
Less: provisions for loan losses	85	105	284	317
(Increase) decrease in accrued interest receivable			(19)	90
Increase (decrease) in accrued interest payable			4	(33)
Decrease in other assets			194	213
(Decrease) in other liabilities			(97)	(65)
Total net cash provided by operating activities			655	914
Investing activities
Education loans acquired			(2,625)	(6,343)
Reduction of education loans:
Installment payments			10,815	11,290
Other investing activities, net			(93)	(70)
Purchases of other securities			(1)	(1)
Proceeds from sales and maturities of other securities			103	19
Purchase of subsidiaries, net of cash and restricted cash acquired				(77)
Total net cash provided by investing activities			8,199	4,818
Financing activities
Borrowings collateralized by loans in trust - issued			7,144	7,024
Borrowings collateralized by loans in trust - repaid			(10,478)	(10,929)
Long-term notes issued			495	1,353
Long-term notes repaid			(1,530)	(1,367)
Other financing activities, net			(77)	(75)
Common stock repurchased			(95)	(440)
Common dividends paid			(126)	(133)
Total net cash used in financing activities			(8,252)	(5,931)
Net increase (decrease) in cash, cash equivalents, restricted cash and restricted cash equivalents			602	(199)
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of period			4,646	4,712
Cash, cash equivalents, restricted cash and restricted cash equivalents at end of period	5,248	4,513	5,248	4,513
Cash disbursements made (refunds received) for:
Interest			2,515	2,121
Income taxes paid			55	107
Income taxes received			(3)
Reconciliation of the Consolidated Statements of Cash Flows to the Consolidated Balance Sheets:
Cash and cash equivalents	2,143	1,248	2,143	1,248
Restricted cash and restricted cash equivalents	3,105	3,265	3,105	3,265
Cash, cash equivalents, restricted cash and restricted cash equivalents at end of period	$ 5,248	$ 4,513	5,248	4,513
Noncash activity
Investing activity - Education loans				1,552
Operating activity - Other assets acquired and other liabilities assumed, net				14
Financing activity - Borrowings assumed in acquisition of education loans				1,566
Asset-backed Securities, Securitized Loans and Receivables [Member]
Financing activities
Asset-backed commercial paper conduits, net			$ (3,585)	$ (1,364)

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	1. Basis of Presentation The accompanying unaudited, consolidated financial statements of Navient have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. The consolidated financial statements include the accounts of Navient 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. In the opinion of management, all adjustments considered necessary for a fair statement of the results for the interim periods have been included. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results for the year ending December 31, 2018 or for any other period. These unaudited financial statements should be read in conjunction with the audited financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2017 (the “2017 Form 10-K”). Definitions for certain capitalized terms used but not otherwise defined in this Quarterly Report on Form 10-Q can be found in our 2017 Form 10-K. Reclassifications Certain reclassifications have been made to the balances as of and for the three and nine months ended September 30, 2017 to be consistent with classifications adopted for 2018, and had no effect on net income, total assets, or total liabilities. Recently Issued Accounting Pronouncements Effective in 2018 Revenue Recognition As of January 1, 2018, we adopted Accounting Standard Codification (“ASC”) 606, “Revenue from Contracts with Customers,” which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to its customers. The contract transaction price is allocated to each distinct contractual performance obligation and recognized as revenue at a point in time or over time when or as the good or service is provided to the customer and the performance obligation is satisfied. Generally, our performance obligations are satisfied over time. In conjunction with our implementation plan, we identified revenue streams related to asset recovery and other business processing within our Federal Education Loans and Business Processing segments that are within the scope of the new standard and reviewed related contracts. We determined there was no material change in the timing of our recognition of our asset recovery and business processing revenue or expenses and we did not record a cumulative adjustment as of January 1, 2018 as a result of the adoption of ASC 606. In connection with adopting ASC 606, we recognized $8 million of revenue and $5 million of expenses in the nine months ended September 30, 2018 related to a contract in our Business Processing segment that would have not been recognized under the prior accounting standard until a later period. 1. The new guidance does not apply to financial instruments and transfers and servicing that are accounted for under other U.S. GAAP. Accordingly, the new revenue recognition guidance does not have an impact on our recognition of revenue and costs associated with our loan portfolios, investments, derivatives and servicing contracts. However, we considered the ASC 606 principal versus agent guidance with respect to certain asset recovery guarantor servicing contracts pursuant to which we serve in a portfolio management role and use third-party collection agencies. We determined that we are required under the new accounting standard to reflect payments to third-party collection agencies as revenue and operating expense. Under the prior accounting standards, we netted payments to third-party collection agencies against revenue. We adopted the new accounting standard using the “cumulative effect transition adjustment” which results in prospectively making this change in 2018. This change in accounting policy resulted in both asset recovery revenue and operating expense in the Federal Education Loan segment being $14 million and $33 million higher for the three and nine months ended September 30, 2018, respectively, with no impact on net income. See “Note 11 – Revenue from Contracts with Customers Accounted in Accordance with ASC 606” for the new required disclosures. Classification and Measurement On January 5, 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities,” which reconsiders the classification and measurement of financial instruments. The new standard requires certain equity instruments be measured at fair value, with fair value changes recognized in earnings. In addition, the standard requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption. It was effective for the Company as of January 1, 2018. The adoption of this new accounting standard is immaterial to our consolidated financial statements and footnote disclosures. Intra-Entity Transfer of Assets On October 24, 2016, the FASB issued ASU No. 2016-16, “Income Taxes — Intra-Entity Transfer of Assets Other and Inventory,” which requires recognition of the income tax consequences of an intra-entity transfer of non-inventory assets when the transfer occurs. The new standard was effective for the Company as of January 1, 2018. The adoption of this new accounting standard is immaterial to our consolidated financial statements and footnote disclosures. Income Taxes On February 14, 2018, the FASB issued ASU No. 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which allows reclassification from Accumulated Other Comprehensive Income (Loss) (“AOCI”), as required by ASC No. 740, “Income Taxes,” to retained earnings for the residual tax effects resulting from the Tax Cuts and Jobs Act (“TCJA”) enacted on December 22, 2017. The new standard is effective for the Company as of January 1, 2019. However, early adoption is permitted and the Company adopted the standard on January 1, 2018, resulting in a decrease of $13 million to retained earnings due to the reclassification of AOCI to retained earnings. 1. Effective in 2019 Leases On February 25, 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, for lease arrangements exceeding a twelve-month term, these arrangements must be recognized as assets and liabilities on the balance sheet of the lessee. A right-of-use asset and lease obligation will be recorded for all leases with a term exceeding twelve months, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization/interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption must be calculated using the applicable incremental borrowing rate at the date of adoption. The standard allows the option to apply the new guidance prospectively at the effective date, without adjustment to comparative periods presented with certain practical expedients available. It will be effective for the Company as of January 1, 2019. We continue to assess the impact that adopting this new accounting standard will have on our consolidated financial statements and footnote disclosures but expect it to be immaterial. Hedging Activities On August 28, 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 amendments expand and refine hedge accounting for both nonfinancial and financial risk components and are intended to better align the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. The new standard will be effective for the Company as of January 1, 2019. We continue to assess the impact this new standard will have on our consolidated financial statements and footnote disclosures but expect it to be immaterial. Effective in 2020 Allowance for Loan Losses On June 16, 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 remaining expected credit losses for financial assets held at the reporting date. Our current allowance for loan loss is an incurred loss model. As a result, we expect the new guidance will result in an increase to our allowance for loan losses. The standard is to be applied through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The standard is effective for the Company as of January 1, 2020 and will primarily impact the allowance for loan losses related to our Private Education Loans and FFELP Loans. Early adoption is permitted on January 1, 2019. This standard represents a significant change from existing GAAP and may result in material changes to the Company’s accounting for the allowance for loan losses. We are currently evaluating the impact of adopting this accounting standard on our consolidated financial statements and footnote disclosures.

Allowance for Loan Losses

Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2018
Receivables [Abstract]
Allowance for Loan Losses	2. 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 into 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. 2. Allowance for Loan Losses (Continued) Allowance for Loan Losses Metrics Three Months Ended September 30, 2018 (Dollars in millions) FFELP Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 82 $ 1,297 $ 10 $ 1,389 Total provision 10 75 — 85 Net adjustment resulting from the change in the charge-off rate (1) — (32 ) — (32 ) Net charge-offs remaining (2) (13 ) (116 ) — (129 ) Total net charge-offs (13 ) (148 ) — (161 ) Reclassification of interest reserve (3) — 2 — 2 Ending balance $ 79 $ 1,226 $ 10 $ 1,315 Allowance Ending Balance: Individually evaluated for impairment — TDR $ — $ 1,134 $ 9 $ 1,143 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79 92 1 172 Purchased Non-Credit Impaired Loans acquired at a discount (4) — — — — Purchased Credit Impaired Loans (4) — — — — Ending total allowance $ 79 $ 1,226 $ 10 $ 1,315 Loans Ending Balance: Individually evaluated for impairment — TDR $ — $ 10,497 $ 29 $ 10,526 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 70,778 11,459 49 82,286 Purchased Non-Credit Impaired Loans acquired at a discount (4) 2,941 2,282 — 5,223 Purchased Credit Impaired Loans (4) — 231 — 231 Ending total loans (5) $ 73,719 $ 24,469 $ 78 $ 98,266 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 % 2.08 % — % Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment (1) — % .57 % — % Allowance coverage of charge-offs 1.5 2.1 — Allowance as a percentage of the ending total loan balance .11 % 5.01 % 12.71 % Allowance as a percentage of the ending loans in repayment .13 % 5.57 % 12.71 % Ending total loans (5) $ 73,719 $ 24,469 $ 78 Average loans in repayment $ 61,956 $ 22,158 $ 77 Ending loans in repayment $ 60,959 $ 21,997 $ 78 (1) In third-quarter 2018, the portion of the loan amount charged off at default on Private Education Loans increased from 79 percent to 80.5 percent. This did not impact the provision for loan losses as previously this had been reserved through the allowance for loan losses. This charge resulted in a $32 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 September 30, 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 $38 million and $343 million, respectively, as of September 30, 2018 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 2018. (5) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. 2. Allowance for Loan Losses (Continued) Three Months Ended September 30, 2017 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 61 $ 1,286 $ 15 $ 1,362 Total provision 10 95 — 105 Charge-offs (1) (10 ) (96 ) (3 ) (109 ) Reclassification of interest reserve (2) — 2 — 2 Ending balance $ 61 $ 1,287 $ 12 $ 1,360 Allowance Ending Balance: Individually evaluated for impairment — TDR $ — $ 1,169 $ 10 $ 1,179 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 61 118 2 181 Purchased Non-Credit Impaired Loans acquired at a discount (3) — — — — Purchased Credit Impaired Loans (3) — — — — Ending total allowance $ 61 $ 1,287 $ 12 $ 1,360 Loans Ending Balance: Individually evaluated for impairment - TDR $ — 10,961 30 $ 10,991 Collectively evaluated for impairment Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79,923 11,790 34 91,747 Purchased Non-Credit Impaired Loans acquired at a discount (3) 3,362 2,656 — 6,018 Purchased Credit Impaired Loans (3) — 258 — 258 Ending total loans (4) $ 83,285 $ 25,665 $ 64 $ 109,014 Charge-offs as a percentage of average loans in repayment .05 % 1.63 % 16.22 % Allowance coverage of charge-offs 1.7 3.4 .9 Allowance as a percentage of the ending total loan balance .07 % 5.02 % 18.59 % Allowance as a percentage of the ending loans in repayment .09 % 5.73 % 18.59 % Ending total loans (4) $ 83,285 $ 25,665 $ 64 Average loans in repayment $ 68,168 $ 23,112 $ 85 Ending loans in repayment $ 66,220 $ 22,448 $ 64 (1) 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. (2) 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. (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 September 30, 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 $45 million and $405 million, respectively, as of September 30, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 2017. (4) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. 2. Allowance for Loan Losses (Continued) Nine Months Ended September 30, 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 60 224 — 284 Net adjustment resulting from the change in the charge-off rate (1) — (32 ) — (32 ) Net charge-offs remaining (2) (41 ) (269 ) — (310 ) Total net charge-offs (41 ) (301 ) — (342 ) Reclassification of interest reserve (3) — 6 — 6 Ending balance $ 79 $ 1,226 $ 10 $ 1,315 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,134 $ 9 $ 1,143 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79 92 1 172 Purchased Non-Credit Impaired Loans acquired at a discount (4) — — — — Purchased Credit Impaired Loans (4) — — — — Ending total allowance $ 79 $ 1,226 $ 10 $ 1,315 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,497 $ 29 $ 10,526 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 70,778 11,459 49 82,286 Purchased Non-Credit Impaired Loans acquired at a discount (4) 2,941 2,282 — 5,223 Purchased Credit Impaired Loans (4) — 231 — 231 Ending total loans (5) $ 73,719 $ 24,469 $ 78 $ 98,266 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 % 1.61 % — % Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment (1) — % .19 % — % Allowance coverage of charge-offs 1.4 3.0 — Allowance as a percentage of the ending total loan balance .11 % 5.01 % 13.02 % Allowance as a percentage of the ending loans in repayment .13 % 5.57 % 13.02 % Ending total loans (5) $ 73,719 $ 24,469 $ 78 Average loans in repayment $ 63,934 $ 22,367 $ 74 Ending loans in repayment $ 60,959 $ 21,997 $ 78 (1) In third-quarter 2018, the portion of the loan amount charged off at default on Private Education Loans increased from 79 percent to 80.5 percent. This charge resulted in a $32 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 September 30, 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 $38 million and $343 million, respectively, as of September 30, 2018 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 2018. (5) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. 2. Allowance for Loan Losses (Continued) Nine Months Ended September 30, 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 30 285 2 317 Charge-offs (1) (36 ) (355 ) (5 ) (396 ) Reclassification of interest reserve (2) — 6 — 6 Ending balance $ 61 $ 1,287 $ 12 $ 1,360 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,169 $ 10 $ 1,179 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 61 118 2 181 Purchased Non-Credit Impaired Loans acquired at a discount (3) — — — — Purchased Credit Impaired Loans (3) — — — — Ending total allowance $ 61 $ 1,287 $ 12 $ 1,360 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,961 $ 30 $ 10,991 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79,923 11,790 34 91,747 Purchased Non-Credit Impaired Loans acquired at a discount (3) 3,362 2,656 — 6,018 Purchased Credit Impaired Loans (3) — 258 — 258 Ending total loans (4) $ 83,285 $ 25,665 $ 64 $ 109,014 Charge-offs as a percentage of average loans in repayment .07 % 2.14 % 3.92 % Allowance coverage of charge-offs 1.3 2.7 1.7 Allowance as a percentage of the ending total loan balance .07 % 5.02 % 18.59 % Allowance as a percentage of the ending loans in repayment .09 % 5.73 % 18.59 % Ending total loans (4) $ 83,285 $ 25,665 $ 64 Average loans in repayment $ 68,791 $ 22,180 $ 186 Ending loans in repayment $ 66,220 $ 22,448 $ 64 (1) 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. (2) 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. (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 September 30, 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 $45 million and $405 million, respectively, as of September 30, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 2017. (4) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. 2. 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 September 30, 2018 December 31, 2017 (Dollars in millions) Balance % Balance % Loans in-school/grace/deferment (1) $ 4,160 $ 4,711 Loans in forbearance (2) 8,600 8,533 Loans in repayment and percentage of each status: Loans current 54,005 88.6 % 59,264 87.3 % Loans delinquent 31-60 days (3) 1,978 3.2 2,638 3.9 Loans delinquent 61-90 days (3) 947 1.6 1,763 2.6 Loans delinquent greater than 90 days (3) 4,029 6.6 4,188 6.2 Total FFELP Loans in repayment 60,959 100 % 67,853 100 % Total FFELP Loans, gross 73,719 81,097 FFELP Loan unamortized premium 617 666 Total FFELP Loans 74,336 81,763 FFELP Loan allowance for losses (79 ) (60 ) FFELP Loans, net $ 74,257 $ 81,703 Percentage of FFELP Loans in repayment 82.7 % 83.7 % Delinquencies as a percentage of FFELP Loans in repayment 11.4 % 12.7 % FFELP Loans in forbearance as a percentage of loans in repayment and forbearance 12.4 % 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. 2. 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 Loan Credit Quality Indicators TDRs September 30, 2018 December 31, 2017 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 9,283 92 % $ 9,647 92 % FICO below 640 848 8 889 8 Total $ 10,131 100 % $ 10,536 100 % School Type: Not-for-profit $ 7,997 79 % $ 8,247 78 % For-profit 2,134 21 2,289 22 Total $ 10,131 100 % $ 10,536 100 % Cosigners: With cosigner $ 6,258 62 % $ 6,441 61 % Without cosigner 3,873 38 4,095 39 Total $ 10,131 100 % $ 10,536 100 % Seasoning (1) 1-12 payments $ 365 4 % $ 506 5 % 13-24 payments 491 5 644 6 25-36 payments 723 7 947 9 37-48 payments 1,026 10 1,271 12 More than 48 payments 7,071 70 6,691 63 Not yet in repayment 455 4 477 5 Total $ 10,131 100 % $ 10,536 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2) Balance equals the gross Private Education Loans. 2. Allowance for Loan Losses (Continued) Private Education Loan Credit Quality Indicators Non-TDRs September 30, 2018 December 31, 2017 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 13,142 96 % $ 13,752 96 % FICO below 640 508 4 592 4 Total $ 13,650 100 % $ 14,344 100 % School Type: Not-for-profit $ 11,499 84 % $ 12,431 87 % For-profit 2,151 16 1,913 13 Total $ 13,650 100 % $ 14,344 100 % Cosigners: With cosigner $ 7,453 55 % $ 9,193 64 % Without cosigner 6,197 45 5,151 36 Total $ 13,650 100 % $ 14,344 100 % Seasoning (1) 1-12 payments $ 2,553 19 % $ 1,424 10 % 13-24 payments 758 6 437 3 25-36 payments 334 2 466 3 37-48 payments 450 3 867 6 More than 48 payments 9,118 67 10,566 74 Not yet in repayment 437 3 584 4 Total $ 13,650 100 % $ 14,344 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2) Balance equals the gross Private Education Loans. 2. Allowance for Loan Losses (Continued) Private Education Loan Delinquencies TDRs September 30, 2018 December 31, 2017 (Dollars in millions) Balance % Balance % Loans in-school/grace/deferment (1) $ 455 $ 477 Loans in forbearance (2) 707 681 Loans in repayment and percentage of each status: Loans current 7,767 86.6 % 8,333 88.9 % Loans delinquent 31-60 days (3) 385 4.3 351 3.7 Loans delinquent 61-90 days (3) 250 2.8 207 2.2 Loans delinquent greater than 90 days (3) 567 6.3 487 5.2 Total TDR loans in repayment 8,969 100 % 9,378 100 % Total TDR loans, gross 10,131 10,536 TDR loans unamortized discount (213 ) (225 ) Total TDR loans 9,918 10,311 TDR loans receivable for partially charged-off loans 366 385 TDR loans allowance for losses (1,134 ) (1,171 ) TDR loans, net $ 9,150 $ 9,525 Percentage of TDR loans in repayment 88.5 % 89.0 % Delinquencies as a percentage of TDR loans in repayment 13.4 % 11.1 % Loans in forbearance as a percentage of TDR loans in repayment and forbearance 7.3 % 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. 2. Allowance for Loan Losses (Continued) Private Education Loan Delinquencies Non-TDRs September 30, 2018 December 31, 2017 (Dollars in millions) Balance % Balance % Loans in-school/grace/deferment (1) $ 437 $ 584 Loans in forbearance (2) 185 214 Loans in repayment and percentage of each status: Loans current 12,838 98.6 % 13,257 97.9 % Loans delinquent 31-60 days (3) 82 .6 120 .9 Loans delinquent 61-90 days (3) 39 .3 59 .4 Loans delinquent greater than 90 days (3) 69 .5 110 .8 Total non-TDR loans in repayment 13,028 100 % 13,546 100 % Total non-TDR loans, gross 13,650 14,344 Non-TDR loans unamortized discount (583 ) (699 ) Total non-TDR loans 13,067 13,645 Non-TDR loans receivable for partially charged-off loans 322 375 Non-TDR loans allowance for losses (92 ) (126 ) Non-TDR loans, net $ 13,297 $ 13,894 Percentage of non-TDR loans in repayment 95.4 % 94.4 % Delinquencies as a percentage of non-TDR loans in repayment 1.4 % 2.1 % Loans in forbearance as a percentage of non- TDR loans in repayment and forbearance 1.4 % 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. 2. Allowance for Loan Losses (Continued) 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. We refer to the remaining loan balance as the “receivable for partially charged-off loans.” Actual recoveries are applied against this receivable balance. If actual periodic recoveries are less than expected, the difference is immediately charged off through the allowance for Private Education Loan losses. The following table summarizes the activity in the receivable for partially charged-off Private Education Loans. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Receivable at beginning of period $ 724 $ 784 $ 760 $ 815 Expected future recoveries of current period defaults (1) 29 24 68 88 Recoveries (2) (33 ) (37 ) (107 ) (121 ) Charge-offs (3) (32 ) — (33 ) (11 ) Receivable at end of period $ 688 $ 771 $ 688 $ 771 (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-quarter 2018, the portion of the loan amount charged off at default increased from 79 percent to 80.5 percent. This change resulted in a $32 million reduction to the balance of the receivable for partially charged-off loans. These amounts are included in total charge-offs as reported in the “Allowance for Private Education Loan Losses” table. 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 64 percent and 61 percent of the loans granted forbearance have qualified as a TDR loan at September 30, 2018 and December 31, 2017, respectively. The unpaid principal balance of TDR loans that were in an interest rate reduction program as of September 30, 2018 and December 31, 2017 was $2.0 billion and $2.7 billion, respectively. 2. Allowance for Loan Losses (Continued) At September 30, 2018 and December 31, 2017, 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) September 30, 2018 December 31, 2017 Recorded investment (1) $ 10,482 $ 10,890 Total ending loans (2) $ 10,497 $ 10,921 Related allowance $ 1,134 $ 1,171 (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. The following tables provide the average recorded investment and interest income recognized for our TDR loans. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Average recorded investment $ 10,568 $ 10,944 $ 10,717 $ 11,016 Interest income recognized $ 196 $ 180 $ 563 $ 528 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. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Modified loans (1) $ 163 $ 200 $ 470 $ 618 Charge-offs (2) $ 123 $ 80 $ 243 $ 280 Payment default $ 35 $ 43 $ 105 $ 144 (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. 2. Allowance for Loan Losses (Continued) 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 September 30, 2018 TDR $ 198 $ 28 $ 19 Non-TDR 160 4 8 Total $ 358 $ 32 $ 27 December 31, 2017 TDR $ 196 $ 20 $ 20 Non-TDR 187 4 6 Total $ 383 $ 24 $ 26

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Borrowings	3. Borrowings The following table summarizes our borrowings. September 30, 2018 December 31, 2017 (Dollars in millions) Short Term Long Term Total Short Term Long Term Total Unsecured borrowings: Senior unsecured debt (1) $ 2,162 $ 10,765 $ 12,927 $ 1,306 $ 12,624 $ 13,930 Total unsecured borrowings 2,162 10,765 12,927 1,306 12,624 13,930 Secured borrowings: FFELP Loan securitizations (2) — 68,456 68,456 — 71,208 71,208 Private Education Loan securitizations (3) 1,257 11,579 12,836 686 12,646 13,332 FFELP Loan — other facilities — 4,408 4,408 1,536 6,830 8,366 Private Education Loan — other facilities 1,391 1,379 2,770 684 1,710 2,394 Other (4) 204 — 204 538 — 538 Total secured borrowings 2,852 85,822 88,674 3,444 92,394 95,838 Total before hedge accounting adjustments 5,014 96,587 101,601 4,750 105,018 109,768 Hedge accounting adjustments (7 ) (498 ) (505 ) 21 (6 ) 15 Total $ 5,007 $ 96,089 $ 101,096 $ 4,771 $ 105,012 $ 109,783 (1) Includes principal amount of $2.2 billion and $1.3 billion of short-term debt as of September 30, 2018 and December 31, 2017, respectively. Includes principal amount of $10.9 billion and $12.7 billion of long-term debt as of September 30, 2018 and December 31, 2017, respectively. (2) Includes $81 million of long-term debt related to the FFELP Loan asset-backed securitization repurchase facilities (“Repurchase Facilities”) as of September 30, 2018. (3) Includes $1.3 billion and $686 million of short-term debt related to the Private Education Loan asset-backed securitization repurchase facilities (“Repurchase Facilities”) as of September 30, 2018 and December 31, 2017, respectively. Includes $1.1 billion and $1.3 billion of long-term debt related to the Repurchase Facilities as of September 30, 2018, and December 31, 2017, respectively. (4) “Other” primarily includes the obligation to return cash collateral held related to derivative exposures. 3. Borrowings (Continued) Variable Interest Entities We consolidated the following financing VIEs as of September 30, 2018 and December 31, 2017, as we are the primary beneficiary. As a result, these VIEs are accounted for as secured borrowings. September 30, 2018 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets Total Secured Borrowings — VIEs: FFELP Loan securitizations (1) $ — $ 68,456 $ 68,456 $ 69,280 $ 2,366 $ 1,237 $ 72,883 Private Education Loan securitizations (2) 1,257 11,579 12,836 16,170 528 209 16,907 FFELP Loan — other facilities — 4,097 4,097 4,200 71 103 4,374 Private Education Loan — other facilities 1,391 1,379 2,770 3,739 89 30 3,858 Total before hedge accounting adjustments 2,648 85,511 88,159 93,389 3,054 1,579 98,022 Hedge accounting adjustments — (404 ) (404 ) — — (554 ) (554 ) Total $ 2,648 $ 85,107 $ 87,755 $ 93,389 $ 3,054 $ 1,025 $ 97,468 December 31, 2017 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets Total Secured Borrowings — VIEs: FFELP Loan securitizations (1) $ — $ 71,208 $ 71,208 $ 72,145 $ 2,335 $ 1,078 $ 75,558 Private Education Loan securitizations (2) 686 12,646 13,332 17,739 484 237 18,460 FFELP Loan — other facilities 1,536 3,999 5,535 5,565 204 156 5,925 Private Education Loan — other facilities 684 1,710 2,394 3,147 68 31 3,246 Total before hedge accounting adjustments 2,906 89,563 92,469 98,596 3,091 1,502 103,189 Hedge accounting adjustments — (246 ) (246 ) — — (342 ) (342 ) Total $ 2,906 $ 89,317 $ 92,223 $ 98,596 $ 3,091 $ 1,160 $ 102,847 (1) Includes $81 million of long-term debt and $2 million of restricted cash related to the FFELP Loan Repurchase Facilities as of September 30, 2018. (2) Includes $1.3 billion of short-term debt, $1.1 billion of long-term debt and $127 million of restricted cash related to the Private Education Loan Repurchase Facilities as of September 30, 2018. Includes $686 million of short-term debt, $1.3 billion of long-term debt and $96 million of restricted cash related to the Private Education Loan Repurchase Facilities as of December 31, 2017.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	4. Derivative Financial Instruments Our risk management strategy and use of and accounting for derivatives have not materially changed from that discussed in our 2017 Form 10-K. Please refer to “Note 7 — Derivative Financial Instruments” in our 2017 Form 10-K for a full discussion. Summary of Derivative Financial Statement Impact The following tables summarize the fair values and notional amounts of all derivative instruments at September 30, 2018 and December 31, 2017, and their impact on other comprehensive income and earnings for the three and nine months ended September 30, 2018 and 2017. 4. Derivative Financial Instruments (Continued) Impact of Derivatives on Consolidated Balance Sheet Cash Flow Fair Value Trading Total (Dollars in millions) Hedged Risk Exposure Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Fair Values (1) Derivative Assets: Interest rate swaps Interest rate $ — $ 95 $ 143 $ 290 $ 4 $ 7 $ 147 $ 392 Cross-currency interest rate swaps Foreign currency and interest rate — — 18 88 — — 18 88 Total derivative assets (2) — 95 161 378 4 7 165 480 Derivative Liabilities: Interest rate swaps Interest rate — (16 ) (67 ) (102 ) (61 ) (71 ) (128 ) (189 ) Floor Income Contracts Interest rate — — — — (31 ) (74 ) (31 ) (74 ) Cross-currency interest rate swaps Foreign currency and interest rate — — (567 ) (410 ) (46 ) (44 ) (613 ) (454 ) Other (3) Interest rate — — — — (6 ) (18 ) (6 ) (18 ) Total derivative liabilities (2) — (16 ) (634 ) (512 ) (144 ) (207 ) (778 ) (735 ) Net total derivatives $ — $ 79 $ (473 ) $ (134 ) $ (140 ) $ (200 ) $ (613 ) $ (255 ) (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) September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Gross position $ 165 $ 480 $ (778 ) $ (735 ) Impact of master netting agreements (23 ) (42 ) 23 42 Derivative values with impact of master netting agreements (as carried on balance sheet) 142 438 (755 ) (693 ) Cash collateral (held) pledged (203 ) (536 ) 245 235 Net position $ (61 ) $ (98 ) $ (510 ) $ (458 ) (3) 4. Derivative Financial Instruments (Continued) The above fair values at September 30, 2018 reflect rule changes adopted by clearing organizations that require entities to treat derivative assets, liabilities and the related variation margin as a settlement of the derivative position for legal and accounting purposes, rather than recording these positions on a gross basis with a related collateral receivable or payable. As a result, the tables above reflect a reduction of $286 million of derivative assets and $233 million of derivative liabilities as of September 30, 2018, that previously were reported on a gross basis but are now settled and not subject to collateral. The above fair values also 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 September 30, 2018 and December 31, 2017 by $16 million and $6 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 September 30, 2018 and December 31, 2017 by $21 million and $30 million, respectively. Cash Flow Fair Value Trading Total (Dollars in billions) Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Notional Values: Interest rate swaps $ 26.5 $ 24.1 $ 11.6 $ 12.4 $ 61.6 $ 72.0 $ 99.7 $ 108.5 Floor Income Contracts — — — — 27.9 21.9 27.9 21.9 Cross-currency interest rate swaps — — 4.6 6.7 .3 .3 4.9 7.0 Other (1) — — — — .3 .5 .3 .5 Total derivatives $ 26.5 $ 24.1 $ 16.2 $ 19.1 $ 90.1 $ 94.7 $ 132.8 $ 137.9 (1) “Other” includes derivatives related to our Total Return Swap Facility. 4. Derivative Financial Instruments (Continued) Impact of Derivatives on Consolidated Statements of Income Total Gains (Losses) (1) Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Fair Value Hedges: (2) Interest Rate Swaps Gains (losses) recognized in net income on derivatives $ (63 ) $ (28 ) $ (321 ) $ (94 ) Gains (losses) recognized in net income on hedged items 66 39 356 62 Net fair value hedge ineffectiveness gains (losses) 3 11 35 (32 ) Cross currency interest rate swaps Gains (losses) recognized in net income on derivatives (19 ) 261 (227 ) 837 Gains (losses) recognized in net income on hedged items 28 (262 ) 157 (866 ) Net fair value hedge ineffectiveness gains (losses) 9 (1 ) (70 ) (29 ) Total fair value hedges 12 10 (35 ) (61 ) Cash Flow Hedges (2) Interest rate swaps (3) — — — — Total cash flow hedges — — — — Trading Interest rate swaps (8 ) 6 10 16 Floor income contracts 6 15 39 43 Cross currency interest rate swaps (9 ) (1 ) (7 ) 5 Other 1 (5 ) 3 (19 ) Total trading derivatives (10 ) 15 45 45 Gains (losses) on derivative and hedging activities, net $ 2 $ 25 $ 10 $ (16 ) (1) Recorded in “Gains (losses) on derivative and hedging activities, net” in the consolidated statements of income. (2) The accrued interest income (expense) on fair value hedges and cash flow hedges is recorded in net interest income (expense) and is excluded from this table. (3) Represents ineffectiveness related to cash flow hedges. 4. Derivative Financial Instruments (Continued) Collateral Collateral held and pledged related to derivative exposures between us and our derivative counterparties are detailed in the following table: (Dollars in millions) September 30, 2018 December 31, 2017 Collateral held: Cash (obligation to return cash collateral is recorded in short-term borrowings) $ 203 $ 536 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) 116 297 Total collateral held $ 319 $ 833 Derivative asset at fair value including accrued interest $ 143 $ 618 Collateral pledged to others: Cash (right to receive return of cash collateral is recorded in investments) $ 245 $ 235 Total collateral pledged $ 245 $ 235 Derivative liability at fair value including accrued interest and premium receivable $ 745 $ 659 (1) (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 $156 million with our counterparties. Downgrades in our unsecured credit rating would not result in any additional collateral requirements, except to increase the frequency of collateral calls. Trust related derivatives do not contain credit contingent features related to our or the trusts’ credit ratings.

Other Assets

Other Assets	9 Months Ended
	Sep. 30, 2018
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Other Assets	5. Other Assets The following table provides the detail of our other assets. (Dollars in millions) September 30, 2018 December 31, 2017 Accrued interest receivable, net $ 1,863 $ 1,965 Benefit and insurance-related investments 488 481 Income tax asset, net current and deferred 269 380 Derivatives at fair value 142 438 Fixed assets, net 138 156 Accounts receivable 107 108 Other loans, net 68 59 Other 378 438 Total $ 3,453 $ 4,025

Business Combinations, Goodwill

Business Combinations, Goodwill and Acquired Intangible Assets	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Business Combinations, Goodwill and Acquired Intangible Assets	6. 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 percent 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 have engaged an independent appraiser to assist in the valuation of the assets acquired and liabilities assumed including identifiable intangible assets, primarily the trade name and developed technology. The purchase price allocation will be completed in the fourth quarter 2018. The preliminary estimate of goodwill is $74 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 three and nine months ended September 30, 2018 and 2017, as the pro forma impact was deemed immaterial. Acquisition of Duncan Solutions In July 2017, Navient acquired a 100 percent 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, primarily customer relationships, the trade name and developed technology. 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 three and nine months ended September 30, 2018 and 2017, as the pro forma impact was deemed immaterial. Goodwill Goodwill resulting from our acquisitions is assigned to a reporting unit or units. A reporting unit is the same or one level below an operating segment. As discussed in “Note 12 – Segment Reporting," we have the following new reportable operating segments effective first-quarter 2018: Federal Education Loans, Consumer Lending, Business Processing and Other. As a result of this change in our reporting structure, our reporting units with goodwill as of September 30, 2018 include (1) FFELP Loans and Federal Education Loan Servicing, both of which are included in our Federal Education Loans reportable operating segment, (2) Private Education Loans and Private Education Refinance Loans (inclusive of what formerly constituted our Earnest reporting unit), both of which are included in our Consumer Lending reportable operating segment, and (3) Government Services (inclusive of what formerly constituted our Gila reporting unit and other government services lines of business previously included in our Contingency reporting unit) and Healthcare Services, both of which are included in our Business Processing reportable operating segment. There was no change in our allocation of goodwill as a result of this change in reportable operating segments and reporting units. 6. Business Combinations, Goodwill and Acquired Intangible Assets (Continued) Interim Goodwill and Acquired Intangible Asset Impairment Testing In third-quarter 2018, we wrote off a $16 million toll services relationship intangible asset as a result of receiving a notice of termination related to a toll services contract in our Government Services reporting unit. As a result of this termination, we also performed a valuation of the $136 million of goodwill within this reporting unit and concluded the goodwill was not impaired as the fair value of the reporting unit was 56 percent greater than the book basis. We estimated the fair value of the reporting unit utilizing a market approach which applies market-based revenue, EBITDA and net income multiples from comparable publicly-traded companies to the reporting unit’s revenue, EBITDA and net income indicators.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity The following table summarizes common share repurchases and issuances. Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Common stock repurchased (1) 6,881,592 11,346,367 6,881,592 29,646,374 Average purchase price per share $ 13.90 $ 14.55 $ 13.90 $ 14.85 Shares repurchased related to employee stock-based compensation plans (2) 175,241 131,374 3,732,745 1,741,529 Average purchase price per share $ 13.90 $ 15.34 $ 13.77 $ 15.56 Common shares issued (3) 395,615 385,676 5,529,853 3,535,988 (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. The closing price of our common stock on September 28, 2018 was $13.48. Dividend and Share Repurchase Program In September 30, 2018, we paid a common stock dividend of $0.16 per share. In the three and nine months ended September 30, 2018, we repurchased 6.9 million common shares for $95 million. Our board of directors authorized a new $500 million share repurchase program in September 2018. As of September 30, 2018, the remaining common share repurchase authority was $565 million. In the nine months ended September 30, 2017, we repurchased 29.6 million shares of common stock for $440 million.

Earnings per Common Share

Earnings per Common Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings per Common Share	8. Earnings per Common Share Basic earnings 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. Three Months Ended September 30, Nine Months Ended September 30, (In millions, except per share data) 2018 2017 2018 2017 Numerator: Net income attributable to Navient Corporation $ 114 $ 176 $ 323 $ 376 Denominator: Weighted average shares used to compute basic EPS 260 269 263 279 Effect of dilutive securities: Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units, derivative contracts and Employee Stock Purchase Plan (“ESPP”) (1) 4 5 4 6 Dilutive potential common shares (2) 4 5 4 6 Weighted average shares used to compute diluted EPS 264 274 267 285 Basic earnings per common share attributable to Navient Corporation $ .44 $ .65 $ 1.23 $ 1.35 Diluted earnings per common share attributable to Navient Corporation $ .43 $ .64 $ 1.21 $ 1.32 (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, and derivative contracts determined by the reverse treasury stock method. (2) For the three months ended September 30, 2018 and 2017, securities covering approximately 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. For the nine months ended September 30, 2018 and 2017, securities covering approximately 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

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	9. Fair Value Measurements We use estimates of fair value in applying various accounting standards in 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. Please refer to “Note 12 — Fair Value Measurements” in our 2017 Form 10-K for a full discussion. During the three and nine months ended September 30, 2018, there were no significant transfers of financial instruments between levels, or changes in our methodology or assumptions used to value our financial instruments. 9. Fair Value Measurements (Continued) The following table summarizes the valuation of our financial instruments that are marked-to-market on a recurring basis. Fair Value Measurements on a Recurring Basis September 30, 2018 December 31, 2017 (Dollars in millions) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Available-for-sale investments: Agency residential mortgage- backed securities $ — $ — $ — $ — $ — $ — $ — $ — Other — 2 — 2 — 2 — 2 Total available-for-sale investments — 2 — 2 — 2 — 2 Derivative instruments: (1) Interest rate swaps — 144 3 147 — 388 4 392 Cross-currency interest rate swaps — — 18 18 — — 88 88 Total derivative assets (2) — 144 21 165 — 388 92 480 Total $ — $ 146 $ 21 $ 167 $ — $ 390 $ 92 $ 482 Liabilities (3) Derivative instruments (1) Interest rate swaps $ — $ (96 ) $ (32 ) $ (128 ) $ — $ (144 ) $ (45 ) $ (189 ) Floor Income Contracts — (31 ) — (31 ) — (74 ) — (74 ) Cross-currency interest rate swaps — (46 ) (567 ) (613 ) — (44 ) (410 ) (454 ) Other — — (6 ) (6 ) — — (18 ) (18 ) Total derivative liabilities (2) — (173 ) (605 ) (778 ) — (262 ) (473 ) (735 ) Total $ — $ (173 ) $ (605 ) $ (778 ) $ — $ (262 ) $ (473 ) $ (735 ) (1) Fair value of derivative instruments excludes accrued interest and the value of collateral. (2) See “Note 4—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. 9. 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. Three Months Ended September 30, 2018 2017 Derivative instruments Derivative instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (33 ) $ (529 ) $ (8 ) $ (570 ) $ (48 ) $ (666 ) $ (22 ) $ (736 ) Total gains/(losses): Included in earnings (1) 3 (52 ) 1 (48 ) 1 231 (5 ) 227 Included in other comprehensive income — — — — — — — — Settlements 1 32 1 34 1 30 3 34 Transfers in and/or out of level 3 — — — — — — — — Balance, end of period $ (29 ) $ (549 ) $ (6 ) $ (584 ) $ (46 ) $ (405 ) $ (24 ) $ (475 ) Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date (2) $ 4 $ (20 ) $ 2 $ (14 ) $ 3 $ 227 $ (2 ) $ 228 Nine Months Ended September 30, 2018 2017 Derivative instruments Derivative instruments (Dollars in millions) Interest Rate Cross Currency Interest Rate Swaps Other Total Derivative Instruments Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (41 ) $ (322 ) $ (18 ) $ (381 ) $ (46 ) $ (1,243 ) $ (13 ) $ (1,302 ) Total gains/(losses): Included in earnings (1) 10 (317 ) 7 (300 ) (4 ) 750 (19 ) 727 Included in other comprehensive income — — — — — — — — Settlements 2 90 5 97 4 88 8 100 Transfers in and/or out of level 3 — — — — — — — — Balance, end of period $ (29 ) $ (549 ) $ (6 ) $ (584 ) $ (46 ) $ (405 ) $ (24 ) $ (475 ) Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date (2) $ 11 $ (200 ) $ 12 $ (177 ) $ — $ 712 $ (11 ) $ 701 (1) “Included in earnings” is comprised of the following amounts recorded in the specified line item in the consolidated statements of income: Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Gains (losses) on derivative and hedging activities, net $ (16 ) $ 257 $ (210 ) $ 815 Interest expense (32 ) (30 ) (90 ) (88 ) Total $ (48 ) $ 227 $ (300 ) $ 727 (2) Recorded in “gains (losses) on derivative and hedging activities, net” in the consolidated statements of income. 9. 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 September 30, 2018 Valuation Technique Input Range (Weighted Average) Derivatives Prime/LIBOR basis swaps $ (29 ) Discounted cash flow Constant Prepayment Rate 7% Bid/ask adjustment to .08% — .08% discount rate (.08%) Cross-currency interest rate swaps (549 ) Discounted cash flow Constant Prepayment Rate 4% Other (6 ) Total $ (584 ) 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. 9. Fair Value Measurements (Continued) The following table summarizes the fair values of our financial assets and liabilities, including derivative financial instruments. September 30, 2018 December 31, 2017 (Dollars in millions) Fair Value Carrying Value Difference Fair Value Carrying Value Difference Earning assets FFELP Loans $ 74,504 $ 74,257 $ 247 $ 82,271 $ 81,703 $ 568 Private Education Loans 23,420 22,447 973 24,421 23,419 1,002 Cash and investments (1) 5,544 5,544 — 5,034 5,034 — Total earning assets 103,468 102,248 1,220 111,726 110,156 1,570 Interest-bearing liabilities Short-term borrowings 5,034 5,007 (27 ) 4,783 4,771 (12 ) Long-term borrowings 96,482 96,089 (393 ) 104,921 105,012 91 Total interest-bearing liabilities 101,516 101,096 (420 ) 109,704 109,783 79 Derivative financial instruments Floor Income Contracts (31 ) (31 ) — (74 ) (74 ) — Interest rate swaps 19 19 — 203 203 — Cross-currency interest rate swaps (595 ) (595 ) — (366 ) (366 ) — Other (6 ) (6 ) — (18 ) (18 ) — Excess of net asset fair value over carrying value $ 800 $ 1,649 (1) “Cash and investments” includes available-for-sale investments that consist of investments that are primarily agency securities whose cost basis is $2 million and $2 million at September 30, 2018 and December 31, 2017, respectively, versus a fair value of $2 million and $2 million at September 30, 2018 and December 31, 2017, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies 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, the FCPA, 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, 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. 10. Commitments and Contingencies (Continued) At this point in time, the Company is unable to anticipate the timing of a resolution or the ultimate 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 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 of the District of Columbia, Kansas, Oregon, Colorado, New Jersey and New York. We may receive additional CIDs or subpoenas 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. • 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 December 2014, Solutions received a subpoena from the New York Department of Financial Services (the “NY DFS”) as part of the NY DFS’s 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. The CFPB, Washington Attorney General and Illinois Attorney General lawsuits relate to matters which were covered under the CIDs or the NORA letter discussed above. In addition, various State Attorneys General have filed suits alleging violations of various state and federal consumer protection laws covering matters similar to those covered by the CIDs or the NORA letter. For more information about these cases, see the section above entitled “Legal Proceedings.” As stated above, we have denied these allegations and intend to vigorously defend against the allegations in each of these cases. 10. Commitments and Contingencies (Continued) With respect to alleged civil violations of the Servicemembers Civil Relief Act (the “SCRA”), Solutions and Sallie Mae Bank entered into a consent order with the U.S. Department of Justice (“DOJ”) in May 2014. The DOJ consent order (the “DOJ Order”) covered all loans either owned by Sallie Mae Bank or serviced by Solutions from November 28, 2005 until the effective date of the settlement. The DOJ Order expired by its terms on September 29, 2018, and the related case was dismissed with prejudice on October 4, 2018. Under the terms of the Separation 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 all 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, other than fines or penalties directly levied against Sallie Mae Bank and other matters specifically excluded. Navient has no additional reserves related to indemnification matters with SLM BankCo as of September 30, 2018. 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. A hearing was held in April 2017 and a ruling has not yet been issued. 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 as part of the total reserve for pending regulatory matters discussed previously 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. 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. 10. Commitments and Contingencies (Continued) 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.

Revenue from Contract with Cust

Revenue from Contract with Customers Accounted in Accordance with ASC 606	9 Months Ended
	Sep. 30, 2018
Revenue From Contract With Customer [Abstract]
Revenue from Contract with Customers Accounted in Accordance with ASC 606	11. Revenue from Contracts with Customers Accounted in Accordance with ASC 606 We account for certain contract revenue in accordance with ASC 606. Servicing contract revenue is not accounted for under ASC 606. Contract 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 the United States Department of Education (“ED”), Guarantor agencies and other institutions. 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 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. Substantially all our revenue from contracts with customers 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). 11. Revenue from Contracts with Customers Accounted in Accordance with ASC 606 (Continued) 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 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (Dollars in millions) Federal Education Loans Business Processing Total Revenue Federal Education Loans Business Processing Total Revenue Federal Education Loan asset recovery services $ 22 $ — $ 22 $ 61 $ — $ 61 Government services — 40 40 — 134 134 Healthcare services — 24 24 — 68 68 Total $ 22 $ 64 $ 86 $ 61 $ 202 $ 263 Revenue by Client Type Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (Dollars in millions) Federal Education Loans Business Processing Total Revenue Federal Education Loans Business Processing Total Revenue Federal government $ 5 $ 2 $ 7 $ 7 $ 5 $ 12 Guarantor agencies 14 — 14 44 — 44 Other institutions 3 — 3 10 — 10 State and local government — 21 21 — 70 70 Tolling authorities — 17 17 — 59 59 Hospitals and other healthcare providers — 24 24 — 68 68 Total $ 22 $ 64 $ 86 $ 61 $ 202 $ 263 As of January 1, 2018, and September 30, 2018, there was $63 million and $77 million, respectively, of net accounts receivable related to these contracts. Navient had no material contract assets or contract liabilities.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Reporting	12. Segment Reporting In the fourth quarter of 2017, Navient entered the Private Education Refinance Loan origination market. This new activity changed the way the Company manages the business, reviews operating performance and allocates resources. This resulted in the following four new reportable operating segments, effective first-quarter 2018: (1) Federal Education Loans (2) Consumer Lending (3) Business Processing and (4) Other. In connection with this change in reportable operating segments, there was also a change in how unallocated overhead is defined. 12. Segment Reporting (Continued) The following table shows the realignment of our business lines (operating segments) from the prior reportable operating segments to the new reportable operating segments: Business Lines New Reportable Operating Segment Prior Reportable Operating Segment FFELP Loans Federal Education Loans FFELP Loans Federal Education Loans Servicing Federal Education Loans Business Services Federal Education Loans Asset Recovery Federal Education Loans Business Services Private Education Refinance Loans Consumer Lending Private Education Loans Private Education Loans – Other Consumer Lending Private Education Loans Other Consumer Loans Consumer Lending Other Non-Education Government Services Business Processing Business Services Non-Education Healthcare Services Business Processing Business Services Unallocated Overhead Expenses Other Other Corporate Liquidity Portfolio Other 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. As a result of this change in segment reporting in the first quarter of 2018, prior periods have been recast for comparison purposes. Federal Education Loans Segment In its Federal Education Loans 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. 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. (Dollars in millions) September 30, 2018 December 31, 2017 FFELP Loans, net $ 74,257 $ 81,703 Cash and investments (1) 2,510 2,821 Other 2,113 2,601 Total assets $ 78,880 $ 87,125 (1) Includes restricted cash and investments. 12. Segment Reporting (Continued) Consumer Lending Segment In its Consumer Lending segment, Navient holds, originates and acquires consumer loans and performs servicing activities on its own 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. (Dollars in millions) September 30, 2018 December 31, 2017 Private Education Loans, net $ 22,447 $ 23,419 Cash and investments (1) 706 706 Other 1,115 1,143 Total assets $ 24,268 $ 25,268 (1) Includes restricted cash and investments. Business Processing Segment In its Business Processing segment, Navient performs business processing services for over 600 non-education related government and healthcare clients. Government services include receivables management services and account processing solutions. With over $13 billion of inventory, our integrated solutions technology and superior data driven approach allows state governments, agencies, court systems, municipalities and toll authorities 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 non-profit/religious-affiliated hospital systems, teaching hospitals, urban medical centers, for-profit healthcare systems, critical access hospitals, children’s hospitals and large physician groups. At September 30, 2018 and December 31, 2017, the Business Processing segment had total assets of $447 million and $466 million, respectively, on a GAAP basis. Other Segment Our Other segment primarily consists of the following activities: our corporate liquidity portfolio and the repurchase of debt, unallocated overhead (corporate overhead and certain information technology costs), 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 corporate overhead is 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 and stock-based compensation expense. Unallocated information technology costs are related to infrastructure and operations. At September 30, 2018 and December 31, 2017, the Other segment had total assets of $2.9 billion and $2.1 billion, respectively, on a GAAP basis. 12. 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 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 from our Core Earnings presentations are: 1. 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 2. 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. 12. Segment Reporting (Continued) Segment Results and Reconciliations to GAAP Three Months Ended September 30, 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 $ 774 $ 455 $ — $ — $ 1,229 $ 3 $ (18 ) $ (15 ) $ 1,214 Other loans 1 — — — 1 — — — 1 Cash and investments 12 4 — 10 26 — — — 26 Total interest income 787 459 — 10 1,256 3 (18 ) (15 ) 1,241 Total interest expense 624 257 — 48 929 9 (3 ) 6 935 Net interest income (loss) 163 202 — (38 ) 327 (6 ) (15 ) (21 ) 306 Less: provisions for loan losses 10 75 — — 85 — — — 85 Net interest income (loss) after provisions for loan losses 153 127 — (38 ) 242 (6 ) (15 ) (21 ) 221 Other income (loss): Servicing revenue 67 3 — — 70 — — — 70 Asset recovery and business processing revenue 42 — 64 — 106 — — — 106 Other income (loss) 18 — — 3 21 6 3 9 30 Losses on debt repurchases — — — (1 ) (1 ) — — — (1 ) Total other income (loss) 127 3 64 2 196 6 3 9 205 Expenses: Direct operating expenses 87 38 59 — 184 — — — 184 Overhead expenses — — — 71 71 — — — 71 Operating expenses 87 38 59 71 255 — — — 255 Goodwill and acquired intangible asset impairment and amortization — — — — — — 23 23 23 Restructuring/other reorganization expenses — — — 1 1 — — — 1 Total expenses 87 38 59 72 256 — 23 23 279 Income (loss) before income tax expense (benefit) 193 92 5 (108 ) 182 — (35 ) (35 ) 147 Income tax expense (benefit) (2) 45 20 1 (24 ) 42 — (9 ) (9 ) 33 Net income (loss) $ 148 $ 72 $ 4 $ (84 ) $ 140 $ — $ (26 ) $ (26 ) $ 114 (1) Core Earnings adjustments to GAAP: Three Months Ended September 30, 2018 (Dollars in millions) Net Derivative Accounting Net Impact of Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ (21 ) $ — $ (21 ) Total other income (loss) 9 — 9 Goodwill and acquired intangible asset impairment and amortization — 23 23 Total Core Earnings adjustments to GAAP $ (12 ) $ (23 ) (35 ) Income tax expense (benefit) (9 ) Net income (loss) $ (26 ) (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. 12. Segment Reporting (Continued) Three Months Ended September 30, 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 $ 678 $ 445 $ — $ — $ 1,123 $ 16 $ (13 ) $ 3 $ 1,126 Other loans 2 — — — 2 — — — 2 Cash and investments 9 1 — 2 12 — — — 12 Total interest income 689 446 — 2 1,137 16 (13 ) 3 1,140 Total interest expense 531 221 — 40 792 (5 ) (2 ) (7 ) 785 Net interest income (loss) 158 225 — (38 ) 345 21 (11 ) 10 355 Less: provisions for loan losses 10 95 — — 105 — — — 105 Net interest income (loss) after provisions for loan losses 148 130 — (38 ) 240 21 (11 ) 10 250 Other income (loss): Servicing revenue 72 3 — — 75 — — — 75 Asset recovery and business processing revenue 102 — 55 — 157 — — — 157 Other income (loss) 1 — — 2 3 (21 ) 47 26 29 Gains on sales of loans and investments 3 — — — 3 — — — 3 Losses on debt repurchases — — — (1 ) (1 ) — — — (1 ) Total other income (loss) 178 3 55 1 237 (21 ) 47 26 263 Expenses: Direct operating expenses 77 39 49 — 165 — — — 165 Overhead expenses — — — 73 73 — — — 73 Operating expenses 77 39 49 73 238 — — — 238 Goodwill and acquired intangible asset impairment and amortization — — — — — — 6 6 6 Total expenses 77 39 49 73 238 — 6 6 244 Income (loss) before income tax expense (benefit) 249 94 6 (110 ) 239 — 30 30 269 Income tax expense (benefit) (2) 92 34 2 (41 ) 87 — 6 6 93 Net income (loss) $ 157 $ 60 $ 4 $ (69 ) $ 152 $ — $ 24 $ 24 $ 176 (1) Core Earnings adjustments to GAAP: Three Months Ended September 30, 2017 (Dollars in millions) Net Derivative Accounting Net Impact of Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ 10 $ — $ 10 Total other income (loss) 26 — 26 Goodwill and acquired intangible asset impairment and amortization — 6 6 Total Core Earnings adjustments to GAAP $ 36 $ (6 ) 30 Income tax expense (benefit) 6 Net income (loss) $ 24 (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. 12. Segment Reporting (Continued) Nine Months Ended September 30, 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 $ 2,281 $ 1,327 $ — $ — $ 3,608 $ 14 $ (53 ) $ (39 ) $ 3,569 Other loans 3 1 — — 4 — — — 4 Cash and investments 31 9 — 26 66 — — — 66 Total interest income 2,315 1,337 — 26 3,678 14 (53 ) (39 ) 3,639 Total interest expense 1,817 746 — 139 2,702 13 (8 ) 5 2,707 Net interest income (loss) 498 591 — (113 ) 976 1 (45 ) (44 ) 932 Less: provisions for loan losses 60 224 — — 284 — — — 284 Net interest income (loss) after provisions for loan losses 438 367 — (113 ) 692 1 (45 ) (44 ) 648 Other income (loss): Servicing revenue 201 9 — — 210 — — — 210 Asset recovery and business processing revenue 112 — 201 — 313 — — — 313 Other income (loss) 20 — — 6 26 (1 ) 14 13 39 Losses on debt repurchases — — — (9 ) (9 ) — — — (9 ) Total other income (loss) 333 9 201 (3 ) 540 (1 ) 14 13 553 Expenses: Direct operating expenses 202 133 172 — 507 — — — 507 Overhead expenses — — — 224 224 — — — 224 Operating expenses 202 133 172 224 731 — — — 731 Goodwill and acquired intangible asset impairment and amortization — — — — — — 39 39 39 Restructuring/other reorganization expenses — — — 10 10 — — — 10 Total expenses 202 133 172 234 741 — 39 39 780 Income (loss) before income tax expense (benefit) 569 243 29 (350 ) 491 — (70 ) (70 ) 421 Income tax expense (benefit) (2) 130 56 7 (81 ) 112 — (14 ) (14 ) 98 Net income (loss) $ 439 $ 187 $ 22 $ (269 ) $ 379 $ — $ (56 ) $ (56 ) $ 323 (1) Core Earnings adjustments to GAAP: Nine Months Ended September 30, 2018 (Dollars in millions) Net Derivative Accounting Net Impact of Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ (44 ) $ — $ (44 ) Total other income (loss) 13 — 13 Goodwill and acquired intangible asset impairment and amortization — 39 39 Total Core Earnings adjustments to GAAP $ (31 ) $ (39 ) (70 ) Income tax expense (benefit) (14 ) Net income (loss) $ (56 ) (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. 12. Segment Reporting (Continued) Nine Months Ended September 30, 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 $ 1,966 $ 1,204 $ — $ — $ 3,170 $ 54 $ (41 ) $ 13 $ 3,183 Other loans 12 — — — 12 — — — 12 Cash and investments 20 3 — 6 29 — — — 29 Total interest income 1,998 1,207 — 6 3,211 54 (41 ) 13 3,224 Total interest expense 1,486 601 — 102 2,189 (3 ) (8 ) (11 ) 2,178 Net interest income (loss) 512 606 — (96 ) 1,022 57 (33 ) 24 1,046 Less: provisions for loan losses 32 285 — — 317 — — — 317 Net interest income (loss) after provisions for loan losses 480 321 — (96 ) 705 57 (33 ) 24 729 Other income (loss): Servicing revenue 215 6 — — 221 — — — 221 Asset recovery and business processing revenue 215 — 152 — 367 — — — 367 Other income (loss) 2 — — 11 13 (57 ) 31 (26 ) (13 ) Gains on sales of loans and investments 3 — — — 3 — — — 3 Losses on debt repurchases — — — (1 ) (1 ) — — — (1 ) Total other income (loss) 435 6 152 10 603 (57 ) 31 (26 ) 577 Expenses: Direct operating expenses 245 111 131 — 487 — — — 487 Overhead expenses — — — 220 220 — — — 220 Operating expenses 245 111 131 220 707 — — — 707 Goodwill and acquired intangible asset impairment and amortization — — — — — — 17 17 17 Total expenses 245 111 131 220 707 — 17 17 724 Income (loss) before income tax expense (benefit) 670 216 21 (306 ) 601 — (19 ) (19 ) 582 Income tax expense (benefit) (2) 244 79 8 (112 ) 219 — (13 ) (13 ) 206 Net income (loss) $ 426 $ 137 $ 13 $ (194 ) $ 382 $ — $ (6 ) $ (6 ) $ 376 (1) Core Earnings adjustments to GAAP: Nine Months Ended September 30, 2017 (Dollars in millions) Net Impact of Derivative Accounting Net Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ 24 $ — $ 24 Total other income (loss) (26 ) — (26 ) Goodwill and acquired intangible asset impairment and amortization — 17 17 Total Core Earnings adjustments to GAAP $ (2 ) $ (17 ) (19 ) Income tax expense (benefit) (13 ) Net income (loss) $ (6 ) (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. 12. Segment Reporting (Continued) Summary of Core Earnings Adjustments to GAAP Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Core Earnings adjustments to GAAP: Net impact of derivative accounting (1) $ (12 ) $ 36 $ (31 ) $ (2 ) Net impact of goodwill and acquired intangible assets (2) (23 ) (6 ) (39 ) (17 ) Net tax effect (3) 9 (6 ) 14 13 Total Core Earnings adjustments to GAAP $ (26 ) $ 24 $ (56 ) $ (6 ) (1) Derivative accounting: (2) Goodwill and acquired intangible assets: (3) Net tax effect:

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited, consolidated financial statements of Navient have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. The consolidated financial statements include the accounts of Navient 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. In the opinion of management, all adjustments considered necessary for a fair statement of the results for the interim periods have been included. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results for the year ending December 31, 2018 or for any other period. These unaudited financial statements should be read in conjunction with the audited financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2017 (the “2017 Form 10-K”). Definitions for certain capitalized terms used but not otherwise defined in this Quarterly Report on Form 10-Q can be found in our 2017 Form 10-K.
Reclassifications	Reclassifications Certain reclassifications have been made to the balances as of and for the three and nine months ended September 30, 2017 to be consistent with classifications adopted for 2018, and had no effect on net income, total assets, or total liabilities.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Effective in 2018 Revenue Recognition As of January 1, 2018, we adopted Accounting Standard Codification (“ASC”) 606, “Revenue from Contracts with Customers,” which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to its customers. The contract transaction price is allocated to each distinct contractual performance obligation and recognized as revenue at a point in time or over time when or as the good or service is provided to the customer and the performance obligation is satisfied. Generally, our performance obligations are satisfied over time. In conjunction with our implementation plan, we identified revenue streams related to asset recovery and other business processing within our Federal Education Loans and Business Processing segments that are within the scope of the new standard and reviewed related contracts. We determined there was no material change in the timing of our recognition of our asset recovery and business processing revenue or expenses and we did not record a cumulative adjustment as of January 1, 2018 as a result of the adoption of ASC 606. In connection with adopting ASC 606, we recognized $8 million of revenue and $5 million of expenses in the nine months ended September 30, 2018 related to a contract in our Business Processing segment that would have not been recognized under the prior accounting standard until a later period. 1. The new guidance does not apply to financial instruments and transfers and servicing that are accounted for under other U.S. GAAP. Accordingly, the new revenue recognition guidance does not have an impact on our recognition of revenue and costs associated with our loan portfolios, investments, derivatives and servicing contracts. However, we considered the ASC 606 principal versus agent guidance with respect to certain asset recovery guarantor servicing contracts pursuant to which we serve in a portfolio management role and use third-party collection agencies. We determined that we are required under the new accounting standard to reflect payments to third-party collection agencies as revenue and operating expense. Under the prior accounting standards, we netted payments to third-party collection agencies against revenue. We adopted the new accounting standard using the “cumulative effect transition adjustment” which results in prospectively making this change in 2018. This change in accounting policy resulted in both asset recovery revenue and operating expense in the Federal Education Loan segment being $14 million and $33 million higher for the three and nine months ended September 30, 2018, respectively, with no impact on net income. See “Note 11 – Revenue from Contracts with Customers Accounted in Accordance with ASC 606” for the new required disclosures. Classification and Measurement On January 5, 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities,” which reconsiders the classification and measurement of financial instruments. The new standard requires certain equity instruments be measured at fair value, with fair value changes recognized in earnings. In addition, the standard requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption. It was effective for the Company as of January 1, 2018. The adoption of this new accounting standard is immaterial to our consolidated financial statements and footnote disclosures. Intra-Entity Transfer of Assets On October 24, 2016, the FASB issued ASU No. 2016-16, “Income Taxes — Intra-Entity Transfer of Assets Other and Inventory,” which requires recognition of the income tax consequences of an intra-entity transfer of non-inventory assets when the transfer occurs. The new standard was effective for the Company as of January 1, 2018. The adoption of this new accounting standard is immaterial to our consolidated financial statements and footnote disclosures. Income Taxes On February 14, 2018, the FASB issued ASU No. 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income,” which allows reclassification from Accumulated Other Comprehensive Income (Loss) (“AOCI”), as required by ASC No. 740, “Income Taxes,” to retained earnings for the residual tax effects resulting from the Tax Cuts and Jobs Act (“TCJA”) enacted on December 22, 2017. The new standard is effective for the Company as of January 1, 2019. However, early adoption is permitted and the Company adopted the standard on January 1, 2018, resulting in a decrease of $13 million to retained earnings due to the reclassification of AOCI to retained earnings. 1. Effective in 2019 Leases On February 25, 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, for lease arrangements exceeding a twelve-month term, these arrangements must be recognized as assets and liabilities on the balance sheet of the lessee. A right-of-use asset and lease obligation will be recorded for all leases with a term exceeding twelve months, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization/interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption must be calculated using the applicable incremental borrowing rate at the date of adoption. The standard allows the option to apply the new guidance prospectively at the effective date, without adjustment to comparative periods presented with certain practical expedients available. It will be effective for the Company as of January 1, 2019. We continue to assess the impact that adopting this new accounting standard will have on our consolidated financial statements and footnote disclosures but expect it to be immaterial. Hedging Activities On August 28, 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 amendments expand and refine hedge accounting for both nonfinancial and financial risk components and are intended to better align the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. The new standard will be effective for the Company as of January 1, 2019. We continue to assess the impact this new standard will have on our consolidated financial statements and footnote disclosures but expect it to be immaterial. Effective in 2020 Allowance for Loan Losses On June 16, 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 remaining expected credit losses for financial assets held at the reporting date. Our current allowance for loan loss is an incurred loss model. As a result, we expect the new guidance will result in an increase to our allowance for loan losses. The standard is to be applied through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The standard is effective for the Company as of January 1, 2020 and will primarily impact the allowance for loan losses related to our Private Education Loans and FFELP Loans. Early adoption is permitted on January 1, 2019. This standard represents a significant change from existing GAAP and may result in material changes to the Company’s accounting for the allowance for loan losses. We are currently evaluating the impact of adopting this accounting standard on our consolidated financial statements and footnote disclosures.

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2018
Allowance for Credit Losses and Recorded Investments in Loans	Allowance for Loan Losses Metrics Three Months Ended September 30, 2018 (Dollars in millions) FFELP Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 82 $ 1,297 $ 10 $ 1,389 Total provision 10 75 — 85 Net adjustment resulting from the change in the charge-off rate (1) — (32 ) — (32 ) Net charge-offs remaining (2) (13 ) (116 ) — (129 ) Total net charge-offs (13 ) (148 ) — (161 ) Reclassification of interest reserve (3) — 2 — 2 Ending balance $ 79 $ 1,226 $ 10 $ 1,315 Allowance Ending Balance: Individually evaluated for impairment — TDR $ — $ 1,134 $ 9 $ 1,143 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79 92 1 172 Purchased Non-Credit Impaired Loans acquired at a discount (4) — — — — Purchased Credit Impaired Loans (4) — — — — Ending total allowance $ 79 $ 1,226 $ 10 $ 1,315 Loans Ending Balance: Individually evaluated for impairment — TDR $ — $ 10,497 $ 29 $ 10,526 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 70,778 11,459 49 82,286 Purchased Non-Credit Impaired Loans acquired at a discount (4) 2,941 2,282 — 5,223 Purchased Credit Impaired Loans (4) — 231 — 231 Ending total loans (5) $ 73,719 $ 24,469 $ 78 $ 98,266 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 % 2.08 % — % Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment (1) — % .57 % — % Allowance coverage of charge-offs 1.5 2.1 — Allowance as a percentage of the ending total loan balance .11 % 5.01 % 12.71 % Allowance as a percentage of the ending loans in repayment .13 % 5.57 % 12.71 % Ending total loans (5) $ 73,719 $ 24,469 $ 78 Average loans in repayment $ 61,956 $ 22,158 $ 77 Ending loans in repayment $ 60,959 $ 21,997 $ 78 (1) In third-quarter 2018, the portion of the loan amount charged off at default on Private Education Loans increased from 79 percent to 80.5 percent. This did not impact the provision for loan losses as previously this had been reserved through the allowance for loan losses. This charge resulted in a $32 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 September 30, 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 $38 million and $343 million, respectively, as of September 30, 2018 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 2018. (5) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. Three Months Ended September 30, 2017 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 61 $ 1,286 $ 15 $ 1,362 Total provision 10 95 — 105 Charge-offs (1) (10 ) (96 ) (3 ) (109 ) Reclassification of interest reserve (2) — 2 — 2 Ending balance $ 61 $ 1,287 $ 12 $ 1,360 Allowance Ending Balance: Individually evaluated for impairment — TDR $ — $ 1,169 $ 10 $ 1,179 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 61 118 2 181 Purchased Non-Credit Impaired Loans acquired at a discount (3) — — — — Purchased Credit Impaired Loans (3) — — — — Ending total allowance $ 61 $ 1,287 $ 12 $ 1,360 Loans Ending Balance: Individually evaluated for impairment - TDR $ — 10,961 30 $ 10,991 Collectively evaluated for impairment Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79,923 11,790 34 91,747 Purchased Non-Credit Impaired Loans acquired at a discount (3) 3,362 2,656 — 6,018 Purchased Credit Impaired Loans (3) — 258 — 258 Ending total loans (4) $ 83,285 $ 25,665 $ 64 $ 109,014 Charge-offs as a percentage of average loans in repayment .05 % 1.63 % 16.22 % Allowance coverage of charge-offs 1.7 3.4 .9 Allowance as a percentage of the ending total loan balance .07 % 5.02 % 18.59 % Allowance as a percentage of the ending loans in repayment .09 % 5.73 % 18.59 % Ending total loans (4) $ 83,285 $ 25,665 $ 64 Average loans in repayment $ 68,168 $ 23,112 $ 85 Ending loans in repayment $ 66,220 $ 22,448 $ 64 (1) 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. (2) 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. (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 September 30, 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 $45 million and $405 million, respectively, as of September 30, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 2017. (4) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. 2. Allowance for Loan Losses (Continued) Nine Months Ended September 30, 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 60 224 — 284 Net adjustment resulting from the change in the charge-off rate (1) — (32 ) — (32 ) Net charge-offs remaining (2) (41 ) (269 ) — (310 ) Total net charge-offs (41 ) (301 ) — (342 ) Reclassification of interest reserve (3) — 6 — 6 Ending balance $ 79 $ 1,226 $ 10 $ 1,315 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,134 $ 9 $ 1,143 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79 92 1 172 Purchased Non-Credit Impaired Loans acquired at a discount (4) — — — — Purchased Credit Impaired Loans (4) — — — — Ending total allowance $ 79 $ 1,226 $ 10 $ 1,315 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,497 $ 29 $ 10,526 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 70,778 11,459 49 82,286 Purchased Non-Credit Impaired Loans acquired at a discount (4) 2,941 2,282 — 5,223 Purchased Credit Impaired Loans (4) — 231 — 231 Ending total loans (5) $ 73,719 $ 24,469 $ 78 $ 98,266 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 % 1.61 % — % Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment (1) — % .19 % — % Allowance coverage of charge-offs 1.4 3.0 — Allowance as a percentage of the ending total loan balance .11 % 5.01 % 13.02 % Allowance as a percentage of the ending loans in repayment .13 % 5.57 % 13.02 % Ending total loans (5) $ 73,719 $ 24,469 $ 78 Average loans in repayment $ 63,934 $ 22,367 $ 74 Ending loans in repayment $ 60,959 $ 21,997 $ 78 (1) In third-quarter 2018, the portion of the loan amount charged off at default on Private Education Loans increased from 79 percent to 80.5 percent. This charge resulted in a $32 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 September 30, 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 $38 million and $343 million, respectively, as of September 30, 2018 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 2018. (5) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. 2. Allowance for Loan Losses (Continued) Nine Months Ended September 30, 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 30 285 2 317 Charge-offs (1) (36 ) (355 ) (5 ) (396 ) Reclassification of interest reserve (2) — 6 — 6 Ending balance $ 61 $ 1,287 $ 12 $ 1,360 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,169 $ 10 $ 1,179 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 61 118 2 181 Purchased Non-Credit Impaired Loans acquired at a discount (3) — — — — Purchased Credit Impaired Loans (3) — — — — Ending total allowance $ 61 $ 1,287 $ 12 $ 1,360 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,961 $ 30 $ 10,991 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 79,923 11,790 34 91,747 Purchased Non-Credit Impaired Loans acquired at a discount (3) 3,362 2,656 — 6,018 Purchased Credit Impaired Loans (3) — 258 — 258 Ending total loans (4) $ 83,285 $ 25,665 $ 64 $ 109,014 Charge-offs as a percentage of average loans in repayment .07 % 2.14 % 3.92 % Allowance coverage of charge-offs 1.3 2.7 1.7 Allowance as a percentage of the ending total loan balance .07 % 5.02 % 18.59 % Allowance as a percentage of the ending loans in repayment .09 % 5.73 % 18.59 % Ending total loans (4) $ 83,285 $ 25,665 $ 64 Average loans in repayment $ 68,791 $ 22,180 $ 186 Ending loans in repayment $ 66,220 $ 22,448 $ 64 (1) 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. (2) 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. (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 September 30, 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 $45 million and $405 million, respectively, as of September 30, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of September 30, 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 September 30, 2018 December 31, 2017 (Dollars in millions) Balance % Balance % Loans in-school/grace/deferment (1) $ 4,160 $ 4,711 Loans in forbearance (2) 8,600 8,533 Loans in repayment and percentage of each status: Loans current 54,005 88.6 % 59,264 87.3 % Loans delinquent 31-60 days (3) 1,978 3.2 2,638 3.9 Loans delinquent 61-90 days (3) 947 1.6 1,763 2.6 Loans delinquent greater than 90 days (3) 4,029 6.6 4,188 6.2 Total FFELP Loans in repayment 60,959 100 % 67,853 100 % Total FFELP Loans, gross 73,719 81,097 FFELP Loan unamortized premium 617 666 Total FFELP Loans 74,336 81,763 FFELP Loan allowance for losses (79 ) (60 ) FFELP Loans, net $ 74,257 $ 81,703 Percentage of FFELP Loans in repayment 82.7 % 83.7 % Delinquencies as a percentage of FFELP Loans in repayment 11.4 % 12.7 % FFELP Loans in forbearance as a percentage of loans in repayment and forbearance 12.4 % 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 September 30, 2018 December 31, 2017 (Dollars in millions) Balance % Balance % Loans in-school/grace/deferment (1) $ 455 $ 477 Loans in forbearance (2) 707 681 Loans in repayment and percentage of each status: Loans current 7,767 86.6 % 8,333 88.9 % Loans delinquent 31-60 days (3) 385 4.3 351 3.7 Loans delinquent 61-90 days (3) 250 2.8 207 2.2 Loans delinquent greater than 90 days (3) 567 6.3 487 5.2 Total TDR loans in repayment 8,969 100 % 9,378 100 % Total TDR loans, gross 10,131 10,536 TDR loans unamortized discount (213 ) (225 ) Total TDR loans 9,918 10,311 TDR loans receivable for partially charged-off loans 366 385 TDR loans allowance for losses (1,134 ) (1,171 ) TDR loans, net $ 9,150 $ 9,525 Percentage of TDR loans in repayment 88.5 % 89.0 % Delinquencies as a percentage of TDR loans in repayment 13.4 % 11.1 % Loans in forbearance as a percentage of TDR loans in repayment and forbearance 7.3 % 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 September 30, 2018 December 31, 2017 (Dollars in millions) Balance % Balance % Loans in-school/grace/deferment (1) $ 437 $ 584 Loans in forbearance (2) 185 214 Loans in repayment and percentage of each status: Loans current 12,838 98.6 % 13,257 97.9 % Loans delinquent 31-60 days (3) 82 .6 120 .9 Loans delinquent 61-90 days (3) 39 .3 59 .4 Loans delinquent greater than 90 days (3) 69 .5 110 .8 Total non-TDR loans in repayment 13,028 100 % 13,546 100 % Total non-TDR loans, gross 13,650 14,344 Non-TDR loans unamortized discount (583 ) (699 ) Total non-TDR loans 13,067 13,645 Non-TDR loans receivable for partially charged-off loans 322 375 Non-TDR loans allowance for losses (92 ) (126 ) Non-TDR loans, net $ 13,297 $ 13,894 Percentage of non-TDR loans in repayment 95.4 % 94.4 % Delinquencies as a percentage of non-TDR loans in repayment 1.4 % 2.1 % Loans in forbearance as a percentage of non- TDR loans in repayment and forbearance 1.4 % 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) September 30, 2018 December 31, 2017 Recorded investment (1) $ 10,482 $ 10,890 Total ending loans (2) $ 10,497 $ 10,921 Related allowance $ 1,134 $ 1,171 (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. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Modified loans (1) $ 163 $ 200 $ 470 $ 618 Charge-offs (2) $ 123 $ 80 $ 243 $ 280 Payment default $ 35 $ 43 $ 105 $ 144 (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	The following tables provide the average recorded investment and interest income recognized for our TDR loans. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Average recorded investment $ 10,568 $ 10,944 $ 10,717 $ 11,016 Interest income recognized $ 196 $ 180 $ 563 $ 528
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 Loan Credit Quality Indicators TDRs September 30, 2018 December 31, 2017 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 9,283 92 % $ 9,647 92 % FICO below 640 848 8 889 8 Total $ 10,131 100 % $ 10,536 100 % School Type: Not-for-profit $ 7,997 79 % $ 8,247 78 % For-profit 2,134 21 2,289 22 Total $ 10,131 100 % $ 10,536 100 % Cosigners: With cosigner $ 6,258 62 % $ 6,441 61 % Without cosigner 3,873 38 4,095 39 Total $ 10,131 100 % $ 10,536 100 % Seasoning (1) 1-12 payments $ 365 4 % $ 506 5 % 13-24 payments 491 5 644 6 25-36 payments 723 7 947 9 37-48 payments 1,026 10 1,271 12 More than 48 payments 7,071 70 6,691 63 Not yet in repayment 455 4 477 5 Total $ 10,131 100 % $ 10,536 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2) Balance equals the gross Private Education Loans. Private Education Loan Credit Quality Indicators Non-TDRs September 30, 2018 December 31, 2017 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 13,142 96 % $ 13,752 96 % FICO below 640 508 4 592 4 Total $ 13,650 100 % $ 14,344 100 % School Type: Not-for-profit $ 11,499 84 % $ 12,431 87 % For-profit 2,151 16 1,913 13 Total $ 13,650 100 % $ 14,344 100 % Cosigners: With cosigner $ 7,453 55 % $ 9,193 64 % Without cosigner 6,197 45 5,151 36 Total $ 13,650 100 % $ 14,344 100 % Seasoning (1) 1-12 payments $ 2,553 19 % $ 1,424 10 % 13-24 payments 758 6 437 3 25-36 payments 334 2 466 3 37-48 payments 450 3 867 6 More than 48 payments 9,118 67 10,566 74 Not yet in repayment 437 3 584 4 Total $ 13,650 100 % $ 14,344 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2) Balance equals the gross Private Education Loans.
Receivable for Partially Charged-Off Private Education Loans	The following table summarizes the activity in the receivable for partially charged-off Private Education Loans. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Receivable at beginning of period $ 724 $ 784 $ 760 $ 815 Expected future recoveries of current period defaults (1) 29 24 68 88 Recoveries (2) (33 ) (37 ) (107 ) (121 ) Charge-offs (3) (32 ) — (33 ) (11 ) Receivable at end of period $ 688 $ 771 $ 688 $ 771 (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-quarter 2018, the portion of the loan amount charged off at default increased from 79 percent to 80.5 percent. This change resulted in a $32 million reduction to the balance of the receivable for partially charged-off loans. 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 September 30, 2018 TDR $ 198 $ 28 $ 19 Non-TDR 160 4 8 Total $ 358 $ 32 $ 27 December 31, 2017 TDR $ 196 $ 20 $ 20 Non-TDR 187 4 6 Total $ 383 $ 24 $ 26

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Company's Borrowings	The following table summarizes our borrowings. September 30, 2018 December 31, 2017 (Dollars in millions) Short Term Long Term Total Short Term Long Term Total Unsecured borrowings: Senior unsecured debt (1) $ 2,162 $ 10,765 $ 12,927 $ 1,306 $ 12,624 $ 13,930 Total unsecured borrowings 2,162 10,765 12,927 1,306 12,624 13,930 Secured borrowings: FFELP Loan securitizations (2) — 68,456 68,456 — 71,208 71,208 Private Education Loan securitizations (3) 1,257 11,579 12,836 686 12,646 13,332 FFELP Loan — other facilities — 4,408 4,408 1,536 6,830 8,366 Private Education Loan — other facilities 1,391 1,379 2,770 684 1,710 2,394 Other (4) 204 — 204 538 — 538 Total secured borrowings 2,852 85,822 88,674 3,444 92,394 95,838 Total before hedge accounting adjustments 5,014 96,587 101,601 4,750 105,018 109,768 Hedge accounting adjustments (7 ) (498 ) (505 ) 21 (6 ) 15 Total $ 5,007 $ 96,089 $ 101,096 $ 4,771 $ 105,012 $ 109,783 (1) Includes principal amount of $2.2 billion and $1.3 billion of short-term debt as of September 30, 2018 and December 31, 2017, respectively. Includes principal amount of $10.9 billion and $12.7 billion of long-term debt as of September 30, 2018 and December 31, 2017, respectively. (2) Includes $81 million of long-term debt related to the FFELP Loan asset-backed securitization repurchase facilities (“Repurchase Facilities”) as of September 30, 2018. (3) Includes $1.3 billion and $686 million of short-term debt related to the Private Education Loan asset-backed securitization repurchase facilities (“Repurchase Facilities”) as of September 30, 2018 and December 31, 2017, respectively. Includes $1.1 billion and $1.3 billion of long-term debt related to the Repurchase Facilities as of September 30, 2018, and December 31, 2017, respectively. (4) “Other” primarily includes the obligation to return cash collateral held related to derivative exposures.
Financing VIEs	We consolidated the following financing VIEs as of September 30, 2018 and December 31, 2017, as we are the primary beneficiary. As a result, these VIEs are accounted for as secured borrowings. September 30, 2018 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets Total Secured Borrowings — VIEs: FFELP Loan securitizations (1) $ — $ 68,456 $ 68,456 $ 69,280 $ 2,366 $ 1,237 $ 72,883 Private Education Loan securitizations (2) 1,257 11,579 12,836 16,170 528 209 16,907 FFELP Loan — other facilities — 4,097 4,097 4,200 71 103 4,374 Private Education Loan — other facilities 1,391 1,379 2,770 3,739 89 30 3,858 Total before hedge accounting adjustments 2,648 85,511 88,159 93,389 3,054 1,579 98,022 Hedge accounting adjustments — (404 ) (404 ) — — (554 ) (554 ) Total $ 2,648 $ 85,107 $ 87,755 $ 93,389 $ 3,054 $ 1,025 $ 97,468 December 31, 2017 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets Total Secured Borrowings — VIEs: FFELP Loan securitizations (1) $ — $ 71,208 $ 71,208 $ 72,145 $ 2,335 $ 1,078 $ 75,558 Private Education Loan securitizations (2) 686 12,646 13,332 17,739 484 237 18,460 FFELP Loan — other facilities 1,536 3,999 5,535 5,565 204 156 5,925 Private Education Loan — other facilities 684 1,710 2,394 3,147 68 31 3,246 Total before hedge accounting adjustments 2,906 89,563 92,469 98,596 3,091 1,502 103,189 Hedge accounting adjustments — (246 ) (246 ) — — (342 ) (342 ) Total $ 2,906 $ 89,317 $ 92,223 $ 98,596 $ 3,091 $ 1,160 $ 102,847 (1) Includes $81 million of long-term debt and $2 million of restricted cash related to the FFELP Loan Repurchase Facilities as of September 30, 2018. (2) Includes $1.3 billion of short-term debt, $1.1 billion of long-term debt and $127 million of restricted cash related to the Private Education Loan Repurchase Facilities as of September 30, 2018. Includes $686 million of short-term debt, $1.3 billion of long-term debt and $96 million of restricted cash related to the Private Education Loan Repurchase Facilities as of December 31, 2017.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Impact of Derivatives on Consolidated Balance Sheet	The following tables summarize the fair values and notional amounts of all derivative instruments at September 30, 2018 and December 31, 2017, and their impact on other comprehensive income and earnings for the three and nine months ended September 30, 2018 and 2017. Impact of Derivatives on Consolidated Balance Sheet Cash Flow Fair Value Trading Total (Dollars in millions) Hedged Risk Exposure Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Fair Values (1) Derivative Assets: Interest rate swaps Interest rate $ — $ 95 $ 143 $ 290 $ 4 $ 7 $ 147 $ 392 Cross-currency interest rate swaps Foreign currency and interest rate — — 18 88 — — 18 88 Total derivative assets (2) — 95 161 378 4 7 165 480 Derivative Liabilities: Interest rate swaps Interest rate — (16 ) (67 ) (102 ) (61 ) (71 ) (128 ) (189 ) Floor Income Contracts Interest rate — — — — (31 ) (74 ) (31 ) (74 ) Cross-currency interest rate swaps Foreign currency and interest rate — — (567 ) (410 ) (46 ) (44 ) (613 ) (454 ) Other (3) Interest rate — — — — (6 ) (18 ) (6 ) (18 ) Total derivative liabilities (2) — (16 ) (634 ) (512 ) (144 ) (207 ) (778 ) (735 ) Net total derivatives $ — $ 79 $ (473 ) $ (134 ) $ (140 ) $ (200 ) $ (613 ) $ (255 ) (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:
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) September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Gross position $ 165 $ 480 $ (778 ) $ (735 ) Impact of master netting agreements (23 ) (42 ) 23 42 Derivative values with impact of master netting agreements (as carried on balance sheet) 142 438 (755 ) (693 ) Cash collateral (held) pledged (203 ) (536 ) 245 235 Net position $ (61 ) $ (98 ) $ (510 ) $ (458 ) (3)
Derivative Notional Values	Cash Flow Fair Value Trading Total (Dollars in billions) Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Sep 30, 2018 Dec 31, 2017 Notional Values: Interest rate swaps $ 26.5 $ 24.1 $ 11.6 $ 12.4 $ 61.6 $ 72.0 $ 99.7 $ 108.5 Floor Income Contracts — — — — 27.9 21.9 27.9 21.9 Cross-currency interest rate swaps — — 4.6 6.7 .3 .3 4.9 7.0 Other (1) — — — — .3 .5 .3 .5 Total derivatives $ 26.5 $ 24.1 $ 16.2 $ 19.1 $ 90.1 $ 94.7 $ 132.8 $ 137.9 (1) “Other” includes derivatives related to our Total Return Swap Facility.
Impact of Derivatives on Consolidated Statements of Income	Impact of Derivatives on Consolidated Statements of Income Total Gains (Losses) (1) Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Fair Value Hedges: (2) Interest Rate Swaps Gains (losses) recognized in net income on derivatives $ (63 ) $ (28 ) $ (321 ) $ (94 ) Gains (losses) recognized in net income on hedged items 66 39 356 62 Net fair value hedge ineffectiveness gains (losses) 3 11 35 (32 ) Cross currency interest rate swaps Gains (losses) recognized in net income on derivatives (19 ) 261 (227 ) 837 Gains (losses) recognized in net income on hedged items 28 (262 ) 157 (866 ) Net fair value hedge ineffectiveness gains (losses) 9 (1 ) (70 ) (29 ) Total fair value hedges 12 10 (35 ) (61 ) Cash Flow Hedges (2) Interest rate swaps (3) — — — — Total cash flow hedges — — — — Trading Interest rate swaps (8 ) 6 10 16 Floor income contracts 6 15 39 43 Cross currency interest rate swaps (9 ) (1 ) (7 ) 5 Other 1 (5 ) 3 (19 ) Total trading derivatives (10 ) 15 45 45 Gains (losses) on derivative and hedging activities, net $ 2 $ 25 $ 10 $ (16 ) (1) Recorded in “Gains (losses) on derivative and hedging activities, net” in the consolidated statements of income. (2) The accrued interest income (expense) on fair value hedges and cash flow hedges is recorded in net interest income (expense) and is excluded from this table. (3) Represents ineffectiveness related to cash flow hedges.
Collateral Held and Pledged	Collateral held and pledged related to derivative exposures between us and our derivative counterparties are detailed in the following table: (Dollars in millions) September 30, 2018 December 31, 2017 Collateral held: Cash (obligation to return cash collateral is recorded in short-term borrowings) $ 203 $ 536 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) 116 297 Total collateral held $ 319 $ 833 Derivative asset at fair value including accrued interest $ 143 $ 618 Collateral pledged to others: Cash (right to receive return of cash collateral is recorded in investments) $ 245 $ 235 Total collateral pledged $ 245 $ 235 Derivative liability at fair value including accrued interest and premium receivable $ 745 $ 659 (1) (2) The trusts do not have the ability to sell or re-pledge securities they hold as collateral.

Other Assets (Tables)

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2018
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) September 30, 2018 December 31, 2017 Accrued interest receivable, net $ 1,863 $ 1,965 Benefit and insurance-related investments 488 481 Income tax asset, net current and deferred 269 380 Derivatives at fair value 142 438 Fixed assets, net 138 156 Accounts receivable 107 108 Other loans, net 68 59 Other 378 438 Total $ 3,453 $ 4,025

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Common Share Repurchases and Issuances	The following table summarizes common share repurchases and issuances. Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Common stock repurchased (1) 6,881,592 11,346,367 6,881,592 29,646,374 Average purchase price per share $ 13.90 $ 14.55 $ 13.90 $ 14.85 Shares repurchased related to employee stock-based compensation plans (2) 175,241 131,374 3,732,745 1,741,529 Average purchase price per share $ 13.90 $ 15.34 $ 13.77 $ 15.56 Common shares issued (3) 395,615 385,676 5,529,853 3,535,988 (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.

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Earnings per Common Share	Basic earnings 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. Three Months Ended September 30, Nine Months Ended September 30, (In millions, except per share data) 2018 2017 2018 2017 Numerator: Net income attributable to Navient Corporation $ 114 $ 176 $ 323 $ 376 Denominator: Weighted average shares used to compute basic EPS 260 269 263 279 Effect of dilutive securities: Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units, derivative contracts and Employee Stock Purchase Plan (“ESPP”) (1) 4 5 4 6 Dilutive potential common shares (2) 4 5 4 6 Weighted average shares used to compute diluted EPS 264 274 267 285 Basic earnings per common share attributable to Navient Corporation $ .44 $ .65 $ 1.23 $ 1.35 Diluted earnings per common share attributable to Navient Corporation $ .43 $ .64 $ 1.21 $ 1.32 (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, and derivative contracts determined by the reverse treasury stock method. (2) For the three months ended September 30, 2018 and 2017, securities covering approximately 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. For the nine months ended September 30, 2018 and 2017, securities covering approximately 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

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Valuation of Financial Instruments that are Marked-to-Market on Recurring Basis	The following table summarizes the valuation of our financial instruments that are marked-to-market on a recurring basis. Fair Value Measurements on a Recurring Basis September 30, 2018 December 31, 2017 (Dollars in millions) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Available-for-sale investments: Agency residential mortgage- backed securities $ — $ — $ — $ — $ — $ — $ — $ — Other — 2 — 2 — 2 — 2 Total available-for-sale investments — 2 — 2 — 2 — 2 Derivative instruments: (1) Interest rate swaps — 144 3 147 — 388 4 392 Cross-currency interest rate swaps — — 18 18 — — 88 88 Total derivative assets (2) — 144 21 165 — 388 92 480 Total $ — $ 146 $ 21 $ 167 $ — $ 390 $ 92 $ 482 Liabilities (3) Derivative instruments (1) Interest rate swaps $ — $ (96 ) $ (32 ) $ (128 ) $ — $ (144 ) $ (45 ) $ (189 ) Floor Income Contracts — (31 ) — (31 ) — (74 ) — (74 ) Cross-currency interest rate swaps — (46 ) (567 ) (613 ) — (44 ) (410 ) (454 ) Other — — (6 ) (6 ) — — (18 ) (18 ) Total derivative liabilities (2) — (173 ) (605 ) (778 ) — (262 ) (473 ) (735 ) Total $ — $ (173 ) $ (605 ) $ (778 ) $ — $ (262 ) $ (473 ) $ (735 ) (1) Fair value of derivative instruments excludes accrued interest and the value of collateral. (2) See “Note 4—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	9. 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. Three Months Ended September 30, 2018 2017 Derivative instruments Derivative instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (33 ) $ (529 ) $ (8 ) $ (570 ) $ (48 ) $ (666 ) $ (22 ) $ (736 ) Total gains/(losses): Included in earnings (1) 3 (52 ) 1 (48 ) 1 231 (5 ) 227 Included in other comprehensive income — — — — — — — — Settlements 1 32 1 34 1 30 3 34 Transfers in and/or out of level 3 — — — — — — — — Balance, end of period $ (29 ) $ (549 ) $ (6 ) $ (584 ) $ (46 ) $ (405 ) $ (24 ) $ (475 ) Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date (2) $ 4 $ (20 ) $ 2 $ (14 ) $ 3 $ 227 $ (2 ) $ 228 Nine Months Ended September 30, 2018 2017 Derivative instruments Derivative instruments (Dollars in millions) Interest Rate Cross Currency Interest Rate Swaps Other Total Derivative Instruments Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (41 ) $ (322 ) $ (18 ) $ (381 ) $ (46 ) $ (1,243 ) $ (13 ) $ (1,302 ) Total gains/(losses): Included in earnings (1) 10 (317 ) 7 (300 ) (4 ) 750 (19 ) 727 Included in other comprehensive income — — — — — — — — Settlements 2 90 5 97 4 88 8 100 Transfers in and/or out of level 3 — — — — — — — — Balance, end of period $ (29 ) $ (549 ) $ (6 ) $ (584 ) $ (46 ) $ (405 ) $ (24 ) $ (475 ) Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date (2) $ 11 $ (200 ) $ 12 $ (177 ) $ — $ 712 $ (11 ) $ 701 (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	Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Gains (losses) on derivative and hedging activities, net $ (16 ) $ 257 $ (210 ) $ 815 Interest expense (32 ) (30 ) (90 ) (88 ) Total $ (48 ) $ 227 $ (300 ) $ 727 (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	9. 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 September 30, 2018 Valuation Technique Input Range (Weighted Average) Derivatives Prime/LIBOR basis swaps $ (29 ) Discounted cash flow Constant Prepayment Rate 7% Bid/ask adjustment to .08% — .08% discount rate (.08%) Cross-currency interest rate swaps (549 ) Discounted cash flow Constant Prepayment Rate 4% Other (6 ) Total $ (584 )
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. September 30, 2018 December 31, 2017 (Dollars in millions) Fair Value Carrying Value Difference Fair Value Carrying Value Difference Earning assets FFELP Loans $ 74,504 $ 74,257 $ 247 $ 82,271 $ 81,703 $ 568 Private Education Loans 23,420 22,447 973 24,421 23,419 1,002 Cash and investments (1) 5,544 5,544 — 5,034 5,034 — Total earning assets 103,468 102,248 1,220 111,726 110,156 1,570 Interest-bearing liabilities Short-term borrowings 5,034 5,007 (27 ) 4,783 4,771 (12 ) Long-term borrowings 96,482 96,089 (393 ) 104,921 105,012 91 Total interest-bearing liabilities 101,516 101,096 (420 ) 109,704 109,783 79 Derivative financial instruments Floor Income Contracts (31 ) (31 ) — (74 ) (74 ) — Interest rate swaps 19 19 — 203 203 — Cross-currency interest rate swaps (595 ) (595 ) — (366 ) (366 ) — Other (6 ) (6 ) — (18 ) (18 ) — Excess of net asset fair value over carrying value $ 800 $ 1,649 (1) “Cash and investments” includes available-for-sale investments that consist of investments that are primarily agency securities whose cost basis is $2 million and $2 million at September 30, 2018 and December 31, 2017, respectively, versus a fair value of $2 million and $2 million at September 30, 2018 and December 31, 2017, respectively.

Revenue from Contract with Cu_2

Revenue from Contract with Customers Accounted in Accordance with ASC 606 (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue From Contract With Customer [Abstract]
Summary of Disaggregation of Revenue from Contracts Accounted Under ASC 606 with Customers	11. Revenue from Contracts with Customers Accounted in Accordance with ASC 606 (Continued) 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 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (Dollars in millions) Federal Education Loans Business Processing Total Revenue Federal Education Loans Business Processing Total Revenue Federal Education Loan asset recovery services $ 22 $ — $ 22 $ 61 $ — $ 61 Government services — 40 40 — 134 134 Healthcare services — 24 24 — 68 68 Total $ 22 $ 64 $ 86 $ 61 $ 202 $ 263 Revenue by Client Type Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (Dollars in millions) Federal Education Loans Business Processing Total Revenue Federal Education Loans Business Processing Total Revenue Federal government $ 5 $ 2 $ 7 $ 7 $ 5 $ 12 Guarantor agencies 14 — 14 44 — 44 Other institutions 3 — 3 10 — 10 State and local government — 21 21 — 70 70 Tolling authorities — 17 17 — 59 59 Hospitals and other healthcare providers — 24 24 — 68 68 Total $ 22 $ 64 $ 86 $ 61 $ 202 $ 263

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Results and Reconciliations to GAAP	Three Months Ended September 30, 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 $ 774 $ 455 $ — $ — $ 1,229 $ 3 $ (18 ) $ (15 ) $ 1,214 Other loans 1 — — — 1 — — — 1 Cash and investments 12 4 — 10 26 — — — 26 Total interest income 787 459 — 10 1,256 3 (18 ) (15 ) 1,241 Total interest expense 624 257 — 48 929 9 (3 ) 6 935 Net interest income (loss) 163 202 — (38 ) 327 (6 ) (15 ) (21 ) 306 Less: provisions for loan losses 10 75 — — 85 — — — 85 Net interest income (loss) after provisions for loan losses 153 127 — (38 ) 242 (6 ) (15 ) (21 ) 221 Other income (loss): Servicing revenue 67 3 — — 70 — — — 70 Asset recovery and business processing revenue 42 — 64 — 106 — — — 106 Other income (loss) 18 — — 3 21 6 3 9 30 Losses on debt repurchases — — — (1 ) (1 ) — — — (1 ) Total other income (loss) 127 3 64 2 196 6 3 9 205 Expenses: Direct operating expenses 87 38 59 — 184 — — — 184 Overhead expenses — — — 71 71 — — — 71 Operating expenses 87 38 59 71 255 — — — 255 Goodwill and acquired intangible asset impairment and amortization — — — — — — 23 23 23 Restructuring/other reorganization expenses — — — 1 1 — — — 1 Total expenses 87 38 59 72 256 — 23 23 279 Income (loss) before income tax expense (benefit) 193 92 5 (108 ) 182 — (35 ) (35 ) 147 Income tax expense (benefit) (2) 45 20 1 (24 ) 42 — (9 ) (9 ) 33 Net income (loss) $ 148 $ 72 $ 4 $ (84 ) $ 140 $ — $ (26 ) $ (26 ) $ 114 (1) Core Earnings adjustments to GAAP: Three Months Ended September 30, 2018 (Dollars in millions) Net Derivative Accounting Net Impact of Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ (21 ) $ — $ (21 ) Total other income (loss) 9 — 9 Goodwill and acquired intangible asset impairment and amortization — 23 23 Total Core Earnings adjustments to GAAP $ (12 ) $ (23 ) (35 ) Income tax expense (benefit) (9 ) Net income (loss) $ (26 ) (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. Three Months Ended September 30, 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 $ 678 $ 445 $ — $ — $ 1,123 $ 16 $ (13 ) $ 3 $ 1,126 Other loans 2 — — — 2 — — — 2 Cash and investments 9 1 — 2 12 — — — 12 Total interest income 689 446 — 2 1,137 16 (13 ) 3 1,140 Total interest expense 531 221 — 40 792 (5 ) (2 ) (7 ) 785 Net interest income (loss) 158 225 — (38 ) 345 21 (11 ) 10 355 Less: provisions for loan losses 10 95 — — 105 — — — 105 Net interest income (loss) after provisions for loan losses 148 130 — (38 ) 240 21 (11 ) 10 250 Other income (loss): Servicing revenue 72 3 — — 75 — — — 75 Asset recovery and business processing revenue 102 — 55 — 157 — — — 157 Other income (loss) 1 — — 2 3 (21 ) 47 26 29 Gains on sales of loans and investments 3 — — — 3 — — — 3 Losses on debt repurchases — — — (1 ) (1 ) — — — (1 ) Total other income (loss) 178 3 55 1 237 (21 ) 47 26 263 Expenses: Direct operating expenses 77 39 49 — 165 — — — 165 Overhead expenses — — — 73 73 — — — 73 Operating expenses 77 39 49 73 238 — — — 238 Goodwill and acquired intangible asset impairment and amortization — — — — — — 6 6 6 Total expenses 77 39 49 73 238 — 6 6 244 Income (loss) before income tax expense (benefit) 249 94 6 (110 ) 239 — 30 30 269 Income tax expense (benefit) (2) 92 34 2 (41 ) 87 — 6 6 93 Net income (loss) $ 157 $ 60 $ 4 $ (69 ) $ 152 $ — $ 24 $ 24 $ 176 (1) Core Earnings adjustments to GAAP: Three Months Ended September 30, 2017 (Dollars in millions) Net Derivative Accounting Net Impact of Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ 10 $ — $ 10 Total other income (loss) 26 — 26 Goodwill and acquired intangible asset impairment and amortization — 6 6 Total Core Earnings adjustments to GAAP $ 36 $ (6 ) 30 Income tax expense (benefit) 6 Net income (loss) $ 24 (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. Nine Months Ended September 30, 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 $ 2,281 $ 1,327 $ — $ — $ 3,608 $ 14 $ (53 ) $ (39 ) $ 3,569 Other loans 3 1 — — 4 — — — 4 Cash and investments 31 9 — 26 66 — — — 66 Total interest income 2,315 1,337 — 26 3,678 14 (53 ) (39 ) 3,639 Total interest expense 1,817 746 — 139 2,702 13 (8 ) 5 2,707 Net interest income (loss) 498 591 — (113 ) 976 1 (45 ) (44 ) 932 Less: provisions for loan losses 60 224 — — 284 — — — 284 Net interest income (loss) after provisions for loan losses 438 367 — (113 ) 692 1 (45 ) (44 ) 648 Other income (loss): Servicing revenue 201 9 — — 210 — — — 210 Asset recovery and business processing revenue 112 — 201 — 313 — — — 313 Other income (loss) 20 — — 6 26 (1 ) 14 13 39 Losses on debt repurchases — — — (9 ) (9 ) — — — (9 ) Total other income (loss) 333 9 201 (3 ) 540 (1 ) 14 13 553 Expenses: Direct operating expenses 202 133 172 — 507 — — — 507 Overhead expenses — — — 224 224 — — — 224 Operating expenses 202 133 172 224 731 — — — 731 Goodwill and acquired intangible asset impairment and amortization — — — — — — 39 39 39 Restructuring/other reorganization expenses — — — 10 10 — — — 10 Total expenses 202 133 172 234 741 — 39 39 780 Income (loss) before income tax expense (benefit) 569 243 29 (350 ) 491 — (70 ) (70 ) 421 Income tax expense (benefit) (2) 130 56 7 (81 ) 112 — (14 ) (14 ) 98 Net income (loss) $ 439 $ 187 $ 22 $ (269 ) $ 379 $ — $ (56 ) $ (56 ) $ 323 (1) Core Earnings adjustments to GAAP: Nine Months Ended September 30, 2018 (Dollars in millions) Net Derivative Accounting Net Impact of Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ (44 ) $ — $ (44 ) Total other income (loss) 13 — 13 Goodwill and acquired intangible asset impairment and amortization — 39 39 Total Core Earnings adjustments to GAAP $ (31 ) $ (39 ) (70 ) Income tax expense (benefit) (14 ) Net income (loss) $ (56 ) (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. Nine Months Ended September 30, 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 $ 1,966 $ 1,204 $ — $ — $ 3,170 $ 54 $ (41 ) $ 13 $ 3,183 Other loans 12 — — — 12 — — — 12 Cash and investments 20 3 — 6 29 — — — 29 Total interest income 1,998 1,207 — 6 3,211 54 (41 ) 13 3,224 Total interest expense 1,486 601 — 102 2,189 (3 ) (8 ) (11 ) 2,178 Net interest income (loss) 512 606 — (96 ) 1,022 57 (33 ) 24 1,046 Less: provisions for loan losses 32 285 — — 317 — — — 317 Net interest income (loss) after provisions for loan losses 480 321 — (96 ) 705 57 (33 ) 24 729 Other income (loss): Servicing revenue 215 6 — — 221 — — — 221 Asset recovery and business processing revenue 215 — 152 — 367 — — — 367 Other income (loss) 2 — — 11 13 (57 ) 31 (26 ) (13 ) Gains on sales of loans and investments 3 — — — 3 — — — 3 Losses on debt repurchases — — — (1 ) (1 ) — — — (1 ) Total other income (loss) 435 6 152 10 603 (57 ) 31 (26 ) 577 Expenses: Direct operating expenses 245 111 131 — 487 — — — 487 Overhead expenses — — — 220 220 — — — 220 Operating expenses 245 111 131 220 707 — — — 707 Goodwill and acquired intangible asset impairment and amortization — — — — — — 17 17 17 Total expenses 245 111 131 220 707 — 17 17 724 Income (loss) before income tax expense (benefit) 670 216 21 (306 ) 601 — (19 ) (19 ) 582 Income tax expense (benefit) (2) 244 79 8 (112 ) 219 — (13 ) (13 ) 206 Net income (loss) $ 426 $ 137 $ 13 $ (194 ) $ 382 $ — $ (6 ) $ (6 ) $ 376 (1) Core Earnings adjustments to GAAP: Nine Months Ended September 30, 2017 (Dollars in millions) Net Impact of Derivative Accounting Net Goodwill and Acquired Intangible Assets Total Net interest income (loss) after provisions for loan losses $ 24 $ — $ 24 Total other income (loss) (26 ) — (26 ) Goodwill and acquired intangible asset impairment and amortization — 17 17 Total Core Earnings adjustments to GAAP $ (2 ) $ (17 ) (19 ) Income tax expense (benefit) (13 ) Net income (loss) $ (6 ) (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment.
Core Earnings Adjustments to GAAP	Summary of Core Earnings Adjustments to GAAP Three Months Ended September 30, Nine Months Ended September 30, (Dollars in millions) 2018 2017 2018 2017 Core Earnings adjustments to GAAP: Net impact of derivative accounting (1) $ (12 ) $ 36 $ (31 ) $ (2 ) Net impact of goodwill and acquired intangible assets (2) (23 ) (6 ) (39 ) (17 ) Net tax effect (3) 9 (6 ) 14 13 Total Core Earnings adjustments to GAAP $ (26 ) $ 24 $ (56 ) $ (6 ) (1) Derivative accounting: (2) Goodwill and acquired intangible assets: (3) Net tax effect:
Federal Education Loans [Member]
Asset Information for Loans Segment	The following table includes GAAP basis asset information for our Federal Education Loans segment. (Dollars in millions) September 30, 2018 December 31, 2017 FFELP Loans, net $ 74,257 $ 81,703 Cash and investments (1) 2,510 2,821 Other 2,113 2,601 Total assets $ 78,880 $ 87,125 (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. (Dollars in millions) September 30, 2018 December 31, 2017 Private Education Loans, net $ 22,447 $ 23,419 Cash and investments (1) 706 706 Other 1,115 1,143 Total assets $ 24,268 $ 25,268 (1) Includes restricted cash and investments.

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Summary Of Significant Accounting Policies [Line Items]
Contract with customer, revenue recognized	$ 86,000,000	$ 263,000,000
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect		(13,000,000)
Business Processing [Member]
Summary Of Significant Accounting Policies [Line Items]
Contract with customer, revenue recognized	64,000,000	202,000,000
Federal Education Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Contract with customer, revenue recognized	22,000,000	61,000,000
ASU 2014-09 [Member] | Business Processing [Member]
Summary Of Significant Accounting Policies [Line Items]
Contract with customer, revenue recognized		8,000,000
Expenses recognized from contract with customer		5,000,000
ASU 2014-09 [Member] | Federal Education Loans [Member] | Difference Before and After Topic 606 [Member]
Summary Of Significant Accounting Policies [Line Items]
Effect of change in accounting policy on asset recovery	14,000,000	33,000,000
Effect of change in accounting policy on operating expense	$ 14,000,000	33,000,000
Effect of change in accounting policy on net income		$ 0

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail) $ in Billions	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)Loan	Dec. 31, 2017USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Percentage of loans granted forbearance that migrated to TDR classification	64.00%	61.00%
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 | $	$ 2	$ 2.7
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

Allowance for Loan Losses - All

Allowance for Loan Losses - Allowance for Credit Losses and Recorded Investments in Loans (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)SecurityLoan	Sep. 30, 2017USD ($)SecurityLoan	Sep. 30, 2018USD ($)SecurityLoan	Sep. 30, 2017USD ($)SecurityLoan
Allowance for Loan Losses
Beginning balance	$ 1,389	$ 1,362	$ 1,367	$ 1,433
Total provision	85	105	284	317
Net adjustment resulting from the change in the charge-off rate	(32)		(32)
Net charge-offs remaining	(129)		(310)
Total net charge-offs	(161)	(109)	(342)	(396)
Reclassification of interest reserve	2	2	6	6
Ending balance	1,315	1,360	1,315	1,360
Allowance Ending Balance:
Ending Balance: Individually evaluated for impairment — TDR	1,143	1,179	1,143	1,179
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	172	181	172	181
Ending balance	1,315	1,360	1,315	1,360
Loans Ending Balance:
Ending Balance: Individually evaluated for impairment — TDR	10,526	10,991	10,526	10,991
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	82,286	91,747	82,286	91,747
Purchased Non-Credit Impaired Loans acquired at a discount	5,223	6,018	5,223	6,018
Purchased Credit Impaired Loans	231	258	231	258
Ending total loans	98,266	109,014	98,266	109,014
FFELP Loans [Member]
Allowance for Loan Losses
Beginning balance	82	61	60	67
Total provision	10	10	60	30
Net charge-offs remaining	(13)		(41)
Total net charge-offs	(13)	(10)	(41)	(36)
Ending balance	79	61	79	61
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	79	61	79	61
Ending balance	79	61	79	61
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	70,778	79,923	70,778	79,923
Purchased Non-Credit Impaired Loans acquired at a discount	2,941	3,362	2,941	3,362
Ending total loans	$ 73,719	$ 83,285	$ 73,719	$ 83,285
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate	0.09%		0.09%
Allowance coverage of charge-offs | SecurityLoan	1.5	1.7	1.4	1.3
Allowance as a percentage of the ending total loan balance	0.11%	0.07%	0.11%	0.07%
Allowance as a percentage of the ending loans in repayment	0.13%	0.09%	0.13%	0.09%
Average loans in repayment	$ 61,956	$ 68,168	$ 63,934	$ 68,791
Ending loans in repayment	60,959	$ 66,220	60,959	$ 66,220
Charge-offs as a percentage of average loans in repayment		0.05%		0.07%
Private Education Loans [Member]
Allowance for Loan Losses
Beginning balance	1,297	$ 1,286	1,297	$ 1,351
Total provision	75	95	224	285
Net adjustment resulting from the change in the charge-off rate	(32)		(32)
Net charge-offs remaining	(116)		(269)
Total net charge-offs	(148)	(96)	(301)	(355)
Reclassification of interest reserve	2	2	6	6
Ending balance	1,226	1,287	1,226	1,287
Allowance Ending Balance:
Ending Balance: Individually evaluated for impairment — TDR	1,134	1,169	1,134	1,169
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	92	118	92	118
Ending balance	1,226	1,287	1,226	1,287
Loans Ending Balance:
Ending Balance: Individually evaluated for impairment — TDR	10,497	10,961	10,497	10,961
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	11,459	11,790	11,459	11,790
Purchased Non-Credit Impaired Loans acquired at a discount	2,282	2,656	2,282	2,656
Purchased Credit Impaired Loans	231	258	231	258
Ending total loans	$ 24,469	$ 25,665	$ 24,469	$ 25,665
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate	2.08%		1.61%
Net adjustment resulting from the change in charge-off rate as a percentage of average loans in repayment	0.57%		0.19%
Allowance coverage of charge-offs | SecurityLoan	2.1	3.4	3	2.7
Allowance as a percentage of the ending total loan balance	5.01%	5.02%	5.01%	5.02%
Allowance as a percentage of the ending loans in repayment	5.57%	5.73%	5.57%	5.73%
Average loans in repayment	$ 22,158	$ 23,112	$ 22,367	$ 22,180
Ending loans in repayment	21,997	$ 22,448	21,997	$ 22,448
Charge-offs as a percentage of average loans in repayment		1.63%		2.14%
Other Loans [Member]
Allowance for Loan Losses
Beginning balance	10	$ 15	10	$ 15
Total provision				2
Total net charge-offs		(3)		(5)
Ending balance	10	12	10	12
Allowance Ending Balance:
Ending Balance: Individually evaluated for impairment — TDR	9	10	9	10
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	1	2	1	2
Ending balance	10	12	10	12
Loans Ending Balance:
Ending Balance: Individually evaluated for impairment — TDR	29	30	29	30
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	49	34	49	34
Ending total loans	$ 78	$ 64	$ 78	$ 64
Allowance coverage of charge-offs | SecurityLoan		0.9		1.7
Allowance as a percentage of the ending total loan balance	12.71%	18.59%	13.02%	18.59%
Allowance as a percentage of the ending loans in repayment	12.71%	18.59%	13.02%	18.59%
Average loans in repayment	$ 77	$ 85	$ 74	$ 186
Ending loans in repayment	$ 78	$ 64	$ 78	$ 64
Charge-offs as a percentage of average loans in repayment		16.22%		3.92%

Allowance for Loan Losses - A_2

Allowance for Loan Losses - Allowance for Credit Losses and Recorded Investments in Loans (Parenthetical) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounts Notes And Loans Receivable [Line Items]
Net adjustment resulting from the change in the charge-off rate	$ 32,000,000		$ 32,000,000
FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance for loans acquired	0	$ 0	0	$ 0
Loans receivable, discount	38,000,000	45,000,000	38,000,000	45,000,000
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Net adjustment resulting from the change in the charge-off rate	32,000,000		32,000,000
Allowance for loans acquired	0	0	0	0
Loans receivable, discount	$ 343,000,000	$ 405,000,000	$ 343,000,000	$ 405,000,000
Private Education Loans [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Portion of loan amount charged off at default	79.00%		79.00%
Private Education Loans [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Portion of loan amount charged off at default	80.50%		80.50%
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	$ 32,000,000		$ 32,000,000

Allowance for Loan Losses - Age

Allowance for Loan Losses - Age Analysis of Past Due Loans Delinquencies (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Jun. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Loans in repayment and percentage of each status:
Loans allowance for losses	$ (1,315)	$ (1,367)	$ (1,389)	$ (1,360)	$ (1,362)	$ (1,433)
FFELP Loans [Member]
Loans in repayment and percentage of each status:
Total loans in repayment	60,959			66,220
Loans allowance for losses	(79)	(60)	$ (82)	$ (61)	$ (61)	$ (67)
Loans, net	74,257	81,703
Credit Concentration Risk [Member] | Private Education Loans - TDRs [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	10,131	10,536
Loans in repayment and percentage of each status:
Loans current	7,767	8,333
Total loans in repayment	8,969	9,378
Loans unamortized premium (discount)	(213)	(225)
Total loans	9,918	10,311
Loans receivable for partially charged-off loans	366	385
Loans allowance for losses	(1,134)	(1,171)
Loans, net	$ 9,150	$ 9,525
Dimensions of concentration risk	100.00%	100.00%
Credit Concentration Risk [Member] | Private Education Loans - Non-TDRs [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	$ 13,650	$ 14,344
Loans in repayment and percentage of each status:
Total loans in repayment	13,028	13,546
Loans unamortized premium (discount)	(583)	(699)
Total loans	13,067	13,645
Loans receivable for partially charged-off loans	322	375
Loans allowance for losses	(92)	(126)
Loans, net	$ 13,297	$ 13,894
Credit Concentration Risk [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	100.00%	100.00%
Credit Concentration Risk [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	$ 385	$ 351
Credit Concentration Risk [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	$ 82	$ 120
Credit Concentration Risk [Member] | Financing Receivables, 31 to 60 Days Past Due [Member] | Accounts Receivable [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	4.30%	3.70%
Credit Concentration Risk [Member] | Financing Receivables, 31 to 60 Days Past Due [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	0.60%	0.90%
Credit Concentration Risk [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	$ 250	$ 207
Credit Concentration Risk [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	$ 39	$ 59
Credit Concentration Risk [Member] | Financing Receivables, 61 to 90 Days Past Due [Member] | Accounts Receivable [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	2.80%	2.20%
Credit Concentration Risk [Member] | Financing Receivables, 61 to 90 Days Past Due [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	0.30%	0.40%
Credit Concentration Risk [Member] | Financing Receivables, 90 Days Past Due [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 567	$ 487
Credit Concentration Risk [Member] | Financing Receivables, 90 Days Past Due [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 69	$ 110
Credit Concentration Risk [Member] | Financing Receivables, 90 Days Past Due [Member] | Accounts Receivable [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	6.30%	5.20%
Credit Concentration Risk [Member] | Financing Receivables, 90 Days Past Due [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	0.50%	0.80%
Credit Concentration Risk [Member] | Financing Receivables, Current [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Loans current	$ 12,838	$ 13,257
Credit Concentration Risk [Member] | Financing Receivables, Current [Member] | Accounts Receivable [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	86.60%	88.90%
Credit Concentration Risk [Member] | Financing Receivables, Current [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	98.60%	97.90%
Credit Concentration Risk [Member] | Financing Receivables, Loans In Repayment [Member] | Accounts Receivable [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	88.50%	89.00%
Credit Concentration Risk [Member] | Financing Receivables, Loans In Repayment [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	95.40%	94.40%
Credit Concentration Risk [Member] | Financing Receivables, Delinquent Loans in Repayment [Member] | Accounts Receivable [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	13.40%	11.10%
Credit Concentration Risk [Member] | Financing Receivables, Delinquent Loans in Repayment [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	1.40%	2.10%
Credit Concentration Risk [Member] | Financing Receivables, Forbearance, Loans In Repayment [Member] | Accounts Receivable [Member] | Private Education Loans - TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	7.30%	6.80%
Credit Concentration Risk [Member] | Financing Receivables, Forbearance, Loans In Repayment [Member] | Accounts Receivable [Member] | Private Education Loans - Non-TDRs [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	1.40%	1.60%
Credit Concentration Risk [Member] | School/Grace/Deferment [Member] | Private Education Loans - TDRs [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	$ 455	$ 477
Credit Concentration Risk [Member] | School/Grace/Deferment [Member] | Private Education Loans - Non-TDRs [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	437	584
Credit Concentration Risk [Member] | Forbearance [Member] | Private Education Loans - TDRs [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	707	681
Credit Concentration Risk [Member] | Forbearance [Member] | Private Education Loans - Non-TDRs [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	185	214
Credit Concentration Risk [Member] | FFELP Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	73,719	81,097
Loans in repayment and percentage of each status:
Loans current	54,005	59,264
Total loans in repayment	60,959	67,853
Loans unamortized premium (discount)	617	666
Total loans	74,336	81,763
Loans allowance for losses	(79)	(60)
Loans, net	$ 74,257	$ 81,703
Credit Concentration Risk [Member] | FFELP Loans [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	100.00%	100.00%
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, 31 to 60 Days Past Due [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 1,978	$ 2,638
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, 31 to 60 Days Past Due [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	3.20%	3.90%
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, 61 to 90 Days Past Due [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 947	$ 1,763
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, 61 to 90 Days Past Due [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	1.60%	2.60%
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, 90 Days Past Due [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 4,029	$ 4,188
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, 90 Days Past Due [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	6.60%	6.20%
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, Current [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	88.60%	87.30%
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, Loans In Repayment [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	82.70%	83.70%
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, Delinquent Loans in Repayment [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	11.40%	12.70%
Credit Concentration Risk [Member] | FFELP Loans [Member] | Financing Receivables, Forbearance, Loans In Repayment [Member] | Accounts Receivable [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	12.40%	11.20%
Credit Concentration Risk [Member] | FFELP Loans [Member] | School/Grace/Deferment [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	$ 4,160	$ 4,711
Credit Concentration Risk [Member] | FFELP Loans [Member] | Forbearance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	$ 8,600	$ 8,533

Allowance for Loan Losses - Pri

Allowance for Loan Losses - Private Education Loan Portfolio Stratified by Key Credit Quality Indicators (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Private Education Loans - TDRs [Member] | Original Winning FICO Scores [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 10,131	$ 10,536
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 9,283	$ 9,647
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 848	$ 889
Total Private Education Loan Credit Quality Indicators, Percent	8.00%	8.00%
Private Education Loans - TDRs [Member] | School Type [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 10,131	$ 10,536
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 7,997	$ 8,247
Total Private Education Loan Credit Quality Indicators, Percent	79.00%	78.00%
Private Education Loans - TDRs [Member] | School Type [Member] | For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 2,134	$ 2,289
Total Private Education Loan Credit Quality Indicators, Percent	21.00%	22.00%
Private Education Loans - TDRs [Member] | Cosigners [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 10,131	$ 10,536
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 6,258	$ 6,441
Total Private Education Loan Credit Quality Indicators, Percent	62.00%	61.00%
Private Education Loans - TDRs [Member] | Cosigners [Member] | Without Cosigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 3,873	$ 4,095
Total Private Education Loan Credit Quality Indicators, Percent	38.00%	39.00%
Private Education Loans - TDRs [Member] | Seasoning [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 10,131	$ 10,536
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 365	$ 506
Total Private Education Loan Credit Quality Indicators, Percent	4.00%	5.00%
Private Education Loans - TDRs [Member] | Seasoning [Member] | 13-24 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 491	$ 644
Total Private Education Loan Credit Quality Indicators, Percent	5.00%	6.00%
Private Education Loans - TDRs [Member] | Seasoning [Member] | 25-36 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 723	$ 947
Total Private Education Loan Credit Quality Indicators, Percent	7.00%	9.00%
Private Education Loans - TDRs [Member] | Seasoning [Member] | 37-48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 1,026	$ 1,271
Total Private Education Loan Credit Quality Indicators, Percent	10.00%	12.00%
Private Education Loans - TDRs [Member] | Seasoning [Member] | More than 48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 7,071	$ 6,691
Total Private Education Loan Credit Quality Indicators, Percent	70.00%	63.00%
Private Education Loans - TDRs [Member] | Seasoning [Member] | Not Yet in Repayment [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 455	$ 477
Total Private Education Loan Credit Quality Indicators, Percent	4.00%	5.00%
Private Education Loans - Non-TDRs [Member] | Original Winning FICO Scores [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 13,650	$ 14,344
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 13,142	$ 13,752
Total Private Education Loan Credit Quality Indicators, Percent	96.00%	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 Loan Credit Quality Indicators	$ 508	$ 592
Total Private Education Loan Credit Quality Indicators, Percent	4.00%	4.00%
Private Education Loans - Non-TDRs [Member] | School Type [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 13,650	$ 14,344
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 11,499	$ 12,431
Total Private Education Loan Credit Quality Indicators, Percent	84.00%	87.00%
Private Education Loans - Non-TDRs [Member] | School Type [Member] | For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 2,151	$ 1,913
Total Private Education Loan Credit Quality Indicators, Percent	16.00%	13.00%
Private Education Loans - Non-TDRs [Member] | Cosigners [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 13,650	$ 14,344
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 7,453	$ 9,193
Total Private Education Loan Credit Quality Indicators, Percent	55.00%	64.00%
Private Education Loans - Non-TDRs [Member] | Cosigners [Member] | Without Cosigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 6,197	$ 5,151
Total Private Education Loan Credit Quality Indicators, Percent	45.00%	36.00%
Private Education Loans - Non-TDRs [Member] | Seasoning [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 13,650	$ 14,344
Total Private Education Loan Credit Quality Indicators, 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 Loan Credit Quality Indicators	$ 2,553	$ 1,424
Total Private Education Loan Credit Quality Indicators, Percent	19.00%	10.00%
Private Education Loans - Non-TDRs [Member] | Seasoning [Member] | 13-24 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 758	$ 437
Total Private Education Loan Credit Quality Indicators, Percent	6.00%	3.00%
Private Education Loans - Non-TDRs [Member] | Seasoning [Member] | 25-36 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 334	$ 466
Total Private Education Loan Credit Quality Indicators, Percent	2.00%	3.00%
Private Education Loans - Non-TDRs [Member] | Seasoning [Member] | 37-48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 450	$ 867
Total Private Education Loan Credit Quality Indicators, Percent	3.00%	6.00%
Private Education Loans - Non-TDRs [Member] | Seasoning [Member] | More than 48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 9,118	$ 10,566
Total Private Education Loan Credit Quality Indicators, Percent	67.00%	74.00%
Private Education Loans - Non-TDRs [Member] | Seasoning [Member] | Not Yet in Repayment [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loan Credit Quality Indicators	$ 437	$ 584
Total Private Education Loan Credit Quality Indicators, Percent	3.00%	4.00%

Allowance for Loan Losses - Rec

Allowance for Loan Losses - Receivable for Partially Charged-Off Private Education Loans (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Charge-offs	$ (161)	$ (109)	$ (342)	$ (396)
Private Education Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Receivable at beginning of period			23,419
Charge-offs	(148)	(96)	(301)	(355)
Receivable at end of period	22,447		22,447
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	724	784	760	815
Expected future recoveries of current period defaults	29	24	68	88
Recoveries	(33)	(37)	(107)	(121)
Charge-offs	(32)		(33)	(11)
Receivable at end of period	$ 688	$ 771	$ 688	$ 771

Allowance for Loan Losses - R_2

Allowance for Loan Losses - Receivable for Partially Charged-Off Private Education Loans (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate	$ 32	$ 32
Private Education Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate	$ 32	$ 32
Private Education Loans [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	79.00%	79.00%
Private Education Loans [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	80.50%	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	$ 32	$ 32

Allowance for Loan Losses - R_3

Allowance for Loan Losses - Recorded Investment, Unpaid Principal Balance and Related Allowance for TDR Loans (Detail) - TDR [Member] - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable Impaired [Line Items]
Recorded investment	$ 10,482	$ 10,890
Total ending loans	10,497	10,921
Related allowance	$ 1,134	$ 1,171

Allowance for Loan Losses - Ave

Allowance for Loan Losses - Average Recorded Investment and Interest Income Recognized for TDR (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Receivables [Abstract]
Impaired financing receivable, Average recorded investment	$ 10,568	$ 10,944	$ 10,717	$ 11,016
Impaired financing receivable, Interest income recognized	$ 196	$ 180	$ 563	$ 528

Allowance for Loan Losses - Loa

Allowance for Loan Losses - Loans Modified Accounts for TDR (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Receivables [Abstract]
Modified loans	$ 163	$ 200	$ 470	$ 618
Charge-offs	123	80	243	280
Payment default	$ 35	$ 43	$ 105	$ 144

Allowance for Loan Losses - Acc

Allowance for Loan Losses - Accrued Interest Receivable (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	$ 1,863	$ 1,965
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	358	383
Accrued Interest Receivable, Allowance for Uncollectible Interest	27	26
Private Education Loans [Member] | TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	198	196
Accrued Interest Receivable, Allowance for Uncollectible Interest	19	20
Private Education Loans [Member] | Non-TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	160	187
Accrued Interest Receivable, Allowance for Uncollectible Interest	8	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	32	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	28	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	$ 4	$ 4

Borrowings - Company's Borrowin

Borrowings - Company's Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Short-term borrowings	$ 5,007	$ 4,771
Long-term borrowings	96,089	105,012
Total	101,096	109,783
Total Before Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Short-term borrowings	5,014	4,750
Long-term borrowings	96,587	105,018
Total	101,601	109,768
Total Before Hedge Accounting Adjustments [Member] | Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,162	1,306
Long-term borrowings	10,765	12,624
Total	12,927	13,930
Total Before Hedge Accounting Adjustments [Member] | Total Unsecured Borrowings [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,162	1,306
Long-term borrowings	10,765	12,624
Total	12,927	13,930
Total Before Hedge Accounting Adjustments [Member] | FFELP Loan Securitizations [Member]
Debt Instrument [Line Items]
Long-term borrowings	68,456	71,208
Total	68,456	71,208
Total Before Hedge Accounting Adjustments [Member] | Private Education Loan Securitizations [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,257	686
Long-term borrowings	11,579	12,646
Total	12,836	13,332
Total Before Hedge Accounting Adjustments [Member] | FFELP Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings		1,536
Long-term borrowings	4,408	6,830
Total	4,408	8,366
Total Before Hedge Accounting Adjustments [Member] | Private Education Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,391	684
Long-term borrowings	1,379	1,710
Total	2,770	2,394
Total Before Hedge Accounting Adjustments [Member] | Other [Member]
Debt Instrument [Line Items]
Short-term borrowings	204	538
Total	204	538
Total Before Hedge Accounting Adjustments [Member] | Secured Borrowings [Member]
Debt Instrument [Line Items]
Short-term borrowings	2,852	3,444
Long-term borrowings	85,822	92,394
Total	88,674	95,838
Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Short-term borrowings	(7)	21
Long-term borrowings	(498)	(6)
Total	$ (505)	$ 15

Borrowings - Company's Borrow_2

Borrowings - Company's Borrowings (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt	$ 96,089	$ 105,012
Short-term Debt	5,007	4,771
Total Before Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Long-term debt	96,587	105,018
Short-term Debt	5,014	4,750
Total Before Hedge Accounting Adjustments [Member] | FFELP Loan Securitizations Asset-backed Repurchase Facilities [Member]
Debt Instrument [Line Items]
Long-term debt	81
Total Before Hedge Accounting Adjustments [Member] | Private Education Loan Securitizations Repurchase Facilities [Member]
Debt Instrument [Line Items]
Long-term debt	1,100	1,300
Short-term Debt	1,300	686
Total Before Hedge Accounting Adjustments [Member] | Short Term Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt principal amount	2,200	1,300
Total Before Hedge Accounting Adjustments [Member] | Long Term Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt principal amount	$ 10,900	$ 12,700

Borrowings - Financing VIEs (De

Borrowings - Financing VIEs (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Securities Financing Transaction [Line Items]
Short-term borrowings	$ 5,007	$ 4,771
Long-term borrowings	96,089	105,012
Total	101,096	109,783
Total Before Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	5,014	4,750
Long-term borrowings	96,587	105,018
Total	101,601	109,768
Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	(7)	21
Long-term borrowings	(498)	(6)
Total	(505)	15
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	2,648	2,906
Long-term borrowings	85,107	89,317
Total	87,755	92,223
Loans	93,389	98,596
Cash	3,054	3,091
Other assets, Net	1,025	1,160
Total Carrying Amount of Assets Securing Debt Outstanding	97,468	102,847
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | FFELP Loan Securitizations [Member]
Securities Financing Transaction [Line Items]
Long-term borrowings	68,456	71,208
Total	68,456	71,208
Loans	69,280	72,145
Cash	2,366	2,335
Other assets, Net	1,237	1,078
Total Carrying Amount of Assets Securing Debt Outstanding	72,883	75,558
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | Private Education Loan Securitizations [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	1,257	686
Long-term borrowings	11,579	12,646
Total	12,836	13,332
Loans	16,170	17,739
Cash	528	484
Other assets, Net	209	237
Total Carrying Amount of Assets Securing Debt Outstanding	16,907	18,460
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | FFELP Loan - Other Facilities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings		1,536
Long-term borrowings	4,097	3,999
Total	4,097	5,535
Loans	4,200	5,565
Cash	71	204
Other assets, Net	103	156
Total Carrying Amount of Assets Securing Debt Outstanding	4,374	5,925
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | Private Education Loan - Other Facilities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	1,391	684
Long-term borrowings	1,379	1,710
Total	2,770	2,394
Loans	3,739	3,147
Cash	89	68
Other assets, Net	30	31
Total Carrying Amount of Assets Securing Debt Outstanding	3,858	3,246
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | Total Before Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	2,648	2,906
Long-term borrowings	85,511	89,563
Total	88,159	92,469
Loans	93,389	98,596
Cash	3,054	3,091
Other assets, Net	1,579	1,502
Total Carrying Amount of Assets Securing Debt Outstanding	98,022	103,189
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Long-term borrowings	(404)	(246)
Total	(404)	(246)
Other assets, Net	(554)	(342)
Total Carrying Amount of Assets Securing Debt Outstanding	$ (554)	$ (342)

Borrowings - Financing VIEs (Pa

Borrowings - Financing VIEs (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Securities Financing Transaction [Line Items]
Long-term debt	$ 96,089	$ 105,012
Short-term Debt	5,007	4,771
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Long-term debt	85,107	89,317
Restricted cash	3,054	3,091
Short-term Debt	2,648	2,906
FFELP Loan Securitizations Repurchase Facilities [Member] | Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Long-term debt	81
Restricted cash	2
Private Education Loan Securitizations Repurchase Facilities [Member] | Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Long-term debt	1,100	1,300
Restricted cash	127	96
Short-term Debt	$ 1,300	$ 686

Derivative Financial Instrume_3

Derivative Financial Instruments - Impact of Derivatives on Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Derivative Assets:
Derivative assets	$ 165	$ 480
Derivative Liabilities:
Derivative liabilities	(778)	(735)
Net total derivatives	(613)	(255)
Designated as Hedging Instrument [Member] | Cash Flow [Member]
Derivative Assets:
Derivative assets		95
Derivative Liabilities:
Derivative liabilities		(16)
Net total derivatives		79
Designated as Hedging Instrument [Member] | Fair Value [Member]
Derivative Assets:
Derivative assets	161	378
Derivative Liabilities:
Derivative liabilities	(634)	(512)
Net total derivatives	(473)	(134)
Trading [Member]
Derivative Assets:
Derivative assets	4	7
Derivative Liabilities:
Derivative liabilities	(144)	(207)
Net total derivatives	(140)	(200)
Interest Rate Swaps [Member]
Derivative Assets:
Derivative assets	147	392
Derivative Liabilities:
Derivative liabilities	(128)	(189)
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Cash Flow [Member]
Derivative Assets:
Derivative assets		95
Derivative Liabilities:
Derivative liabilities		(16)
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Fair Value [Member]
Derivative Assets:
Derivative assets	143	290
Derivative Liabilities:
Derivative liabilities	(67)	(102)
Interest Rate Swaps [Member] | Trading [Member]
Derivative Assets:
Derivative assets	4	7
Derivative Liabilities:
Derivative liabilities	(61)	(71)
Cross-Currency Interest Rate Swaps [Member]
Derivative Assets:
Derivative assets	18	88
Derivative Liabilities:
Derivative liabilities	(613)	(454)
Cross-Currency Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Fair Value [Member]
Derivative Assets:
Derivative assets	18	88
Derivative Liabilities:
Derivative liabilities	(567)	(410)
Cross-Currency Interest Rate Swaps [Member] | Trading [Member]
Derivative Liabilities:
Derivative liabilities	(46)	(44)
Floor Income Contracts [Member]
Derivative Liabilities:
Derivative liabilities	(31)	(74)
Floor Income Contracts [Member] | Trading [Member]
Derivative Liabilities:
Derivative liabilities	(31)	(74)
Other [Member]
Derivative Liabilities:
Derivative liabilities	(6)	(18)
Other [Member] | Trading [Member]
Derivative Liabilities:
Derivative liabilities	$ (6)	$ (18)

Derivative Financial Instrume_4

Derivative Financial Instruments - Gross Positions without Impact of Master Netting Agreements (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Derivatives Fair Value [Line Items]
Derivative assets	$ 165	$ 480
Derivative values with impact of master netting agreements (as carried on balance sheet), Assets	142	438
Cash collateral (held) pledged, Assets	(203)	(536)
Derivative liabilities	(778)	(735)
Cash collateral (held) pledged, Liabilities	245	235
Other Assets [Member]
Derivatives Fair Value [Line Items]
Derivative assets	165	480
Impact of master netting agreements, Assets	(23)	(42)
Derivative values with impact of master netting agreements (as carried on balance sheet), Assets	142	438
Cash collateral (held) pledged, Assets	(203)	(536)
Net position, Assets	(61)	(98)
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivative liabilities	(778)	(735)
Impact of master netting agreements, Liabilities	23	42
Derivative values with impact of master netting agreements (as carried on balance sheet), Liabilities	(755)	(693)
Cash collateral (held) pledged, Liabilities	245	235
Net position, Liabilities	$ (510)	$ (458)

Derivative Financial Instrume_5

Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Reduction of derivative assets	$ 286
Reduction of derivative liabilities	233
Decrease in valuation due to net credit risk adjustments	16	$ 6
Decrease in valuation due to liquidity adjustments	21	30
Derivative liability at fair value including accrued interest and premium receivable	745	$ 659
Counterparty [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liability at fair value including accrued interest and premium receivable	$ 156

Derivative Financial Instrume_6

Derivative Financial Instruments - Derivative Notional Values (Detail) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Total Derivative Notional Values	$ 132,800,000,000	$ 137,900,000,000
Designated as Hedging Instrument [Member] | Cash Flow [Member]
Derivative [Line Items]
Total Derivative Notional Values	26,500,000,000	24,100,000,000
Designated as Hedging Instrument [Member] | Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	16,200,000,000	19,100,000,000
Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	90,100,000,000	94,700,000,000
Interest Rate Swaps [Member]
Derivative [Line Items]
Total Derivative Notional Values	99,700,000,000	108,500,000,000
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Cash Flow [Member]
Derivative [Line Items]
Total Derivative Notional Values	26,500,000,000	24,100,000,000
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	11,600,000,000	12,400,000,000
Interest Rate Swaps [Member] | Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	61,600,000,000	72,000,000,000
Floor Income Contracts [Member]
Derivative [Line Items]
Total Derivative Notional Values	27,900,000,000	21,900,000,000
Floor Income Contracts [Member] | Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	27,900,000,000	21,900,000,000
Cross-Currency Interest Rate Swaps [Member]
Derivative [Line Items]
Total Derivative Notional Values	4,900,000,000	7,000,000,000
Cross-Currency Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	4,600,000,000	6,700,000,000
Cross-Currency Interest Rate Swaps [Member] | Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	300,000,000	300,000,000
Other [Member]
Derivative [Line Items]
Total Derivative Notional Values	300,000,000	500,000,000
Other [Member] | Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	$ 300,000,000	$ 500,000,000

Derivative Financial Instrume_7

Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative and hedging activities, net	$ 2	$ 25	$ 10	$ (16)
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	(63)	(28)	(321)	(94)
Gains (losses) recognized in net income on hedged items	66	39	356	62
Net fair value hedge ineffectiveness gains (losses)	3	11	35	(32)
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	(19)	261	(227)	837
Gains (losses) recognized in net income on hedged items	28	(262)	157	(866)
Net fair value hedge ineffectiveness gains (losses)	9	(1)	(70)	(29)
Gains (losses) on derivative and hedging activities, net	12	10	(35)	(61)
Trading [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative and hedging activities, net	(10)	15	45	45
Trading [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative and hedging activities, net	(8)	6	10	16
Trading [Member] | Cross-Currency Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative and hedging activities, net	(9)	(1)	(7)	5
Trading [Member] | Floor Income Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative and hedging activities, net	6	15	39	43
Trading [Member] | Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative and hedging activities, net	$ 1	$ (5)	$ 3	$ (19)

Derivative Financial Instrume_8

Derivative Financial Instruments - Collateral Held and Pledged (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Collateral held:
Cash (obligation to return cash collateral is recorded in short-term borrowings)	$ 203	$ 536
Securities at fair value — on-balance sheet securitization derivatives (not recorded in financial statements)	116	297
Total collateral held	319	833
Derivative asset at fair value including accrued interest	143	618
Collateral pledged to others:
Cash (right to receive return of cash collateral is recorded in investments)	245	235
Total collateral pledged	245	235
Derivative liability at fair value including accrued interest and premium receivable	$ 745	$ 659

Other Assets - Schedule of Othe

Other Assets - Schedule of Other Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Offsetting [Abstract]
Accrued interest receivable, net	$ 1,863	$ 1,965
Benefit and insurance-related investments	488	481
Income tax asset, net current and deferred	269	380
Derivatives at fair value	142	438
Fixed assets, net	138	156
Accounts receivable	107	108
Other loans, net	68	59
Other	378	438
Total	$ 3,453	$ 4,025

Business Combinations, Goodwi_2

Business Combinations, Goodwill and Acquired Intangible Assets - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended	9 Months Ended
	Nov. 30, 2017	Jul. 31, 2017	Sep. 30, 2018	Sep. 30, 2018	Jul. 31, 2018
Government Services [Member]
Business Acquisition [Line Items]
Goodwill			$ 136,000,000	$ 136,000,000
Goodwill impairment loss			$ 0
Reporting unit, percentage of fair value is greater than book value			56.00%	56.00%
Government Services [Member] | Toll Services [Member]
Business Acquisition [Line Items]
Impairment of intangible assets			$ 16,000,000
Earnest [Member]
Business Acquisition [Line Items]
Controlling interest percentage	95.00%
Payments to acquire business, cash	$ 149,000,000
Business acquisition, effective date of acquisition				Nov. 30, 2017
Goodwill	$ 74,000,000
Duncan Solutions [Member]
Business Acquisition [Line Items]
Controlling interest percentage		100.00%
Payments to acquire business, cash		$ 86,000,000
Business acquisition, effective date of acquisition				Jul. 31, 2017
Goodwill					$ 39,000,000

Stockholders' Equity - Common S

Stockholders' Equity - Common Share Repurchases and Issuances (Detail) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Equity, Class of Treasury Stock [Line Items]
Average purchase price per share	$ 13.90	$ 14.55	$ 13.90	$ 14.85
Shares repurchased related to employee stock-based compensation plans	175,241	131,374	3,732,745	1,741,529
Average purchase price per share	$ 13.90	$ 15.34	$ 13.77	$ 15.56
Common shares issued	395,615	385,676	5,529,853	3,535,988
Common Stock Shares Outstanding [Member]
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased	6,881,592	11,346,367	6,881,592	29,646,374
Shares repurchased related to employee stock-based compensation plans	175,241	131,374	3,732,745	1,741,529
Common shares issued	395,615	385,676	5,529,853	3,535,988

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 28, 2018
Class of Stock [Line Items]
Common stock dividend paid	$ 0.16	$ 0.16	$ 0.16	$ 0.48	$ 0.48
Purchase price of common stock repurchased on open market			$ 165,000,000		$ 440,000,000
Authorized share repurchased program amount	$ 500,000,000	$ 500,000,000		$ 500,000,000
Common Stock [Member]
Class of Stock [Line Items]
Closing price of common stock						$ 13.48
Authorized common share repurchased program remaining available amount	$ 565,000,000	$ 565,000,000		$ 565,000,000
Common Stock Shares Outstanding [Member]
Class of Stock [Line Items]
Common shares repurchased		6,881,592	11,346,367	6,881,592	29,646,374
Purchase price of common stock repurchased on open market		$ 95,000,000		$ 95,000,000	$ 440,000,000

Earnings per Common Share - Sch

Earnings per Common Share - Schedule of Earnings per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator:
Net income attributable to Navient Corporation	$ 114	$ 176	$ 323	$ 376
Denominator:
Weighted average shares used to compute basic EPS	260	269	263	279
Effect of dilutive securities:
Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units, derivative contracts and Employee Stock Purchase Plan (“ESPP”)	4	5	4	6
Dilutive potential common shares	4	5	4	6
Weighted average shares used to compute diluted EPS	264	274	267	285
Basic earnings per common share attributable to Navient Corporation	$ 0.44	$ 0.65	$ 1.23	$ 1.35
Diluted earnings per common share attributable to Navient Corporation	$ 0.43	$ 0.64	$ 1.21	$ 1.32

Earnings per Common Share - S_2

Earnings per Common Share - Schedule of Earnings per Common Share (Parenthetical) (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Securities not included in the computation of diluted earnings per share	6	5	6	5

Fair Value Measurements - Valua

Fair Value Measurements - Valuation of Financial Instruments that are Marked-to-Market on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Available-for-sale investments:
Available-for-sale investments	$ 2	$ 2
Derivative assets	165	480
Derivative liabilities	(778)	(735)
Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	147	392
Derivative liabilities	(128)	(189)
Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	18	88
Derivative liabilities	(613)	(454)
Floor Income Contracts [Member]
Available-for-sale investments:
Derivative liabilities	(31)	(74)
Other [Member]
Available-for-sale investments:
Derivative liabilities	(6)	(18)
Fair Value Measurements Recurring [Member]
Available-for-sale investments:
Available-for-sale investments	2	2
Derivative assets	165	480
Total	167	482
Derivative liabilities	(778)	(735)
Total	(778)	(735)
Fair Value Measurements Recurring [Member] | Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	147	392
Derivative liabilities	(128)	(189)
Fair Value Measurements Recurring [Member] | Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	18	88
Derivative liabilities	(613)	(454)
Fair Value Measurements Recurring [Member] | Floor Income Contracts [Member]
Available-for-sale investments:
Derivative liabilities	(31)	(74)
Fair Value Measurements Recurring [Member] | Other [Member]
Available-for-sale investments:
Derivative liabilities	(6)	(18)
Fair Value Measurements Recurring [Member] | Other [Member]
Available-for-sale investments:
Available-for-sale investments	2	2
Fair Value Measurements Recurring [Member] | Level 2 [Member]
Available-for-sale investments:
Available-for-sale investments	2	2
Derivative assets	144	388
Total	146	390
Derivative liabilities	(173)	(262)
Total	(173)	(262)
Fair Value Measurements Recurring [Member] | Level 2 [Member] | Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	144	388
Derivative liabilities	(96)	(144)
Fair Value Measurements Recurring [Member] | Level 2 [Member] | Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative liabilities	(46)	(44)
Fair Value Measurements Recurring [Member] | Level 2 [Member] | Floor Income Contracts [Member]
Available-for-sale investments:
Derivative liabilities	(31)	(74)
Fair Value Measurements Recurring [Member] | Level 2 [Member] | Other [Member]
Available-for-sale investments:
Available-for-sale investments	2	2
Fair Value Measurements Recurring [Member] | Level 3 [Member]
Available-for-sale investments:
Derivative assets	21	92
Total	21	92
Derivative liabilities	(605)	(473)
Total	(605)	(473)
Fair Value Measurements Recurring [Member] | Level 3 [Member] | Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	3	4
Derivative liabilities	(32)	(45)
Fair Value Measurements Recurring [Member] | Level 3 [Member] | Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	18	88
Derivative liabilities	(567)	(410)
Fair Value Measurements Recurring [Member] | Level 3 [Member] | Other [Member]
Available-for-sale investments:
Derivative liabilities	$ (6)	$ (18)

Fair Value Measurements - Chang

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	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ (570)	$ (736)	$ (381)	$ (1,302)
Total gains/(losses):
Included in earnings	(48)	227	(300)	727
Included in other comprehensive income	0	0	0	0
Settlements	34	34	97	100
Transfers in and/or out of level 3	0	0	0	0
Balance, end of period	(584)	(475)	(584)	(475)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	(14)	228	(177)	701
Interest Rate Swaps [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	(33)	(48)	(41)	(46)
Total gains/(losses):
Included in earnings	3	1	10	(4)
Included in other comprehensive income	0	0	0	0
Settlements	1	1	2	4
Transfers in and/or out of level 3	0	0	0	0
Balance, end of period	(29)	(46)	(29)	(46)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	4	3	11
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	(529)	(666)	(322)	(1,243)
Total gains/(losses):
Included in earnings	(52)	231	(317)	750
Included in other comprehensive income	0	0	0	0
Settlements	32	30	90	88
Transfers in and/or out of level 3	0	0	0	0
Balance, end of period	(549)	(405)	(549)	(405)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	(20)	227	(200)	712
Other [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	(8)	(22)	(18)	(13)
Total gains/(losses):
Included in earnings	1	(5)	7	(19)
Included in other comprehensive income	0	0	0	0
Settlements	1	3	5	8
Transfers in and/or out of level 3	0	0	0	0
Balance, end of period	(6)	(24)	(6)	(24)
Change in mark-to-market gains/(losses) relating to instruments still held at the reporting date	$ 2	$ (2)	$ 12	$ (11)

Fair Value Measurements - Inclu

Fair Value Measurements - Included in Earnings (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gains (losses) on derivative and hedging activities, net	$ (48)	$ 227	$ (300)	$ 727
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	(16)	257	(210)	815
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	$ (32)	$ (30)	$ (90)	$ (88)

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Data Used in Recurring Valuations of Level 3 (Detail) $ in Millions	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Interest Rate Swaps [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	$ 19	$ 203
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	(595)	(366)
Other [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	(6)	$ (18)
Level 3 [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	(584)
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	$ (549)
Derivative Asset (Liability) Net, Valuation Technique [Extensible List]	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Derivatives	4
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	$ (6)
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	$ (29)
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	7
Level 3 [Member] | Prime/LIBOR Basis Swaps [Member] | Interest Rate Swaps [Member] | Bid/ask adjustment to discount rate [Member] | Minimum [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] | Maximum [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] | Weighted Average [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivatives	(0.08)

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total earning assets, Carrying Value	$ 102,248	$ 110,156
Short-term borrowings, Carrying Value	5,007	4,771
Long-term borrowings, Carrying Value	96,089	105,012
Total	101,096	109,783
Total earning assets, Fair Value	103,468	111,726
Short-term borrowings, Fair Value	5,034	4,783
Long-term borrowings, Fair Value	96,482	104,921
Total interest-bearing liabilities, Fair Value	101,516	109,704
FFELP Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	74,257	81,703
Loans receivable, Fair Value	74,504	82,271
Floor Income Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(31)	(74)
Derivative financial instruments, Fair Value	(31)	(74)
Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	19	203
Derivative financial instruments, Fair Value	19	203
Cross-Currency Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(595)	(366)
Derivative financial instruments, Fair Value	(595)	(366)
Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(6)	(18)
Derivative financial instruments, Fair Value	(6)	(18)
Private Education Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	22,447	23,419
Loans receivable, Fair Value	23,420	24,421
Difference [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total earning assets, Fair Value	1,220	1,570
Short-term borrowings, Fair Value	(27)	(12)
Long-term borrowings, Fair Value	(393)	91
Total interest-bearing liabilities, Fair Value	(420)	79
Excess of net asset fair value over carrying value	800	1,649
Difference [Member] | FFELP Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable, Fair Value	247	568
Difference [Member] | Private Education Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable, Fair Value	973	1,002
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and investments	5,544	5,034
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and investments	$ 5,544	$ 5,034

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Available-for-sale investments, cost basis	$ 2	$ 2
Available-for-sale investments, fair value	$ 2	$ 2

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Sep. 30, 2018	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

Revenue from Contract with Cu_3

Revenue from Contract with Customers Accounted in Accordance with ASC 606 - Summary of Disaggregation of Revenue from Contracts Accounted Under ASC 606 with Customers (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 86	$ 263
Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	7	12
Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	14	44
Other Institutions [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	3	10
State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	21	70
Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	17	59
Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	24	68
Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	22	61
Federal Education Loans [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	5	7
Federal Education Loans [Member] | Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	14	44
Federal Education Loans [Member] | Other Institutions [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	3	10
Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	64	202
Business Processing [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	2	5
Business Processing [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	21	70
Business Processing [Member] | Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	17	59
Business Processing [Member] | Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	24	68
Federal Education Loan Asset Recovery Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	22	61
Federal Education Loan Asset Recovery Services [Member] | Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	22	61
Government Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	40	134
Government Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	40	134
Healthcare Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	24	68
Healthcare Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 24	$ 68

Revenue from Contract with Cu_4

Revenue from Contract with Customers Accounted in Accordance with ASC 606 - Additional Information (Detail) - USD ($)	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Accounts receivable	$ 107,000,000		$ 108,000,000
ASU 2014-09 [Member]
Disaggregation Of Revenue [Line Items]
Accounts receivable	77,000,000	$ 63,000,000
Contract assets	0
Contract liability	$ 0

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)SegmentClient	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Number of reportable operating segments | Segment	4
Accounts Receivable	$ 107	$ 108
Total assets	$ 106,493	114,991
Business Processing [Member]
Segment Reporting Information [Line Items]
Number of clients for business processing services | Client	600
Total assets	$ 447	466
Business Processing [Member] | Non-education Loan [Member]
Segment Reporting Information [Line Items]
Accounts Receivable	13,000
Other Segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 2,900	$ 2,100

Segment Reporting - Asset Infor

Segment Reporting - Asset Information for Loans Segment (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Other	$ 3,453	$ 4,025
Total assets	106,493	114,991
Federal Education Loans [Member]
Segment Reporting Information [Line Items]
Loans, net	74,257	81,703
Cash and investments	2,510	2,821
Other	2,113	2,601
Total assets	78,880	87,125
Consumer Lending [Member]
Segment Reporting Information [Line Items]
Loans, net	22,447	23,419
Cash and investments	706	706
Other	1,115	1,143
Total assets	$ 24,268	$ 25,268

Segment Reporting - Segment Res

Segment Reporting - Segment Results and Reconciliations to GAAP (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
Cash and investments	$ 26	$ 12	$ 66	$ 29
Total interest income	1,241	1,140	3,639	3,224
Total interest expense	935	785	2,707	2,178
Net interest income	306	355	932	1,046
Less: provisions for loan losses	85	105	284	317
Net interest income after provisions for loan losses	221	250	648	729
Other income (loss):
Servicing revenue	86		263
Asset recovery and business processing revenue	106	157	313	367
Other income (loss)	30	29	39	(13)
Gains on sales of loans and investments		3		3
Losses on debt repurchases	(1)	(1)	(9)	(1)
Total other income	205	263	553	577
Expenses:
Direct operating expenses	184	165	507	487
Overhead expenses	71	73	224	220
Total operating expenses	255	238	731	707
Goodwill and acquired intangible asset impairment and amortization	23	6	39	17
Restructuring/other reorganization expenses	1		10
Total expenses	279	244	780	724
Income before income tax expense	147	269	421	582
Income tax expense (benefit)	33	93	98	206
Net income (loss)	114	176	323	376
Federal Education Loans [Member]
Other income (loss):
Servicing revenue	22		61
Business Processing [Member]
Other income (loss):
Servicing revenue	64		202
Education Loan Portfolio [Member]
Interest income:
Total interest income	1,214	1,126	3,569	3,183
Other Loans [Member]
Interest income:
Total interest income	1	2	4	12
Servicing Revenue [Member]
Other income (loss):
Servicing revenue	70	75	210	221
Operating Segments [Member]
Interest income:
Cash and investments	26	12	66	29
Total interest income	1,256	1,137	3,678	3,211
Total interest expense	929	792	2,702	2,189
Net interest income	327	345	976	1,022
Less: provisions for loan losses	85	105	284	317
Net interest income after provisions for loan losses	242	240	692	705
Other income (loss):
Asset recovery and business processing revenue	106	157	313	367
Other income (loss)	21	3	26	13
Gains on sales of loans and investments		3		3
Losses on debt repurchases	(1)	(1)	(9)	(1)
Total other income	196	237	540	603
Expenses:
Direct operating expenses	184	165	507	487
Overhead expenses	71	73	224	220
Total operating expenses	255	238	731	707
Restructuring/other reorganization expenses	1		10
Total expenses	256	238	741	707
Income before income tax expense	182	239	491	601
Income tax expense (benefit)	42	87	112	219
Net income (loss)	140	152	379	382
Operating Segments [Member] | Federal Education Loans [Member]
Interest income:
Cash and investments	12	9	31	20
Total interest income	787	689	2,315	1,998
Total interest expense	624	531	1,817	1,486
Net interest income	163	158	498	512
Less: provisions for loan losses	10	10	60	32
Net interest income after provisions for loan losses	153	148	438	480
Other income (loss):
Asset recovery and business processing revenue	42	102	112	215
Other income (loss)	18	1	20	2
Gains on sales of loans and investments		3		3
Total other income	127	178	333	435
Expenses:
Direct operating expenses	87	77	202	245
Total operating expenses	87	77	202	245
Total expenses	87	77	202	245
Income before income tax expense	193	249	569	670
Income tax expense (benefit)	45	92	130	244
Net income (loss)	148	157	439	426
Operating Segments [Member] | Other Segment [Member]
Interest income:
Cash and investments	10	2	26	6
Total interest income	10	2	26	6
Total interest expense	48	40	139	102
Net interest income	(38)	(38)	(113)	(96)
Net interest income after provisions for loan losses	(38)	(38)	(113)	(96)
Other income (loss):
Other income (loss)	3	2	6	11
Losses on debt repurchases	(1)	(1)	(9)	(1)
Total other income	2	1	(3)	10
Expenses:
Overhead expenses	71	73	224	220
Total operating expenses	71	73	224	220
Restructuring/other reorganization expenses	1		10
Total expenses	72	73	234	220
Income before income tax expense	(108)	(110)	(350)	(306)
Income tax expense (benefit)	(24)	(41)	(81)	(112)
Net income (loss)	(84)	(69)	(269)	(194)
Operating Segments [Member] | Consumer Lending [Member]
Interest income:
Cash and investments	4	1	9	3
Total interest income	459	446	1,337	1,207
Total interest expense	257	221	746	601
Net interest income	202	225	591	606
Less: provisions for loan losses	75	95	224	285
Net interest income after provisions for loan losses	127	130	367	321
Other income (loss):
Total other income	3	3	9	6
Expenses:
Direct operating expenses	38	39	133	111
Total operating expenses	38	39	133	111
Total expenses	38	39	133	111
Income before income tax expense	92	94	243	216
Income tax expense (benefit)	20	34	56	79
Net income (loss)	72	60	187	137
Operating Segments [Member] | Business Processing [Member]
Other income (loss):
Asset recovery and business processing revenue	64	55	201	152
Total other income	64	55	201	152
Expenses:
Direct operating expenses	59	49	172	131
Total operating expenses	59	49	172	131
Total expenses	59	49	172	131
Income before income tax expense	5	6	29	21
Income tax expense (benefit)	1	2	7	8
Net income (loss)	4	4	22	13
Operating Segments [Member] | Education Loan Portfolio [Member]
Interest income:
Total interest income	1,229	1,123	3,608	3,170
Operating Segments [Member] | Education Loan Portfolio [Member] | Federal Education Loans [Member]
Interest income:
Total interest income	774	678	2,281	1,966
Operating Segments [Member] | Education Loan Portfolio [Member] | Consumer Lending [Member]
Interest income:
Total interest income	455	445	1,327	1,204
Operating Segments [Member] | Other Loans [Member]
Interest income:
Total interest income	1	2	4	12
Operating Segments [Member] | Other Loans [Member] | Federal Education Loans [Member]
Interest income:
Total interest income	1	2	3	12
Operating Segments [Member] | Other Loans [Member] | Consumer Lending [Member]
Interest income:
Total interest income			1
Operating Segments [Member] | Servicing Revenue [Member]
Other income (loss):
Servicing revenue	70	75	210	221
Operating Segments [Member] | Servicing Revenue [Member] | Federal Education Loans [Member]
Other income (loss):
Servicing revenue	67	72	201	215
Operating Segments [Member] | Servicing Revenue [Member] | Consumer Lending [Member]
Other income (loss):
Servicing revenue	3	3	9	6
Adjustments [Member] | Reclassifications [Member]
Interest income:
Total interest income	3	16	14	54
Total interest expense	9	(5)	13	(3)
Net interest income	(6)	21	1	57
Net interest income after provisions for loan losses	(6)	21	1	57
Other income (loss):
Other income (loss)	6	(21)	(1)	(57)
Total other income	6	(21)	(1)	(57)
Adjustments [Member] | Additions (Subtractions) [Member]
Interest income:
Total interest income	(18)	(13)	(53)	(41)
Total interest expense	(3)	(2)	(8)	(8)
Net interest income	(15)	(11)	(45)	(33)
Net interest income after provisions for loan losses	(15)	(11)	(45)	(33)
Other income (loss):
Other income (loss)	3	47	14	31
Total other income	3	47	14	31
Expenses:
Goodwill and acquired intangible asset impairment and amortization	23	6	39	17
Total expenses	23	6	39	17
Income before income tax expense	(35)	30	(70)	(19)
Income tax expense (benefit)	(9)	6	(14)	(13)
Net income (loss)	(26)	24	(56)	(6)
Adjustments [Member] | Total Adjustments [Member]
Interest income:
Total interest income	(15)	3	(39)	13
Total interest expense	6	(7)	5	(11)
Net interest income	(21)	10	(44)	24
Net interest income after provisions for loan losses	(21)	10	(44)	24
Other income (loss):
Other income (loss)	9	26	13	(26)
Total other income	9	26	13	(26)
Expenses:
Goodwill and acquired intangible asset impairment and amortization	23	6	39	17
Total expenses	23	6	39	17
Income before income tax expense	(35)	30	(70)	(19)
Income tax expense (benefit)	(9)	6	(14)	(13)
Net income (loss)	(26)	24	(56)	(6)
Adjustments [Member] | Education Loan Portfolio [Member] | Reclassifications [Member]
Interest income:
Total interest income	3	16	14	54
Adjustments [Member] | Education Loan Portfolio [Member] | Additions (Subtractions) [Member]
Interest income:
Total interest income	(18)	(13)	(53)	(41)
Adjustments [Member] | Education Loan Portfolio [Member] | Total Adjustments [Member]
Interest income:
Total interest income	$ (15)	$ 3	$ (39)	$ 13

Segment Reporting - Segment R_2

Segment Reporting - Segment Result and Reconciliations to GAAP - Core Earnings Adjustments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses	$ 221	$ 250	$ 648	$ 729
Total other income (loss)	205	263	553	577
Goodwill and acquired intangible asset impairment and amortization	23	6	39	17
Income tax expense (benefit)	33	93	98	206
Net income attributable to Navient Corporation	114	176	323	376
Total Adjustments [Member] | Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income (loss) after provisions for loan losses	(21)	10	(44)	24
Total other income (loss)	9	26	13	(26)
Goodwill and acquired intangible asset impairment and amortization	23	6	39	17
Total Core Earnings adjustments to GAAP	(35)	30	(70)	(19)
Income tax expense (benefit)	(9)	6	(14)	(13)
Net income attributable to Navient Corporation	(26)	24	(56)	(6)
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	23	6	39	17
Total Core Earnings adjustments to GAAP	(23)	(6)	(39)	(17)
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	(21)	10	(44)	24
Total other income (loss)	9	26	13	(26)
Total Core Earnings adjustments to GAAP	$ (12)	$ 36	$ (31)	$ (2)

Segment Reporting - Core Earnin

Segment Reporting - Core Earnings Adjustments to GAAP (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Core Earnings adjustments to GAAP:
Net tax effect	$ (33)	$ (93)	$ (98)	$ (206)
Net income attributable to Navient Corporation	114	176	323	376
Total Adjustments [Member] | Adjustments [Member]
Core Earnings adjustments to GAAP:
Core Earnings adjustments to GAAP	(35)	30	(70)	(19)
Net tax effect	9	(6)	14	13
Net income attributable to Navient Corporation	(26)	24	(56)	(6)
Net Impact of Goodwill and Acquired Intangible Assets [Member] | Total Adjustments [Member] | Adjustments [Member]
Core Earnings adjustments to GAAP:
Core Earnings adjustments to GAAP	(23)	(6)	(39)	(17)
Net Impact of Derivative Accounting [Member] | Total Adjustments [Member] | Adjustments [Member]
Core Earnings adjustments to GAAP:
Core Earnings adjustments to GAAP	$ (12)	$ 36	$ (31)	$ (2)

Segment Reporting - Core Earn_2

Segment Reporting - Core Earnings Adjustments to GAAP (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2018USD ($)
Segment Reporting [Abstract]
Amount that will be equal to mark-to-market gain or loss over the life of the contract	$ 0