Navient (NAVI) 8-K3 May 182017 FY Other EventsFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document - Document and Entity Information [Line Items]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	NAVI
Entity Registrant Name	NAVIENT CORP
Entity Central Index Key	1,593,538
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		263,388,482
Entity Public Float			$ 4.5

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets
Loans, net	$ 105,122	$ 111,070
Investments
Available-for-sale	2	3
Other	268	347
Total investments	270	350
Cash and cash equivalents	1,518	1,253
Restricted cash and investments	3,246	3,600
Goodwill and acquired intangible assets, net	810	670
Other assets	4,025	4,193
Total assets	114,991	121,136
Liabilities
Short-term borrowings	4,771	2,334
Long-term borrowings	105,012	112,368
Other liabilities	1,723	2,711
Total liabilities	111,506	117,413
Commitments and contingencies
Equity
Common stock, par value $0.01 per share; 1.125 billion shares authorized: 440 million and 436 million shares issued, respectively	4	4
Additional paid-in capital	3,077	3,022
Accumulated other comprehensive income (net of tax expense of $36 and $3, respectively)	61	6
Retained earnings	3,004	2,890
Total Navient Corporation stockholders’ equity before treasury stock	6,146	5,922
Less: Common stock held in treasury at cost: 177 million and 145 million shares, respectively	(2,692)	(2,223)
Total Navient Corporation stockholders’ equity	3,454	3,699
Noncontrolling interest	31	24
Total equity	3,485	3,723
Total liabilities and equity	114,991	121,136
FFELP Loans [Member]
Assets
Loans, net	81,703	87,730
Private Education Loans [Member]
Assets
Loans, net	23,419	23,340
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Assets
Loans, net	98,596	104,008
Investments
Restricted cash	3,091	3,434
Other assets, net	1,160	(11)
Liabilities
Short-term borrowings	2,906	1,078
Long-term borrowings	89,317	95,492
Net assets of consolidated variable interest entities	10,624	10,861
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| FFELP Loans [Member]
Assets
Loans, net	77,710	83,429
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Private Education Loans [Member]
Assets
Loans, net	$ 20,886	20,500
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Other Loans [Member]
Assets
Loans, net		$ 79

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Allowance for loans losses	$ 1,367	$ 1,433
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,125,000,000	1,125,000,000
Common stock, shares issued	440,000,000	436,000,000
Tax expense for accumulated other comprehensive income	$ 36	$ 3
Common stock held in treasury	177,000,000	145,000,000
FFELP Loans [Member]
Allowance for loans losses	$ 60	$ 67
Private Education Loans [Member]
Allowance for loans losses	$ 1,297	$ 1,351

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Total interest income	$ 4,383	$ 4,146	$ 4,295
Cash and investments	43	22	8
Total interest income	4,383	4,146	4,295
Total interest expense	2,971	2,441	2,074
Net interest income	1,412	1,705	2,221
Less: provisions for loan losses	426	429	581
Net interest income after provisions for loan losses	986	1,276	1,640
Other income (loss):
Servicing revenue	290	304	340
Asset recovery and business processing revenue	475	390	367
Other income	9	7	17
Gains (losses) on sales of loans and investments	3		(9)
Gains (losses) on debt repurchases	(3)	1	21
Gains (losses) on derivative and hedging activities, net	22	117	166
Total other income	796	819	902
Expenses:
Salaries and benefits	519	500	467
Other operating expenses	447	451	451
Total operating expenses	966	951	918
Goodwill and acquired intangible asset impairment and amortization expense	23	36	12
Restructuring/other reorganization expenses	29		32
Total expenses	1,018	987	962
Income from continuing operations, before income tax expense	764	1,108	1,580
Income tax expense	472	427	597
Net income from continuing operations	292	681	983
Income from discontinued operations, net of tax expense			1
Net income attributable to Navient Corporation	$ 292	$ 681	$ 984
Basic earnings per common share attributable to Navient Corporation	$ 1.06	$ 2.15	$ 2.62
Average common shares outstanding	275	316	376
Diluted earnings per common share attributable to Navient Corporation	$ 1.04	$ 2.12	$ 2.58
Average common and common equivalent shares outstanding	281	322	382
Dividends per common share attributable to Navient Corporation	$ 0.64	$ 0.64	$ 0.64
FFELP Loans [Member]
Interest income:
Total interest income	$ 2,693	$ 2,528	$ 2,524
Total interest income	2,693	2,528	2,524
Less: provisions for loan losses	42	43	46
Private Education Loans [Member]
Interest income:
Total interest income	1,634	1,587	1,756
Total interest income	1,634	1,587	1,756
Less: provisions for loan losses	382	383	538
Other Loans [Member]
Interest income:
Total interest income	13	9	7
Total interest income	$ 13	$ 9	$ 7

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement - Consolidated Statements of Comprehensive Income [Line Items]
Net income	$ 292	$ 681	$ 984
Other comprehensive income (loss):
Unrealized hedging gains (losses) on derivatives	89	91	(93)
Reclassification adjustments for derivative (gains) losses included in net income (interest expense)	(1)	(1)	(1)
Total unrealized gains (losses) on derivatives	88	90	(94)
Income tax (expense) benefit	(33)	(33)	34
Other comprehensive income (loss), net of tax expense (benefit)	55	57	(60)
Total comprehensive income attributable to Navient Corporation	$ 347	$ 738	$ 924

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Treasury Stock [Member]	Common Stock Shares Outstanding [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total Stockholders' Equity [Member]	Noncontrolling Interest [Member]
Beginning Balance, Value at Dec. 31, 2014	$ 4,144	$ 4	$ (432)		$ 2,893	$ 9	$ 1,670	$ 4,144
Beginning Balance, Shares at Dec. 31, 2014		425,637,635	(23,902,829)	401,734,806
Comprehensive income:
Net income	984						984	984
Other comprehensive income (loss), net of tax	(60)					(60)		(60)
Total comprehensive income	924							924
Cash dividends:
Common stock	(240)						(240)	(240)
Issuance of common shares	$ 34				34			34
Issuance of common shares, Shares	4,924,021	4,924,021		4,924,021
Tax impact of employee stock-based compensation plans	$ 11				11			11
Stock-based compensation expense	29				29			29
Common stock repurchased	(945)		$ (945)					(945)
Common stock repurchased, Shares			(56,043,711)	(56,043,711)
Shares repurchased related to employee stock-based compensation plans	$ (48)		$ (48)					(48)
Shares repurchased related to employee stock-based compensation plans, Shares	(2,404,328)		(2,404,328)	(2,404,328)
Noncontrolling interests in businesses	$ 24								$ 24
Ending Balance, Value at Dec. 31, 2015	3,933	$ 4	$ (1,425)		2,967	(51)	2,414	3,909	24
Ending Balance, Shares at Dec. 31, 2015		430,561,656	(82,350,868)	348,210,788
Comprehensive income:
Net income	681						681	681
Other comprehensive income (loss), net of tax	57					57		57
Total comprehensive income	738							738
Cash dividends:
Common stock	(201)						(201)	(201)
Dividend equivalent units related to employeestock-based compensation plans	(4)						(4)	(4)
Issuance of common shares	$ 35				35			35
Issuance of common shares, Shares	5,476,010	5,476,010		5,476,010
Tax impact of employee stock-based compensation plans	$ (6)				(6)			(6)
Stock-based compensation expense	26				26			26
Common stock repurchased	(755)		$ (755)					(755)
Common stock repurchased, Shares			(59,625,325)	(59,625,325)
Shares repurchased related to employee stock-based compensation plans	$ (43)		$ (43)					(43)
Shares repurchased related to employee stock-based compensation plans, Shares	(3,197,355)		(3,197,355)	(3,197,355)
Ending Balance, Value at Dec. 31, 2016	$ 3,723	$ 4	$ (2,223)		3,022	6	2,890	3,699	24
Ending Balance, Shares at Dec. 31, 2016		436,037,666	(145,173,548)	290,864,118
Comprehensive income:
Net income	292						292	292
Other comprehensive income (loss), net of tax	55					55		55
Total comprehensive income	347							347
Cash dividends:
Common stock	(176)						(176)	(176)
Dividend equivalent units related to employeestock-based compensation plans	(2)						(2)	(2)
Issuance of common shares	$ 20				20			20
Issuance of common shares, Shares	3,680,479	3,680,479		3,680,479
Stock-based compensation expense	$ 35				35			35
Common stock repurchased	(440)		$ (440)					(440)
Common stock repurchased, Shares			(29,646,374)	(29,646,374)
Shares repurchased related to employee stock-based compensation plans	$ (29)		$ (29)					(29)
Shares repurchased related to employee stock-based compensation plans, Shares	(1,847,651)		(1,847,651)	(1,847,651)
Noncontrolling interests in businesses	$ 7								7
Ending Balance, Value at Dec. 31, 2017	$ 3,485	$ 4	$ (2,692)		$ 3,077	$ 61	$ 3,004	$ 3,454	$ 31
Ending Balance, Shares at Dec. 31, 2017		439,718,145	(176,667,573)	263,050,572

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividends per common share attributable to Navient Corporation	$ 0.64	$ 0.64	$ 0.64
Retained Earnings [Member]
Dividends per common share attributable to Navient Corporation	0.64	0.64	0.64
Total Stockholders' Equity [Member]
Dividends per common share attributable to Navient Corporation	$ 0.64	$ 0.64	$ 0.64

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities
Net income	$ 292	$ 681	$ 984
Adjustments to reconcile net income to net cash provided by operating activities:
Losses (gains) on debt repurchases	3	(1)	(21)
Goodwill and acquired intangible asset impairment and amortization expense	23	36	12
Stock-based compensation expense	35	26	29
Unrealized gains on derivative and hedging activities	(83)	(328)	(781)
Provisions for losses	426	429	581
(Increase) decrease in restricted cash — other	(1)	10	66
(Increase) decrease in accrued interest receivable	(29)	(26)	175
Increase (decrease) in accrued interest payable	11	(92)	(42)
Decrease in other assets	485	628	1,046
Decrease in other liabilities	(5)	(6)	(139)
Total net cash provided by operating activities	1,157	1,357	1,910
Investing activities
Education loans acquired	(7,456)	(3,683)	(3,736)
Reduction of education loans:
Installment payments	14,738	14,923	13,933
Proceeds from sales of education loans			569
Other investing activities, net	(87)	35	131
Proceeds from maturities of available-for-sale securities		2	1
Purchases of other securities	(1)	(44)	(187)
Proceeds from maturities of other securities	23	49	97
Purchase of subsidiaries, net of cash acquired	(216)		(342)
Total net cash provided by investing activities	7,496	11,411	10,686
Financing activities
Borrowings collateralized by loans in trust — issued	8,440	6,691	5,011
Borrowings collateralized by loans in trust — repaid	(13,919)	(13,226)	(14,706)
Long-term notes issued	1,613	1,231	493
Long-term notes repaid	(1,464)	(2,603)	(2,787)
Other financing activities, net	(79)	(244)	(245)
Common stock repurchased	(440)	(755)	(945)
Common dividends paid	(176)	(201)	(240)
Total net cash used in financing activities	(8,388)	(13,109)	(12,445)
Net increase (decrease) in cash and cash equivalents	265	(341)	151
Cash and cash equivalents at beginning of period	1,253	1,594	1,443
Cash and cash equivalents at end of period	1,518	1,253	1,594
Cash disbursements made (refunds received) for:
Interest	2,872	2,301	1,981
Income taxes paid	157	249	88
Income taxes received	(1)	(4)	(14)
Noncash activity:
Investing activity - Education loans and restricted cash acquired	1,746
Operating activity - Other assets acquired and other liabilities assumed, net	137
Financing activity - Borrowings assumed in acquisition of education loans and restricted cash	1,883
Asset-backed Securities, Securitized Loans and Receivables [Member]
Financing activities
Asset-backed commercial paper conduits, net	(2,363)	(4,002)	974
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Reduction of education loans:
Decrease in restricted cash — variable interest entities	$ 495	$ 129	$ 220

Organization and Business

Organization and Business	12 Months Ended
Organization and Business	Dec. 31, 2017
Organization and Business	1. Navient’s Business Navient is a leading provider of asset management and business processing solutions for education, health care, and government clients at the federal, state, and local levels. We help our clients and millions of Americans achieve financial success through services and support. Headquartered in Wilmington, Delaware, Navient employs team members in western New York, northeastern Pennsylvania, Indiana, Delaware, Tennessee, Texas, Virginia, Wisconsin, California and other locations. Navient is the largest private sector holder of education loans insured or federally guaranteed under the Federal Family Education Loan Program (“FFELP”). We also hold the largest portfolio of Private Education Loans. We also have begun originating Private Education Refinance Loans. Navient services its own portfolio of education loans, as well as education loans owned by the United States Department of Education (“ED”), financial institutions and nonprofit education lenders. Navient is one of the largest servicers to ED under its Direct Student Loan Program (“DSLP”). Our data-driven insight, service and innovation support customers on the path to successful education loan repayment. The Company leverages its scale and expertise to provide business processing solutions to a variety of clients, including federal agencies, state and local governments, regional authorities, courts, hospitals, health care systems and other health care providers, and financial service providers. Navient also provides business processing solutions to education-related clients, such as guaranty agencies and colleges and universities. For all our clients, we aim to improve their financial performance, optimize their operations, and maintain compassionate, compliant service for their customers and constituents.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
Significant Accounting Policies	Dec. 31, 2017
Significant Accounting Policies	2. Use of Estimates Our financial reporting and accounting policies conform to generally accepted accounting principles in the United States of America (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Current market conditions increase the risk and complexity of the judgments in these estimates and actual results could differ from estimates. Key accounting policies that include the most significant judgments, estimates and assumptions include the allowance for loan losses, the effective interest rate method (amortization of education loan and debt premiums and discounts), goodwill and intangible asset impairment assessment, fair value measurement, the consolidation of variable interest entities, and derivative accounting. Consolidation The consolidated financial statements include the accounts of Navient Corporation and its majority-owned and controlled subsidiaries and those Variable Interest Entities (“VIEs”) for which we are the primary beneficiary, after eliminating the effects of intercompany accounts and transactions. We consolidate any VIEs where we have determined we are the primary beneficiary. A VIE is a legal entity that does not have sufficient equity at risk to finance its own operations, or whose equity holders do not have the power to direct the activities that most significantly affect the economic performance of the entity, or whose equity holders do not share proportionately in the losses or benefits of the entity. The primary beneficiary of the VIE is the entity which has both: (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses or receive benefits of the entity that could potentially be significant to the VIE. As it relates to our securitizations and other secured borrowing facilities that are VIEs as of December 31, 2017, we are the servicer of the related education loan assets and own the Residual Interest of the securitization trusts and secured borrowing facilities. As a result, we are the primary beneficiary and consolidate those VIEs. Fair Value Measurement We use estimates of fair value in applying various accounting standards for our financial statements. Fair value measurements are used in one of four ways: • In the consolidated balance sheet with changes in fair value recorded in the consolidated statement of income; • In the consolidated balance sheet with changes in fair value recorded in the accumulated other comprehensive income section of the consolidated statement of changes in stockholders’ equity; • In the consolidated balance sheet for instruments carried at lower of cost or fair value with impairment charges recorded in the consolidated statement of income; and • In the notes to the financial statements. Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between willing and able market participants. In general, our policy in estimating fair value is to first look at observable market prices for identical assets and liabilities in active markets, where available. When these are not available, other inputs are used to model fair value such as prices of similar instruments, yield curves, volatilities, prepayment speeds, default rates and credit spreads, relying first on observable data from active markets. Depending on current market conditions, additional adjustments to fair value may be based on factors such as liquidity, credit, and bid/offer spreads. Transaction costs are not included in the determination of fair value. When possible, we seek to validate the model’s output to market transactions. Depending on the availability of observable inputs and prices, different valuation models could produce materially different fair value estimates. The values presented may not represent future fair values and may not be realizable. We categorize our fair value estimates based on a hierarchical framework associated with three levels of price transparency utilized in measuring financial instruments at fair value. Classification is based on the lowest level of input that is significant to the fair value of the instrument. The three levels are as follows: • Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the measurement date. The types of financial instruments included in level 1 are highly liquid instruments with quoted prices. • Level 2 — Inputs from active markets, other than quoted prices for identical instruments, are used to determine fair value. Significant inputs are directly observable from active markets for substantially the full term of the asset or liability being valued. • Level 3 — Pricing inputs significant to the valuation are unobservable. Inputs are developed based on the best information available. However, significant judgment is required by us in developing the inputs. Loans Loans, consisting primarily of federally insured education loans and Private Education Loans, that we have the ability and intent to hold for the foreseeable future are classified as held-for-investment and are carried at amortized cost. Amortized cost includes the unamortized premiums, discounts, and capitalized origination costs and fees, all of which are amortized to interest income as further discussed below. Loans which are held-for-investment also have an allowance for loan loss as needed. Any loans we have not classified as held-for-investment are classified as held-for-sale, and carried at the lower of cost or fair value. Loans are classified as held-for-sale when we have the intent and ability to sell such loans. Loans which are held-for-sale do not have the associated premium, discount, and capitalized origination costs and fees amortized into interest income. In addition, once a loan is classified as held-for-sale, there is no further adjustment to the loan’s allowance for loan losses that existed immediately prior to the reclassification to held-for-sale. Allowance for Loan Losses Purchased Credit Impaired (“PCI”) Loans Loans acquired with evidence of deterioration of credit quality since origination for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable are PCI loans accounted for under Accounting Standard Codification (“ASC”) 310-30, “Loans and Debt Securities Acquired with Deteriorated Credit Quality.” When considering whether evidence of credit quality deterioration exists as of the purchase date, the Company considers loan guarantees and the following credit attributes: delinquency status, use of forbearance, recent borrower FICO scores, use of loan modification programs, and borrowers who have filed for bankruptcy. The Company aggregates loans with common risk characteristics into pools and accounts for each pool as a single asset with a single composite interest rate and an aggregate expectation of cash flows. The pools are initially recorded at fair value. The Company recognizes interest income based on each pool’s effective interest rate which is based on our estimate of all cash flows expected to be received and includes an assumption about prepayment rates. The pools are tested quarterly for impairment by re-estimating the future cash flows to be received from the pools. If the new estimated cash flows result in a pool’s effective interest rate increasing, then this new yield is used prospectively over the remaining life of the pool. If the new estimated cash flows result in a pool’s effective interest rate decreasing, the pool is impaired and written down through a valuation allowance to maintain the effective interest rate. Loans classified as PCI do not have charge-offs reported nor are they reported as Trouble Debt Restructuring (“TDR”) loans. Based on the credit attributes discussed above, we determined that $261 million principal amount of Private Education Loans acquired in 2017 are accounted for as PCI loans with a fair value and resulting carry value of $101 million as of the acquisition date. As of acquisition, this portfolio’s contractually required payments receivable (the total undiscounted amount of all uncollected contractual principal and interest payments both past due and scheduled for the future, adjusted for prepayments) was $411 million with an estimated accretable yield (income expected to be recognized in future periods) of $108 million. As of December 31, 2017, the carrying amount was $97 million with no valuation allowance recorded. Purchased Non-Credit Impaired Loans Loans acquired that do not have evidence of credit deterioration since origination are recorded at fair value with no allowance for loan losses established at the acquisition date. Loan premiums and discounts are amortized as a part of interest income using the interest method under ASC 310-20, “Nonrefundable Fees and Other Costs.” An allowance for loan losses would be established if incurred losses in the loans exceed the remaining unamortized discount recorded at the time of acquisition (i.e., the next two years of expected charge-offs as well as any additional TDR allowance required is greater than the remaining discount). As a result of this policy, to the extent that actual charge-offs exceed any related allowance for loan losses recognized post-acquisition, provision for loan losses is recorded when the loans are charged off. Charge-offs are recorded through the allowance for loan losses. In 2017, we acquired Private Education Loans with unpaid principal balance of $2.8 billion at a discount of $424 million and FFELP Loans with an unpaid principal balance of $3.5 billion at a discount of $47 million, that are accounted for under this policy. No allowance for loan losses has been established for these loans as of December 31, 2017, as the remaining purchased discount associated with the Private Education Loans of $392 million and FFELP Loans of $43 million as of December 31, 2017 remains greater than the incurred losses. Allowance for Private Education Loan Losses We consider a loan to be impaired when, based on current information, a loss has been incurred and it is probable that we will not receive all contractual amounts due. When making our assessment as to whether a loan is impaired, we also take into account more than insignificant delays in payment. We generally evaluate impaired loans on an aggregate basis by grouping similar loans. Impaired loans also include those loans which are individually assessed for impairment at a loan level, such as in a troubled debt restructuring (“TDR”). We maintain an allowance for loan losses at an amount sufficient to absorb losses incurred in our portfolios at the reporting date based on a projection of estimated probable credit losses incurred in the portfolio. Our Private Education Loan portfolio contains TDR and non-TDR loans. For customers experiencing financial difficulty, certain Private Education Loans for which we have granted a forbearance of greater than three months, an interest rate reduction or an extended repayment plan are classified as TDRs. The allowance requirements are different based on these designations. In determining the allowance for loan losses on our non-TDR portfolio, we estimate the principal amount of loans that will default over the next two years (two years being the expected period between a loss event and default) and how much we expect to recover over time related to the defaulted amount. Expected defaults less our expected recoveries equal the allowance related to this portfolio. Our historical experience indicates that, on average, the time between the date that a customer experiences a default causing event (i.e., the loss trigger event) and the date that we charge off the unrecoverable portion of that loan is two years. Separately, for our TDR portfolio, we estimate an allowance amount sufficient to cover life-of-loan expected losses through an impairment calculation based on the difference between the loan’s basis and the present value of expected future cash flows (which would include life-of-loan default and recovery assumptions) discounted at the loan’s original effective interest rate. Our TDR portfolio is comprised mostly of loans with forbearance usage greater than three months and interest rate reductions. The separate allowance estimates for our TDR and non-TDR portfolios are combined into our total allowance for Private Education Loan losses. In estimating both the non-TDR and TDR allowance amounts, we start with historical experience of customer default behavior. We make judgments about which historical period to start with and then make further judgments about whether that historical experience is representative of future expectations and whether additional adjustments may be needed to those historical default rates. We also take the economic environment into consideration when calculating the allowance for loan losses. We analyze key economic statistics and the effect we expect them to have on future defaults. Key economic statistics analyzed as part of the allowance for loan losses are primarily unemployment rates. Our allowance for loan losses is estimated using an analysis of delinquent and current accounts. Our model is used to estimate the likelihood that a loan may progress through the various delinquency stages and ultimately charge off. The evaluation of the allowance for loan losses is inherently subjective, as it requires material estimates that may be susceptible to significant changes. The estimate for the allowance for loan losses is subject to a number of assumptions. If actual future performance in delinquency, charge-offs and recoveries are significantly different than estimated, this could materially affect our estimate of the allowance for loan losses and the related provision for loan losses on our income statement. We determine the collectability of our Private Education Loan portfolio by evaluating certain risk characteristics. We consider school type, credit score (FICO), existence of a cosigner, loan status and loan seasoning as the key credit quality indicators because they have the most significant effect on our determination of the adequacy of our allowance for loan losses. The type of school customers attend can have an impact on their graduation rate and job prospects after graduation and therefore affects their ability to make payments. Credit scores are an indicator of the credit worthiness of a customer and the higher the credit score the more likely it is the customer will be able to make all of their contractual payments. Loan status affects the credit risk because a past due loan is more likely to result in a credit loss than an up-to-date loan. Additionally, loans in a deferred payment status have different credit risk profiles compared with those in current payment status. Of the portfolio in repayment, loan seasoning is an important factor. It affects credit risk because a loan with a history of making payments generally has a lower incidence of default than a loan with a history of making infrequent or no payments. The existence of a cosigner lowers the likelihood of default. We monitor and update these credit quality indicators in the analysis of the adequacy of our allowance for loan losses on a quarterly basis. To estimate the probable credit losses incurred in the loan portfolio at the reporting date, we use historical experience of customer payment behavior in connection with the key credit quality indicators and incorporate management expectations regarding macroeconomic and collection performance factors. Our model is based upon the most recent twelve months of actual collection experience as the starting point for the non-TDR portfolio and the most recent approximate 10 years for the TDR portfolio and applies expected macroeconomic changes and collection procedure changes to estimate expected losses caused by loss events incurred as of the balance sheet date. Our model for the non-TDR portfolio places a greater emphasis on the more recent default experience rather than the default experience for older historical periods, as we believe the more recent default experience is more indicative of the probable losses incurred in the loan portfolio today that will default over the next two years. The TDR portfolio uses a longer historical default experience since we are projecting life of loan remaining losses. Similar to estimating defaults, we use historical customer payment behavior to estimate the timing and amount of future recoveries on charged-off loans. We use judgment in determining whether historical performance is representative of what we expect to collect in the future. We then apply the default and collection rate projections to each category of loans. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. Additionally, we consider changes in laws and regulations that could potentially impact the allowance for loan losses. More judgment has been required over the last several years, compared with years prior, in light of the U.S. economy and its effect on our customers’ ability to pay their obligations. We believe that our model reflects recent customer behavior, loan performance, and collection performance, as well as expectations about economic factors. Our collection policies allow for periods of nonpayment for customers requesting additional payment grace periods upon leaving school or experiencing temporary difficulty meeting payment obligations. This is referred to as forbearance status and is considered in our allowance for loan losses. The loss confirmation period is in alignment with our typical collection cycle and takes into account these periods of nonpayment. Our allowance for Private Education Loan losses also provides for possible additional future charge-offs as they occur related to the receivable for partially charged-off Private Education Loans. At the end of each month, for loans that are 212 days past due, we charge off the estimated loss of a defaulted loan balance. Actual recoveries are applied against the remaining loan balance that was not charged off. We refer to this remaining loan balance as the “receivable for partially charged-off loans.” If actual periodic recoveries are less than expected, the difference is immediately charged off through the allowance for loan losses with an offsetting reduction in the receivable for partially charged-off Private Education Loans. If actual periodic recoveries are greater than expected, they will be reflected as a recovery through the allowance for Private Education Loan losses once the cumulative recovery amount exceeds the cumulative amount originally expected to be recovered. Private Education Loans which defaulted between 2007 through March 31, 2015, experienced collection performance below our pre-financial crisis experience. As a result, we began building a reserve for shortfalls in recoveries until we could determine the long-term post-default recovery rate. In the second quarter of 2015, the portion of the loan amount charged off at default increased from 73 percent to 79 percent. This did not impact the provision for loan losses as previously this had been reserved through the allowance for loan losses. This change resulted in a $330 million reduction to the balance of the receivable for partially charged-off loans. Allowance for FFELP Loan Losses FFELP Loans are insured as to their principal and accrued interest in the event of default subject to a Risk Sharing level based on the date of loan disbursement. These insurance obligations are supported by contractual rights against the United States. For loans disbursed after October 1, 1993, and before July 1, 2006, we receive 98 percent reimbursement on all qualifying default claims. For loans disbursed on or after July 1, 2006, we receive 97 percent reimbursement. For loans disbursed prior to October 1, 1993, we receive 100 percent reimbursement. Similar to the allowance for Private Education Loan losses, the allowance for FFELP Loan losses uses historical experience of customer default behavior and a two-year loss confirmation period to estimate the credit losses incurred in the loan portfolio at the reporting date. We apply the default rate projections, net of applicable Risk Sharing, to each category for the current period to perform our quantitative calculation. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. For FFELP Loans that have lost their government insurance and have been charged off, any subsequent cash recoveries benefit the allowance for loan losses when received. Investments Our available-for-sale investment portfolio consists of investments that are carried at fair value, with the temporary changes in fair value carried as a separate component of stockholders’ equity, net of taxes. The amortized cost of debt securities in this category is adjusted for premiums and accretion of discounts, which are amortized using the effective interest rate method. Other-than-temporary impairment is evaluated by considering several factors, including the length of time and extent to which the fair value has been less than the amortized cost basis, the financial condition and near-term prospects of the security (considering factors such as adverse conditions specific to the security and ratings agency actions), and the intent and ability to retain the investment to allow for an anticipated recovery in fair value. The entire fair value loss on a security that is other-than-temporary impairment is recorded in earnings if we intend to sell the security or if it is more likely than not that we will be required to sell the security before the expected recovery of the loss. However, if the impairment is other-than-temporary, and those two conditions do not exist, the portion of the impairment related to credit losses is recorded in earnings and the impairment related to other factors is recorded in other comprehensive income. Securities classified as trading are accounted for at fair value with unrealized gains and losses included in investment income. Securities that we have the intent and ability to hold to maturity are classified as held-to-maturity and are accounted for at amortized cost unless the security is determined to have an other-than-temporary impairment. In this case it is accounted for in the same manner described above. We also have other investments, primarily a receivable for cash collateral posted to derivative counterparties which is accounted for at amortized cost in other investments. Cash and Cash Equivalents Cash and cash equivalents can include term federal funds, Eurodollar deposits, commercial paper, asset-backed commercial paper, treasuries and money market funds with original terms to maturity of less than three months. Restricted Cash and Investments Restricted cash primarily includes amounts held in education loan securitization trusts and other secured borrowings. This cash must be used to make payments related to trust obligations. Amounts on deposit in these accounts are primarily the result of timing differences between when principal and interest is collected on the trust assets and when principal and interest is paid on trust liabilities. As such, changes in this balance are reflected in investing activities in the statement of cash flows. Securities pledged as collateral related to our derivative portfolio, where the counterparty has rights to replace the securities, are classified as restricted. When the counterparty does not have these rights, the security is recorded in investments and disclosed as pledged collateral in the notes. Additionally, certain counterparties require cash collateral pledged to us to be segregated and held in restricted cash accounts. Goodwill and Acquired Intangible Assets Goodwill is not amortized but is tested periodically for impairment. We test goodwill for impairment annually as of October 1 at the reporting unit level, which is the same as or one level below a business segment. Goodwill is also tested at interim periods if an event occurs or circumstances change that would indicate the carrying amount may be impaired. We assess qualitative factors to determine whether it is “more-likely-than-not” that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. The “more-likely-than-not” threshold is defined as having a likelihood of more than 50 percent. If, after assessing relevant qualitative factors, we conclude that it is “more-likely-than-not” that the fair value of a reporting unit as of October 1 is less than its carrying amount, we will complete Step 1 of the goodwill impairment analysis. Step 1 consists of a comparison of the fair value of the reporting unit to the reporting unit’s carrying value, including goodwill. If the carrying value of the reporting unit exceeds the fair value, Step 2 in the goodwill impairment analysis is performed to measure the amount of impairment loss, if any. Step 2 of the goodwill impairment analysis compares the implied fair value of the reporting unit’s goodwill to the carrying value of the reporting unit’s goodwill. The implied fair value of goodwill is determined in a manner consistent with determining goodwill in a business combination. If the carrying amount of the reporting unit’s goodwill exceeds the implied fair value of the goodwill, an impairment loss is recognized in an amount equal to that excess. Acquired intangible assets include, but are not limited to, trade names, customer and other relationships, and non-compete agreements. Acquired intangible assets with finite lives are amortized over their estimated useful lives in proportion to their estimated economic benefit. Finite-lived acquired intangible assets are reviewed for impairment using an undiscounted cash flow analysis when an event occurs or circumstances change indicating the carrying amount of a finite-lived asset or asset group may not be recoverable. If the carrying amount of the asset or asset groups exceeds the undiscounted cash flows, the fair value of the asset or asset group is determined using an acceptable valuation technique. An impairment loss would be recognized if the carrying amount of the asset Securitization Accounting Our securitizations use a two-step structure with a special purpose entity that legally isolates the transferred assets from us, even in the event of bankruptcy. Transactions receiving sale treatment are also structured to ensure that the holders of the beneficial interests issued are not constrained from pledging or exchanging their interests, and that we do not maintain effective control over the transferred assets. If these criteria are not met, then the transaction is accounted for as an on-balance sheet secured borrowing. In all cases, irrespective of whether they qualify as accounting sales our securitizations are legally structured to be sales of assets that isolate the transferred assets from us. If a securitization qualifies as a sale, we then assess whether we are the primary beneficiary of the securitization trust (VIE) and are required to consolidate such trust. If we are the primary beneficiary, then no gain or loss is recognized. See “Consolidation” of this Note 2 for additional information regarding the accounting rules for consolidation when we are the primary beneficiary of these trusts. Irrespective of whether a securitization receives sale or on-balance sheet treatment, our continuing involvement with our securitization trusts is generally limited to: • Owning the equity certificates of certain trusts. • The servicing of the education loan assets within the securitization trusts, on both a pre- and post-default basis. • Our acting as administrator for the securitization transactions we sponsored, which includes remarketing certain bonds at future dates. • Our responsibilities relative to representation and warranty violations. • Temporarily advancing to the trust certain borrower benefits afforded the borrowers of education loans that have been securitized. These advances subsequently are returned to us in the next quarter. • Certain back-to-back derivatives entered into by us contemporaneously with the execution of derivatives by certain Private Education Loan securitization trusts. • The option held by us to buy certain delinquent loans from certain Private Education Loan securitization trusts. • The option to exercise the clean-up call and purchase the education loans from the trust when the asset balance is 10 percent or less of the original loan balance. • The option, on some trusts, to purchase education loans aggregating up to 10 percent of the trust’s initial pool balance. • The option (in certain trusts) to call rate reset notes in instances where the remarketing process has failed. The investors of the securitization trusts have no recourse to our other assets should there be a failure of the trusts to pay when due. Generally, the only arrangements under which we have to provide financial support to the trusts are representation and warranty violations requiring the buyback of loans. Under the terms of the transaction documents of certain trusts, we have, from time to time, exercised our options to purchase delinquent loans from Private Education Loan trusts, to purchase the remaining loans from trusts once the loan balance falls below 10 percent of the original amount, to purchase education loans up to 10 percent of the trust’s initial balance, or to call rate reset notes. Certain trusts maintain financial arrangements with third parties also typical of securitization transactions, such as derivative contracts (swaps) and bond insurance policies that, in the case of a counterparty failure, could adversely impact the value of any Residual Interest. We do not record servicing assets or servicing liabilities when our securitization trusts are accounted for as on-balance sheet secured financings. As of December 31, 2017, we have $25 million of servicing assets on our balance sheet, of which $11 million is related to Residual Interests in FFELP Loan securitization trusts we sold in 2013 and $14 million is related to the acquisition of Earnest in 2017. Education Loan Interest Income For loans classified as held-for-investment, we recognize education loan interest income as earned, adjusted for the amortization of premiums (which includes purchased premiums and capitalized direct origination costs), discounts and Repayment Borrower Benefits. These adjustments result in income being recognized based upon the expected yield of the loan over its life after giving effect to expected prepayments. We amortize premium and discount on education loans using a CPR which measures the rate at which loans in the portfolio pay down principal compared to their stated terms. In determining the CPR, we only consider payments made in excess of contractually required payments. This would include loan consolidation and other early payoff activity. For Repayment Borrower Benefits, the estimates of their effect on education loan yield are based on analyses of historical payment behavior of customers who are eligible for the incentives and its effect on the ultimate qualification rate for these incentives. We regularly evaluate the assumptions used to estimate the prepayment speeds and the qualification rates used for Repayment Borrower Benefits. In instances where there are changes to the assumptions, amortization is adjusted on a cumulative basis to reflect the change since the acquisition of the loan. Additionally, interest earned on education loans reflects potential non-payment adjustments in accordance with our uncollectible interest recognition policy as discussed further in “Allowance for Loan Losses” of this Note 2. We do not amortize any premiums, discounts or other adjustments to the basis of education loans when they are classified as held-for-sale. See “Allowance for Loan Losses – Purchased Credit Impaired (‘PCI’) Loans” and “–Purchased Non-Credit Impaired Loans” of

Education Loans

Education Loans	12 Months Ended
Education Loans	Dec. 31, 2017
Education Loans	3. Education loans consist of FFELP and Private Education Loans. There are three principal categories of FFELP Loans: Stafford, PLUS, and FFELP Consolidation Loans. Generally, Stafford and PLUS Loans have repayment periods of between five and ten years. FFELP Consolidation Loans have repayment periods of twelve to thirty years. FFELP Loans do not require repayment, or have modified repayment plans, while the customer is in-school and during the grace period immediately upon leaving school. The customer may also be granted a deferment or forbearance for a period of time based on need, during which time the customer is not considered to be in repayment. Interest continues to accrue on loans in the in-school, deferment and forbearance period. FFELP Loans obligate the customer to pay interest at a stated fixed rate or a variable rate reset annually (subject to a cap) on July 1 of each year depending on when the loan was originated and the loan type. FFELP Loans disbursed before April 1, 2006 earn interest at the greater of the borrower’s rate or a floating rate based on the Special Allowance Payment (“SAP”) formula, with the interest earned on the floating rate that exceeds the interest earned from the customer being paid directly by ED. In low or certain declining interest rate environments when education loans are earning at the fixed borrower rate and the interest on the funding for the loans is variable and declining, we can earn additional spread income that we refer to as Floor Income. For loans disbursed after April 1, 2006, FFELP Loans effectively only earn at the SAP rate, as the excess interest earned when the borrower rate exceeds the SAP rate (Floor Income) is required to be rebated to ED. FFELP Loans are insured as to their principal and accrued interest in the event of default subject to a Risk Sharing level based on the date of loan disbursement. These insurance obligations are supported by contractual rights against the United States. For loans disbursed after October 1, 1993 and before July 1, 2006, we receive 98 percent reimbursement on all qualifying default claims. For loans disbursed on or after July 1, 2006, we receive 97 percent reimbursement. Private Education Loans bear the full credit risk of the customer. Private Education Loans generally carry a variable rate indexed to LIBOR or Prime indices. The majority of loans in our portfolio are cosigned. Similar to FFELP loans, Private Education Loans are generally non-dischargeable in bankruptcy. Most loans have repayment terms of 10 to 15 years or more, and for loans made prior to 2009, payments are typically deferred until after graduation. However, since 2009 we began to encourage interest-only or fixed payment options while the customer is enrolled in school. The estimated weighted average life of education loans in our portfolio was approximately 7 years at both December 31, 2017 and 2016. The following table reflects the distribution of our education loan portfolio by program. December 31, 2017 Year Ended December 31, 2017 (Dollars in millions) Ending Balance % of Balance Average Balance Average Effective Interest Rate FFELP Stafford and Other Education Loans, net (1) $ 28,409 27 % $ 30,462 2.94 % FFELP Consolidation Loans, net 53,294 51 54,527 3.30 Private Education Loans, net 23,419 22 23,762 6.88 Total education loans, net $ 105,122 100 % $ 108,751 3.98 % December 31, 2016 Year Ended December 31, 2016 (Dollars in millions) Ending Balance % of Balance Average Balance Average Effective Interest Rate FFELP Stafford and Other Education Loans, net (1) $ 32,319 29 % $ 34,710 2.31 % FFELP Consolidation Loans, net 55,411 50 57,787 2.98 Private Education Loans, net 23,340 21 25,361 6.26 Total education loans, net $ 111,070 100 % $ 117,858 3.49 % (1) Primarily Stafford Loans, but also includes federally guaranteed PLUS and HEAL Loans. As of December 31, 2017 and 2016, 86 percent and 83 percent, respectively, of our education loan portfolio was in repayment. Loan Sales In 2015, we sold $412 million of FFELP Loans for a $12 million gain and $178 million of low-interest rate Private Education Loans for a $21 million loss. There were no loan sales in 2016 or 2017.

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
Allowance for Loan Losses	Dec. 31, 2017
Allowance for Loan Losses	4. 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 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. Allowance for Loan Losses Metrics Year Ended December 31, 2017 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 67 $ 1,351 $ 15 $ 1,433 Total provision 42 382 2 426 Charge-offs (1) (49 ) (443 ) (7 ) (499 ) Reclassification of interest reserve (2) — 7 — 7 Ending balance $ 60 $ 1,297 $ 10 $ 1,367 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,171 $ 9 $ 1,180 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 60 126 1 187 Purchased Non-Credit Impaired Loans acquired at a discount (3) — — — — Purchased Credit Impaired Loans (3) — — — — Ending total allowance $ 60 $ 1,297 $ 10 $ 1,367 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,921 $ 30 $ 10,951 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 77,860 11,861 40 89,761 Purchased Non-Credit Impaired Loans acquired at a discount (3) 3,237 2,610 — 5,847 Purchased Credit Impaired Loans (3) — 248 — 248 Ending total loans (4) $ 81,097 $ 25,640 $ 70 $ 106,807 Charge-offs as a percentage of average loans in repayment .07 % 1.98 % 5.39 % Allowance coverage of charge-offs 1.2 2.9 1.5 Allowance as a percentage of the ending total loan balance (3) .07 % 5.06 % 14.32 % Allowance as a percentage of the ending loans in repayment (3) .09 % 5.66 % 14.32 % Ending total loans (4) $ 81,097 $ 25,640 $ 70 Average loans in repayment $ 68,318 $ 22,342 $ 130 Ending loans in repayment $ 67,853 $ 22,924 $ 70 (1) 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) See “Note 2 — Significant Accounting Policies — Allowance for Loan Losses” for a description of our policy for the $6.5 billion of loans ($3.5 billion of FFELP and $3.0 billion of Private Education) purchased in 2017 accounted for as either Purchased Credit Impaired Loans or Purchased Non-Credit Impaired Loans. The Purchased Credit Impaired Loans’ losses are not provided for by the allowance for loan losses in the above table as these loans are separately reserved for, if needed. No allowance for loan losses has been established for these loans as of December 31, 2017. The losses of the Purchased Non-Credit Impaired Loans acquired at a discount are not provided for by the allowance for loan losses in the above table as the remaining purchased discount associated with the FFELP and Private Education Loans of $43 million and $392 million, respectively, as of December 31, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of December 31, 2017. As a result, excluding the $6.5 billion of loans acquired in 2017, the allowance as a percentage of the ending total loan balance and the allowance as a percentage of the ending loans in repayment would be 0.08 percent and 0.09 percent for FFELP Loans and 5.69 percent and 6.42 percent for Private Education Loans, respectively. (4) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. Year Ended December 31, 2016 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 78 $ 1,471 $ 15 $ 1,564 Total provision 43 383 3 429 Charge-offs (1) (54 ) (513 ) (3 ) (570 ) Reclassification of interest reserve (2) — 10 — 10 Ending balance $ 67 $ 1,351 $ 15 $ 1,433 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,190 $ 11 $ 1,201 Collectively evaluated for impairment 67 161 4 232 Ending total allowance $ 67 $ 1,351 $ 15 $ 1,433 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 11,165 $ 32 $ 11,197 Collectively evaluated for impairment 86,918 13,983 132 101,033 Ending total loans (3) $ 86,918 $ 25,148 $ 164 $ 112,230 Charge-offs as a percentage of average loans in repayment .07 % 2.20 % 2.10 % Allowance coverage of charge-offs 1.2 2.6 7.0 Allowance as a percentage of the ending total loan balance .08 % 5.37 % 9.35 % Allowance as a percentage of the ending loans in repayment .09 % 6.10 % 9.35 % Ending total loans (3) $ 86,918 $ 25,148 $ 164 Average loans in repayment $ 72,714 $ 23,275 $ 104 Ending loans in repayment $ 70,557 $ 22,150 $ 164 (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) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. Year Ended December 31, 2015 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 93 $ 1,916 $ 24 $ 2,033 Total provision 46 538 (3 ) 581 Net adjustment resulting from the change in the charge-off rate (1) — (330 ) — (330 ) Net charge-offs remaining (2) (61 ) (659 ) (6 ) (726 ) Total net charge-offs (61 ) (989 ) (6 ) (1,056 ) Reclassification of interest reserve (3) — 11 — 11 Loan sales — (5 ) — (5 ) Ending balance $ 78 $ 1,471 $ 15 $ 1,564 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,209 $ 12 $ 1,221 Collectively evaluated for impairment 78 262 3 343 Ending total allowance $ 78 $ 1,471 $ 15 $ 1,564 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,965 $ 37 $ 11,002 Collectively evaluated for impairment 95,393 17,431 49 112,873 Ending total loans (4) $ 95,393 $ 28,396 $ 86 $ 123,875 Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate (annualized) (1) .08 % 2.55 % 6.17 % Net adjustment resulting from the change in the charge-off rate as a percentage of average loans in repayment (annualized) (1) — % 1.28 % — % Allowance coverage of net charge-offs, excluding the net adjustment resulting from the change in the charge-off rate (annualized) (1) 1.3 2.2 2.5 Allowance as a percentage of the ending total loan balance .08 % 5.18 % 17.28 % Allowance as a percentage of the ending loans in repayment .11 % 6.00 % 17.28 % Ending total loans (4) $ 95,393 $ 28,396 $ 86 Average loans in repayment $ 75,925 $ 25,802 $ 97 Ending loans in repayment $ 73,838 $ 24,502 $ 86 (1) In 2015, the portion of the loan amount charged off at default on Private Education Loans increased from 73 percent to 79 percent. This did not impact the provision for loan losses as previously this had been reserved through the allowance for loan losses. This change resulted in a $330 million reduction to the balance of the receivable for partially charged-off loans. (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) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. Key Credit Quality Indicators FFELP Loans are substantially insured and guaranteed as to their principal and accrued interest in the event of default; therefore, the key credit quality indicator for this portfolio is loan status. The impact of changes in loan status is incorporated quarterly into the allowance for loan losses calculation. FFELP Loan Delinquencies December 31, 2017 2016 2015 (Dollars in millions) Balance % Balance % Balance % Loans in-school/grace/deferment (1) $ 4,711 $ 5,871 $ 8,257 Loans in forbearance (2) 8,533 10,490 13,298 Loans in repayment and percentage of each status: Loans current 59,264 87.3 % 61,977 87.8 % 62,651 84.8 % Loans delinquent 31-60 days (3) 2,638 3.9 2,820 4.0 3,285 4.5 Loans delinquent 61-90 days (3) 1,763 2.6 1,325 1.9 1,856 2.5 Loans delinquent greater than 90 days (3) 4,188 6.2 4,435 6.3 6,046 8.2 Total FFELP Loans in repayment 67,853 100 % 70,557 100 % 73,838 100 % Total FFELP Loans, gross 81,097 86,918 95,393 FFELP Loan unamortized premium 666 879 1,087 Total FFELP Loans 81,763 87,797 96,480 FFELP Loan allowance for losses (60 ) (67 ) (78 ) FFELP Loans, net $ 81,703 $ 87,730 $ 96,402 Percentage of FFELP Loans in repayment 83.7 % 81.2 % 77.4 % Delinquencies as a percentage of FFELP Loans in repayment 12.7 % 12.2 % 15.2 % FFELP Loans in forbearance as a percentage of loans in repayment and forbearance 11.2 % 12.9 % 15.3 % (1) Loans for customers who may still be attending school or engaging in other permitted educational activities and are not required to make payments on the 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. 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/school type are assessed at origination. The other Private Education Loan key quality indicators can change and are incorporated quarterly into the allowance for loan losses calculation. The following table highlights the principal balance (excluding the receivable for partially charged-off loans) of our Private Education Loan portfolio stratified by the key credit quality indicators. Private Education Loans Credit Quality Indicators TDR December 31, 2017 December 31, 2016 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 9,647 92 % $ 9,863 91 % FICO below 640 889 8 942 9 Total $ 10,536 100 % $ 10,805 100 % School Type: Not-for-profit $ 8,247 78 % $ 8,346 77 % For-profit 2,289 22 2,459 23 Total $ 10,536 100 % $ 10,805 100 % Cosigners: With cosigner $ 6,441 61 % $ 6,486 60 % Without cosigner 4,095 39 4,319 40 Total $ 10,536 100 % $ 10,805 100 % Seasoning (1) 1-12 payments $ 506 5 % $ 754 7 % 13-24 payments 644 6 927 9 25-36 payments 947 9 1,289 12 37-48 payments 1,271 12 1,620 15 More than 48 payments 6,691 63 5,636 52 Not yet in repayment 477 5 579 5 Total $ 10,536 100 % $ 10,805 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2) Balance equals the gross Private Education Loans. Private Education Loans Credit Quality Indicators Non-TDR December 31, 2017 December 31, 2016 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 13,752 96 % $ 13,120 97 % FICO below 640 592 4 408 3 Total $ 14,344 100 % $ 13,528 100 % School Type: Not-for-profit $ 12,431 87 % $ 11,338 84 % For-profit 1,913 13 2,190 16 Total $ 14,344 100 % $ 13,528 100 % Cosigners: With cosigner $ 9,193 64 % $ 9,124 67 % Without cosigner 5,151 36 4,404 33 Total $ 14,344 100 % $ 13,528 100 % Seasoning (1) 1-12 payments $ 1,424 10 % $ 586 4 % 13-24 payments 437 3 344 3 25-36 payments 466 3 619 5 37-48 payments 867 6 1,103 8 More than 48 payments 10,566 74 10,062 74 Not yet in repayment 584 4 814 6 Total $ 14,344 100 % $ 13,528 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2) TDR Private Education Loan Delinquencies December 31, 2017 2016 2015 (Dollars in millions) Balance % Balance % Balance % Loans in-school/grace/deferment (1) $ 477 $ 579 $ 706 Loans in forbearance (2) 681 588 694 Loans in repayment and percentage of each status: Loans current 8,333 88.9 % 8,273 85.8 % 7,887 85.3 % Loans delinquent 31-60 days (3) 351 3.7 412 4.3 414 4.5 Loans delinquent 61-90 days (3) 207 2.2 267 2.8 263 2.9 Loans delinquent greater than 90 days (3) 487 5.2 686 7.1 678 7.3 Total TDR loans in repayment 9,378 100 % 9,638 100 % 9,242 100 % Total TDR loans, gross 10,536 10,805 10,642 TDR loans unamortized discount (225 ) (237 ) (243 ) Total TDR loans 10,311 10,568 10,399 TDR loans receivable for partially charged-off loans 385 360 323 TDR loans allowance for losses (1,171 ) (1,190 ) (1,209 ) TDR loans, net $ 9,525 $ 9,738 $ 9,513 Percentage of TDR loans in repayment 89.0 % 89.2 % 86.8 % Delinquencies as a percentage of TDR loans in repayment 11.1 % 14.2 % 14.7 % Loans in forbearance as a percentage of TDR loans in repayment and forbearance 6.8 % 5.7 % 7.0 % (1) Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not required to make payments on the 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. Non-TDR Private Education Loan Delinquencies December 31, 2017 2016 2015 (Dollars in millions) Balance % Balance % Balance % Loans in-school/grace/deferment (1) $ 584 $ 814 $ 1,334 Loans in forbearance (2) 214 202 279 Loans in repayment and percentage of each status: Loans current 13,257 97.9 % 12,233 97.8 % 14,844 97.3 % Loans delinquent 31-60 days (3) 120 .9 110 .9 163 1.1 Loans delinquent 61-90 days (3) 59 .4 54 .4 85 .6 Loans delinquent greater than 90 days (3) 110 .8 115 .9 168 1.0 Total non-TDR loans in repayment 13,546 100 % 12,512 100 % 15,260 100 % Total non-TDR loans, gross 14,344 13,528 16,873 Non-TDR loans unamortized discount (699 ) (220 ) (288 ) Total non-TDR loans 13,645 13,308 16,585 Non-TDR loans receivable for partially charged-off loans 375 455 558 Non-TDR loans allowance for losses (126 ) (161 ) (262 ) Non-TDR loans, net $ 13,894 $ 13,602 $ 16,881 Percentage of non-TDR loans in repayment 94.4 % 92.5 % 90.4 % Delinquencies as a percentage of non-TDR loans in repayment 2.1 % 2.2 % 2.7 % Loans in forbearance as a percentage of non- TDR loans in repayment and forbearance 1.6 % 1.6 % 1.8 % (1) Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not required to make payments on the loans, e.g., residency periods for medical students or a grace period for bar exam preparation. (2) Loans for customers who have requested extension of grace period generally during employment transition or who have temporarily ceased making full payments due to hardship or other factors such as disaster relief, consistent with established loan program servicing policies and procedures. (3) The period of delinquency is based on the number of days scheduled payments are contractually past due. Receivable for Partially Charged-Off Private Education Loans At the end of each month, for loans that are 212 or more days past due, we charge off the estimated loss of a defaulted loan balance. Actual recoveries are applied against the remaining loan balance that was not charged off. We refer to this remaining loan balance as the “receivable for partially charged-off loans.” If actual periodic recoveries are less than expected, the difference is immediately charged off through the allowance for Private Education Loan losses with an offsetting reduction in the receivable for partially charged-off Private Education Loans. If actual periodic recoveries are greater than expected, they will be reflected as a recovery through the allowance for Private Education Loan losses once the cumulative recovery amount exceeds the cumulative amount originally expected to be recovered. The financial crisis, which began in 2007, impacted our collections on defaulted loans and as a result, Private Education Loans which defaulted from 2007 through March 31, 2015, experienced collection performance below our pre-financial crisis experience. For that reason, until we gained enough data and experience to determine the long-term, post-default recovery rate of 21 percent in second-quarter 2015, we established a reserve for potential shortfalls in recoveries. In the second quarter of 2015, the portion of the loan amount charged off at default increased from 73 percent to 79 percent. This did not impact the provision for loan losses as previously this had been reserved through the allowance for loan losses. This change resulted in a $330 million reduction to the balance of the receivable for partially charged-off loans. The following table summarizes the activity in the receivable for partially charged-off loans. Years Ended December 31, (Dollars in millions) 2017 2016 2015 Receivable at beginning of period $ 815 $ 881 $ 1,245 Expected future recoveries of current period defaults (1) 110 128 183 Recoveries (2) (155 ) (181 ) (191 ) Net adjustment resulting from the change in the charge-off rate (3) — — (330 ) Net charge-offs remaining (4) (10 ) (13 ) (26 ) Total net charge-offs (5) (10 ) (13 ) (356 ) Receivable at end of period $ 760 $ 815 $ 881 (1) Represents our estimate of the amount to be collected in the future. (2) Current period cash collections. (3) In 2015, the portion of the loan amount charged off at default increased from 73 percent to 79 percent. This change resulted in a $330 million reduction to the balance of the receivable for partially charged-off loans. (4) Represents the current period recovery shortfall — the difference between what was expected to be collected and what was actually collected. (5) 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 certain customers when we believe such modifications may increase the ability and willingness of a customer to make payments and thus increase the ultimate overall amount collected on a loan. These modifications generally take the form of a forbearance, a temporary interest rate reduction or an extended repayment plan. For customers experiencing financial difficulty, certain Private Education Loans for which we have granted either a forbearance of greater than three months, an interest rate reduction or an extended repayment plan are classified as TDRs. Approximately 61 percent and 61 percent of the loans granted forbearance have qualified as a TDR loan at December 31, 2017, and 2016, respectively. The unpaid principal balance of TDR loans that were in an interest rate reduction plan as of December 31, 2017 and 2016 was $2.7 billion and $2.6 billion, respectively. At December 31, 2017 and 2016, 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. TDR Loans (Dollars in millions) Recorded Investment (1) Total Ending Loans (2) Related Allowance December 31, 2017 $ 10,890 $ 10,921 $ 1,171 December 31, 2016 11,119 11,165 1,190 (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 table provides the average recorded investment and interest income recognized for our TDR loans. Years Ended December 31, 2017 2016 2015 (Dollars in millions) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Total $ 10,989 $ 708 $ 11,078 $ 667 $ 10,770 $ 653 The following table provides the amount of loans modified in the periods presented that resulted in a TDR. Additionally, the table summarizes charge-offs occurring in the TDR portfolio, as well as TDRs for which a payment default occurred in the current period within 12 months of the loan first being designated as a TDR. We define payment default as 60 days past due for this disclosure. Years Ended December 31, 2017 2016 2015 (Dollars in millions) Modified Loans (1) Charge- Offs (2) Payment- Default Modified Loans (1) Charge- Offs (2) Payment- Default Modified Loans (1) Charge- Offs (2) Payment- Default Total $ 816 $ 346 $ 181 $ 1,169 $ 382 $ 265 $ 1,604 $ 459 $ 403 (1) Represents period ending balance of loans that have been modified during the period and resulted in a TDR. (2) Represents loans that charged off that were classified as TDRs. Accrued Interest Receivable The following table provides information regarding accrued interest receivable on our Private Education Loans. Accrued Interest Receivable As of December 31, (Dollars in millions) Total Greater Than 90 Days Past Due Allowance for Uncollectible Interest 2017 TDR $ 196 $ 20 $ 20 Non-TDR 187 4 6 Total $ 383 $ 24 $ 26 2016 TDR $ 192 $ 28 $ 23 Non-TDR 199 5 7 Total $ 391 $ 33 $ 30 2015 TDR $ 201 $ 28 $ 26 Non-TDR 289 7 9 Total $ 490 $ 35 $ 35

Business Combinations, Goodwill

Business Combinations, Goodwill and Acquired Intangible Assets	12 Months Ended
	Dec. 31, 2017
Business Combinations, Goodwill and Acquired Intangible Assets	5. 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. We anticipate the purchase price allocation will be completed by the end of the second quarter 2018. The preliminary estimate of goodwill is $87 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 Private Education Loans segment and its Earnest reporting unit. Navient has not disclosed the pro forma impact of this acquisition to the results of operations for the years ended December 31, 2017, 2016 and 2015, 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 supports its clients’ parking and tolling operations. We have 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. The preliminary estimate of goodwill is $63 million. We anticipate the purchase price allocation will be completed by the end of the first quarter 2018. 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 Services segment and its Gila reporting unit. Navient has not disclosed the pro forma impact of this acquisition to the results of operations for the years ended December 31, 2017, 2016 and 2015, as the pro forma impact was deemed immaterial. Acquisition of Xtend Healthcare In October 2015, Navient acquired an 89 percent controlling interest in Xtend Healthcare for approximately $164 million, of which $102 million was allocated to goodwill. Xtend Healthcare is a health care revenue cycle management company that provides health insurance claims billing and account resolution, as well as patient billing and customer service. The results of operations of Xtend Healthcare have been included in Navient’s consolidated financial statements since the acquisition date and are reflected in Navient’s Business Services segment and its Xtend reporting unit. Navient has not disclosed the pro forma impact of this acquisition to the results of operations for the year ended December 31, 2015, as the pro forma impact was deemed immaterial. Identifiable intangible assets at the acquisition date included definite life intangible assets with an estimated aggregate fair value of approximately $65 million primarily including customer relationships, developed technology, and the Xtend Healthcare trade name. These intangible assets will be amortized over a period of 10 to 15 years based on the estimated economic benefit derived from each of the underlying assets. Acquisition of Gila In February 2015, Navient acquired a 98 percent majority controlling interest in Gila for approximately $185 million, of which $97 million was allocated to goodwill. Gila is an asset recovery and business processing firm. The firm provides services to state governments, agencies, court systems and municipalities. The results of operations of Gila have been included in Navient’s consolidated financial statements since the acquisition date and are reflected in Navient’s Business Services segment and its Gila reporting unit. Navient has not disclosed the pro forma impact of this acquisition to the results of operations for the year ended December 31, 2015, as the pro forma impact was deemed immaterial. Identifiable intangible assets at the acquisition date included the Gila trade name, initially classified as an indefinite life intangible asset, with an aggregate fair value of approximately $13 million as of the acquisition date. Definite life intangible assets with an estimated aggregate fair value of approximately $71 million as of the acquisition date consist primarily of customer relationships. These intangible assets will be amortized over 7 to 16 years depending on the estimated economic benefit derived from each of the underlying assets. Goodwill All acquisitions must be assigned to a reporting unit or units. A reporting unit is the same as, or one level below, an operating segment. We have four reportable segments: FFELP Loans, Private Education Loans, Business Services and Other. The following table summarizes our goodwill, accumulated impairments and net goodwill for our reporting units and reportable segments. As of December 31, 2017 As of December 31, 2016 (Dollars in millions) Gross Accumulated Impairments and Other Adjustments (1) Net Gross Accumulated Impairments and Other Adjustments (1) Net FFELP Loans reportable segment $ 194 $ (4 ) $ 190 $ 194 $ (4 ) $ 190 Private Education Loans reportable segment: Private Education Loans 147 (41 ) 106 147 (41 ) 106 Earnest 87 — 87 — — — Total Private Education Loans reportable segment (1) 234 (41 ) 193 147 (41 ) 106 Business Services reportable segment: Servicing 50 — 50 50 — 50 Asset Recovery — Contingency 136 (136 ) — 136 (136 ) — Asset Recovery — Gila 160 — 160 97 — 97 Asset Recovery — Xtend Healthcare 108 — 108 102 — 102 Total Business Services reportable segment 454 (136 ) 318 385 (136 ) 249 Total $ 882 $ (181 ) $ 701 $ 726 $ (181 ) $ 545 (1) In conjunction with our Separation from SLM BankCo in 2014, we removed $41 million of goodwill from our balance sheet as required under ASC 350, “Intangibles — Goodwill and Other.” This goodwill was allocated to the consumer banking business retained by SLM BankCo based on relative fair value. Annual Goodwill Impairment Testing — October 1, 2017 We perform our goodwill impairment testing annually in the fourth quarter as of October 1. As part of the 2017 annual impairment testing associated with our FFELP Loans, Private Education Loans and Servicing reporting units, we assessed relevant qualitative factors to determine whether it is “more-likely-than-not” that the fair value of an individual reporting unit is less than its carrying value. We considered the amount of excess fair values over the carrying values of individual reporting units as of October 1, 2016 when we last performed a Step 1 goodwill impairment test and engaged an appraisal firm to estimate the fair values of these reporting units. The fair values of these reporting units at October 1, 2016 were substantially in excess of their carrying amounts. In addition, the cash flows for our FFELP Loans, Private Education Loans and Servicing reporting units are very predictable and the outlook and associated cash flow projections of these reporting units have not changed significantly since our 2016 assessment. No goodwill was deemed impaired for the reporting units after assessing these relevant qualitative factors. We also assessed relevant qualitative factors associated with our Gila reporting unit. We considered the acquisition value, 2017 earnings, 2018 expectations, current customer base, revenue backlog, and short and long-term outlook. Goodwill was not deemed to be impaired for the reporting unit after assessing these relevant qualitative factors. We also considered that our market capitalization was greater than our book equity, the current regulatory and legislative environment, the current economic environment, our 2017 earnings, 2018 expected earnings and analyst expectations regarding our stock price. We viewed these factors as favorable. Regarding our Xtend reporting unit, we retained a third-party appraisal firm to estimate the fair value of the reporting unit as required to perform a Step 1 impairment test of goodwill. We determined a Step 1 impairment test was warranted due to revenue performance since the acquisition being below expectations. The income approach and the market approach were the primary approaches used to estimate the fair value of the reporting unit. Goodwill was not deemed impaired for the Xtend reporting unit. The income approach measures the value of the reporting unit’s future economic benefit determined by its discounted cash flows derived from our projections plus an assumed terminal growth rate adjusted for what we believe a market participant would assume in an acquisition. These projections are generally five to seven-year projections that reflect the anticipated cash flow fluctuations of the reporting unit. Under our guidance, the third-party appraisal firm developed the discount rate for the reporting unit incorporating such factors as the risk-free rate, equity risk premium, industry risk premium, a measure of volatility (Beta) and a company-specific risk premium, to adjust for volatility and uncertainty in the economy and to capture specific risk related to the reporting unit. We considered whether an asset sale or an equity sale would be the most likely sale structure for the reporting unit and valued the reporting unit based on the more likely hypothetical scenario, an asset sale. The discount rate reflects market-based estimates of capital costs and is adjusted for our assessment of a market participant’s view with respect to execution, source concentration and other risks associated with the projected cash flows of the reporting unit. We reviewed and approved the discount rate of 13.5 percent provided by the third-party appraiser including the factors incorporated to develop the discount rate. We and the third-party appraisal firm also considered a market approach to value the reporting unit. Market-based revenue and EBITDA multiples for comparable publicly traded companies and similar transactions were applied to the reporting unit’s revenue and EBITDA indicators to derive a value for the reporting unit. At October 1, 2017, the carrying value of equity of the Xtend reporting unit was $176 million and the percentage of the estimated fair value in excess of the carrying value was 19 percent. We acknowledge that a downturn in the economy coupled with liquidity constraints, and changes in legislation and the regulatory environment could adversely affect the operating results of our reporting units. If the forecasted performance of our reporting units is not achieved, or if our stock price declines resulting in deterioration in our total market capitalization, the fair value of one or more of the reporting units could be significantly reduced, and we may be required to record a charge, which could be material, for an impairment of goodwill associated with these reporting units. Interim Goodwill Impairment Testing — December 31, 2017 We performed interim goodwill impairment testing as of December 31, 2017 for the Gila reporting unit as the December 2017 notification of the loss of a significant toll contract effective January 1, 2019 was deemed a triggering event warranting an impairment assessment. We retained a third-party appraisal firm to estimate the fair value of the reporting unit as required to perform a Step 1 impairment test. Goodwill was not deemed impaired for the Gila reporting unit. The income approach was the primary approach used to fair value the reporting unit. We provided the appraisal firm projections that reflect the anticipated cash flow fluctuations of the reporting unit. These projections incorporated the anticipated cash flow benefit of a lower corporate federal statutory tax rate due to the 2017 “Tax Cuts and Jobs Act.” Under our guidance, the appraisal firm developed a discount rate for the reporting unit incorporating such factors as the risk-free rate, equity risk premium, industry risk premium, a measure of volatility (Beta) and a company-specific risk premium, to adjust for volatility and uncertainty in the economy and to capture specific risk related to the reporting unit. We considered whether an asset sale or an equity sale would be the most likely sale structure for the reporting unit and valued the reporting unit based on the more likely hypothetical scenario, an asset sale. The discount rate reflects market-based estimates of capital costs and is adjusted for our assessment of a market participant’s view with respect to execution, source concentration and other risks associated with the projected cash flows of the reporting unit. We reviewed and approved the discount rate of 15.0 percent provided by the third-party appraiser including the factors incorporated to develop the discount rate. We and the third-party appraisal firm also considered a market approach to value the reporting unit. Market-based revenue and EBITDA multiples for comparable publicly-traded companies and similar transactions were applied to the reporting unit’s revenue and EBITDA indicators to derive a value for the reporting unit. At December 31, 2017, the carrying value of equity of the Gila reporting unit was $245 million and the percentage of the estimated fair value in excess of the carrying value was 9 percent. Acquired Intangible Assets Acquired intangible assets include the following: As of December 31, 2017 As of December 31, 2016 (Dollars in millions) Cost Basis (1) Accumulated Impairment and Amortization (1) Net Cost Basis (1) Accumulated Impairment and Amortization (1) Net Customer, services and lending relationships $ 292 $ (234 ) $ 58 $ 292 $ (219 ) $ 73 Favorable lease 1 — 1 1 — 1 Non-competes 2 (2 ) — 2 (2 ) — Software and technology 104 (85 ) 19 101 (82 ) 19 Trade names and trademarks (2) 48 (18 ) 30 44 (13 ) 31 Total acquired intangible assets $ 447 $ (339 ) $ 108 $ 440 $ (316 ) $ 124 (1) Accumulated impairment and amortization includes impairment amounts only if the acquired intangible asset has been deemed partially impaired. When an acquired intangible asset is considered fully impaired and no longer in use, the cost basis and any accumulated amortization related to the asset is written off. (2) During 2016 we reclassified certain trade names from indefinite life to definite life intangible assets and began to amortize these assets over their expected benefit period. We recorded amortization of acquired intangible assets from continuing operations totaling $23 million, $29 million and $12 million in 2017, 2016 and 2015, respectively. We will continue to amortize our intangible assets with definite useful lives over their remaining estimated useful lives. We estimate amortization expense associated with these intangible assets will be $20 million, $17 million, $14 million, $12 million and $39 million in 2018, 2019, 2020, 2021 and after 2021, respectively.

Borrowings

Borrowings	12 Months Ended
Borrowings	Dec. 31, 2017
Borrowings	6. Borrowings consist of secured borrowings issued through our securitization program, borrowings through secured facilities, unsecured notes issued by us, and other interest-bearing liabilities related primarily to obligations to return cash collateral held. To match the interest rate and currency characteristics of our borrowings with the interest rate and currency characteristics of our assets, we enter into interest rate and foreign currency swaps with independent parties. Under these agreements, we make periodic payments, generally indexed to the related asset rates or rates which are highly correlated to the asset rates, in exchange for periodic payments which generally match our interest obligations on fixed or variable rate notes (see “Note 7 —Derivative Financial Instruments”). Payments and receipts on our interest rate and currency swaps are not reflected in the following tables. The following table summarizes our borrowings. December 31, 2017 December 31, 2016 (Dollars in millions) Short Term Long Term Total Short Term Long Term Total Unsecured borrowings: Senior unsecured debt (1) $ 1,306 $ 12,624 $ 13,930 $ 717 $ 13,029 $ 13,746 Total unsecured borrowings 1,306 12,624 13,930 717 13,029 13,746 Secured borrowings: FFELP Loan securitizations — 71,208 71,208 — 73,522 73,522 Private Education Loan securitizations (2) 686 12,646 13,332 548 14,125 14,673 FFELP Loan — other facilities 1,536 6,830 8,366 — 12,443 12,443 Private Education Loan — other facilities 684 1,710 2,394 464 — 464 Other (3) 538 — 538 606 — 606 Total secured borrowings 3,444 92,394 95,838 1,618 100,090 101,708 Total before hedge accounting adjustments 4,750 105,018 109,768 2,335 113,119 115,454 Hedge accounting adjustments 21 (6 ) 15 (1 ) (751 ) (752 ) Total $ 4,771 $ 105,012 $ 109,783 $ 2,334 $ 112,368 $ 114,702 (1) Includes principal amount of $1.3 billion and $719 million of short-term debt as of December 31, 2017 and 2016, respectively. Includes principal amount of $12.7 billion and $13.1 billion of long-term debt as of December 31, 2017 and 2016, respectively. (2) Includes $686 million and $548 of short-term debt related to the Private Education Loan asset-backed securitization repurchase facilities (“Repurchase Facilities”) as of December 31, 2017 and 2016, respectively. Includes $1.3 billion and $475 million of long-term debt related to the Repurchase Facilities as of December 31, 2017 and 2016, respectively. (3) “Other” primarily includes the obligation to return cash collateral held related to derivative exposures, which includes $0 million and $193 million of securities re-pledged subject to an overnight repurchase transaction as of December 31, 2017 and 2016, respectively. Short-term Borrowings Short-term borrowings have a remaining term to maturity of one year or less. The following tables summarize outstanding short-term borrowings (secured and unsecured), the weighted average interest rates at the end of each period, and the related average balances and weighted average interest rates during the periods. December 31, 2017 Year Ended December 31, 2017 (Dollars in millions) Ending Balance Weighted Average Interest Rate Average Balance Weighted Average Interest Rate Private Education Loan securitizations (1) $ 686 4.65 % $ 706 4.32 % FFELP Loan — other facilities 1,536 2.11 261 1.26 Private Education Loan — other facilities 684 2.92 572 2.42 Senior unsecured debt 1,327 8.06 1,197 6.80 Other interest-bearing liabilities 538 1.33 458 1.27 Total short-term borrowings $ 4,771 4.16 % $ 3,194 4.22 % Maximum outstanding at any month end $ 4,771 December 31, 2016 Year Ended December 31, 2016 (Dollars in millions) Ending Balance Weighted Average Interest Rate Average Balance Weighted Average Interest Rate Private Education Loan securitizations (1) $ 548 3.72 % $ 42 3.81 % FFELP Loan — other facilities — — — — Private Education Loan —other facilities 464 2.02 389 1.83 Senior unsecured debt 716 4.22 1,032 5.01 Other interest-bearing liabilities 606 .96 629 .48 Total short-term borrowings $ 2,334 2.82 % $ 2,092 3.03 % Maximum outstanding at any month end $ 2,637 (1) Relates to Repurchase Facilities. Long-term Borrowings The following tables summarize outstanding long-term borrowings, the weighted average interest rates at the end of the periods, and the related average balances during the periods. December 31, 2017 Weighted Average Year Ended December 31, 2017 (Dollars in millions) Ending Balance (1) Interest Rate (2) Average Balance Floating rate notes: U.S. dollar-denominated: Interest bearing, due 2018-2083 $ 83,209 2.31 % $ 86,186 Non-U.S. dollar-denominated: Interest bearing, due 2023-2041 6,423 .37 7,355 Total floating rate notes 89,632 2.17 93,541 Fixed rate notes: U.S. dollar-denominated: Interest bearing, due 2019-2058 15,114 5.60 15,266 Non-U.S.-dollar denominated: Interest bearing, due 2034-2035 266 2.72 281 Total fixed rate notes 15,380 5.55 15,547 Total long-term borrowings $ 105,012 2.67 % $ 109,088 December 31, 2016 Weighted Average Year Ended December 31, 2016 (Dollars in millions) Ending Balance (1) Interest Rate (2) Average Balance Floating rate notes: U.S. dollar-denominated: Interest bearing, due 2017-2083 $ 88,575 1.65 % $ 93,881 Non-U.S. dollar-denominated: Interest bearing, due 2023-2041 7,265 .28 8,761 Total floating rate notes 95,840 1.54 102,642 Fixed rate notes: U.S. dollar-denominated: Interest bearing, due 2018-2058 16,271 5.65 16,050 Non-U.S.-dollar denominated: Interest bearing, due 2034-2035 257 2.82 281 Total fixed rate notes 16,528 5.60 16,331 Total long-term borrowings $ 112,368 2.14 % $ 118,973 (1) Ending balance is expressed in U.S. dollars using the spot currency exchange rate. Includes fair value adjustments under hedge accounting for notes designated as the hedged item in a fair value hedge. (2) Weighted average interest rate is stated rate relative to currency denomination of debt. As of December 31, 2017, the expected maturities of our long-term borrowings are shown in the following table. Expected Maturity (Dollars in millions) Senior Unsecured Debt Secured Borrowings (1) Total (2) Year of Maturity 2018 $ — $ 11,810 $ 11,810 2019 2,369 10,276 12,645 2020 2,041 9,076 11,117 2021 1,428 7,477 8,905 2022 1,731 6,326 8,057 2023-2039 5,055 47,429 52,484 12,624 92,394 105,018 Hedge accounting adjustments 240 (246 ) (6 ) Total $ 12,864 $ 92,148 $ 105,012 (1) We view our securitization trust debt as long-term based on the contractual maturity dates which range from 2018 to 2083. However, we have projected the expected principal paydowns based on our current estimates regarding the securitized loans’ prepayment speeds for purposes of this disclosure to better reflect how we expect this debt to be paid down over time. The projected principal paydowns in year 2018 include $11.8 billion related to the securitization trust debt. (2) The aggregate principal amount of debt that matures in each period is $11.9 billion in 2018, $12.7 billion in 2019, $11.2 billion in 2020, $9.0 billion in 2021, $8.1 billion in 2022 and $53.0 billion in 2023-2039. Variable Interest Entities We consolidate the following financing VIEs as of December 31, 2017 and 2016, as we are the primary beneficiary. As a result, these VIEs are accounted for as secured borrowings. December 31, 2017 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets, Net Total Secured Borrowings — VIEs: FFELP Loan securitizations $ — $ 71,208 $ 71,208 $ 72,145 $ 2,335 $ 1,078 $ 75,558 Private Education Loan securitizations (1) 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 December 31, 2016 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets, Net Total Secured Borrowings — VIEs: FFELP Loan securitizations $ — $ 73,522 $ 73,522 $ 74,197 $ 2,676 $ 778 $ 77,651 Private Education Loan securitizations (1) 548 14,125 14,673 19,815 455 260 20,530 FFELP Loan — other facilities — 9,046 9,046 9,232 289 172 9,693 Private Education Loan — other facilities 464 — 464 685 10 14 709 Other 66 — 66 79 4 — 83 Total before hedge accounting adjustments 1,078 96,693 97,771 104,008 3,434 1,224 108,666 Hedge accounting adjustments — (1,201 ) (1,201 ) — — (1,235 ) (1,235 ) Total $ 1,078 $ 95,492 $ 96,570 $ 104,008 $ 3,434 $ (11 ) $ 107,431 (1) Includes $686 million of short-term debt, $1.3 billion of long-term debt and $96 million of restricted cash related to the Repurchase Facilities as of December 31, 2017. Includes $548 million of short-term debt, $475 million of long-term debt and $49 million of restricted cash related to the Repurchase Facilities as of December 31, 2016. Securitizations Private Education Loan ABS Repurchase Facilities Since the fourth quarter of 2015, we have closed on $2.5 billion of Private Education Loan ABS Repurchase Facilities. These repurchase facilities are collateralized by Residual Interests in previously issued Private Education Loan ABS trusts. The lenders also have unsecured recourse to Navient Corporation as guarantor for any shortfall in amounts payable. Because these facilities are secured by the Residual Interests in previous securitizations, we show the debt and assets as part of Private Education Loan securitizations in the Secured Borrowings table above. FFELP Loans — Other Secured Borrowing Facilities We have various secured borrowing facilities that we use to finance our FFELP Loans. Liquidity is available under these secured credit facilities to the extent we have eligible collateral and available capacity. The maximum borrowing capacity under these facilities will vary and is subject to each agreement’s borrowing conditions. These include but are not limited to the facility’s size, current usage and the availability and fair value of qualifying unencumbered FFELP Loan collateral. Our borrowings under these facilities are non-recourse. The maturity dates on these facilities range from November 2018 to January 2021. The interest rate on certain facilities can increase under certain circumstances. The facilities are subject to termination under certain circumstances. As of December 31, 2017, there was approximately $8.4 billion outstanding under these facilities, with approximately $9.4 billion of assets securing these facilities. As of December 31, 2017, the maximum unused capacity under these facilities was $2.4 billion. As of December 31, 2017, we had $0.7 billion of unencumbered FFELP Loans. Private Education Loans — Other Secured Borrowing Facilities We have various secured borrowing facilities that we use to finance our Private Education Loans. Liquidity is available under these secured credit facilities to the extent we have eligible collateral and available capacity. The maximum borrowing capacity under these facilities will vary and is subject to each agreement’s borrowing conditions. These include but are not limited to the facility’s size, current usage and the availability and fair value of qualifying unencumbered Private Education Loan collateral. Our borrowings under these facilities are non-recourse. The maturity dates on these facilities range from June 2018 to June 2020. The interest rate on certain facilities can increase under certain circumstances. The facilities are subject to termination under certain circumstances. As of December 31, 2017, there was approximately $2.4 billion outstanding under these facilities, with approximately $3.1 billion of assets securing these facilities. As of December 31, 2017, the maximum unused capacity under these facilities was $925 million. As of December 31, 2017, we had $2.5 billion of unencumbered Private Education Loans. The Private Education Loan ABCP facilities’ borrowing capacity includes a new $750 million revolving credit facility that closed in fourth-quarter 2017 to warehouse Private Education Refinance Loan originations. This facility matures in October 2018. At December 31, 2017, the available capacity under this facility was $328 million. Other Funding Sources Senior Unsecured Debt We issued $1.6 billion, $1.3 billion and $500 million of unsecured debt in 2017, 2016 and 2015, respectively. Debt Repurchases The following table summarizes activity related to our senior unsecured debt and ABS repurchases. “Gains (losses) on debt repurchases” is shown net of hedging-related gains and losses. Years Ended December 31, (Dollars in millions) 2017 2016 2015 Debt principal repurchased $ 513 $ 1,467 $ 1,744 Gains (losses) on debt repurchases (3 ) 1 21

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
Derivative Financial Instruments	Dec. 31, 2017
Derivative Financial Instruments	7. Risk Management Strategy We maintain an overall interest rate risk management strategy that incorporates the use of derivative instruments to minimize the economic effect of interest rate changes. Our goal is to manage interest rate sensitivity by modifying the repricing frequency and underlying index characteristics of certain balance sheet assets and liabilities so the net interest margin is not, on a material basis, adversely affected by movements in interest rates. We do not use derivative instruments to hedge credit risk. As a result of interest rate fluctuations, hedged assets and liabilities will appreciate or depreciate in market value. Income or loss on the derivative instruments that are linked to the hedged assets and liabilities will generally offset the effect of this unrealized appreciation or depreciation for the period the item is being hedged. We view this strategy as a prudent management of interest rate sensitivity. In addition, we utilize derivative contracts to minimize the economic impact of changes in foreign currency exchange rates on certain debt obligations that are denominated in foreign currencies. As foreign currency exchange rates fluctuate, these liabilities will appreciate and depreciate in value. These fluctuations, to the extent the hedge relationship is effective, are offset by changes in the value of the cross-currency interest rate swaps executed to hedge these instruments. Management believes certain derivative transactions entered into as hedges, primarily Floor Income Contracts and basis swaps, are economically effective; however, those transactions generally do not qualify for hedge accounting under GAAP (as discussed below) and thus may adversely impact earnings. Although we use derivatives to minimize the risk of interest rate and foreign currency changes, the use of derivatives does expose us to both market and credit risk. Market risk is the chance of financial loss resulting from changes in interest rates, foreign exchange rates and market liquidity. Credit risk is the risk that a counterparty will not perform its obligations under a contract and it is limited to the loss of the fair value gain in a derivative that the counterparty owes us. When the fair value of a derivative contract is negative, we owe the counterparty and, therefore, have no credit risk exposure to the counterparty; however, the counterparty has exposure to us. We minimize the credit risk in derivative instruments by entering into transactions with highly rated counterparties that are reviewed regularly by our Credit Department. We also maintain a policy of requiring that all derivative contracts be governed by an International Swaps and Derivative Association Master Agreement. Depending on the nature of the derivative transaction, bilateral collateral arrangements related to Navient Corporation contracts generally are required as well. When we have more than one outstanding derivative transaction with the counterparty, and there exists legally enforceable netting provisions with the counterparty (i.e., a legal right to offset receivable and payable derivative contracts), the “net” mark-to-market exposure, less collateral the counterparty has posted to us, represents exposure with the counterparty. When there is a net negative exposure, we consider our exposure to the counterparty to be zero. At December 31, 2017 and 2016, we had a net positive exposure (derivative gain positions to us less collateral which has been posted by counterparties to us) related to Navient Corporation derivatives of $24 million and $110 million, respectively. Our on-balance sheet securitization trusts have $6.7 billion of Euro and British Pound Sterling denominated bonds outstanding as of December 31, 2017. To convert these non-U.S. dollar denominated bonds into U.S. dollar liabilities, the trusts have entered into foreign-currency swaps with highly-rated counterparties. In addition, the trusts have entered into $7.8 billion notional of interest rates swaps which are primarily used to convert Prime received on securitized education loans to LIBOR paid on the bonds. Our securitization trusts with swaps have ISDA documentation with protections against counterparty risk. The collateral calculations contemplated in the ISDA documentation of our securitization trusts require collateral based on the fair value of the derivative which may be adjusted for additional collateral based on rating agency criteria requirements considered within the collateral agreement. The trusts are not required to post collateral to the counterparties. At December 31, 2017 and 2016, the net positive exposure on swaps in securitization trusts was $64 million and $9 million, respectively. Accounting for Derivative Instruments Derivative instruments that are used as part of our interest rate and foreign currency risk management strategy include interest rate swaps, basis swaps, cross-currency interest rate swaps, and interest rate floor contracts with indices that relate to the pricing of specific balance sheet assets and liabilities. The accounting for derivative instruments requires that every derivative instrument, including certain derivative instruments embedded in other contracts, be recorded on the balance sheet as either an asset or liability measured at its fair value. As more fully described below, if certain criteria are met, derivative instruments are classified and accounted for by us as either fair value or cash flow hedges. If these criteria are not met, the derivative financial instruments are accounted for as trading. Fair Value Hedges Fair value hedges are generally used by us to hedge the exposure to changes in fair value of a recognized fixed rate asset or liability. We enter into interest rate swaps to economically convert fixed rate assets into variable rate assets and fixed rate debt into variable rate debt. We also enter into cross-currency interest rate swaps to economically convert foreign currency denominated fixed and floating debt to U.S. dollar denominated variable debt. For fair value hedges, we generally consider all components of the derivative’s gain and/or loss when assessing hedge effectiveness and generally hedge changes in fair values due to interest rates or interest rates and foreign currency exchange rates. Cash Flow Hedges We use cash flow hedges to hedge the exposure to variability in cash flows for a forecasted debt issuance and for exposure to variability in cash flows of floating rate debt. This strategy is used primarily to minimize the exposure to volatility from future changes in interest rates. Gains and losses on the effective portion of a qualifying hedge are recorded in accumulated other comprehensive income and ineffectiveness is recorded immediately to earnings. In the case of a forecasted debt issuance, gains and losses are reclassified to earnings over the period which the stated hedged transaction affects earnings. If we determine it is not probable that the anticipated transaction will occur, gains and losses are reclassified immediately to earnings. In assessing hedge effectiveness, generally all components of each derivative’s gains or losses are included in the assessment. We generally hedge exposure to changes in cash flows due to changes in interest rates or total changes in cash flow. Trading Activities When derivative instruments do not qualify as hedges, they are accounted for as trading instruments where all changes in fair value are recorded through earnings. We sell interest rate floors (Floor Income Contracts) to hedge the embedded Floor Income options in education loan assets. The Floor Income Contracts are written options which have a more stringent hedge effectiveness hurdle to meet. Specifically, our Floor Income Contracts do not qualify for hedge accounting treatment because the pay down of principal of the education loans underlying the Floor Income embedded in those education loans does not exactly match the change in the notional amount of our written Floor Income Contracts. Additionally, the term, the interest rate index and the interest rate index reset frequency of the Floor Income Contracts can be different from that of the education loans. Therefore, Floor Income Contracts do not qualify for hedge accounting treatment, and are recorded as trading instruments. Regardless of the accounting treatment, we consider these contracts to be economic hedges for risk management purposes. We use this strategy to minimize our exposure to changes in interest rates. We use basis swaps to minimize earnings variability caused by having different reset characteristics on our interest-earning assets and interest-bearing liabilities. The specific terms and notional amounts of the swaps are determined based on a review of our asset/liability structure, our assessment of future interest rate relationships, and on other factors such as short-term strategic initiatives. Hedge accounting requires that when using basis swaps, the change in the cash flows of the hedge effectively offset both the change in the cash flows of the asset and the change in the cash flows of the liability. Our basis swaps hedge variable interest rate risk; however, they generally do not meet this effectiveness criterion because the index of the swap does not exactly match the index of the hedged assets. Additionally, some of our FFELP Loans can earn at either a variable or a fixed interest rate depending on market interest rates and, therefore, swaps economically hedging these FFELP Loans do not meet the criteria for hedge accounting treatment. As a result, these swaps are recorded at fair value with changes in fair value reflected currently in the statement of income. Summary of Derivative Financial Statement Impact The following tables summarize the fair values and notional amounts or number of contracts of all derivative instruments at December 31, 2017 and 2016, and their impact on other comprehensive income and earnings for 2017, 2016 and 2015. Impact of Derivatives on Consolidated Balance Sheet Cash Flow Fair Value Trading Total (Dollars in millions) Hedged Risk Exposure Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Fair Values (1) Derivative Assets: Interest rate swaps Interest rate $ 95 $ 78 $ 290 $ 465 $ 7 $ 22 $ 392 $ 565 Cross-currency interest rate swaps Foreign currency and interest rate — — 88 — — — 88 — Total derivative assets (2) 95 78 378 465 7 22 480 565 Derivative Liabilities: Interest rate swaps Interest rate (16 ) (76 ) (102 ) (62 ) (71 ) (70 ) (189 ) (208 ) Floor Income Contracts Interest rate — — — — (74 ) (184 ) (74 ) (184 ) Cross-currency interest rate swaps Foreign currency and interest rate — — (410 ) (1,243 ) (44 ) (53 ) (454 ) (1,296 ) Other (3) Interest rate — — — — (18 ) (13 ) (18 ) (13 ) Total derivative liabilities (2) (16 ) (76 ) (512 ) (1,305 ) (207 ) (320 ) (735 ) (1,701 ) Net total derivatives $ 79 $ 2 $ (134 ) $ (840 ) $ (200 ) $ (298 ) $ (255 ) $ (1,136 ) (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 with the impact of master netting agreements to the balance sheet classification: Other Assets Other Liabilities (Dollar in millions) December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Gross position $ 480 $ 565 $ (735 ) $ (1,701 ) Impact of master netting agreements (42 ) (31 ) 42 31 Derivative values with impact of master netting agreements (as carried on balance sheet) 438 534 (693 ) (1,670 ) Cash collateral (held) pledged (536 ) (345 ) 235 319 Net position, as presented on the balance sheet $ (98 ) $ 189 $ (458 ) $ (1,351 ) (3) “Other” includes derivatives related to our Total Return Swap Facility The above fair values include adjustments 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 certain asset positions at December 31, 2017 and 2016 by $6 million and $0 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 certain asset positions at December 31, 2017 and 2016 by $30 million and $31 million, respectively. Cash Flow Fair Value Trading Total (Dollars in billions) Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Notional Values: Interest rate swaps $ 24.1 $ 15.2 $ 12.4 $ 11.8 $ 72.0 $ 23.8 $ 108.5 $ 50.8 Floor Income Contracts — — — — 21.9 18.5 21.9 18.5 Cross-currency interest rate swaps — — 6.7 8.5 .3 .3 7.0 8.8 Other (1) — — — — .5 2.6 .5 2.6 Total derivatives $ 24.1 $ 15.2 $ 19.1 $ 20.3 $ 94.7 $ 45.2 $ 137.9 $ 80.7 (1) “Other” includes derivatives related to our Total Return Swap Facility. Impact of Derivatives on Consolidated Statements of Income Years Ended December 31, Unrealized Gain (Loss) on Derivatives (1)(2) Realized Gain (Loss) on Derivatives (3) Unrealized Gain (Loss) on Hedged Item (1) Total Gain (Loss) (Dollars in millions) 2017 2016 2015 2017 2016 2015 2017 2016 2015 2017 2016 2015 Fair Value Hedges: Interest rate swaps $ (214 ) $ (288 ) $ (115 ) $ 175 $ 259 $ 345 $ 193 $ 302 $ 140 $ 154 $ 273 $ 370 Cross-currency interest rate swaps 921 (319 ) (794 ) (118 ) (86 ) (7 ) (954 ) 350 921 (151 ) (55 ) 120 Total fair value derivatives 707 (607 ) (909 ) 57 173 338 (761 ) 652 1,061 3 218 490 Cash Flow Hedges: Interest rate swaps — — — (49 ) (50 ) — — — — (49 ) (50 ) — Total cash flow derivatives — — — (49 ) (50 ) — — — — (49 ) (50 ) — Trading: Interest rate swaps (16 ) (13 ) 61 24 42 42 — — — 8 29 103 Floor Income Contracts 150 297 557 (69 ) (246 ) (650 ) — — — 81 51 (93 ) Cross-currency interest rate swaps 8 9 2 (6 ) (4 ) (4 ) — — — 2 5 (2 ) Other (5 ) (10 ) 9 (10 ) (3 ) (3 ) — — — (15 ) (13 ) 6 Total trading derivatives 137 283 629 (61 ) (211 ) (615 ) — — — 76 72 14 Total 844 (324 ) (280 ) (53 ) (88 ) (277 ) (761 ) 652 1,061 30 240 504 Less: realized gains (losses) recorded in interest expense — — — 8 123 338 — — — 8 123 338 Gains (losses) on derivative and hedging activities, net $ 844 $ (324 ) $ (280 ) $ (61 ) $ (211 ) $ (615 ) $ (761 ) $ 652 $ 1,061 $ 22 $ 117 $ 166 (1) Recorded in “Gains (losses) on derivative and hedging activities, net” in the consolidated statements of income. (2) Represents ineffectiveness related to cash flow hedges. (3) For fair value and cash flow hedges, recorded in interest expense. For trading derivatives, recorded in “Gains (losses) on derivative and hedging activities, net.” Impact of Derivatives on Consolidated Statements of Changes in Stockholders’ Equity (net of tax) Years Ended December 31, (Dollars in millions) 2017 2016 2015 Total gains (losses) on cash flow hedges $ 25 $ 26 $ (59 ) Realized (gains) losses recognized in interest expense (1)(2)(3) 30 31 (1 ) Total change in stockholders’ equity for unrealized gains (losses) on derivatives $ 55 $ 57 $ (60 ) (1) Amounts included in “Realized gain (loss) on derivatives” in the “Impact of Derivatives on Consolidated Statements of Income” table above. (2) Includes net settlement income/expense. (3) We expect to reclassify $2 million of after-tax net losses from accumulated other comprehensive income to earnings during the next 12 months related to amortization of terminated hedge relationships. Collateral The following table details collateral held and pledged related to derivative exposure between us and our derivative counterparties. (Dollars in millions) December 31, 2017 December 31, 2016 Collateral held: Cash (obligation to return cash collateral is recorded in short- term borrowings) $ 536 $ 345 Securities at fair value — corporate derivatives (not recorded in financial statements) (1) — 193 Securities at fair value — on-balance sheet securitization derivatives (not recorded in financial statements) (2) 297 230 Total collateral held $ 833 $ 768 Derivative asset at fair value including accrued interest $ 618 $ 689 Collateral pledged to others: Cash (right to receive return of cash collateral is recorded in investments) $ 235 $ 319 Total collateral pledged $ 235 $ 319 Derivative liability at fair value including accrued interest and premium receivable $ 659 $ 1,670 (1) The Company has the ability to sell or re-pledge securities it holds as collateral. (2) The trusts do not have the ability to sell or re-pledge securities they hold as collateral. Our corporate derivatives contain credit contingent features. At our current unsecured credit rating, we have fully collateralized our corporate derivative liability position (including accrued interest and net of premiums receivable) of $217 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	12 Months Ended
Other Assets	Dec. 31, 2017
Other Assets	8. The following table provides the detail of our other assets. (Dollars in millions) December 31, 2017 December 31, 2016 Accrued interest receivable, net $ 1,965 $ 1,663 Benefit and insurance-related investments 481 488 Derivatives at fair value 438 534 Income tax asset, net current and deferred 380 725 Fixed assets, net 156 160 Accounts receivable 108 95 Other loans, net 59 148 Other 438 380 Total $ 4,025 $ 4,193

Stockholders' Equity

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2017
Stockholders' Equity	9. Common Stock Our shareholders have authorized the issuance of 1.125 billion shares of common stock. The par value of Navient common stock is $0.01 per share. At December 31, 2017, 263 million shares were issued and outstanding and 28 million shares were unissued but encumbered for outstanding stock options, restricted stock units and dividend equivalent units for employee compensation and remaining authority for stock-based compensation plans. The stock-based compensation plans are described in “Note 11 — Stock-Based Compensation Plans and Arrangements.” Dividend and Share Repurchase Program In 2017, 2016 and 2015, we paid full-year common stock dividends of $0.64 per share. In 2015, we repurchased 56.0 million shares of common stock for $945 million. In 2016, we repurchased 59.6 million shares of common stock for $755 million, fully utilizing our share repurchase programs. In December 2016, our board of directors authorized a new $600 million share repurchase program effective January 1, 2017. In 2017, we repurchased 29.6 million shares of common stock for $440 million. Effective October 4, 2017, Navient temporarily suspended its remaining share repurchase program to allocate capital towards building book value. On January 24, 2018, we announced that we expect to restart our share repurchases in the second half of 2018. As of December 31, 2017, the remaining repurchase authority was $160 million. The following table summarizes our common share repurchases and issuances. Years Ended December 31, 2017 2016 2015 Common stock repurchased (1) 29,646,374 59,625,325 56,043,711 Average purchase price per share $ 14.85 $ 12.68 $ 16.87 Shares repurchased related to employee stock-based compensation plans (2) 1,847,651 3,197,355 2,404,328 Average purchase price per share $ 15.40 $ 13.21 $ 19.81 Common shares issued (3) 3,680,479 5,476,010 4,924,021 (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 December 31, 2017 was $13.32.

Earnings (Loss) per Common Shar

Earnings (Loss) per Common Share	12 Months Ended
Earnings (Loss) per Common Share	Dec. 31, 2017
Earnings (Loss) per Common Share	10. Basic earnings (loss) per common share (“EPS”) are calculated using the weighted average number of shares of common stock outstanding during each period. A reconciliation of the numerators and denominators of the basic and diluted EPS calculations follows. Years Ended December 31, (In millions, except per share data) 2017 2016 2015 Numerator: Net income attributable to Navient Corporation $ 292 $ 681 $ 984 Denominator: Weighted average shares used to compute basic EPS 275 316 376 Effect of dilutive securities: Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units and Employee Stock Purchase Plan (“ESPP”) (1) 6 6 6 Dilutive potential common shares (2) 6 6 6 Weighted average shares used to compute diluted EPS 281 322 382 Basic earnings per common share attributable to Navient Corporation $ 1.06 $ 2.15 $ 2.62 Diluted earnings per common share attributable to Navient Corporation $ 1.04 $ 2.12 $ 2.58 (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 the ESPP, determined by the treasury stock method. (2) For the years ended December 31, 2017, 2016 and 2015, stock options covering approximately 5 million, 4 million and 6 million shares, respectively, were outstanding but not included in the computation of diluted earnings per share because they were anti-dilutive.

Stock-Based Compensation Plans

Stock-Based Compensation Plans and Arrangements	12 Months Ended
Stock-Based Compensation Plans and Arrangements	Dec. 31, 2017
Stock-Based Compensation Plans and Arrangements	11. We have one active stock-based incentive plan that provides for grants of equity awards to our employees and non-employee directors in various forms including stock options, restricted stock awards, restricted stock units and performance stock units. We also maintain an ESPP. Shares issued under these plans may be either shares reacquired by us or shares that are authorized but unissued. Our Navient Corporation 2014 Omnibus Incentive Plan became effective on April 7, 2014, and 55 million shares are authorized to be issued from this plan as of December 31, 2017. Our Navient Corporation ESPP became effective on May 1, 2014, and 1 million shares are authorized to be issued from this plan as of December 31, 2017. For most awards, expense generally is recognized ratably over the vesting period net of estimated forfeitures, unless the employee meets certain retirement eligibility criteria. For employee awards that meet retirement eligibility criteria, we record the expense generally upon grant and for employees that become retirement eligible during the vesting period, we recognize expense from the grant date to the date on which the employee becomes retirement eligible. The total stock-based compensation cost recognized in 2017, 2016 and 2015 was $35 million, $26 million and $29 million, respectively. As of December 31, 2017, there was $17 million of total unrecognized compensation expense related to unvested stock awards, which is expected to be recognized over a weighted average period of 1.4 years. Stock Options The exercise price of stock options equals the fair market value of our common stock on the date of grant. The maximum contractual term for stock options is 5 years for grants made since 2012, and 10 years for grants made prior to 2012. Most stock options are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date. The fair values of the options granted in the years ended December 31, 2017, 2016 and 2015 were estimated as of the grant date using a Black-Scholes option pricing model with the following weighted average assumptions: Years Ended December 31, 2017 2016 2015 Expected life of the option 3.0 years 3.0 years 2.9 years Expected volatility 34 % 30 % 22 % Risk-free interest rate 1.44 % .90 % .95 % Expected dividend rate 4.13 % 6.97 % 2.99 % Weighted average fair value of options granted $ 2.69 $ 1.01 $ 2.22 The expected life is based in general on observed historical exercise patterns of SLM Corporation’s employees pre-Spin-Off (excluding employees who transitioned to SLM Bank) and Navient’s employees post-Spin-Off. The expected volatility is based in general on implied volatility from publicly-traded options on our stock at the grant date and historical volatility of both our stock and our peer group consistent with the expected life of the option. The risk-free interest rate is based on the U.S. Treasury spot rate at the grant date consistent with the expected life of the option. The dividend yield is based on the projected annual dividend payment per share based on the dividend amount at the grant date, divided by the stock price at the grant date. The following table summarizes Navient’s stock option activity in 2017. (Dollars in millions, except per share data) Number of Options Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (1) Outstanding at December 31, 2016 14,912,004 $ 12.45 Granted 1,308,167 15.48 Exercised (2) (1,497,807 ) 9.57 Canceled (538,638 ) 27.16 Outstanding at December 31, 2017 (3) 14,183,726 12.48 1.9 yrs. $ 37 Exercisable at December 31, 2017 9,653,511 $ 12.34 1.3 yrs. $ 26 (1) The aggregate intrinsic value represents the total intrinsic value (the aggregate difference between our closing stock price on December 31, 2017 and the exercise price of in-the-money options) that would have been received by the option holders if all in-the-money options had been exercised on December 31, 2017. (2) The total intrinsic value of Navient stock options exercised was $9 million, $13 million and $19 million for 2017, 2016 and 2015, respectively. (3) As of December 31, 2017, there was $1 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted average period of 1.8 years. Restricted Stock Restricted stock awards generally are granted to non-employee directors and generally vest upon the director’s election to the board. Outstanding restricted stock is entitled to dividend equivalent units that vest subject to the same vesting requirements or lapse of transfer restrictions, as applicable, as the underlying restricted stock award. The fair value of restricted stock awards is based on our stock price at the grant date. The following table summarizes Navient’s restricted stock activity in 2017. Number of Shares Weighted Average Grant Date Fair Value Non-vested at December 31, 2016 — $ — Granted 59,124 15.39 Vested (1) (50,727 ) 15.37 Canceled (8,397 ) 15.48 Non-vested at December 31, 2017 (2) — $ — (1) The total fair value of Navient shares that vested was $1 million, $1 million and $1 million for 2017, 2016 and 2015, respectively. (2) As of December 31, 2017, there was no unrecognized compensation cost related to restricted stock. Restricted Stock Units and Performance Stock Units Restricted stock units (“RSUs”) and performance stock units (“PSUs”) are equity awards granted to employees that entitle the holder to shares of our common stock when the award vests. RSUs generally are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date, while PSUs vest based on achieving certain corporate performance goals over a three-year performance period. Outstanding RSUs and PSUs are entitled to dividend equivalent units that vest subject to the same vesting requirements or lapse of transfer restrictions, as applicable, as the underlying award. The fair value of RSUs and PSUs is based on our stock price at the grant date. The following table summarizes Navient’s RSU and PSU activity in 2017. Number of RSUs/PSUs Weighted Average Grant Date Fair Value Outstanding at December 31, 2016 4,372,376 $ 12.56 Granted 1,817,218 15.41 Vested and converted to common stock (1) (1,724,568 ) 13.58 Canceled (36,721 ) 12.95 Outstanding at December 31, 2017 (2) 4,428,305 $ 13.33 (1) The total fair value of Navient RSUs and PSUs that vested and converted to common stock was $23 million, $30 million and $29 million for 2017, 2016 and 2015, respectively. (2) As of December 31, 2017, there was $16 million of unrecognized compensation cost related to RSUs and PSUs, which is expected to be recognized over a weighted average period of 1.4 years.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2017
Fair Value Measurements	12. We use estimates of fair value in applying various accounting standards for our financial statements. We categorize our fair value estimates based on a hierarchical framework associated with three levels of price transparency utilized in measuring financial instruments at fair value. Education Loans Our FFELP Loans and Private Education Loans are accounted for at cost or at the lower of cost or market if the loan is held-for-sale. Fair values were determined by modeling loan cash flows using stated terms of the assets and internally-developed assumptions to determine aggregate portfolio yield, net present value and average life. FFELP Loans The significant assumptions used to determine fair value of our FFELP Loans are prepayment speeds, default rates, cost of funds, capital levels and expected Repayment Borrower Benefits to be earned. In addition, the Floor Income component of our FFELP Loan portfolio is valued with option models using both observable market inputs and internally developed inputs. A number of significant inputs into the models are internally derived and not observable to market participants. While the resulting fair value can be validated against market transactions where we are a participant, these markets are not considered active. As such, these are level 3 valuations. Private Education Loans The significant assumptions used to determine fair value of our Private Education Loans are prepayment speeds, default rates, recovery rates, cost of funds and capital levels. A number of significant inputs into the models are internally derived and not observable to market participants nor can the resulting fair values be validated against market transactions. While the resulting fair value can be validated against market transactions where we are a participant, these markets are not considered active. As such, these are level 3 valuations. Cash and Investments (Including “Restricted Cash and Investments”) Cash and cash equivalents are carried at cost. Carrying value approximates fair value. Investments classified as trading or available-for-sale are carried at fair value in the financial statements. Investments in mortgage-backed securities are valued using observable market prices. These securities are primarily collateralized by real estate properties and are guaranteed by either a government sponsored enterprise or the U.S. government. Other investments for which observable prices from active markets are not available were valued through standard bond pricing models using observable market yield curves adjusted for credit and liquidity spreads. These valuations are immaterial to the overall investment portfolio. The fair value of investments in commercial paper, asset-backed commercial paper, or demand deposits that have a remaining term of less than 90 days when purchased are estimated to equal their cost and, when needed, adjustments for liquidity and credit spreads are made depending on market conditions and counterparty credit risks. No additional adjustments were deemed necessary. These are level 2 valuations. Borrowings Borrowings are accounted for at cost in the financial statements except when denominated in a foreign currency or when designated as the hedged item in a fair value hedge relationship. When the hedged risk is the benchmark interest rate (which for us is LIBOR) and not full fair value, the cost basis is adjusted for changes in value due to benchmark interest rates only. Foreign currency-denominated borrowings are re-measured at current spot rates in the financial statements. The full fair value of all borrowings is disclosed. Fair value was determined through standard bond pricing models and option models (when applicable) using the stated terms of the borrowings, observable yield curves, foreign currency exchange rates, volatilities from active markets or from quotes from broker-dealers. Fair value adjustments for unsecured corporate debt are made based on indicative quotes from observable trades and spreads on credit default swaps specific to the Company. Fair value adjustments for secured borrowings are based on indicative quotes from broker-dealers. These adjustments for both secured and unsecured borrowings are material to the overall valuation of these items and, currently, are based on inputs from inactive markets. As such, these are level 3 valuations. Derivative Financial Instruments All derivatives are accounted for at fair value in the financial statements. The fair value of a majority of derivative financial instruments was determined by standard derivative pricing and option models using the stated terms of the contracts and observable market inputs. In some cases, we utilized internally developed inputs that are not observable in the market, and as such, classified these instruments as level 3 fair values. Complex structured derivatives or derivatives that trade in less liquid markets require significant estimates and judgment in determining fair value that cannot be corroborated with market transactions. When determining the fair value of derivatives, we take into account counterparty credit risk for positions where there is exposure to the counterparty on a net basis by assessing exposure net of collateral held. The net exposures for each counterparty are adjusted based on market information available for the specific counterparty, including spreads from credit default swaps. When the counterparty has exposure to us under derivatives with us, we fully collateralize the exposure, minimizing the adjustment necessary to the derivative valuations for our credit risk. While trusts that contain derivatives are not required to post collateral, when the counterparty is exposed to the trust the credit quality and securitized nature of the trusts minimizes any adjustments for the counterparty’s exposure to the trusts. The net credit risk adjustment (adjustments for our exposure to counterparties net of adjustments for the counterparties’ exposure to us) decreased the valuations at December 31, 2017 by $6 million. Inputs specific to each class of derivatives disclosed in the table below are as follows: • Interest rate swaps — Derivatives are valued using standard derivative cash flow models. Derivatives that swap fixed interest payments for LIBOR interest payments (or vice versa) and derivatives swapping quarterly reset LIBOR for daily reset LIBOR or one-month LIBOR were valued using the LIBOR swap yield curve which is an observable input from an active market. These derivatives are level 2 fair value estimates in the hierarchy. Other derivatives swapping LIBOR interest payments for another variable interest payment (primarily Prime) are valued using the LIBOR swap yield curve and observable market spreads for the specified index. The markets for these swaps are generally illiquid as indicated by a wide bid/ask spread. The adjustment made for liquidity decreased the valuations by $30 million at December 31, 2017. These derivatives are level 3 fair value estimates. • Cross-currency interest rate swaps — Derivatives are valued using standard derivative cash flow models. Derivatives hedging foreign-denominated bonds are valued using the LIBOR swap yield curve (for both USD and the foreign-denominated currency), cross-currency basis spreads and forward foreign currency exchange rates. These inputs are observable inputs from active markets. Therefore, the resulting valuation is a level 2 fair value estimate. Amortizing notional derivatives (derivatives whose notional amounts change based on changes in the balance of, or pool of, assets or debt) hedging trust debt use internally derived assumptions for the trust assets’ prepayment speeds and default rates to model the notional amortization. Management makes assumptions concerning the extension features of derivatives hedging rate-reset notes denominated in a foreign currency. These inputs are not market observable; therefore, these derivatives are level 3 fair value estimates. • Floor Income Contracts — Derivatives are valued using an option pricing model. Inputs to the model include the LIBOR swap yield curve and LIBOR interest rate volatilities. The inputs are observable inputs in active markets and these derivatives are level 2 fair value estimates. The carrying value of borrowings designated as the hedged item in a fair value hedge is adjusted for changes in fair value due to benchmark interest rates and foreign-currency exchange rates. These valuations are determined through standard bond pricing models and option models (when applicable) using the stated terms of the borrowings, and observable yield curves, foreign currency exchange rates and volatilities. The following table summarizes the valuation of our financial instruments that are marked-to-market on a recurring basis. During 2017 and 2016, there were no significant transfers of financial instruments between levels. Fair Value Measurements on a Recurring Basis December 31, 2017 December 31, 2016 (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 $ — $ — $ — $ — $ — $ 1 $ — $ 1 Other — 2 — 2 — 2 — 2 Total available-for-sale investments — 2 — 2 — 3 — 3 Derivative instruments: (1) Interest rate swaps — 388 4 392 — 553 12 565 Cross-currency interest rate swaps — — 88 88 — — — — Total derivative assets (2) — 388 92 480 — 553 12 565 Total $ — $ 390 $ 92 $ 482 $ — $ 556 $ 12 $ 568 Liabilities (3) Derivative instruments (1) Interest rate swaps $ — $ (144 ) $ (45 ) $ (189 ) $ — $ (150 ) $ (58 ) $ (208 ) Floor Income Contracts — (74 ) — (74 ) — (184 ) — (184 ) Cross-currency interest rate swaps — (44 ) (410 ) (454 ) — (53 ) (1,243 ) (1,296 ) Other — — (18 ) (18 ) — — (13 ) (13 ) Total derivative liabilities (2) — (262 ) (473 ) (735 ) — (387 ) (1,314 ) (1,701 ) Total $ — $ (262 ) $ (473 ) $ (735 ) $ — $ (387 ) $ (1,314 ) $ (1,701 ) (1) Fair value of derivative instruments excludes accrued interest and the value of collateral. (2) See “Note 7 — Derivative Financial Instruments” for a reconciliation of gross positions without the impact of master netting agreements to the balance sheet classification. (3) Borrowings which are the hedged items in a fair value hedge relationship and which are adjusted for changes in value due to benchmark interest rates only are not carried at full fair value and are not reflected in this table. The following tables summarize the change in balance sheet carrying value associated with level 3 financial instruments carried at fair value on a recurring basis. Year Ended December 31, 2017 Derivative Instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (46 ) $ (1,243 ) $ (13 ) $ (1,302 ) Total gains/(losses) (realized and unrealized): Included in earnings (1) — 803 (15 ) 788 Included in other comprehensive income — — — — Settlements 5 118 10 133 Transfers in and/or out of level 3 — — — — Balance, end of period $ (41 ) $ (322 ) $ (18 ) $ (381 ) Change in unrealized gains/(losses) relating to instruments still held at the reporting date (2) $ 5 $ 795 $ (5 ) $ 795 Year Ended December 31, 2016 Derivative Instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (44 ) $ (903 ) $ (2 ) $ (949 ) Total gains/(losses) (realized and unrealized): Included in earnings (1) 3 (428 ) (14 ) (439 ) Included in other comprehensive income — — — — Settlements 3 88 3 94 Transfers in and/or out of level 3 (3) (8 ) — — (8 ) Balance, end of period $ (46 ) $ (1,243 ) $ (13 ) $ (1,302 ) Change in unrealized gains/(losses) relating to instruments still held at the reporting date (2) $ 7 $ (340 ) $ (11 ) $ (344 ) Year Ended December 31, 2015 Derivative Instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (88 ) $ (117 ) $ (11 ) $ (216 ) Total gains/(losses) (realized and unrealized): Included in earnings (1) 39 (796 ) 6 (751 ) Included in other comprehensive income — — — — Settlements 5 10 3 18 Transfers in and/or out of level 3 — — — — Balance, end of period $ (44 ) $ (903 ) $ (2 ) $ (949 ) Change in unrealized gains/(losses) relating to instruments still held at the reporting date (2) $ 37 $ (783 ) $ 9 $ (737 ) (1) “Included in earnings” is comprised of the following amounts recorded in the specified line item in the consolidated statements of income: Years Ended December 31, (Dollars in millions) 2017 2016 2015 Gains (losses) on derivative and hedging activities, net $ 906 $ (351 ) $ (741 ) Interest expense (118 ) (88 ) (10 ) Total $ 788 $ (439 ) $ (751 ) (2) Recorded in “gains (losses) on derivative and hedging activities, net” in the consolidated statements of income. (3) Consumer Price Index/LIBOR basis swaps were transferred from level 3 to level 2 in the fourth quarter of 2016 due to the conclusion that these swaps now trade in an active market. The following table presents the significant inputs that are unobservable or from inactive markets used in the recurring valuations of the level 3 financial instruments detailed above. (Dollars in millions) Fair Value at December 31, 2017 Valuation Technique Input Range (Weighted Average) Derivatives Prime/LIBOR basis swaps $ (41 ) Discounted cash flow Constant Prepayment Rate 6% Bid/ask adjustment to discount rate .08% — .08% (.08%) Cross-currency interest rate swaps (322 ) Discounted cash flow Constant Prepayment Rate 4% Other (18 ) Total $ (381 ) The significant inputs that are unobservable or from inactive markets related to our level 3 derivatives detailed in the table above would be expected to have the following impacts to the valuations: • Prime/LIBOR basis swaps — These swaps do not actively trade in the markets as indicated by a wide bid/ask spread. A wider bid/ask spread will result in a decrease in the overall valuation. In addition, the unobservable inputs include Constant Prepayment Rates of the underlying securitization trust the swap references. A decrease in this input will result in a longer weighted average life of the swap which will increase the value for swaps in a gain position and decrease the value for swaps in a loss position, everything else equal. The opposite is true for an increase in the input. • Cross-currency interest rate swaps — The unobservable inputs used in these valuations are Constant Prepayment Rates of the underlying securitization trust the swap references. A decrease in this input will result in a longer weighted average life of the swap. All else equal in a typical currency market, this will result in a decrease to the valuation due to the delay in the cash flows of the currency exchanges as well as diminished liquidity in the forward exchange markets as you increase the term. The opposite is true for an increase in the input. The following table summarizes the fair values of our financial assets and liabilities, including derivative financial instruments. December 31, 2017 December 31, 2016 (Dollars in millions) Fair Value Carrying Value Difference Fair Value Carrying Value Difference Earning assets FFELP Loans $ 82,271 $ 81,703 $ 568 $ 86,626 $ 87,730 $ (1,104 ) Private Education Loans 24,421 23,419 1,002 23,191 23,340 (149 ) Cash and investments (1) 5,034 5,034 — 5,203 5,203 — Total earning assets 111,726 110,156 1,570 115,020 116,273 (1,253 ) Interest-bearing liabilities Short-term borrowings 4,783 4,771 (12 ) 2,346 2,334 (12 ) Long-term borrowings 104,921 105,012 91 109,826 112,368 2,542 Total interest-bearing liabilities 109,704 109,783 79 112,172 114,702 2,530 Derivative financial instruments Floor Income Contracts (74 ) (74 ) — (184 ) (184 ) — Interest rate swaps 203 203 — 357 357 — Cross-currency interest rate swaps (366 ) (366 ) — (1,296 ) (1,296 ) — Other (18 ) (18 ) — (13 ) (13 ) — Excess of net asset fair value over carrying value $ 1,649 $ 1,277 (1) “Cash and investments” includes available-for-sale investments whose cost basis is $2 million and $3 million at December 31, 2017 and 2016, respectively, versus a fair value of $2 million and $3 million at December 31, 2017 and 2016, respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2017
Commitments and Contingencies	13. 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. On January 18, 2017, 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. On October 5, 2017, the Attorney General for the Commonwealth of Pennsylvania initiated a civil action against Navient Corporation and Navient Solutions, LLC, containing similar alleged violations of the CFPA and the Pennsylvania Unfair Trade Practices and Consumer Protection Law. We refer to the Illinois Attorney General, the Pennsylvania Attorney General and the Washington Attorney General collectively as the “Attorneys General.” We intend to vigorously defend against the allegations in each of these cases. For additional information on these civil actions, please refer to section entitled “Regulatory Matters” below. At this point in time, the Company is unable to anticipate the timing of a resolution or the 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 With respect to alleged civil violations of the Servicemembers Civil Relief Act (the “SCRA”), Navient Solutions, LLC (“Solutions”), a wholly owned subsidiary of Navient, and Sallie Mae Bank entered into a consent order with the DOJ in May 2014. The DOJ consent order (the “DOJ Order”) covers all loans either owned by Sallie Mae Bank or serviced by Solutions from November 28, 2005 until the effective date of the settlement. In the third quarter of 2016, the Company completed the distributions from the fund by distributing the remaining funds to charities approved by the DOJ pursuant to the terms of the order. The total reserves established by the Company in 2013 and 2014 to cover these costs were $177 million, and as of December 31, 2017, substantially all of this amount had been paid to customers or credited or refunded to customer accounts. The final cost of these proceedings will remain uncertain until the remaining consent order is lifted or terminates in accordance with its terms in late 2018. The Company believes it has fulfilled the terms of the DOJ Order. 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 State of Illinois Office of Attorney General and the State of Washington Office of the 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 and Kansas. • In April 2014, Solutions received a CID from the Consumer Financial Protection Bureau (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 is 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 the CFPB’s 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. On January 18, 2017, 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 Federal and State consumer protection statutes, including the DFPA, FCRA, FDCPA and various state consumer protection laws. On October 5, 2017, the Attorney General for the Commonwealth of Pennsylvania initiated a civil action against Navient Corporation and Navient Solutions, LLC, alleging violations of the CFPA and the Pennsylvania Unfair Trade Practices and Consumer Protection Law. These civil actions are related to matters which were covered under the CIDs and the NORA letter discussed above that were previously issued by the CFPB and the Attorneys General. The Company filed its Motion to Dismiss on March 20, 2017 with respect to the Attorneys General actions and on March 24, 2017 with respect to the CFPB action. In relation to the CFPB action, after a hearing, our Motion to Dismiss was denied in full in August 2017. In relation to the Washington action, following a hearing, our Motion to Dismiss was denied in full in July 2017. In relation to the Illinois action, a hearing on our Motion to Dismiss was held on July 18, 2017 and no ruling has been issued as of the date of this Form 10-K. 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 Attorneys General. In relation to the Pennsylvania Attorney General lawsuit, the Company filed its Motion to Dismiss on December 22, 2017. This motion has not been heard by the court. 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. As stated above, we intend to vigorously defend against the allegations in each of these cases. 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. Under the terms of the Separation Agreement, 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 December 31, 2017. OIG Audit The Office of the Inspector General (the “OIG”) of ED commenced an audit regarding Special Allowance Payments (“SAP”) on September 10, 2007. On September 25, 2013, we received the final audit determination of Federal Student Aid (the “Final Audit Determination”) on the final audit report issued by the OIG on August 3, 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 relating to this Final Audit Determination to the Administrative Actions and Appeals Service Group of ED. A hearing on this matter 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 numerous requests, subpoenas and orders for documents, testimony and information in connection with various aspects of our regulated activities. 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. 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. 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.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2017
Income Taxes	14. Reconciliations of the statutory U.S. federal income tax rates to our effective tax rate for continuing operations follow: Years Ended December 31, 2017 2016 2015 Statutory rate 35.0 % 35.0 % 35.0 % DTA Remeasurement Loss (1) 27.2 — — Net excess tax benefits related to stock-based incentive payments (.7 ) — — State tax, net of federal benefit .8 3.8 2.6 Other, net (.5 ) (.3 ) .1 Effective tax rate 61.8 % 38.5 % 37.7 % (1) The TCJA, enacted on December 22, 2017, made significant changes to all aspects of income taxation, including a reduction to the corporate federal statutory tax rate. GAAP requires the effects of the TCJA to be recognized in the period the law is enacted, even though the effective date of the law for most provisions is January 1, 2018. The primary impact to us is the reduction to the corporate federal statutory tax rate from 35 percent to 21 percent as of January 1, 2018. This rate reduction required us to remeasure our deferred tax asset at December 31, 2017, at the 21 percent corporate federal statutory tax rate and resulted in a DTA Remeasurement Loss of $208 million for GAAP, which is reflected as incremental income tax expense in the fourth quarter of 2017. The effective tax rate varies from the statutory U.S. federal rate of 35 percent primarily due to the DTA Remeasurement Loss and the net excess tax benefits related to stock-based incentive payments for the year ended December 31, 2017, and the impact of state taxes, net of federal benefit, for the years ended December 31, 2017, 2016 and 2015. Income tax expense consists of: December 31, (Dollars in millions) 2017 2016 2015 Current provision/(benefit): Federal $ 77 $ 246 $ 136 State (3 ) 47 22 Foreign 3 1 — Total current provision/(benefit) 77 294 158 Deferred provision/(benefit): Federal 385 115 398 State 11 18 41 Foreign (1 ) — — Total deferred provision/(benefit) 395 133 439 Provision for income tax expense/(benefit) $ 472 $ 427 $ 597 The tax effect of temporary differences that give rise to deferred tax assets and liabilities include the following: December 31, (Dollars in millions) 2017 2016 Deferred tax assets: Loan reserves $ 317 $ 581 Education loan premiums and discounts, net 52 74 Operating loss and credit carryovers 22 5 Stock-based compensation plans 18 32 Accrued expenses not currently deductible 24 33 Market value adjustments on education loans, investments and derivatives 9 65 Deferred revenue — 37 Other 14 40 Total deferred tax assets 456 867 Deferred tax liabilities: Unrealized derivatives and investment gains and losses, net 23 3 Original issue discount on borrowings 11 27 Debt repurchases 8 — Other 22 35 Total deferred tax liabilities 64 65 Net deferred tax assets $ 392 $ 802 Included in operating loss and credit carryovers is a valuation allowance of $42 million and $7 million as of December 31, 2017 and 2016, respectively, against a portion of the Company’s federal and state deferred tax assets. The valuation allowance is primarily attributable to deferred tax assets for federal and state net operating loss carryforwards that management believes it is more likely than not will expire prior to being realized. The ultimate realization of the deferred tax assets is dependent upon the generation of future taxable income of the appropriate character (i.e. capital or ordinary) during the period in which the temporary differences become deductible. Management considers, among other things, the economic slowdown, the scheduled reversals of deferred tax liabilities, and the history of positive taxable income available for net operating loss carrybacks in evaluating the realizability of the deferred tax assets. As of December 31, 2017, we have gross federal net operating loss (“NOL”) carryforwards of $110 million (which begin to expire in 2029) and gross state NOL carryforwards of $576 million (which begin to expire in 2021). Tax-effected NOL amounts of $23 million (federal) and $39 million (state) have corresponding valuation allowances of $8 million (federal) and $34 million (state). We also have $2 million in foreign tax credit carryforwards. Accounting for Uncertainty in Income Taxes The following table summarizes changes in unrecognized tax benefits: December 31, (Dollars in millions) 2017 2016 2015 Unrecognized tax benefits at beginning of year $ 73.0 $ 56.3 $ 51.9 Increases resulting from tax positions taken during a prior period .7 19.9 1.6 Decreases resulting from tax positions taken during a prior period (1.8 ) (5.6 ) (1.8 ) Increases resulting from tax positions taken during the current period 4.4 4.4 6.9 Decreases related to settlements with taxing authorities (5.1 ) (.1 ) — Increases related to settlements with taxing authorities — — — Reductions related to the lapse of statute of limitations (13.8 ) (1.9 ) (2.3 ) Unrecognized tax benefits at end of year $ 57.4 $ 73.0 $ 56.3 As of December 31, 2017, the gross unrecognized tax benefits are $57.4 million. Included in the $57.4 million are $45.3 million of unrecognized tax benefits that, if recognized, would favorably impact the effective tax rate. The Company or one of its subsidiaries files income tax returns at the U.S. federal level, in most U.S. states, and various foreign jurisdictions. All periods prior to 2014 are closed for federal examination purposes. Various combinations of subsidiaries, tax years, and jurisdictions remain open for review, subject to statute of limitations periods (typically 3 to 4 prior years). We do not expect the resolution of open audits to have a material impact on our unrecognized tax benefits.

Segment Reporting

Segment Reporting	12 Months Ended
Segment Reporting	Dec. 31, 2017
Segment Reporting	15. 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, effective first-quarter 2018. This resulted in the following four new reportable operating segments: (1) Federal Education Loans (2) Consumer Lending (3) Business Processing and (4) Other. These new reportable operating segments now primarily distinguish between our legacy federal education loan businesses and our growth businesses. In connection with this change in reportable operating segments, there was also a change in how unallocated overhead is defined. 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 the Department of Education and other institutions. Although FFELP Loans are no longer originated, we continue to pursue acquisitions of FFELP Loan portfolios as well as servicing and asset recovery services contracts. These acquisitions leverage our servicing scale and generate incremental earnings and cash flow. In this segment, we generate revenue primarily through net interest income on the FFELP Loan portfolio (after provision for loan losses) as well as servicing and asset recovery services revenue. This segment is expected to generate significant amounts of earnings and cash flow over the remaining life of the portfolio. Navient is currently the largest private sector holder of FFELP Loans as well as the largest servicer and collector of loans made under the FFELP program, and the majority of our income has been derived, directly or indirectly, from our portfolio of FFELP Loans and the servicing and asset recovery we provide for Guarantors and third-party owners of FFELP Loans. In 2010, Congress passed legislation ending the origination of education loans under FFELP. As a result, the revenue we earn in this segment is expected to decline over time. The Higher Education Act of 1965 (“HEA”) continues to regulate every aspect of FFELP Loans, including ongoing communications with borrowers and default aversion requirements. Failure to service FFELP Loans properly could jeopardize the insurance, guarantees and federal support on these loans. The insurance and guarantees on Navient’s existing FFELP Loans were not affected by the termination of FFELP originations. FFELP Loans Navient’s portfolio of FFELP Loans as of December 31, 2017 was $81.7 billion. We expect this portfolio to have an amortization period in excess of 20 years with a 7-year remaining weighted average life. Navient’s goal is to maximize the amount and optimize the timing of the cash flows generated by its FFELP Loan portfolio and as part of that Navient seeks to acquire FFELP Loan portfolios from third parties. During the year ended 2017, Navient acquired $5.7 billion of FFELP Loans compared to $3.6 billion in 2016 and $3.7 billion in 2015. FFELP Loans are insured or guaranteed by state or not-for-profit agencies and are protected by contractual rights to recovery from the United States pursuant to guaranty agreements among ED and these agencies. These guaranty agreements generally cover at least 97 percent of a FFELP Loan’s principal and accrued interest for loans disbursed. As a result of the long-term funding strategy used for our FFELP Loan portfolio and the insurance and guarantees provided on these loans, the portfolio generates consistent and predictable cash flows. As of December 31, 2017, approximately 84 percent of the FFELP Loans held by Navient were funded to term with non-recourse, long-term securitization debt. Federal Education Since 2009, Navient has been one of four TIVAS that provides loan servicing for federal loans owned by ED. We continually strive to help our customers successfully navigate the repayment of their loans. Under the contract, we seek to improve on the performance metrics that determine the allocation of new accounts under the servicing contract with ED. Under this servicing contract as of December 31, 2017, we service approximately 6.1 million accounts, or $205.9 billion in loans. We earned $150 million of revenue under the contract for the year ended December 31, 2017. This contract currently expires in 2019. On April 4, 2016, ED published the first part of a two-part RFP related to a new servicing platform for the DSLP. The first part of the RFP focused on screening candidates’ capabilities relative to certain published criteria. In July 2016, Navient was selected as one of three companies eligible to submit responses in the second part of the RFP process. In January 2017, Navient submitted its bid for ED’s single servicing solution contract. While ED announced in May 2017 that it planned to select a single servicer for the DSLP, in August of 2017, the Department cancelled the prior RFP and announced a new upcoming solicitation for the FSA Next Generation Processing and Servicing Environment. Based upon the statements from ED, it is anticipated that the new environment will provide for a single data processing platform to house all student loan information while at the same time allowing for customer account servicing to be performed either by a single contract servicer or by multiple contract servicers. On February 20, 2018, ED issued Phase 1 of a new RFP entitled the Solicitation for the Next Generation Financial Services Environment which is intended to centralize student loan servicing on a single platform. Responses to Phase 1 are due by April 6, 2018. In December 2016, Great Lakes Higher Education Assistance Corp. (“Great Lakes”) assumed control of United Student Aid Funds, Inc. (“USAF”). As part of this transfer, Great Lakes terminated our contracts with USAF and Northwest Education Loan Association (“NELA”), effective as of December 31, 2017. At the same time, they notified us of their intent to rebid the services we provided for USAF, NELA and Great Lakes. In the third quarter of 2017, we entered into a new contract with Great Lakes in which we agreed to provide asset recovery and portfolio management services on the combined Great Lakes, USAF and NELA portfolios. We were not awarded the default aversion services component of the contract, which resulted in the recognition of $47 million of previously deferred revenue, net of a reserve. Including the $47 million of previously deferred revenue, education related fee revenues related to these services totaled $238 million in 2017 compared to $172 million in 2016. Since 1997, Navient has provided asset recovery services on defaulted education loans to ED. In February 2015, ED did not grant an additional term extension (“ATE”) and this contract expired by its terms on February 21, 2015. As a result, our Pioneer Credit Recovery (“Pioneer”) subsidiary stopped receiving new account placements under the contract. Shortly after that decision by ED, Pioneer filed a bid protest against ED, which bid protest was eventually consolidated with several other related protests. In an effort to resolve that litigation, in May 2017, ED awarded Pioneer a new ATE on substantially similar terms to the additional term extensions awarded to other contractors in 2015. In December 2017, Pioneer received new accounts under that new contract. In January 2018, ED completed its ongoing procurement for replacement collection contracts originally begun in 2016. Neither Pioneer nor our other subsidiary, General Revenue Corporation, received a contract award. In February 2018, Pioneer filed a bid protest which protest has been consolidated with the other protests on this procurement. As of the date of this report, ED has the right to place additional accounts with Pioneer under its ATE during the pendency of the new protests. ED’s ability to do so may be affected by any temporary restraining order or injunction granted by the court in the consolidated protests. As a leading provider of asset recovery services, Pioneer Credit Recovery has a long track record of assisting individuals who default on their student loan payments to recover from the negative consequences of default. Since 2012, Navient and its subsidiaries have helped more than 261,000 borrowers successfully rehabilitate their loans. The following table includes GAAP basis asset information for our Federal Education Loans segment. December 31, (Dollars in millions) 2017 2016 FFELP Loans, net $ 81,703 $ 87,730 Cash and investments (1) 2,821 3,299 Other 2,601 2,226 Total assets $ 87,125 $ 93,255 (1) Includes restricted cash and investments. 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. With over 40 years of experience, we have seen that borrowers who graduate gain the benefit of their investment in education with higher levels of employment, higher incomes and stronger financial health. Our loan products are focused on helping consumers refinance their education loans at the lower rates they have earned. We believe our product offerings, digital marketing strategies and origination platform provide a unique competitive advantage. Earnest, which was acquired in November 2017, originated $900 million of Private Education Refinance Loans in 2017. At December 31, 2017, Navient held $761 million of Private Education Refinance Loans. Navient is currently the largest holder of Private Education Loans. Navient’s portfolio of Private Education Loans as of December 31, 2017 was $23.4 billion. We expect this portfolio to have an amortization period in excess of 20 years with a 6-year remaining weighted average life. Navient’s goal is to maximize and optimize the timing of the cash flows generated by its Private Education Loan portfolio. Unlike FFELP Loans, the holder of a Private Education Loan bears the full credit risk of the borrower and any cosigner. Navient believes the credit risk of the Private Education Loans it owns is well managed through the rigorous underwriting practices and risk-based pricing applied when the loans were originated, the continued high levels of qualified cosigners, our internal servicing and risk mitigation practices, and our careful use of forbearance and loan modification programs. Navient believes that these elements and practices reduce the risk of payment interruptions and defaults on its Private Education Loan portfolio. As of December 31, 2017, approximately 55 percent of the Private Education Loans held by Navient were funded to term with non-recourse, long-term securitization debt. The following table includes GAAP basis asset information for our Consumer Lending segment. December 31, (Dollars in millions) 2017 2016 Private Education Loans, net $ 23,419 $ 23,340 Cash and investments (1) 706 667 Other 1,143 1,562 Total assets $ 25,268 $ 25,569 (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 $11 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. Years Ended December 31, (Dollars in billions) 2017 2016 2015 Revenue from government services $ 134 $ 106 $ 86 Revenue from healthcare services 78 68 13 Total fee revenue $ 212 $ 174 $ 99 Contingent collection receivables inventory (in billions) $ 11.4 $ 10.1 $ 9.9 At December 31, 2017 and 2016, the Business Processing segment had total assets of $466 million and $373 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, regulatory-related costs, 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, and stock-based compensation expense. Unallocated information technology costs are related to infrastructure and operations. At December 31, 2017 and 2016, the Other segment had total assets of $2.1 billion and $1.9 billion, respectively, on a GAAP basis. 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 three items, discussed below, that are either related to the Spin-Off or create significant volatility 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 three items we remove to result in our “Core Earnings” presentations are: 1. Unrealized 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; 2. The accounting for goodwill and acquired intangible assets; and 3. The financial results attributable to the operations of SLM BankCo prior to the Spin-Off and related restructuring and reorganization expense incurred in connection with the Spin-Off, including the restructuring expenses related to the restructuring initiative launched in second-quarter 2015 to simplify and streamline the Company’s management structure post-Spin-Off. For GAAP purposes, Navient reflected the deemed distribution of SLM BankCo on April 30, 2014. For “Core Earnings,” we exclude the consumer banking business (SLM BankCo) as if it had never been a part of Navient’s historical results prior to the deemed distribution of SLM BankCo on April 30, 2014. 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. Segment Results and Reconciliations to GAAP Year Ended December 31, 2017 Total Adjustments (Dollars in millions) Federal Education Loans Consumer Lending Business Processing Other “Core Earnings” Reclassifications Additions/ (Subtractions) Total Adjustments (1) Total GAAP Interest income: Education loans $ 2,679 $ 1,634 $ — $ — $ 4,313 $ 69 $ (55 ) $ 14 $ 4,327 Other loans 13 — — — 13 — — — 13 Cash and investments 29 5 — 9 43 — — — 43 Total interest income 2,721 1,639 — 9 4,369 69 (55 ) 14 4,383 Total interest expense 2,022 825 — 143 2,990 (8 ) (11 ) (19 ) 2,971 Net interest income (loss) 699 814 — (134 ) 1,379 77 (44 ) 33 1,412 Less: provisions for loan losses 44 382 — — 426 — — — 426 Net interest income (loss) after provisions for loan losses 655 432 — (134 ) 953 77 (44 ) 33 986 Other income (loss): Servicing revenue 280 10 — — 290 — — — 290 Asset recovery and business processing revenue 263 — 212 — 475 — — — 475 Other income 3 — — 16 19 (77 ) 89 12 31 Gains on sales of loans and investments 3 — — — 3 — — — 3 Losses on debt repurchases — — — (3 ) (3 ) — — — (3 ) Total other income (loss) 549 10 212 13 784 (77 ) 89 12 796 Expenses: Direct operating expenses 316 156 187 — 659 — — — 659 Overhead expenses — — — 307 307 — — — 307 Operating expenses 316 156 187 307 966 — — — 966 Goodwill and acquired intangible asset impairment and amortization — — — — — — 23 23 23 Restructuring/other reorganization expenses — — — 29 29 — — — 29 Total expenses 316 156 187 336 995 — 23 23 1,018 Income (loss) before income tax expense (benefit) 888 286 25 (457 ) 742 — 22 22 764 Income tax expense (benefit) ( 2) 321 103 9 58 491 — (19 ) (19 ) 472 Net income (loss) $ 567 $ 183 $ 16 $ (515 ) $ 251 $ — $ 41 $ 41 $ 292 (1) “Core Earnings” adjustments to GAAP: Year Ended December 31, 2017 (Dollars in millions) Net Impact of Derivative Accounting Net Impact of Acquired Intangibles Total Net interest income after provisions for loan losses $ 33 $ — $ 33 Total other income (loss) 12 — 12 Goodwill and acquired intangible asset impairment and amortization — 23 23 Total “Core Earnings” adjustments to GAAP $ 45 $ (23 ) 22 Income tax expense (benefit) (19 ) Net income (loss) $ 41 (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment with the impact of the DTA Remeasurement Loss included in the Other segment. Year Ended December 31, 2016 Total Adjustments (Dollars in millions) Federal Education Loans Consumer Lending Business Processing Other “Core Earnings” Reclassifications Additions/ (Subtractions) Total Adjustments (1) Total GAAP Interest income: Education loans $ 2,395 $ 1,587 $ — $ — $ 3,982 $ 247 $ (114 ) $ 133 $ 4,115 Other loans 9 — — — 9 — — — 9 Cash and investments 16 2 — 4 22 — — — 22 Total interest income 2,420 1,589 — 4 4,013 247 (114 ) 133 4,146 Total interest expense 1,597 704 — 109 2,410 31 — 31 2,441 Net interest income (loss) 823 885 — (105 ) 1,603 216 (114 ) 102 1,705 Less: provisions for loan losses 46 383 — — 429 — — — 429 Net interest income (loss) after provisions for loan losses 777 502 — (105 ) 1,174 216 (114 ) 102 1,276 Other income (loss): Servicing revenue 289 15 — — 304 — — — 304 Asset recovery and business processing revenue 216 — 174 — 390 — — — 390 Other income — — — 14 14 (216 ) 326 110 124 Gains on debt repurchases — — — 1 1 — — — 1 Total other income (loss) 505 15 174 15 709 (216 ) 326 110 819 Expenses: Direct operating expenses 366 149 149 — 664 — — — 664 Overhead expenses — — — 287 287 — — — 287 Operating expenses 366 149 149 287 951 — — — 951 Goodwill and acquired intangible asset impairment and amortization — — — — — — 36 36 36 Restructuring/other reorganization expenses — — — — — — — — — Total expenses 366 149 149 287 951 — 36 36 987 Income (loss) before income tax expense (benefit) 916 368 25 (377 ) 932 — 176 176 1,108 Income tax expense (benefit) ( 2) 338 137 9 (139 ) 345 — 82 82 427 Net income (loss) $ 578 $ 231 $ 16 $ (238 ) $ 587 $ — $ 94 $ 94 $ 681 (1) “Core Earnings” adjustments to GAAP: Year Ended December 31, 2016 (Dollars in millions) Net Impact of Derivative Accounting Net Impact of Acquired Intangibles Total Net interest income after provisions for loan losses $ 102 $ — $ 102 Total other income (loss) 110 — 110 Goodwill and acquired intangible asset impairment and amortization — 36 36 Total “Core Earnings” adjustments to GAAP $ 212 $ (36 ) 176 Income tax expense (benefit) 82 Net income (loss) $ 94 (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. Year Ended December 31, 2015 Total Adjustments (Dollars in millions) Federal Education Loans Consumer Lending Business Processing Other “Core Earnings” Reclassi- fications Additions/ (Subtractions) Total Adjustments (1) Total GAAP Interest income: Education loans $ 2,112 $ 1,756 $ — $ — $ 3,868 $ 650 $ (238 ) $ 412 $ 4,280 Other loans 7 — — — 7 — — — 7 Cash and investments 6 — — 2 8 — — — 8 Total interest income 2,125 1,756 — 2 3,883 650 (238 ) 412 4,295 Total interest expense 1,247 680 — 110 2,037 37 — 37 2,074 Net interest income (loss) 878 1,076 — (108 ) 1,846 613 (238 ) 375 2,221 Less: provisions for loan losses 43 538 — — 581 — — — 581 Net interest income (loss) after provisions for loan losses 835 538 — (108 ) 1,265 613 (238 ) 375 1,640 Other income (loss): Servicing revenue 319 21 — — 340 — — — 340 Asset recovery and business processing revenue 268 — 99 — 367 — — — 367 Other income 3 — — 12 15 (613 ) 781 168 183 Gains (losses) on sales of loans and investments 11 (21 ) — 1 (9 ) — — — (9 ) Gains on debt repurchases — — — 21 21 — — — 21 Total other income (loss) 601 — 99 34 734 (613 ) 781 168 902 Expenses: Direct operating expenses 401 151 83 — 635 — — — 635 Overhead expenses — — — 283 283 — — — 283 Operating expenses 401 151 83 283 918 — — — 918 Goodwill and acquired intangible asset impairment and amortization — — — — — — 12 12 12 Restructuring/other reorganization expenses — — — — — — 32 32 32 Total expenses 401 151 83 283 918 — 44 44 962 Income (loss) from continuing operations, before income tax expense (benefit) 1,035 387 16 (357 ) 1,081 — 499 499 1,580 Income tax expense (benefit) ( 2) 384 143 6 (132 ) 401 — 196 196 597 Net income (loss) from continuing operations 651 244 10 (225 ) 680 — 303 303 983 Income from discontinued operations, net of tax expense — — — 1 1 — — — 1 Net income (loss) $ 651 $ 244 $ 10 $ (224 ) $ 681 $ — $ 303 $ 303 $ 984 (1) “Core Earnings” adjustments to GAAP: Year Ended December 31, 2015 (Dollars in millions) Net Impact from Spin-Off of SLM BankCo Net Impact of Derivative Accounting Net Impact of Acquired Intangibles Total Net interest income after provisions for loan losses $ — $ 375 $ — $ 375 Total other income (loss) — 168 — 168 Goodwill and acquired intangible asset impairment and amortization — — 12 12 Restructuring/other reorganization expenses 32 — — 32 Total “Core Earnings” adjustments to GAAP $ (32 ) $ 543 $ (12 ) 499 Income tax expense (benefit) 196 Net income (loss) $ 303 (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. Summary of “Core Earnings” Adjustments to GAAP Years Ended December 31, (Dollars in millions) 2017 2016 2015 “Core Earnings” adjustments to GAAP: Net impact of the removal of SLM BankCo’s operations and restructuring and reorganization expense in connection with the Spin-Off (1) $ — $ — $ (32 ) Net impact of derivative accounting (2) 45 212 543 Net impact of goodwill and acquired intangible assets (3) (23 ) (36 ) (12 ) Net tax effect (4) 19 (82 ) (196 ) Total “Core Earnings” adjustments to GAAP $ 41 $ 94 $ 303 (1) SLM BankCo’s operations and restructuring and other reorganization expense in connection with the Spin-Off: (2) Derivative accounting: (3) Goodwill and acquired intangible assets: (4) Net Tax Effect:

Quarterly Financial Information

Quarterly Financial Information (unaudited)	12 Months Ended
Quarterly Financial Information (unaudited)	Dec. 31, 2017
Quarterly Financial Information (unaudited)	16. 2017 (Dollars in millions, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Net interest income $ 340 $ 351 $ 355 $ 366 Less: provisions for loan losses 107 105 105 109 Net interest income after provisions for loan losses 233 246 250 257 Other income 168 187 238 181 Gains (losses) on derivative and hedging activities, net (16 ) (25 ) 25 38 Operating expenses 238 230 238 260 Goodwill and acquired intangible asset impairment and amortization expense 6 6 6 5 Restructuring/other reorganization expenses — — — 29 Income tax expense 53 60 93 266 Net income (loss) attributable to Navient Corporation $ 88 $ 112 $ 176 $ (84 ) Basic earnings (loss) per common share attributable to Navient Corporation $ .31 $ .40 $ .65 $ (.32 ) Diluted earnings (loss) per common share attributable to Navient Corporation $ .30 $ .39 $ .64 $ (.32 ) 2016 (Dollars in millions, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Net interest income $ 486 $ 429 $ 412 $ 378 Less: provisions for loan losses 111 110 106 102 Net interest income after provisions for loan losses 375 319 306 276 Other income 159 151 174 218 Gains (losses) on derivative and hedging activities, net 1 (28 ) 137 6 Operating expenses 247 230 228 246 Goodwill and acquired intangible asset impairment and amortization expense 4 6 12 13 Restructuring/other reorganization expenses — — — — Income tax expense 103 81 147 96 Net income attributable to Navient Corporation $ 181 $ 125 $ 230 $ 145 Basic earnings per common share attributable to Navient Corporation $ .53 $ .39 $ .74 $ .49 Diluted earnings per common share attributable to Navient Corporation $ .53 $ .38 $ .73 $ .48

Significant Accounting Polici25

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2017
Use of Estimates	Use of Estimates Our financial reporting and accounting policies conform to generally accepted accounting principles in the United States of America (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Current market conditions increase the risk and complexity of the judgments in these estimates and actual results could differ from estimates. Key accounting policies that include the most significant judgments, estimates and assumptions include the allowance for loan losses, the effective interest rate method (amortization of education loan and debt premiums and discounts), goodwill and intangible asset impairment assessment, fair value measurement, the consolidation of variable interest entities, and derivative accounting.
Consolidation	Consolidation The consolidated financial statements include the accounts of Navient Corporation and its majority-owned and controlled subsidiaries and those Variable Interest Entities (“VIEs”) for which we are the primary beneficiary, after eliminating the effects of intercompany accounts and transactions. We consolidate any VIEs where we have determined we are the primary beneficiary. A VIE is a legal entity that does not have sufficient equity at risk to finance its own operations, or whose equity holders do not have the power to direct the activities that most significantly affect the economic performance of the entity, or whose equity holders do not share proportionately in the losses or benefits of the entity. The primary beneficiary of the VIE is the entity which has both: (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses or receive benefits of the entity that could potentially be significant to the VIE. As it relates to our securitizations and other secured borrowing facilities that are VIEs as of December 31, 2017, we are the servicer of the related education loan assets and own the Residual Interest of the securitization trusts and secured borrowing facilities. As a result, we are the primary beneficiary and consolidate those VIEs.
Fair Value Measurement	Fair Value Measurement We use estimates of fair value in applying various accounting standards for our financial statements. Fair value measurements are used in one of four ways: • In the consolidated balance sheet with changes in fair value recorded in the consolidated statement of income; • In the consolidated balance sheet with changes in fair value recorded in the accumulated other comprehensive income section of the consolidated statement of changes in stockholders’ equity; • In the consolidated balance sheet for instruments carried at lower of cost or fair value with impairment charges recorded in the consolidated statement of income; and • In the notes to the financial statements. Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between willing and able market participants. In general, our policy in estimating fair value is to first look at observable market prices for identical assets and liabilities in active markets, where available. When these are not available, other inputs are used to model fair value such as prices of similar instruments, yield curves, volatilities, prepayment speeds, default rates and credit spreads, relying first on observable data from active markets. Depending on current market conditions, additional adjustments to fair value may be based on factors such as liquidity, credit, and bid/offer spreads. Transaction costs are not included in the determination of fair value. When possible, we seek to validate the model’s output to market transactions. Depending on the availability of observable inputs and prices, different valuation models could produce materially different fair value estimates. The values presented may not represent future fair values and may not be realizable. We categorize our fair value estimates based on a hierarchical framework associated with three levels of price transparency utilized in measuring financial instruments at fair value. Classification is based on the lowest level of input that is significant to the fair value of the instrument. The three levels are as follows: • Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the measurement date. The types of financial instruments included in level 1 are highly liquid instruments with quoted prices. • Level 2 — Inputs from active markets, other than quoted prices for identical instruments, are used to determine fair value. Significant inputs are directly observable from active markets for substantially the full term of the asset or liability being valued. • Level 3 — Pricing inputs significant to the valuation are unobservable. Inputs are developed based on the best information available. However, significant judgment is required by us in developing the inputs.
Loans	Loans Loans, consisting primarily of federally insured education loans and Private Education Loans, that we have the ability and intent to hold for the foreseeable future are classified as held-for-investment and are carried at amortized cost. Amortized cost includes the unamortized premiums, discounts, and capitalized origination costs and fees, all of which are amortized to interest income as further discussed below. Loans which are held-for-investment also have an allowance for loan loss as needed. Any loans we have not classified as held-for-investment are classified as held-for-sale, and carried at the lower of cost or fair value. Loans are classified as held-for-sale when we have the intent and ability to sell such loans. Loans which are held-for-sale do not have the associated premium, discount, and capitalized origination costs and fees amortized into interest income. In addition, once a loan is classified as held-for-sale, there is no further adjustment to the loan’s allowance for loan losses that existed immediately prior to the reclassification to held-for-sale.
Allowance for Loan Losses	Allowance for Loan Losses Purchased Credit Impaired (“PCI”) Loans Loans acquired with evidence of deterioration of credit quality since origination for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable are PCI loans accounted for under Accounting Standard Codification (“ASC”) 310-30, “Loans and Debt Securities Acquired with Deteriorated Credit Quality.” When considering whether evidence of credit quality deterioration exists as of the purchase date, the Company considers loan guarantees and the following credit attributes: delinquency status, use of forbearance, recent borrower FICO scores, use of loan modification programs, and borrowers who have filed for bankruptcy. The Company aggregates loans with common risk characteristics into pools and accounts for each pool as a single asset with a single composite interest rate and an aggregate expectation of cash flows. The pools are initially recorded at fair value. The Company recognizes interest income based on each pool’s effective interest rate which is based on our estimate of all cash flows expected to be received and includes an assumption about prepayment rates. The pools are tested quarterly for impairment by re-estimating the future cash flows to be received from the pools. If the new estimated cash flows result in a pool’s effective interest rate increasing, then this new yield is used prospectively over the remaining life of the pool. If the new estimated cash flows result in a pool’s effective interest rate decreasing, the pool is impaired and written down through a valuation allowance to maintain the effective interest rate. Loans classified as PCI do not have charge-offs reported nor are they reported as Trouble Debt Restructuring (“TDR”) loans. Based on the credit attributes discussed above, we determined that $261 million principal amount of Private Education Loans acquired in 2017 are accounted for as PCI loans with a fair value and resulting carry value of $101 million as of the acquisition date. As of acquisition, this portfolio’s contractually required payments receivable (the total undiscounted amount of all uncollected contractual principal and interest payments both past due and scheduled for the future, adjusted for prepayments) was $411 million with an estimated accretable yield (income expected to be recognized in future periods) of $108 million. As of December 31, 2017, the carrying amount was $97 million with no valuation allowance recorded. Purchased Non-Credit Impaired Loans Loans acquired that do not have evidence of credit deterioration since origination are recorded at fair value with no allowance for loan losses established at the acquisition date. Loan premiums and discounts are amortized as a part of interest income using the interest method under ASC 310-20, “Nonrefundable Fees and Other Costs.” An allowance for loan losses would be established if incurred losses in the loans exceed the remaining unamortized discount recorded at the time of acquisition (i.e., the next two years of expected charge-offs as well as any additional TDR allowance required is greater than the remaining discount). As a result of this policy, to the extent that actual charge-offs exceed any related allowance for loan losses recognized post-acquisition, provision for loan losses is recorded when the loans are charged off. Charge-offs are recorded through the allowance for loan losses. In 2017, we acquired Private Education Loans with unpaid principal balance of $2.8 billion at a discount of $424 million and FFELP Loans with an unpaid principal balance of $3.5 billion at a discount of $47 million, that are accounted for under this policy. No allowance for loan losses has been established for these loans as of December 31, 2017, as the remaining purchased discount associated with the Private Education Loans of $392 million and FFELP Loans of $43 million as of December 31, 2017 remains greater than the incurred losses. Allowance for Private Education Loan Losses We consider a loan to be impaired when, based on current information, a loss has been incurred and it is probable that we will not receive all contractual amounts due. When making our assessment as to whether a loan is impaired, we also take into account more than insignificant delays in payment. We generally evaluate impaired loans on an aggregate basis by grouping similar loans. Impaired loans also include those loans which are individually assessed for impairment at a loan level, such as in a troubled debt restructuring (“TDR”). We maintain an allowance for loan losses at an amount sufficient to absorb losses incurred in our portfolios at the reporting date based on a projection of estimated probable credit losses incurred in the portfolio. Our Private Education Loan portfolio contains TDR and non-TDR loans. For customers experiencing financial difficulty, certain Private Education Loans for which we have granted a forbearance of greater than three months, an interest rate reduction or an extended repayment plan are classified as TDRs. The allowance requirements are different based on these designations. In determining the allowance for loan losses on our non-TDR portfolio, we estimate the principal amount of loans that will default over the next two years (two years being the expected period between a loss event and default) and how much we expect to recover over time related to the defaulted amount. Expected defaults less our expected recoveries equal the allowance related to this portfolio. Our historical experience indicates that, on average, the time between the date that a customer experiences a default causing event (i.e., the loss trigger event) and the date that we charge off the unrecoverable portion of that loan is two years. Separately, for our TDR portfolio, we estimate an allowance amount sufficient to cover life-of-loan expected losses through an impairment calculation based on the difference between the loan’s basis and the present value of expected future cash flows (which would include life-of-loan default and recovery assumptions) discounted at the loan’s original effective interest rate. Our TDR portfolio is comprised mostly of loans with forbearance usage greater than three months and interest rate reductions. The separate allowance estimates for our TDR and non-TDR portfolios are combined into our total allowance for Private Education Loan losses. In estimating both the non-TDR and TDR allowance amounts, we start with historical experience of customer default behavior. We make judgments about which historical period to start with and then make further judgments about whether that historical experience is representative of future expectations and whether additional adjustments may be needed to those historical default rates. We also take the economic environment into consideration when calculating the allowance for loan losses. We analyze key economic statistics and the effect we expect them to have on future defaults. Key economic statistics analyzed as part of the allowance for loan losses are primarily unemployment rates. Our allowance for loan losses is estimated using an analysis of delinquent and current accounts. Our model is used to estimate the likelihood that a loan may progress through the various delinquency stages and ultimately charge off. The evaluation of the allowance for loan losses is inherently subjective, as it requires material estimates that may be susceptible to significant changes. The estimate for the allowance for loan losses is subject to a number of assumptions. If actual future performance in delinquency, charge-offs and recoveries are significantly different than estimated, this could materially affect our estimate of the allowance for loan losses and the related provision for loan losses on our income statement. We determine the collectability of our Private Education Loan portfolio by evaluating certain risk characteristics. We consider school type, credit score (FICO), existence of a cosigner, loan status and loan seasoning as the key credit quality indicators because they have the most significant effect on our determination of the adequacy of our allowance for loan losses. The type of school customers attend can have an impact on their graduation rate and job prospects after graduation and therefore affects their ability to make payments. Credit scores are an indicator of the credit worthiness of a customer and the higher the credit score the more likely it is the customer will be able to make all of their contractual payments. Loan status affects the credit risk because a past due loan is more likely to result in a credit loss than an up-to-date loan. Additionally, loans in a deferred payment status have different credit risk profiles compared with those in current payment status. Of the portfolio in repayment, loan seasoning is an important factor. It affects credit risk because a loan with a history of making payments generally has a lower incidence of default than a loan with a history of making infrequent or no payments. The existence of a cosigner lowers the likelihood of default. We monitor and update these credit quality indicators in the analysis of the adequacy of our allowance for loan losses on a quarterly basis. To estimate the probable credit losses incurred in the loan portfolio at the reporting date, we use historical experience of customer payment behavior in connection with the key credit quality indicators and incorporate management expectations regarding macroeconomic and collection performance factors. Our model is based upon the most recent twelve months of actual collection experience as the starting point for the non-TDR portfolio and the most recent approximate 10 years for the TDR portfolio and applies expected macroeconomic changes and collection procedure changes to estimate expected losses caused by loss events incurred as of the balance sheet date. Our model for the non-TDR portfolio places a greater emphasis on the more recent default experience rather than the default experience for older historical periods, as we believe the more recent default experience is more indicative of the probable losses incurred in the loan portfolio today that will default over the next two years. The TDR portfolio uses a longer historical default experience since we are projecting life of loan remaining losses. Similar to estimating defaults, we use historical customer payment behavior to estimate the timing and amount of future recoveries on charged-off loans. We use judgment in determining whether historical performance is representative of what we expect to collect in the future. We then apply the default and collection rate projections to each category of loans. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. Additionally, we consider changes in laws and regulations that could potentially impact the allowance for loan losses. More judgment has been required over the last several years, compared with years prior, in light of the U.S. economy and its effect on our customers’ ability to pay their obligations. We believe that our model reflects recent customer behavior, loan performance, and collection performance, as well as expectations about economic factors. Our collection policies allow for periods of nonpayment for customers requesting additional payment grace periods upon leaving school or experiencing temporary difficulty meeting payment obligations. This is referred to as forbearance status and is considered in our allowance for loan losses. The loss confirmation period is in alignment with our typical collection cycle and takes into account these periods of nonpayment. Our allowance for Private Education Loan losses also provides for possible additional future charge-offs as they occur related to the receivable for partially charged-off Private Education Loans. At the end of each month, for loans that are 212 days past due, we charge off the estimated loss of a defaulted loan balance. Actual recoveries are applied against the remaining loan balance that was not charged off. We refer to this remaining loan balance as the “receivable for partially charged-off loans.” If actual periodic recoveries are less than expected, the difference is immediately charged off through the allowance for loan losses with an offsetting reduction in the receivable for partially charged-off Private Education Loans. If actual periodic recoveries are greater than expected, they will be reflected as a recovery through the allowance for Private Education Loan losses once the cumulative recovery amount exceeds the cumulative amount originally expected to be recovered. Private Education Loans which defaulted between 2007 through March 31, 2015, experienced collection performance below our pre-financial crisis experience. As a result, we began building a reserve for shortfalls in recoveries until we could determine the long-term post-default recovery rate. In the second quarter of 2015, the portion of the loan amount charged off at default increased from 73 percent to 79 percent. This did not impact the provision for loan losses as previously this had been reserved through the allowance for loan losses. This change resulted in a $330 million reduction to the balance of the receivable for partially charged-off loans. Allowance for FFELP Loan Losses FFELP Loans are insured as to their principal and accrued interest in the event of default subject to a Risk Sharing level based on the date of loan disbursement. These insurance obligations are supported by contractual rights against the United States. For loans disbursed after October 1, 1993, and before July 1, 2006, we receive 98 percent reimbursement on all qualifying default claims. For loans disbursed on or after July 1, 2006, we receive 97 percent reimbursement. For loans disbursed prior to October 1, 1993, we receive 100 percent reimbursement. Similar to the allowance for Private Education Loan losses, the allowance for FFELP Loan losses uses historical experience of customer default behavior and a two-year loss confirmation period to estimate the credit losses incurred in the loan portfolio at the reporting date. We apply the default rate projections, net of applicable Risk Sharing, to each category for the current period to perform our quantitative calculation. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. For FFELP Loans that have lost their government insurance and have been charged off, any subsequent cash recoveries benefit the allowance for loan losses when received.
Investments	Investments Our available-for-sale investment portfolio consists of investments that are carried at fair value, with the temporary changes in fair value carried as a separate component of stockholders’ equity, net of taxes. The amortized cost of debt securities in this category is adjusted for premiums and accretion of discounts, which are amortized using the effective interest rate method. Other-than-temporary impairment is evaluated by considering several factors, including the length of time and extent to which the fair value has been less than the amortized cost basis, the financial condition and near-term prospects of the security (considering factors such as adverse conditions specific to the security and ratings agency actions), and the intent and ability to retain the investment to allow for an anticipated recovery in fair value. The entire fair value loss on a security that is other-than-temporary impairment is recorded in earnings if we intend to sell the security or if it is more likely than not that we will be required to sell the security before the expected recovery of the loss. However, if the impairment is other-than-temporary, and those two conditions do not exist, the portion of the impairment related to credit losses is recorded in earnings and the impairment related to other factors is recorded in other comprehensive income. Securities classified as trading are accounted for at fair value with unrealized gains and losses included in investment income. Securities that we have the intent and ability to hold to maturity are classified as held-to-maturity and are accounted for at amortized cost unless the security is determined to have an other-than-temporary impairment. In this case it is accounted for in the same manner described above. We also have other investments, primarily a receivable for cash collateral posted to derivative counterparties which is accounted for at amortized cost in other investments.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents can include term federal funds, Eurodollar deposits, commercial paper, asset-backed commercial paper, treasuries and money market funds with original terms to maturity of less than three months.
Restricted Cash and Investments	Restricted Cash and Investments Restricted cash primarily includes amounts held in education loan securitization trusts and other secured borrowings. This cash must be used to make payments related to trust obligations. Amounts on deposit in these accounts are primarily the result of timing differences between when principal and interest is collected on the trust assets and when principal and interest is paid on trust liabilities. As such, changes in this balance are reflected in investing activities in the statement of cash flows. Securities pledged as collateral related to our derivative portfolio, where the counterparty has rights to replace the securities, are classified as restricted. When the counterparty does not have these rights, the security is recorded in investments and disclosed as pledged collateral in the notes. Additionally, certain counterparties require cash collateral pledged to us to be segregated and held in restricted cash accounts.
Goodwill and Acquired Intangible Assets	Goodwill and Acquired Intangible Assets Goodwill is not amortized but is tested periodically for impairment. We test goodwill for impairment annually as of October 1 at the reporting unit level, which is the same as or one level below a business segment. Goodwill is also tested at interim periods if an event occurs or circumstances change that would indicate the carrying amount may be impaired. We assess qualitative factors to determine whether it is “more-likely-than-not” that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. The “more-likely-than-not” threshold is defined as having a likelihood of more than 50 percent. If, after assessing relevant qualitative factors, we conclude that it is “more-likely-than-not” that the fair value of a reporting unit as of October 1 is less than its carrying amount, we will complete Step 1 of the goodwill impairment analysis. Step 1 consists of a comparison of the fair value of the reporting unit to the reporting unit’s carrying value, including goodwill. If the carrying value of the reporting unit exceeds the fair value, Step 2 in the goodwill impairment analysis is performed to measure the amount of impairment loss, if any. Step 2 of the goodwill impairment analysis compares the implied fair value of the reporting unit’s goodwill to the carrying value of the reporting unit’s goodwill. The implied fair value of goodwill is determined in a manner consistent with determining goodwill in a business combination. If the carrying amount of the reporting unit’s goodwill exceeds the implied fair value of the goodwill, an impairment loss is recognized in an amount equal to that excess. Acquired intangible assets include, but are not limited to, trade names, customer and other relationships, and non-compete agreements. Acquired intangible assets with finite lives are amortized over their estimated useful lives in proportion to their estimated economic benefit. Finite-lived acquired intangible assets are reviewed for impairment using an undiscounted cash flow analysis when an event occurs or circumstances change indicating the carrying amount of a finite-lived asset or asset group may not be recoverable. If the carrying amount of the asset or asset groups exceeds the undiscounted cash flows, the fair value of the asset or asset group is determined using an acceptable valuation technique. An impairment loss would be recognized if the carrying amount of the asset
Securitization Accounting	Securitization Accounting Our securitizations use a two-step structure with a special purpose entity that legally isolates the transferred assets from us, even in the event of bankruptcy. Transactions receiving sale treatment are also structured to ensure that the holders of the beneficial interests issued are not constrained from pledging or exchanging their interests, and that we do not maintain effective control over the transferred assets. If these criteria are not met, then the transaction is accounted for as an on-balance sheet secured borrowing. In all cases, irrespective of whether they qualify as accounting sales our securitizations are legally structured to be sales of assets that isolate the transferred assets from us. If a securitization qualifies as a sale, we then assess whether we are the primary beneficiary of the securitization trust (VIE) and are required to consolidate such trust. If we are the primary beneficiary, then no gain or loss is recognized. See “Consolidation” of this Note 2 for additional information regarding the accounting rules for consolidation when we are the primary beneficiary of these trusts. Irrespective of whether a securitization receives sale or on-balance sheet treatment, our continuing involvement with our securitization trusts is generally limited to: • Owning the equity certificates of certain trusts. • The servicing of the education loan assets within the securitization trusts, on both a pre- and post-default basis. • Our acting as administrator for the securitization transactions we sponsored, which includes remarketing certain bonds at future dates. • Our responsibilities relative to representation and warranty violations. • Temporarily advancing to the trust certain borrower benefits afforded the borrowers of education loans that have been securitized. These advances subsequently are returned to us in the next quarter. • Certain back-to-back derivatives entered into by us contemporaneously with the execution of derivatives by certain Private Education Loan securitization trusts. • The option held by us to buy certain delinquent loans from certain Private Education Loan securitization trusts. • The option to exercise the clean-up call and purchase the education loans from the trust when the asset balance is 10 percent or less of the original loan balance. • The option, on some trusts, to purchase education loans aggregating up to 10 percent of the trust’s initial pool balance. • The option (in certain trusts) to call rate reset notes in instances where the remarketing process has failed. The investors of the securitization trusts have no recourse to our other assets should there be a failure of the trusts to pay when due. Generally, the only arrangements under which we have to provide financial support to the trusts are representation and warranty violations requiring the buyback of loans. Under the terms of the transaction documents of certain trusts, we have, from time to time, exercised our options to purchase delinquent loans from Private Education Loan trusts, to purchase the remaining loans from trusts once the loan balance falls below 10 percent of the original amount, to purchase education loans up to 10 percent of the trust’s initial balance, or to call rate reset notes. Certain trusts maintain financial arrangements with third parties also typical of securitization transactions, such as derivative contracts (swaps) and bond insurance policies that, in the case of a counterparty failure, could adversely impact the value of any Residual Interest. We do not record servicing assets or servicing liabilities when our securitization trusts are accounted for as on-balance sheet secured financings. As of December 31, 2017, we have $25 million of servicing assets on our balance sheet, of which $11 million is related to Residual Interests in FFELP Loan securitization trusts we sold in 2013 and $14 million is related to the acquisition of Earnest in 2017.
Education Loan Interest Income	Education Loan Interest Income For loans classified as held-for-investment, we recognize education loan interest income as earned, adjusted for the amortization of premiums (which includes purchased premiums and capitalized direct origination costs), discounts and Repayment Borrower Benefits. These adjustments result in income being recognized based upon the expected yield of the loan over its life after giving effect to expected prepayments. We amortize premium and discount on education loans using a CPR which measures the rate at which loans in the portfolio pay down principal compared to their stated terms. In determining the CPR, we only consider payments made in excess of contractually required payments. This would include loan consolidation and other early payoff activity. For Repayment Borrower Benefits, the estimates of their effect on education loan yield are based on analyses of historical payment behavior of customers who are eligible for the incentives and its effect on the ultimate qualification rate for these incentives. We regularly evaluate the assumptions used to estimate the prepayment speeds and the qualification rates used for Repayment Borrower Benefits. In instances where there are changes to the assumptions, amortization is adjusted on a cumulative basis to reflect the change since the acquisition of the loan. Additionally, interest earned on education loans reflects potential non-payment adjustments in accordance with our uncollectible interest recognition policy as discussed further in “Allowance for Loan Losses” of this Note 2. We do not amortize any premiums, discounts or other adjustments to the basis of education loans when they are classified as held-for-sale. See “Allowance for Loan Losses – Purchased Credit Impaired (‘PCI’) Loans” and “–Purchased Non-Credit Impaired Loans” of this Note 2 for discussion of the interest income methodology related to those portfolios.
Interest Expense	Interest Expense Interest expense is based upon contractual interest rates adjusted for the amortization of debt issuance costs, premiums and discounts. Our interest expense may also be adjusted for net payments/receipts related to interest rate and foreign currency swap agreements that qualify and are designated as hedges. Interest expense also includes the amortization of deferred gains and losses on closed hedge transactions that qualified as hedges. Amortization of debt issuance costs, premiums, discounts and terminated hedge-basis adjustments are recognized using the effective interest rate method.
Servicing Revenue	Servicing Revenue We perform loan servicing functions for third-parties in return for a servicing fee. Our compensation is typically based on a per-unit fee arrangement or a percentage of the loans outstanding. We recognize servicing revenues associated with these activities based upon the contractual arrangements as the services are rendered. We recognize late fees on third-party serviced loans as well as on loans in our portfolio according to the contractual provisions of the promissory notes, as well as our expectation of collectability.
Asset Recovery And Business Processing Revenue	Asset Recovery and Business Processing Revenue Asset recovery fees are received for collections or rehabilitation of delinquent or defaulted debt on behalf of clients performed on a contingency basis. Revenue is earned and recognized upon the completion of rehabilitation activities or upon receipt of the delinquent customer funds. We also receive fees from Guarantor agencies for performing default aversion services on delinquent loans prior to default. The fee is received when the loan is initially placed with us and we are obligated to provide such services for the remaining life of the loan for no additional fee. In the event that the loan defaults, in accordance with certain contracts, we are obligated to rebate a portion of the fee to the Guarantor agency in proportion to the principal and interest outstanding when the loan defaults. We defer the fees received, net of an estimate of future rebates owed due to subsequent defaults, and recognize such fees over the service period which is estimated to be the life of the loan. In the third quarter of 2017, $47 million of previously deferred asset recovery revenue, net of a reserve, was recognized as revenue related to loans for which the Company performs these default aversion services. In the third quarter of 2017, the Company was notified that it would no longer perform these services after 2017 due to the termination of the related contract as of December 31, 2017. In accordance with GAAP, we recognized this previously deferred revenue during the third-quarter 2017 to reflect a shortened period over which it is expected to be earned. Business processing fees are received generally based on processing transactions. Revenue is earned and recognized upon the completion of processing the transaction and in some cases also upon the processing of a payment.
Transfer of Financial Assets and Extinguishments of Liabilities	Transfer of Financial Assets and Extinguishments of Liabilities We account for loan sales and debt repurchases in accordance with the applicable accounting guidance. Our securitizations and other secured borrowings are accounted for as on-balance sheet secured borrowings. See “Securitization Accounting” of this Note 2 for further discussion on the criteria assessed to determine whether a transfer of financial assets is a sale or a secured borrowing. If a transfer of loans qualifies as a sale, we derecognize the loan and recognize a gain or loss as the difference between the carrying basis of the loan sold and liabilities retained and the compensation received. We periodically repurchase our outstanding debt in the open market or through public tender offers. We record a gain or loss on the early extinguishment of debt based upon the difference between the carrying cost of the debt and the amount paid to the third party and is net of hedging gains and losses when the debt is in a qualifying hedge relationship. We recognize the results of a transfer of loans and the extinguishment of debt based upon the settlement date of the transaction.
Derivative Accounting	Derivative Accounting The accounting guidance for our derivative instruments, which primarily includes interest rate swaps, cross-currency interest rate swaps and Floor Income Contracts, requires that every derivative instrument, including certain derivative instruments embedded in other contracts, be recorded at fair value on the balance sheet as either an asset or liability. Derivative positions are recorded as net positions by counterparty based on master netting arrangements exclusive of accrued interest and cash collateral held or pledged. Many of our derivatives, mainly fixed to variable or variable to fixed interest rate swaps and cross-currency interest rate swaps, qualify as effective hedges. For these derivatives, the relationship between the hedging instrument and the hedged items (including the hedged risk and method for assessing effectiveness), as well as the risk management objective and strategy for undertaking various hedge transactions at the inception of the hedging relationship, is documented. Each derivative is designated to either a specific (or pool of) asset(s) or liability(ies) on the balance sheet or expected future cash flows, and designated as either a “fair value” or a “cash flow” hedge. Fair value hedges are designed to hedge our exposure to changes in fair value of a fixed rate or foreign denominated asset or liability, while cash flow hedges are designed to hedge our exposure to variability of either a floating rate asset’s or liability’s cash flows or an expected fixed rate debt issuance. For effective fair value hedges, both the derivative and the hedged item (for the risk being hedged) are marked-to-market with any difference reflecting ineffectiveness and recorded immediately in the statement of income. For effective cash flow hedges, the change in the fair value of the derivative is recorded in other comprehensive income, net of tax, and recognized in earnings in the same period as the earnings effects of the hedged item. The ineffective portion of a cash flow hedge is recorded immediately through earnings. The assessment of the hedge’s effectiveness is performed at inception and on an ongoing basis, generally using regression testing. For hedges of a pool of assets or liabilities, tests are performed to demonstrate the similarity of individual instruments of the pool. When it is determined that a derivative is not currently an effective hedge, ineffectiveness is recognized for the full change in value of the derivative with no offsetting mark-to-market of the hedged item for the current period. If it is also determined the hedge will not be effective in the future, we discontinue the hedge accounting prospectively, cease recording changes in the fair value of the hedged item, and begin amortization of any basis adjustments that exist related to the hedged item. We also have derivatives, primarily Floor Income Contracts and certain basis swaps, that we believe are effective economic hedges but do not qualify for hedge accounting treatment. These derivatives are classified as “trading” and as a result they are marked-to-market through earnings with no consideration for the fair value fluctuation of the economically hedged item. The “gains (losses) on derivative and hedging activities, net” line item in the consolidated statements of income includes the unrealized changes in the fair value of our derivatives (except effective cash flow hedges which are recorded in other comprehensive income), the unrealized changes in fair value of hedged items in qualifying fair value hedges, as well as the realized changes in fair value related to derivative net settlements and dispositions that do not qualify for hedge accounting. Net settlement income/expense on derivatives that qualify as hedges are included with the income or expense of the hedged item (mainly interest expense).
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation We recognize stock-based compensation cost in our consolidated statements of income using the fair value based method. Under this method we determine the fair value of the stock-based compensation at the time of the grant and recognize the resulting compensation expense over the grant’s vesting period. We record stock-based compensation expense net of estimated forfeitures and as such, only those stock-based awards that we expect to vest are recorded. We estimate the forfeiture rate based on historical forfeitures of equity awards and adjust the rate to reflect changes in facts and circumstances, if any. Ultimately, the total expense recognized over the vesting period will equal the fair value of awards that actually vest.
Restructuring and Other Reorganization Expenses	Restructuring and Other Reorganization Expenses From time to time we implement plans to restructure our business. In conjunction with these restructuring plans, involuntary benefit arrangements, disposal costs (including contract termination costs and other exit costs), as well as certain other costs that are incremental and incurred as a direct result of our restructuring plans, are classified as restructuring expenses in the consolidated statements of income. The Company administers the Navient Corporation Employee Severance Plan and the Navient Corporation Executive Severance Plan for Senior Officers (collectively, “the Severance Plan”). The Severance Plan provides severance benefits in the event of termination of the Company’s full-time employees and part-time employees who work at least 24 hours per week. The Severance Plan establishes specified benefits based on base salary, job level immediately preceding termination and years of service upon involuntary termination of employment. The benefits payable under the Severance Plan relate to past service, and they accumulate and vest. Accordingly, we recognize severance expenses to be paid pursuant to the Severance Plan when payment of such benefits is probable and can be reasonably estimated in accordance with ASC 712, “Compensation — Nonretirement Postemployment Benefits.” Such benefits, include severance pay calculated based on the Severance Plan, medical and dental benefits, and outplacement services expenses. Contract termination costs are expensed at the earlier of (1) the contract termination date or (2) the cease use date under the contract. Other exit costs are expensed as incurred and classified as restructuring expenses if (1) the cost is incremental to and incurred as a direct result of planned restructuring activities and (2) the cost is not associated with or incurred to generate revenues subsequent to our consummation of the related restructuring activities. Other reorganization expenses include certain internal costs and third-party costs incurred in connection with our cost reduction initiatives. During the fourth quarter of 2017, the Company incurred $29 million of restructuring and other reorganization expense in connection with an effort that will reduce costs and improve operating efficiency. The charge related primarily to severance-related costs. During the second quarter of 2015, the Company launched an initiative to simplify and streamline its management structure following the Spin-Off of SLM BankCo to improve the operating efficiency and effectiveness of the organization. As part of the Company’s streamlining efforts, restructuring and other reorganization expenses of $29 million were recognized in 2015, primarily related to severance costs.
Income Taxes	Income Taxes We account for income taxes under the asset and liability approach which requires the recognition of deferred tax liabilities and assets for the expected future tax consequences of temporary differences between the carrying amounts and tax basis of our assets and liabilities. To the extent tax laws change, deferred tax assets and liabilities are adjusted in the period that the tax change is enacted. See “Note 14 – Income Taxes” for a description of the impact of the “Tax Cuts and Jobs Act” (“TCJA”) on the net deferred tax asset as of December 31, 2017. “Income tax expense/(benefit)” includes (i) deferred tax expense/(benefit), which represents the net change in the deferred tax asset or liability balance during the year plus any change in a valuation allowance and (ii) current tax expense/(benefit), which represents the amount of tax currently payable to or receivable from a tax authority plus amounts accrued for unrecognized tax benefits. Income tax expense/(benefit) excludes the tax effects related to adjustments recorded in equity. If we have an uncertain tax position, then that tax position is recognized only if it is more likely than not to be sustained upon examination based on the technical merits of the position. The amount of tax benefit recognized in the financial statements is the largest amount of benefit that is more than 50 percent likely of being sustained upon ultimate settlement of the uncertain tax position. We recognize interest related to unrecognized tax benefits in income tax expense/(benefit) and penalties, if any, in operating expenses.
Earnings (Loss) per Common Share	Earnings (Loss) per Common Share We compute earnings (loss) per common share (“EPS”) by dividing net income allocated to common shareholders by the weighted average common shares outstanding. Net income allocated to common shareholders represents net income applicable to common shareholders. Diluted earnings per common share is computed by dividing income allocated to common shareholders by the weighted average common shares outstanding plus amounts representing the dilutive effect of stock options outstanding, restricted stock, restricted stock units, and the outstanding commitment to issue shares under the Employee Stock Purchase Plan. See “Note 10 — Earnings (Loss) per Common Share” for further discussion.
Reclassifications	Reclassifications Certain reclassifications have been made to the balances as of and for the years ended December 31, 2016 and 2015, to be consistent with classifications adopted for 2017, which had no effect on net income, total assets or total liabilities.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Revenue Recognition On May 28, 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, “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 customers. The new guidance supersedes current U.S. GAAP guidance on revenue recognition and requires the use of more estimates and judgements than the current revenue standards. The new guidance does not apply to revenue associated with financial instruments that are accounted for under other U.S. GAAP. Accordingly, the new revenue recognition guidance does not have an impact on our consolidated results of operations associated with our loan portfolios, investments and derivatives. We adopted the new standard as of January 1, 2018, the effective date, utilizing the cumulative effect transition method. In conjunction with our implementation plan, we identified revenue streams within our Business Services segment that are within scope of the new standard and reviewed related contracts. We concluded that the new standard does not result in a material change in the timing of revenue or expense recognition, or the presentation/classification of such revenue and expense. Under the new standard, we will expand our revenue disclosures in the first quarter of 2018. Classification and Measurement On January 5, 2016, the FASB issued 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 will be effective for the Company as of January 1, 2018. We have concluded that adopting this new accounting standard will be immaterial to our consolidated financial statements and footnote disclosures. 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, lease arrangements exceeding a twelve-month term 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 requires the use of the modified retrospective transition method, which will require adjustment to all comparative periods presented. It will be effective for the Company as of January 1, 2019. Early adoption is permitted. 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. Stock Compensation On March 30, 2016, the FASB issued ASU No. 2016-09, “Compensation — Stock Compensation,” which identifies areas for simplification involving several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, an option to recognize gross stock compensation expense with actual forfeitures recognized as they occur, as well as certain classifications on the statement of cash flows. The new standard also requires that all excess tax benefits and tax deficiencies that pertain to employee stock-based incentive payments be recognized within income tax expense in the consolidated statements of income, rather than as previously reported within additional paid-in capital. The new standard was adopted on January 1, 2017. In the year ended December 31, 2017, this new standard resulted in a $5 million reduction to income tax expense. 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 departure 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. 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 is effective for the Company as of January 1, 2018. We have concluded that adopting this new accounting standard will be immaterial to our consolidated financial statements and footnote disclosures. Hedging Activities On August 28, 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging,” which better aligns 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 in some situations 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. Early adoption is permitted. We are currently assessing the impact this new standard will have on our consolidated financial statements and footnote disclosures.

Education Loans (Table)

Education Loans (Table)	12 Months Ended
Education Loans (Table)	Dec. 31, 2017
Education Loan Portfolio by Program	The estimated weighted average life of education loans in our portfolio was approximately 7 years at both December 31, 2017 and 2016. The following table reflects the distribution of our education loan portfolio by program. December 31, 2017 Year Ended December 31, 2017 (Dollars in millions) Ending Balance % of Balance Average Balance Average Effective Interest Rate FFELP Stafford and Other Education Loans, net (1) $ 28,409 27 % $ 30,462 2.94 % FFELP Consolidation Loans, net 53,294 51 54,527 3.30 Private Education Loans, net 23,419 22 23,762 6.88 Total education loans, net $ 105,122 100 % $ 108,751 3.98 % December 31, 2016 Year Ended December 31, 2016 (Dollars in millions) Ending Balance % of Balance Average Balance Average Effective Interest Rate FFELP Stafford and Other Education Loans, net (1) $ 32,319 29 % $ 34,710 2.31 % FFELP Consolidation Loans, net 55,411 50 57,787 2.98 Private Education Loans, net 23,340 21 25,361 6.26 Total education loans, net $ 111,070 100 % $ 117,858 3.49 % (1) Primarily Stafford Loans, but also includes federally guaranteed PLUS and HEAL Loans.

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
Allowance for Loan Losses (Tables)	Dec. 31, 2017
Allowance for Credit Losses and Recorded Investments in Loans	Allowance for Loan Losses Metrics Year Ended December 31, 2017 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 67 $ 1,351 $ 15 $ 1,433 Total provision 42 382 2 426 Charge-offs (1) (49 ) (443 ) (7 ) (499 ) Reclassification of interest reserve (2) — 7 — 7 Ending balance $ 60 $ 1,297 $ 10 $ 1,367 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,171 $ 9 $ 1,180 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 60 126 1 187 Purchased Non-Credit Impaired Loans acquired at a discount (3) — — — — Purchased Credit Impaired Loans (3) — — — — Ending total allowance $ 60 $ 1,297 $ 10 $ 1,367 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,921 $ 30 $ 10,951 Collectively evaluated for impairment: Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans 77,860 11,861 40 89,761 Purchased Non-Credit Impaired Loans acquired at a discount (3) 3,237 2,610 — 5,847 Purchased Credit Impaired Loans (3) — 248 — 248 Ending total loans (4) $ 81,097 $ 25,640 $ 70 $ 106,807 Charge-offs as a percentage of average loans in repayment .07 % 1.98 % 5.39 % Allowance coverage of charge-offs 1.2 2.9 1.5 Allowance as a percentage of the ending total loan balance (3) .07 % 5.06 % 14.32 % Allowance as a percentage of the ending loans in repayment (3) .09 % 5.66 % 14.32 % Ending total loans (4) $ 81,097 $ 25,640 $ 70 Average loans in repayment $ 68,318 $ 22,342 $ 130 Ending loans in repayment $ 67,853 $ 22,924 $ 70 (1) 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) See “Note 2 — Significant Accounting Policies — Allowance for Loan Losses” for a description of our policy for the $6.5 billion of loans ($3.5 billion of FFELP and $3.0 billion of Private Education) purchased in 2017 accounted for as either Purchased Credit Impaired Loans or Purchased Non-Credit Impaired Loans. The Purchased Credit Impaired Loans’ losses are not provided for by the allowance for loan losses in the above table as these loans are separately reserved for, if needed. No allowance for loan losses has been established for these loans as of December 31, 2017. The losses of the Purchased Non-Credit Impaired Loans acquired at a discount are not provided for by the allowance for loan losses in the above table as the remaining purchased discount associated with the FFELP and Private Education Loans of $43 million and $392 million, respectively, as of December 31, 2017 is greater than the incurred losses and as a result no allowance for loan losses has been established for these loans as of December 31, 2017. As a result, excluding the $6.5 billion of loans acquired in 2017, the allowance as a percentage of the ending total loan balance and the allowance as a percentage of the ending loans in repayment would be 0.08 percent and 0.09 percent for FFELP Loans and 5.69 percent and 6.42 percent for Private Education Loans, respectively. (4) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. Year Ended December 31, 2016 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 78 $ 1,471 $ 15 $ 1,564 Total provision 43 383 3 429 Charge-offs (1) (54 ) (513 ) (3 ) (570 ) Reclassification of interest reserve (2) — 10 — 10 Ending balance $ 67 $ 1,351 $ 15 $ 1,433 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,190 $ 11 $ 1,201 Collectively evaluated for impairment 67 161 4 232 Ending total allowance $ 67 $ 1,351 $ 15 $ 1,433 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 11,165 $ 32 $ 11,197 Collectively evaluated for impairment 86,918 13,983 132 101,033 Ending total loans (3) $ 86,918 $ 25,148 $ 164 $ 112,230 Charge-offs as a percentage of average loans in repayment .07 % 2.20 % 2.10 % Allowance coverage of charge-offs 1.2 2.6 7.0 Allowance as a percentage of the ending total loan balance .08 % 5.37 % 9.35 % Allowance as a percentage of the ending loans in repayment .09 % 6.10 % 9.35 % Ending total loans (3) $ 86,918 $ 25,148 $ 164 Average loans in repayment $ 72,714 $ 23,275 $ 104 Ending loans in repayment $ 70,557 $ 22,150 $ 164 (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) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans. Year Ended December 31, 2015 (Dollars in millions) FFELP Loans Private Education Loans Other Loans Total Allowance for Loan Losses Beginning balance $ 93 $ 1,916 $ 24 $ 2,033 Total provision 46 538 (3 ) 581 Net adjustment resulting from the change in the charge-off rate (1) — (330 ) — (330 ) Net charge-offs remaining (2) (61 ) (659 ) (6 ) (726 ) Total net charge-offs (61 ) (989 ) (6 ) (1,056 ) Reclassification of interest reserve (3) — 11 — 11 Loan sales — (5 ) — (5 ) Ending balance $ 78 $ 1,471 $ 15 $ 1,564 Allowance Ending Balance: Individually evaluated for impairment - TDR $ — $ 1,209 $ 12 $ 1,221 Collectively evaluated for impairment 78 262 3 343 Ending total allowance $ 78 $ 1,471 $ 15 $ 1,564 Loans Ending Balance: Individually evaluated for impairment - TDR $ — $ 10,965 $ 37 $ 11,002 Collectively evaluated for impairment 95,393 17,431 49 112,873 Ending total loans (4) $ 95,393 $ 28,396 $ 86 $ 123,875 Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate (annualized) (1) .08 % 2.55 % 6.17 % Net adjustment resulting from the change in the charge-off rate as a percentage of average loans in repayment (annualized) (1) — % 1.28 % — % Allowance coverage of net charge-offs, excluding the net adjustment resulting from the change in the charge-off rate (annualized) (1) 1.3 2.2 2.5 Allowance as a percentage of the ending total loan balance .08 % 5.18 % 17.28 % Allowance as a percentage of the ending loans in repayment .11 % 6.00 % 17.28 % Ending total loans (4) $ 95,393 $ 28,396 $ 86 Average loans in repayment $ 75,925 $ 25,802 $ 97 Ending loans in repayment $ 73,838 $ 24,502 $ 86 (1) In 2015, the portion of the loan amount charged off at default on Private Education Loans increased from 73 percent to 79 percent. This did not impact the provision for loan losses as previously this had been reserved through the allowance for loan losses. This change resulted in a $330 million reduction to the balance of the receivable for partially charged-off loans. (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) Ending total loans for Private Education Loans includes the receivable for partially charged-off loans.
Age Analysis of Past Due Loans Delinquencies	FFELP Loan Delinquencies December 31, 2017 2016 2015 (Dollars in millions) Balance % Balance % Balance % Loans in-school/grace/deferment (1) $ 4,711 $ 5,871 $ 8,257 Loans in forbearance (2) 8,533 10,490 13,298 Loans in repayment and percentage of each status: Loans current 59,264 87.3 % 61,977 87.8 % 62,651 84.8 % Loans delinquent 31-60 days (3) 2,638 3.9 2,820 4.0 3,285 4.5 Loans delinquent 61-90 days (3) 1,763 2.6 1,325 1.9 1,856 2.5 Loans delinquent greater than 90 days (3) 4,188 6.2 4,435 6.3 6,046 8.2 Total FFELP Loans in repayment 67,853 100 % 70,557 100 % 73,838 100 % Total FFELP Loans, gross 81,097 86,918 95,393 FFELP Loan unamortized premium 666 879 1,087 Total FFELP Loans 81,763 87,797 96,480 FFELP Loan allowance for losses (60 ) (67 ) (78 ) FFELP Loans, net $ 81,703 $ 87,730 $ 96,402 Percentage of FFELP Loans in repayment 83.7 % 81.2 % 77.4 % Delinquencies as a percentage of FFELP Loans in repayment 12.7 % 12.2 % 15.2 % FFELP Loans in forbearance as a percentage of loans in repayment and forbearance 11.2 % 12.9 % 15.3 % (1) Loans for customers who may still be attending school or engaging in other permitted educational activities and are not required to make payments on the 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. TDR Private Education Loan Delinquencies December 31, 2017 2016 2015 (Dollars in millions) Balance % Balance % Balance % Loans in-school/grace/deferment (1) $ 477 $ 579 $ 706 Loans in forbearance (2) 681 588 694 Loans in repayment and percentage of each status: Loans current 8,333 88.9 % 8,273 85.8 % 7,887 85.3 % Loans delinquent 31-60 days (3) 351 3.7 412 4.3 414 4.5 Loans delinquent 61-90 days (3) 207 2.2 267 2.8 263 2.9 Loans delinquent greater than 90 days (3) 487 5.2 686 7.1 678 7.3 Total TDR loans in repayment 9,378 100 % 9,638 100 % 9,242 100 % Total TDR loans, gross 10,536 10,805 10,642 TDR loans unamortized discount (225 ) (237 ) (243 ) Total TDR loans 10,311 10,568 10,399 TDR loans receivable for partially charged-off loans 385 360 323 TDR loans allowance for losses (1,171 ) (1,190 ) (1,209 ) TDR loans, net $ 9,525 $ 9,738 $ 9,513 Percentage of TDR loans in repayment 89.0 % 89.2 % 86.8 % Delinquencies as a percentage of TDR loans in repayment 11.1 % 14.2 % 14.7 % Loans in forbearance as a percentage of TDR loans in repayment and forbearance 6.8 % 5.7 % 7.0 % (1) Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not required to make payments on the 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. Non-TDR Private Education Loan Delinquencies December 31, 2017 2016 2015 (Dollars in millions) Balance % Balance % Balance % Loans in-school/grace/deferment (1) $ 584 $ 814 $ 1,334 Loans in forbearance (2) 214 202 279 Loans in repayment and percentage of each status: Loans current 13,257 97.9 % 12,233 97.8 % 14,844 97.3 % Loans delinquent 31-60 days (3) 120 .9 110 .9 163 1.1 Loans delinquent 61-90 days (3) 59 .4 54 .4 85 .6 Loans delinquent greater than 90 days (3) 110 .8 115 .9 168 1.0 Total non-TDR loans in repayment 13,546 100 % 12,512 100 % 15,260 100 % Total non-TDR loans, gross 14,344 13,528 16,873 Non-TDR loans unamortized discount (699 ) (220 ) (288 ) Total non-TDR loans 13,645 13,308 16,585 Non-TDR loans receivable for partially charged-off loans 375 455 558 Non-TDR loans allowance for losses (126 ) (161 ) (262 ) Non-TDR loans, net $ 13,894 $ 13,602 $ 16,881 Percentage of non-TDR loans in repayment 94.4 % 92.5 % 90.4 % Delinquencies as a percentage of non-TDR loans in repayment 2.1 % 2.2 % 2.7 % Loans in forbearance as a percentage of non- TDR loans in repayment and forbearance 1.6 % 1.6 % 1.8 % (1) Deferment includes customers who have returned to school or are engaged in other permitted educational activities and are not required to make payments on the 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. TDR Loans (Dollars in millions) Recorded Investment (1) Total Ending Loans (2) Related Allowance December 31, 2017 $ 10,890 $ 10,921 $ 1,171 December 31, 2016 11,119 11,165 1,190 (1) Recorded investment is equal to the unpaid principal balance (which includes the receivable for partially charged-off loans), accrued interest and unamortized discount. (2) Total ending loans includes the receivable for partially charged-off loans.
Entity Loan Modification Program [Member]
Loans Modified Accounts for TDR	The following table provides the amount of loans modified in the periods presented that resulted in a TDR. Additionally, the table summarizes charge-offs occurring in the TDR portfolio, as well as TDRs for which a payment default occurred in the current period within 12 months of the loan first being designated as a TDR. We define payment default as 60 days past due for this disclosure. Years Ended December 31, 2017 2016 2015 (Dollars in millions) Modified Loans (1) Charge- Offs (2) Payment- Default Modified Loans (1) Charge- Offs (2) Payment- Default Modified Loans (1) Charge- Offs (2) Payment- Default Total $ 816 $ 346 $ 181 $ 1,169 $ 382 $ 265 $ 1,604 $ 459 $ 403 (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 table provides the average recorded investment and interest income recognized for our TDR loans. Years Ended December 31, 2017 2016 2015 (Dollars in millions) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Total $ 10,989 $ 708 $ 11,078 $ 667 $ 10,770 $ 653
Private Education Loans [Member]
Private Education Loan Portfolio Stratified by Key Credit Quality Indicators	The following table highlights the principal balance (excluding the receivable for partially charged-off loans) of our Private Education Loan portfolio stratified by the key credit quality indicators. Private Education Loans Credit Quality Indicators TDR December 31, 2017 December 31, 2016 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 9,647 92 % $ 9,863 91 % FICO below 640 889 8 942 9 Total $ 10,536 100 % $ 10,805 100 % School Type: Not-for-profit $ 8,247 78 % $ 8,346 77 % For-profit 2,289 22 2,459 23 Total $ 10,536 100 % $ 10,805 100 % Cosigners: With cosigner $ 6,441 61 % $ 6,486 60 % Without cosigner 4,095 39 4,319 40 Total $ 10,536 100 % $ 10,805 100 % Seasoning (1) 1-12 payments $ 506 5 % $ 754 7 % 13-24 payments 644 6 927 9 25-36 payments 947 9 1,289 12 37-48 payments 1,271 12 1,620 15 More than 48 payments 6,691 63 5,636 52 Not yet in repayment 477 5 579 5 Total $ 10,536 100 % $ 10,805 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2) Balance equals the gross Private Education Loans. Private Education Loans Credit Quality Indicators Non-TDR December 31, 2017 December 31, 2016 (Dollars in millions) Balance (2) % of Balance Balance (2) % of Balance Credit Quality Indicators Original Winning FICO Scores: FICO 640 and above $ 13,752 96 % $ 13,120 97 % FICO below 640 592 4 408 3 Total $ 14,344 100 % $ 13,528 100 % School Type: Not-for-profit $ 12,431 87 % $ 11,338 84 % For-profit 1,913 13 2,190 16 Total $ 14,344 100 % $ 13,528 100 % Cosigners: With cosigner $ 9,193 64 % $ 9,124 67 % Without cosigner 5,151 36 4,404 33 Total $ 14,344 100 % $ 13,528 100 % Seasoning (1) 1-12 payments $ 1,424 10 % $ 586 4 % 13-24 payments 437 3 344 3 25-36 payments 466 3 619 5 37-48 payments 867 6 1,103 8 More than 48 payments 10,566 74 10,062 74 Not yet in repayment 584 4 814 6 Total $ 14,344 100 % $ 13,528 100 % (1) Number of months in active repayment for which a scheduled payment was received. (2)
Receivable For Partially Charged Off Loans	The following table summarizes the activity in the receivable for partially charged-off loans. Years Ended December 31, (Dollars in millions) 2017 2016 2015 Receivable at beginning of period $ 815 $ 881 $ 1,245 Expected future recoveries of current period defaults (1) 110 128 183 Recoveries (2) (155 ) (181 ) (191 ) Net adjustment resulting from the change in the charge-off rate (3) — — (330 ) Net charge-offs remaining (4) (10 ) (13 ) (26 ) Total net charge-offs (5) (10 ) (13 ) (356 ) Receivable at end of period $ 760 $ 815 $ 881 (1) Represents our estimate of the amount to be collected in the future. (2) Current period cash collections. (3) In 2015, the portion of the loan amount charged off at default increased from 73 percent to 79 percent. This change resulted in a $330 million reduction to the balance of the receivable for partially charged-off loans. (4) Represents the current period recovery shortfall — the difference between what was expected to be collected and what was actually collected. (5) 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. Accrued Interest Receivable As of December 31, (Dollars in millions) Total Greater Than 90 Days Past Due Allowance for Uncollectible Interest 2017 TDR $ 196 $ 20 $ 20 Non-TDR 187 4 6 Total $ 383 $ 24 $ 26 2016 TDR $ 192 $ 28 $ 23 Non-TDR 199 5 7 Total $ 391 $ 33 $ 30 2015 TDR $ 201 $ 28 $ 26 Non-TDR 289 7 9 Total $ 490 $ 35 $ 35

Business Combinations, Goodwi28

Business Combinations, Goodwill and Acquired Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Carrying Value of Equity and Percentage of Fair Value in Excess of Carrying Value	The following table summarizes our goodwill, accumulated impairments and net goodwill for our reporting units and reportable segments. As of December 31, 2017 As of December 31, 2016 (Dollars in millions) Gross Accumulated Impairments and Other Adjustments (1) Net Gross Accumulated Impairments and Other Adjustments (1) Net FFELP Loans reportable segment $ 194 $ (4 ) $ 190 $ 194 $ (4 ) $ 190 Private Education Loans reportable segment: Private Education Loans 147 (41 ) 106 147 (41 ) 106 Earnest 87 — 87 — — — Total Private Education Loans reportable segment (1) 234 (41 ) 193 147 (41 ) 106 Business Services reportable segment: Servicing 50 — 50 50 — 50 Asset Recovery — Contingency 136 (136 ) — 136 (136 ) — Asset Recovery — Gila 160 — 160 97 — 97 Asset Recovery — Xtend Healthcare 108 — 108 102 — 102 Total Business Services reportable segment 454 (136 ) 318 385 (136 ) 249 Total $ 882 $ (181 ) $ 701 $ 726 $ (181 ) $ 545 (1) In conjunction with our Separation from SLM BankCo in 2014, we removed $41 million of goodwill from our balance sheet as required under ASC 350, “Intangibles — Goodwill and Other.” This goodwill was allocated to the consumer banking business retained by SLM BankCo based on relative fair value.
Acquired Intangible Assets	Acquired intangible assets include the following: As of December 31, 2017 As of December 31, 2016 (Dollars in millions) Cost Basis (1) Accumulated Impairment and Amortization (1) Net Cost Basis (1) Accumulated Impairment and Amortization (1) Net Customer, services and lending relationships $ 292 $ (234 ) $ 58 $ 292 $ (219 ) $ 73 Favorable lease 1 — 1 1 — 1 Non-competes 2 (2 ) — 2 (2 ) — Software and technology 104 (85 ) 19 101 (82 ) 19 Trade names and trademarks (2) 48 (18 ) 30 44 (13 ) 31 Total acquired intangible assets $ 447 $ (339 ) $ 108 $ 440 $ (316 ) $ 124 (1) Accumulated impairment and amortization includes impairment amounts only if the acquired intangible asset has been deemed partially impaired. When an acquired intangible asset is considered fully impaired and no longer in use, the cost basis and any accumulated amortization related to the asset is written off. (2) During 2016 we reclassified certain trade names from indefinite life to definite life intangible assets and began to amortize these assets over their expected benefit period.

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
Borrowings (Tables)	Dec. 31, 2017
Company's Borrowings	The following table summarizes our borrowings. December 31, 2017 December 31, 2016 (Dollars in millions) Short Term Long Term Total Short Term Long Term Total Unsecured borrowings: Senior unsecured debt (1) $ 1,306 $ 12,624 $ 13,930 $ 717 $ 13,029 $ 13,746 Total unsecured borrowings 1,306 12,624 13,930 717 13,029 13,746 Secured borrowings: FFELP Loan securitizations — 71,208 71,208 — 73,522 73,522 Private Education Loan securitizations (2) 686 12,646 13,332 548 14,125 14,673 FFELP Loan — other facilities 1,536 6,830 8,366 — 12,443 12,443 Private Education Loan — other facilities 684 1,710 2,394 464 — 464 Other (3) 538 — 538 606 — 606 Total secured borrowings 3,444 92,394 95,838 1,618 100,090 101,708 Total before hedge accounting adjustments 4,750 105,018 109,768 2,335 113,119 115,454 Hedge accounting adjustments 21 (6 ) 15 (1 ) (751 ) (752 ) Total $ 4,771 $ 105,012 $ 109,783 $ 2,334 $ 112,368 $ 114,702 (1) Includes principal amount of $1.3 billion and $719 million of short-term debt as of December 31, 2017 and 2016, respectively. Includes principal amount of $12.7 billion and $13.1 billion of long-term debt as of December 31, 2017 and 2016, respectively. (2) Includes $686 million and $548 of short-term debt related to the Private Education Loan asset-backed securitization repurchase facilities (“Repurchase Facilities”) as of December 31, 2017 and 2016, respectively. Includes $1.3 billion and $475 million of long-term debt related to the Repurchase Facilities as of December 31, 2017 and 2016, respectively. (3) “Other” primarily includes the obligation to return cash collateral held related to derivative exposures, which includes $0 million and $193 million of securities re-pledged subject to an overnight repurchase transaction as of December 31, 2017 and 2016, respectively.
Outstanding Short-Term Borrowings	The following tables summarize outstanding short-term borrowings (secured and unsecured), the weighted average interest rates at the end of each period, and the related average balances and weighted average interest rates during the periods. December 31, 2017 Year Ended December 31, 2017 (Dollars in millions) Ending Balance Weighted Average Interest Rate Average Balance Weighted Average Interest Rate Private Education Loan securitizations (1) $ 686 4.65 % $ 706 4.32 % FFELP Loan — other facilities 1,536 2.11 261 1.26 Private Education Loan — other facilities 684 2.92 572 2.42 Senior unsecured debt 1,327 8.06 1,197 6.80 Other interest-bearing liabilities 538 1.33 458 1.27 Total short-term borrowings $ 4,771 4.16 % $ 3,194 4.22 % Maximum outstanding at any month end $ 4,771 December 31, 2016 Year Ended December 31, 2016 (Dollars in millions) Ending Balance Weighted Average Interest Rate Average Balance Weighted Average Interest Rate Private Education Loan securitizations (1) $ 548 3.72 % $ 42 3.81 % FFELP Loan — other facilities — — — — Private Education Loan —other facilities 464 2.02 389 1.83 Senior unsecured debt 716 4.22 1,032 5.01 Other interest-bearing liabilities 606 .96 629 .48 Total short-term borrowings $ 2,334 2.82 % $ 2,092 3.03 % Maximum outstanding at any month end $ 2,637 (1) Relates to Repurchase Facilities.
Long-Term Borrowings	The following tables summarize outstanding long-term borrowings, the weighted average interest rates at the end of the periods, and the related average balances during the periods. December 31, 2017 Weighted Average Year Ended December 31, 2017 (Dollars in millions) Ending Balance (1) Interest Rate (2) Average Balance Floating rate notes: U.S. dollar-denominated: Interest bearing, due 2018-2083 $ 83,209 2.31 % $ 86,186 Non-U.S. dollar-denominated: Interest bearing, due 2023-2041 6,423 .37 7,355 Total floating rate notes 89,632 2.17 93,541 Fixed rate notes: U.S. dollar-denominated: Interest bearing, due 2019-2058 15,114 5.60 15,266 Non-U.S.-dollar denominated: Interest bearing, due 2034-2035 266 2.72 281 Total fixed rate notes 15,380 5.55 15,547 Total long-term borrowings $ 105,012 2.67 % $ 109,088 December 31, 2016 Weighted Average Year Ended December 31, 2016 (Dollars in millions) Ending Balance (1) Interest Rate (2) Average Balance Floating rate notes: U.S. dollar-denominated: Interest bearing, due 2017-2083 $ 88,575 1.65 % $ 93,881 Non-U.S. dollar-denominated: Interest bearing, due 2023-2041 7,265 .28 8,761 Total floating rate notes 95,840 1.54 102,642 Fixed rate notes: U.S. dollar-denominated: Interest bearing, due 2018-2058 16,271 5.65 16,050 Non-U.S.-dollar denominated: Interest bearing, due 2034-2035 257 2.82 281 Total fixed rate notes 16,528 5.60 16,331 Total long-term borrowings $ 112,368 2.14 % $ 118,973 (1) Ending balance is expressed in U.S. dollars using the spot currency exchange rate. Includes fair value adjustments under hedge accounting for notes designated as the hedged item in a fair value hedge. (2) Weighted average interest rate is stated rate relative to currency denomination of debt.
Expected Maturities of Long-term Borrowings	As of December 31, 2017, the expected maturities of our long-term borrowings are shown in the following table. Expected Maturity (Dollars in millions) Senior Unsecured Debt Secured Borrowings (1) Total (2) Year of Maturity 2018 $ — $ 11,810 $ 11,810 2019 2,369 10,276 12,645 2020 2,041 9,076 11,117 2021 1,428 7,477 8,905 2022 1,731 6,326 8,057 2023-2039 5,055 47,429 52,484 12,624 92,394 105,018 Hedge accounting adjustments 240 (246 ) (6 ) Total $ 12,864 $ 92,148 $ 105,012 (1) We view our securitization trust debt as long-term based on the contractual maturity dates which range from 2018 to 2083. However, we have projected the expected principal paydowns based on our current estimates regarding the securitized loans’ prepayment speeds for purposes of this disclosure to better reflect how we expect this debt to be paid down over time. The projected principal paydowns in year 2018 include $11.8 billion related to the securitization trust debt. (2) The aggregate principal amount of debt that matures in each period is $11.9 billion in 2018, $12.7 billion in 2019, $11.2 billion in 2020, $9.0 billion in 2021, $8.1 billion in 2022 and $53.0 billion in 2023-2039.
Financing VIEs	We consolidate the following financing VIEs as of December 31, 2017 and 2016, as we are the primary beneficiary. As a result, these VIEs are accounted for as secured borrowings. December 31, 2017 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets, Net Total Secured Borrowings — VIEs: FFELP Loan securitizations $ — $ 71,208 $ 71,208 $ 72,145 $ 2,335 $ 1,078 $ 75,558 Private Education Loan securitizations (1) 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 December 31, 2016 Debt Outstanding Carrying Amount of Assets Securing Debt Outstanding (Dollars in millions) Short Term Long Term Total Loans Cash Other Assets, Net Total Secured Borrowings — VIEs: FFELP Loan securitizations $ — $ 73,522 $ 73,522 $ 74,197 $ 2,676 $ 778 $ 77,651 Private Education Loan securitizations (1) 548 14,125 14,673 19,815 455 260 20,530 FFELP Loan — other facilities — 9,046 9,046 9,232 289 172 9,693 Private Education Loan — other facilities 464 — 464 685 10 14 709 Other 66 — 66 79 4 — 83 Total before hedge accounting adjustments 1,078 96,693 97,771 104,008 3,434 1,224 108,666 Hedge accounting adjustments — (1,201 ) (1,201 ) — — (1,235 ) (1,235 ) Total $ 1,078 $ 95,492 $ 96,570 $ 104,008 $ 3,434 $ (11 ) $ 107,431 (1) Includes $686 million of short-term debt, $1.3 billion of long-term debt and $96 million of restricted cash related to the Repurchase Facilities as of December 31, 2017. Includes $548 million of short-term debt, $475 million of long-term debt and $49 million of restricted cash related to the Repurchase Facilities as of December 31, 2016.
Gains (Losses) on Debt Repurchases	The following table summarizes activity related to our senior unsecured debt and ABS repurchases. “Gains (losses) on debt repurchases” is shown net of hedging-related gains and losses. Years Ended December 31, (Dollars in millions) 2017 2016 2015 Debt principal repurchased $ 513 $ 1,467 $ 1,744 Gains (losses) on debt repurchases (3 ) 1 21

Derivative Financial Instrume30

Derivative Financial Instruments (Tables)	12 Months Ended
Derivative Financial Instruments (Tables)	Dec. 31, 2017
Impact of Derivatives on Consolidated Balance Sheet	The following tables summarize the fair values and notional amounts or number of contracts of all derivative instruments at December 31, 2017 and 2016, and their impact on other comprehensive income and earnings for 2017, 2016 and 2015. Impact of Derivatives on Consolidated Balance Sheet Cash Flow Fair Value Trading Total (Dollars in millions) Hedged Risk Exposure Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Fair Values (1) Derivative Assets: Interest rate swaps Interest rate $ 95 $ 78 $ 290 $ 465 $ 7 $ 22 $ 392 $ 565 Cross-currency interest rate swaps Foreign currency and interest rate — — 88 — — — 88 — Total derivative assets (2) 95 78 378 465 7 22 480 565 Derivative Liabilities: Interest rate swaps Interest rate (16 ) (76 ) (102 ) (62 ) (71 ) (70 ) (189 ) (208 ) Floor Income Contracts Interest rate — — — — (74 ) (184 ) (74 ) (184 ) Cross-currency interest rate swaps Foreign currency and interest rate — — (410 ) (1,243 ) (44 ) (53 ) (454 ) (1,296 ) Other (3) Interest rate — — — — (18 ) (13 ) (18 ) (13 ) Total derivative liabilities (2) (16 ) (76 ) (512 ) (1,305 ) (207 ) (320 ) (735 ) (1,701 ) Net total derivatives $ 79 $ 2 $ (134 ) $ (840 ) $ (200 ) $ (298 ) $ (255 ) $ (1,136 ) (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 with 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 with the impact of master netting agreements to the balance sheet classification: Other Assets Other Liabilities (Dollar in millions) December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 Gross position $ 480 $ 565 $ (735 ) $ (1,701 ) Impact of master netting agreements (42 ) (31 ) 42 31 Derivative values with impact of master netting agreements (as carried on balance sheet) 438 534 (693 ) (1,670 ) Cash collateral (held) pledged (536 ) (345 ) 235 319 Net position, as presented on the balance sheet $ (98 ) $ 189 $ (458 ) $ (1,351 ) (3) “Other” includes derivatives related to our Total Return Swap Facility
Derivative Notional Values	Cash Flow Fair Value Trading Total (Dollars in billions) Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Dec. 31, 2017 Dec. 31, 2016 Notional Values: Interest rate swaps $ 24.1 $ 15.2 $ 12.4 $ 11.8 $ 72.0 $ 23.8 $ 108.5 $ 50.8 Floor Income Contracts — — — — 21.9 18.5 21.9 18.5 Cross-currency interest rate swaps — — 6.7 8.5 .3 .3 7.0 8.8 Other (1) — — — — .5 2.6 .5 2.6 Total derivatives $ 24.1 $ 15.2 $ 19.1 $ 20.3 $ 94.7 $ 45.2 $ 137.9 $ 80.7 (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 Years Ended December 31, Unrealized Gain (Loss) on Derivatives (1)(2) Realized Gain (Loss) on Derivatives (3) Unrealized Gain (Loss) on Hedged Item (1) Total Gain (Loss) (Dollars in millions) 2017 2016 2015 2017 2016 2015 2017 2016 2015 2017 2016 2015 Fair Value Hedges: Interest rate swaps $ (214 ) $ (288 ) $ (115 ) $ 175 $ 259 $ 345 $ 193 $ 302 $ 140 $ 154 $ 273 $ 370 Cross-currency interest rate swaps 921 (319 ) (794 ) (118 ) (86 ) (7 ) (954 ) 350 921 (151 ) (55 ) 120 Total fair value derivatives 707 (607 ) (909 ) 57 173 338 (761 ) 652 1,061 3 218 490 Cash Flow Hedges: Interest rate swaps — — — (49 ) (50 ) — — — — (49 ) (50 ) — Total cash flow derivatives — — — (49 ) (50 ) — — — — (49 ) (50 ) — Trading: Interest rate swaps (16 ) (13 ) 61 24 42 42 — — — 8 29 103 Floor Income Contracts 150 297 557 (69 ) (246 ) (650 ) — — — 81 51 (93 ) Cross-currency interest rate swaps 8 9 2 (6 ) (4 ) (4 ) — — — 2 5 (2 ) Other (5 ) (10 ) 9 (10 ) (3 ) (3 ) — — — (15 ) (13 ) 6 Total trading derivatives 137 283 629 (61 ) (211 ) (615 ) — — — 76 72 14 Total 844 (324 ) (280 ) (53 ) (88 ) (277 ) (761 ) 652 1,061 30 240 504 Less: realized gains (losses) recorded in interest expense — — — 8 123 338 — — — 8 123 338 Gains (losses) on derivative and hedging activities, net $ 844 $ (324 ) $ (280 ) $ (61 ) $ (211 ) $ (615 ) $ (761 ) $ 652 $ 1,061 $ 22 $ 117 $ 166 (1) Recorded in “Gains (losses) on derivative and hedging activities, net” in the consolidated statements of income. (2) Represents ineffectiveness related to cash flow hedges. (3) For fair value and cash flow hedges, recorded in interest expense. For trading derivatives, recorded in “Gains (losses) on derivative and hedging activities, net.”
Impact of Derivatives on Consolidated Statements of Changes in Stockholders' Equity	Impact of Derivatives on Consolidated Statements of Changes in Stockholders’ Equity (net of tax) Years Ended December 31, (Dollars in millions) 2017 2016 2015 Total gains (losses) on cash flow hedges $ 25 $ 26 $ (59 ) Realized (gains) losses recognized in interest expense (1)(2)(3) 30 31 (1 ) Total change in stockholders’ equity for unrealized gains (losses) on derivatives $ 55 $ 57 $ (60 ) (1) Amounts included in “Realized gain (loss) on derivatives” in the “Impact of Derivatives on Consolidated Statements of Income” table above. (2) Includes net settlement income/expense. (3) We expect to reclassify $2 million of after-tax net losses from accumulated other comprehensive income to earnings during the next 12 months related to amortization of terminated hedge relationships.
Collateral Held and Pledged	The following table details collateral held and pledged related to derivative exposure between us and our derivative counterparties. (Dollars in millions) December 31, 2017 December 31, 2016 Collateral held: Cash (obligation to return cash collateral is recorded in short- term borrowings) $ 536 $ 345 Securities at fair value — corporate derivatives (not recorded in financial statements) (1) — 193 Securities at fair value — on-balance sheet securitization derivatives (not recorded in financial statements) (2) 297 230 Total collateral held $ 833 $ 768 Derivative asset at fair value including accrued interest $ 618 $ 689 Collateral pledged to others: Cash (right to receive return of cash collateral is recorded in investments) $ 235 $ 319 Total collateral pledged $ 235 $ 319 Derivative liability at fair value including accrued interest and premium receivable $ 659 $ 1,670 (1) The Company has the ability to sell or re-pledge securities it holds as collateral. (2) The trusts do not have the ability to sell or re-pledge securities they hold as collateral.

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
Other Assets (Tables)	Dec. 31, 2017
Schedule of Other Assets	The following table provides the detail of our other assets. (Dollars in millions) December 31, 2017 December 31, 2016 Accrued interest receivable, net $ 1,965 $ 1,663 Benefit and insurance-related investments 481 488 Derivatives at fair value 438 534 Income tax asset, net current and deferred 380 725 Fixed assets, net 156 160 Accounts receivable 108 95 Other loans, net 59 148 Other 438 380 Total $ 4,025 $ 4,193

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
Stockholders' Equity (Tables)	Dec. 31, 2017
Common Share Repurchases and Issuances	The following table summarizes our common share repurchases and issuances. Years Ended December 31, 2017 2016 2015 Common stock repurchased (1) 29,646,374 59,625,325 56,043,711 Average purchase price per share $ 14.85 $ 12.68 $ 16.87 Shares repurchased related to employee stock-based compensation plans (2) 1,847,651 3,197,355 2,404,328 Average purchase price per share $ 15.40 $ 13.21 $ 19.81 Common shares issued (3) 3,680,479 5,476,010 4,924,021 (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 (Loss) per Common Sh33

Earnings (Loss) per Common Share (Tables)	12 Months Ended
Earnings (Loss) per Common Share (Tables)	Dec. 31, 2017
Schedule of Earnings (Loss) per Common Share	Basic earnings (loss) per common share (“EPS”) are calculated using the weighted average number of shares of common stock outstanding during each period. A reconciliation of the numerators and denominators of the basic and diluted EPS calculations follows. Years Ended December 31, (In millions, except per share data) 2017 2016 2015 Numerator: Net income attributable to Navient Corporation $ 292 $ 681 $ 984 Denominator: Weighted average shares used to compute basic EPS 275 316 376 Effect of dilutive securities: Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units and Employee Stock Purchase Plan (“ESPP”) (1) 6 6 6 Dilutive potential common shares (2) 6 6 6 Weighted average shares used to compute diluted EPS 281 322 382 Basic earnings per common share attributable to Navient Corporation $ 1.06 $ 2.15 $ 2.62 Diluted earnings per common share attributable to Navient Corporation $ 1.04 $ 2.12 $ 2.58 (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 the ESPP, determined by the treasury stock method. (2) For the years ended December 31, 2017, 2016 and 2015, stock options covering approximately 5 million, 4 million and 6 million shares, respectively, were outstanding but not included in the computation of diluted earnings per share because they were anti-dilutive.

Stock-Based Compensation Plan34

Stock-Based Compensation Plans and Arrangements (Tables)	12 Months Ended
Stock-Based Compensation Plans and Arrangements (Tables)	Dec. 31, 2017
Black-Scholes Model Assumptions for Calculating Stock Option Fair Values	The fair values of the options granted in the years ended December 31, 2017, 2016 and 2015 were estimated as of the grant date using a Black-Scholes option pricing model with the following weighted average assumptions: Years Ended December 31, 2017 2016 2015 Expected life of the option 3.0 years 3.0 years 2.9 years Expected volatility 34 % 30 % 22 % Risk-free interest rate 1.44 % .90 % .95 % Expected dividend rate 4.13 % 6.97 % 2.99 % Weighted average fair value of options granted $ 2.69 $ 1.01 $ 2.22
Stock Option Activity	The following table summarizes Navient’s stock option activity in 2017. (Dollars in millions, except per share data) Number of Options Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (1) Outstanding at December 31, 2016 14,912,004 $ 12.45 Granted 1,308,167 15.48 Exercised (2) (1,497,807 ) 9.57 Canceled (538,638 ) 27.16 Outstanding at December 31, 2017 (3) 14,183,726 12.48 1.9 yrs. $ 37 Exercisable at December 31, 2017 9,653,511 $ 12.34 1.3 yrs. $ 26 (1) The aggregate intrinsic value represents the total intrinsic value (the aggregate difference between our closing stock price on December 31, 2017 and the exercise price of in-the-money options) that would have been received by the option holders if all in-the-money options had been exercised on December 31, 2017. (2) The total intrinsic value of Navient stock options exercised was $9 million, $13 million and $19 million for 2017, 2016 and 2015, respectively. (3) As of December 31, 2017, there was $1 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted average period of 1.8 years.
Restricted Stock Activity	The following table summarizes Navient’s restricted stock activity in 2017. Number of Shares Weighted Average Grant Date Fair Value Non-vested at December 31, 2016 — $ — Granted 59,124 15.39 Vested (1) (50,727 ) 15.37 Canceled (8,397 ) 15.48 Non-vested at December 31, 2017 (2) — $ — (1) The total fair value of Navient shares that vested was $1 million, $1 million and $1 million for 2017, 2016 and 2015, respectively. (2) As of December 31, 2017, there was no unrecognized compensation cost related to restricted stock.
Restricted Stock Unit and Performance Stock Unit Activity	The following table summarizes Navient’s RSU and PSU activity in 2017. Number of RSUs/PSUs Weighted Average Grant Date Fair Value Outstanding at December 31, 2016 4,372,376 $ 12.56 Granted 1,817,218 15.41 Vested and converted to common stock (1) (1,724,568 ) 13.58 Canceled (36,721 ) 12.95 Outstanding at December 31, 2017 (2) 4,428,305 $ 13.33 (1) The total fair value of Navient RSUs and PSUs that vested and converted to common stock was $23 million, $30 million and $29 million for 2017, 2016 and 2015, respectively. (2) As of December 31, 2017, there was $16 million of unrecognized compensation cost related to RSUs and PSUs, which is expected to be recognized over a weighted average period of 1.4 years.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2017
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. During 2017 and 2016, there were no significant transfers of financial instruments between levels. Fair Value Measurements on a Recurring Basis December 31, 2017 December 31, 2016 (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 $ — $ — $ — $ — $ — $ 1 $ — $ 1 Other — 2 — 2 — 2 — 2 Total available-for-sale investments — 2 — 2 — 3 — 3 Derivative instruments: (1) Interest rate swaps — 388 4 392 — 553 12 565 Cross-currency interest rate swaps — — 88 88 — — — — Total derivative assets (2) — 388 92 480 — 553 12 565 Total $ — $ 390 $ 92 $ 482 $ — $ 556 $ 12 $ 568 Liabilities (3) Derivative instruments (1) Interest rate swaps $ — $ (144 ) $ (45 ) $ (189 ) $ — $ (150 ) $ (58 ) $ (208 ) Floor Income Contracts — (74 ) — (74 ) — (184 ) — (184 ) Cross-currency interest rate swaps — (44 ) (410 ) (454 ) — (53 ) (1,243 ) (1,296 ) Other — — (18 ) (18 ) — — (13 ) (13 ) Total derivative liabilities (2) — (262 ) (473 ) (735 ) — (387 ) (1,314 ) (1,701 ) Total $ — $ (262 ) $ (473 ) $ (735 ) $ — $ (387 ) $ (1,314 ) $ (1,701 ) (1) Fair value of derivative instruments excludes accrued interest and the value of collateral. (2) See “Note 7 — Derivative Financial Instruments” for a reconciliation of gross positions without the impact of master netting agreements to the balance sheet classification. (3) Borrowings which are the hedged items in a fair value hedge relationship and which are adjusted for changes in value due to benchmark interest rates only are not carried at full fair value and are not reflected in this table.
Change in Balance Sheet Carrying Value Associated with Level 3 Financial Instruments Carried at Fair Value on Recurring Basis	The following tables summarize the change in balance sheet carrying value associated with level 3 financial instruments carried at fair value on a recurring basis. Year Ended December 31, 2017 Derivative Instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (46 ) $ (1,243 ) $ (13 ) $ (1,302 ) Total gains/(losses) (realized and unrealized): Included in earnings (1) — 803 (15 ) 788 Included in other comprehensive income — — — — Settlements 5 118 10 133 Transfers in and/or out of level 3 — — — — Balance, end of period $ (41 ) $ (322 ) $ (18 ) $ (381 ) Change in unrealized gains/(losses) relating to instruments still held at the reporting date (2) $ 5 $ 795 $ (5 ) $ 795 Year Ended December 31, 2016 Derivative Instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (44 ) $ (903 ) $ (2 ) $ (949 ) Total gains/(losses) (realized and unrealized): Included in earnings (1) 3 (428 ) (14 ) (439 ) Included in other comprehensive income — — — — Settlements 3 88 3 94 Transfers in and/or out of level 3 (3) (8 ) — — (8 ) Balance, end of period $ (46 ) $ (1,243 ) $ (13 ) $ (1,302 ) Change in unrealized gains/(losses) relating to instruments still held at the reporting date (2) $ 7 $ (340 ) $ (11 ) $ (344 ) Year Ended December 31, 2015 Derivative Instruments (Dollars in millions) Interest Rate Swaps Cross Currency Interest Rate Swaps Other Total Derivative Instruments Balance, beginning of period $ (88 ) $ (117 ) $ (11 ) $ (216 ) Total gains/(losses) (realized and unrealized): Included in earnings (1) 39 (796 ) 6 (751 ) Included in other comprehensive income — — — — Settlements 5 10 3 18 Transfers in and/or out of level 3 — — — — Balance, end of period $ (44 ) $ (903 ) $ (2 ) $ (949 ) Change in unrealized gains/(losses) relating to instruments still held at the reporting date (2) $ 37 $ (783 ) $ 9 $ (737 ) (1) “Included in earnings” is comprised of the following amounts recorded in the specified line item in the consolidated statements of income:
Included in Earnings	Years Ended December 31, (Dollars in millions) 2017 2016 2015 Gains (losses) on derivative and hedging activities, net $ 906 $ (351 ) $ (741 ) Interest expense (118 ) (88 ) (10 ) Total $ 788 $ (439 ) $ (751 ) (1) Recorded in “gains (losses) on derivative and hedging activities, net” in the consolidated statements of income. (2) Consumer Price Index/LIBOR basis swaps were transferred from level 3 to level 2 in the fourth quarter of 2016 due to the conclusion that these swaps now trade in an active market.
Unobservable Data Used in Recurring Valuations of Level 3	The following table presents the significant inputs that are unobservable or from inactive markets used in the recurring valuations of the level 3 financial instruments detailed above. (Dollars in millions) Fair Value at December 31, 2017 Valuation Technique Input Range (Weighted Average) Derivatives Prime/LIBOR basis swaps $ (41 ) Discounted cash flow Constant Prepayment Rate 6% Bid/ask adjustment to discount rate .08% — .08% (.08%) Cross-currency interest rate swaps (322 ) Discounted cash flow Constant Prepayment Rate 4% Other (18 ) Total $ (381 )
Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments	The following table summarizes the fair values of our financial assets and liabilities, including derivative financial instruments. December 31, 2017 December 31, 2016 (Dollars in millions) Fair Value Carrying Value Difference Fair Value Carrying Value Difference Earning assets FFELP Loans $ 82,271 $ 81,703 $ 568 $ 86,626 $ 87,730 $ (1,104 ) Private Education Loans 24,421 23,419 1,002 23,191 23,340 (149 ) Cash and investments (1) 5,034 5,034 — 5,203 5,203 — Total earning assets 111,726 110,156 1,570 115,020 116,273 (1,253 ) Interest-bearing liabilities Short-term borrowings 4,783 4,771 (12 ) 2,346 2,334 (12 ) Long-term borrowings 104,921 105,012 91 109,826 112,368 2,542 Total interest-bearing liabilities 109,704 109,783 79 112,172 114,702 2,530 Derivative financial instruments Floor Income Contracts (74 ) (74 ) — (184 ) (184 ) — Interest rate swaps 203 203 — 357 357 — Cross-currency interest rate swaps (366 ) (366 ) — (1,296 ) (1,296 ) — Other (18 ) (18 ) — (13 ) (13 ) — Excess of net asset fair value over carrying value $ 1,649 $ 1,277 (1) “Cash and investments” includes available-for-sale investments whose cost basis is $2 million and $3 million at December 31, 2017 and 2016, respectively, versus a fair value of $2 million and $3 million at December 31, 2017 and 2016, respectively.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2017
Reconciliations of Statutory U.S. Federal Income Tax Rates to Our Effective Tax Rate for Continuing Operations	Reconciliations of the statutory U.S. federal income tax rates to our effective tax rate for continuing operations follow: Years Ended December 31, 2017 2016 2015 Statutory rate 35.0 % 35.0 % 35.0 % DTA Remeasurement Loss (1) 27.2 — — Net excess tax benefits related to stock-based incentive payments (.7 ) — — State tax, net of federal benefit .8 3.8 2.6 Other, net (.5 ) (.3 ) .1 Effective tax rate 61.8 % 38.5 % 37.7 % (1) The TCJA, enacted on December 22, 2017, made significant changes to all aspects of income taxation, including a reduction to the corporate federal statutory tax rate. GAAP requires the effects of the TCJA to be recognized in the period the law is enacted, even though the effective date of the law for most provisions is January 1, 2018. The primary impact to us is the reduction to the corporate federal statutory tax rate from 35 percent to 21 percent as of January 1, 2018. This rate reduction required us to remeasure our deferred tax asset at December 31, 2017, at the 21 percent corporate federal statutory tax rate and resulted in a DTA Remeasurement Loss of $208 million for GAAP, which is reflected as incremental income tax expense in the fourth quarter of 2017.
Components of Provision for Income Tax Expense (Benefit)	Income tax expense consists of: December 31, (Dollars in millions) 2017 2016 2015 Current provision/(benefit): Federal $ 77 $ 246 $ 136 State (3 ) 47 22 Foreign 3 1 — Total current provision/(benefit) 77 294 158 Deferred provision/(benefit): Federal 385 115 398 State 11 18 41 Foreign (1 ) — — Total deferred provision/(benefit) 395 133 439 Provision for income tax expense/(benefit) $ 472 $ 427 $ 597
Schedule of Deferred Tax Assets and Liabilities	The tax effect of temporary differences that give rise to deferred tax assets and liabilities include the following: December 31, (Dollars in millions) 2017 2016 Deferred tax assets: Loan reserves $ 317 $ 581 Education loan premiums and discounts, net 52 74 Operating loss and credit carryovers 22 5 Stock-based compensation plans 18 32 Accrued expenses not currently deductible 24 33 Market value adjustments on education loans, investments and derivatives 9 65 Deferred revenue — 37 Other 14 40 Total deferred tax assets 456 867 Deferred tax liabilities: Unrealized derivatives and investment gains and losses, net 23 3 Original issue discount on borrowings 11 27 Debt repurchases 8 — Other 22 35 Total deferred tax liabilities 64 65 Net deferred tax assets $ 392 $ 802
Summary of Changes in Unrecognized Tax Benefits	The following table summarizes changes in unrecognized tax benefits: December 31, (Dollars in millions) 2017 2016 2015 Unrecognized tax benefits at beginning of year $ 73.0 $ 56.3 $ 51.9 Increases resulting from tax positions taken during a prior period .7 19.9 1.6 Decreases resulting from tax positions taken during a prior period (1.8 ) (5.6 ) (1.8 ) Increases resulting from tax positions taken during the current period 4.4 4.4 6.9 Decreases related to settlements with taxing authorities (5.1 ) (.1 ) — Increases related to settlements with taxing authorities — — — Reductions related to the lapse of statute of limitations (13.8 ) (1.9 ) (2.3 ) Unrecognized tax benefits at end of year $ 57.4 $ 73.0 $ 56.3

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
Segment Reporting (Tables)	Dec. 31, 2017
Segment Revenue Include Healthcare Services	Years Ended December 31, (Dollars in billions) 2017 2016 2015 Revenue from government services $ 134 $ 106 $ 86 Revenue from healthcare services 78 68 13 Total fee revenue $ 212 $ 174 $ 99 Contingent collection receivables inventory (in billions) $ 11.4 $ 10.1 $ 9.9
Segment Results and Reconciliations to GAAP	Segment Results and Reconciliations to GAAP Year Ended December 31, 2017 Total Adjustments (Dollars in millions) Federal Education Loans Consumer Lending Business Processing Other “Core Earnings” Reclassifications Additions/ (Subtractions) Total Adjustments (1) Total GAAP Interest income: Education loans $ 2,679 $ 1,634 $ — $ — $ 4,313 $ 69 $ (55 ) $ 14 $ 4,327 Other loans 13 — — — 13 — — — 13 Cash and investments 29 5 — 9 43 — — — 43 Total interest income 2,721 1,639 — 9 4,369 69 (55 ) 14 4,383 Total interest expense 2,022 825 — 143 2,990 (8 ) (11 ) (19 ) 2,971 Net interest income (loss) 699 814 — (134 ) 1,379 77 (44 ) 33 1,412 Less: provisions for loan losses 44 382 — — 426 — — — 426 Net interest income (loss) after provisions for loan losses 655 432 — (134 ) 953 77 (44 ) 33 986 Other income (loss): Servicing revenue 280 10 — — 290 — — — 290 Asset recovery and business processing revenue 263 — 212 — 475 — — — 475 Other income 3 — — 16 19 (77 ) 89 12 31 Gains on sales of loans and investments 3 — — — 3 — — — 3 Losses on debt repurchases — — — (3 ) (3 ) — — — (3 ) Total other income (loss) 549 10 212 13 784 (77 ) 89 12 796 Expenses: Direct operating expenses 316 156 187 — 659 — — — 659 Overhead expenses — — — 307 307 — — — 307 Operating expenses 316 156 187 307 966 — — — 966 Goodwill and acquired intangible asset impairment and amortization — — — — — — 23 23 23 Restructuring/other reorganization expenses — — — 29 29 — — — 29 Total expenses 316 156 187 336 995 — 23 23 1,018 Income (loss) before income tax expense (benefit) 888 286 25 (457 ) 742 — 22 22 764 Income tax expense (benefit) ( 2) 321 103 9 58 491 — (19 ) (19 ) 472 Net income (loss) $ 567 $ 183 $ 16 $ (515 ) $ 251 $ — $ 41 $ 41 $ 292 (1) “Core Earnings” adjustments to GAAP: Year Ended December 31, 2017 (Dollars in millions) Net Impact of Derivative Accounting Net Impact of Acquired Intangibles Total Net interest income after provisions for loan losses $ 33 $ — $ 33 Total other income (loss) 12 — 12 Goodwill and acquired intangible asset impairment and amortization — 23 23 Total “Core Earnings” adjustments to GAAP $ 45 $ (23 ) 22 Income tax expense (benefit) (19 ) Net income (loss) $ 41 (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment with the impact of the DTA Remeasurement Loss included in the Other segment. Year Ended December 31, 2016 Total Adjustments (Dollars in millions) Federal Education Loans Consumer Lending Business Processing Other “Core Earnings” Reclassifications Additions/ (Subtractions) Total Adjustments (1) Total GAAP Interest income: Education loans $ 2,395 $ 1,587 $ — $ — $ 3,982 $ 247 $ (114 ) $ 133 $ 4,115 Other loans 9 — — — 9 — — — 9 Cash and investments 16 2 — 4 22 — — — 22 Total interest income 2,420 1,589 — 4 4,013 247 (114 ) 133 4,146 Total interest expense 1,597 704 — 109 2,410 31 — 31 2,441 Net interest income (loss) 823 885 — (105 ) 1,603 216 (114 ) 102 1,705 Less: provisions for loan losses 46 383 — — 429 — — — 429 Net interest income (loss) after provisions for loan losses 777 502 — (105 ) 1,174 216 (114 ) 102 1,276 Other income (loss): Servicing revenue 289 15 — — 304 — — — 304 Asset recovery and business processing revenue 216 — 174 — 390 — — — 390 Other income — — — 14 14 (216 ) 326 110 124 Gains on debt repurchases — — — 1 1 — — — 1 Total other income (loss) 505 15 174 15 709 (216 ) 326 110 819 Expenses: Direct operating expenses 366 149 149 — 664 — — — 664 Overhead expenses — — — 287 287 — — — 287 Operating expenses 366 149 149 287 951 — — — 951 Goodwill and acquired intangible asset impairment and amortization — — — — — — 36 36 36 Restructuring/other reorganization expenses — — — — — — — — — Total expenses 366 149 149 287 951 — 36 36 987 Income (loss) before income tax expense (benefit) 916 368 25 (377 ) 932 — 176 176 1,108 Income tax expense (benefit) ( 2) 338 137 9 (139 ) 345 — 82 82 427 Net income (loss) $ 578 $ 231 $ 16 $ (238 ) $ 587 $ — $ 94 $ 94 $ 681 (1) “Core Earnings” adjustments to GAAP: Year Ended December 31, 2016 (Dollars in millions) Net Impact of Derivative Accounting Net Impact of Acquired Intangibles Total Net interest income after provisions for loan losses $ 102 $ — $ 102 Total other income (loss) 110 — 110 Goodwill and acquired intangible asset impairment and amortization — 36 36 Total “Core Earnings” adjustments to GAAP $ 212 $ (36 ) 176 Income tax expense (benefit) 82 Net income (loss) $ 94 (2) Income taxes are based on a percentage of net income before tax for the individual reportable segment. Year Ended December 31, 2015 Total Adjustments (Dollars in millions) Federal Education Loans Consumer Lending Business Processing Other “Core Earnings” Reclassi- fications Additions/ (Subtractions) Total Adjustments (1) Total GAAP Interest income: Education loans $ 2,112 $ 1,756 $ — $ — $ 3,868 $ 650 $ (238 ) $ 412 $ 4,280 Other loans 7 — — — 7 — — — 7 Cash and investments 6 — — 2 8 — — — 8 Total interest income 2,125 1,756 — 2 3,883 650 (238 ) 412 4,295 Total interest expense 1,247 680 — 110 2,037 37 — 37 2,074 Net interest income (loss) 878 1,076 — (108 ) 1,846 613 (238 ) 375 2,221 Less: provisions for loan losses 43 538 — — 581 — — — 581 Net interest income (loss) after provisions for loan losses 835 538 — (108 ) 1,265 613 (238 ) 375 1,640 Other income (loss): Servicing revenue 319 21 — — 340 — — — 340 Asset recovery and business processing revenue 268 — 99 — 367 — — — 367 Other income 3 — — 12 15 (613 ) 781 168 183 Gains (losses) on sales of loans and investments 11 (21 ) — 1 (9 ) — — — (9 ) Gains on debt repurchases — — — 21 21 — — — 21 Total other income (loss) 601 — 99 34 734 (613 ) 781 168 902 Expenses: Direct operating expenses 401 151 83 — 635 — — — 635 Overhead expenses — — — 283 283 — — — 283 Operating expenses 401 151 83 283 918 — — — 918 Goodwill and acquired intangible asset impairment and amortization — — — — — — 12 12 12 Restructuring/other reorganization expenses — — — — — — 32 32 32 Total expenses 401 151 83 283 918 — 44 44 962 Income (loss) from continuing operations, before income tax expense (benefit) 1,035 387 16 (357 ) 1,081 — 499 499 1,580 Income tax expense (benefit) ( 2) 384 143 6 (132 ) 401 — 196 196 597 Net income (loss) from continuing operations 651 244 10 (225 ) 680 — 303 303 983 Income from discontinued operations, net of tax expense — — — 1 1 — — — 1 Net income (loss) $ 651 $ 244 $ 10 $ (224 ) $ 681 $ — $ 303 $ 303 $ 984 (1) “Core Earnings” adjustments to GAAP: Year Ended December 31, 2015 (Dollars in millions) Net Impact from Spin-Off of SLM BankCo Net Impact of Derivative Accounting Net Impact of Acquired Intangibles Total Net interest income after provisions for loan losses $ — $ 375 $ — $ 375 Total other income (loss) — 168 — 168 Goodwill and acquired intangible asset impairment and amortization — — 12 12 Restructuring/other reorganization expenses 32 — — 32 Total “Core Earnings” adjustments to GAAP $ (32 ) $ 543 $ (12 ) 499 Income tax expense (benefit) 196 Net income (loss) $ 303 (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 Years Ended December 31, (Dollars in millions) 2017 2016 2015 “Core Earnings” adjustments to GAAP: Net impact of the removal of SLM BankCo’s operations and restructuring and reorganization expense in connection with the Spin-Off (1) $ — $ — $ (32 ) Net impact of derivative accounting (2) 45 212 543 Net impact of goodwill and acquired intangible assets (3) (23 ) (36 ) (12 ) Net tax effect (4) 19 (82 ) (196 ) Total “Core Earnings” adjustments to GAAP $ 41 $ 94 $ 303 (1) SLM BankCo’s operations and restructuring and other reorganization expense in connection with the Spin-Off: (2) Derivative accounting: (3) Goodwill and acquired intangible assets: (4) Net Tax Effect:
FFELP Loans Segment [Member]
Asset Information for Loans Segment	The following table includes GAAP basis asset information for our Federal Education Loans segment. December 31, (Dollars in millions) 2017 2016 FFELP Loans, net $ 81,703 $ 87,730 Cash and investments (1) 2,821 3,299 Other 2,601 2,226 Total assets $ 87,125 $ 93,255 (1) Includes restricted cash and investments.
Private Education Loans Segment [Member]
Asset Information for Loans Segment	The following table includes GAAP basis asset information for our Consumer Lending segment. December 31, (Dollars in millions) 2017 2016 Private Education Loans, net $ 23,419 $ 23,340 Cash and investments (1) 706 667 Other 1,143 1,562 Total assets $ 25,268 $ 25,569 (1) Includes restricted cash and investments.

Quarterly Financial Informati38

Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
Quarterly Financial Information (unaudited) (Tables)	Dec. 31, 2017
Schedule of Quarterly Financial Information	2017 (Dollars in millions, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Net interest income $ 340 $ 351 $ 355 $ 366 Less: provisions for loan losses 107 105 105 109 Net interest income after provisions for loan losses 233 246 250 257 Other income 168 187 238 181 Gains (losses) on derivative and hedging activities, net (16 ) (25 ) 25 38 Operating expenses 238 230 238 260 Goodwill and acquired intangible asset impairment and amortization expense 6 6 6 5 Restructuring/other reorganization expenses — — — 29 Income tax expense 53 60 93 266 Net income (loss) attributable to Navient Corporation $ 88 $ 112 $ 176 $ (84 ) Basic earnings (loss) per common share attributable to Navient Corporation $ .31 $ .40 $ .65 $ (.32 ) Diluted earnings (loss) per common share attributable to Navient Corporation $ .30 $ .39 $ .64 $ (.32 ) 2016 (Dollars in millions, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Net interest income $ 486 $ 429 $ 412 $ 378 Less: provisions for loan losses 111 110 106 102 Net interest income after provisions for loan losses 375 319 306 276 Other income 159 151 174 218 Gains (losses) on derivative and hedging activities, net 1 (28 ) 137 6 Operating expenses 247 230 228 246 Goodwill and acquired intangible asset impairment and amortization expense 4 6 12 13 Restructuring/other reorganization expenses — — — — Income tax expense 103 81 147 96 Net income attributable to Navient Corporation $ 181 $ 125 $ 230 $ 145 Basic earnings per common share attributable to Navient Corporation $ .53 $ .39 $ .74 $ .49 Diluted earnings per common share attributable to Navient Corporation $ .53 $ .38 $ .73 $ .48

Significant Accounting Polici39

Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended			12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2015	Dec. 31, 2017	Dec. 31, 2015	Jun. 01, 2017	Dec. 31, 2016	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Loans, net	$ 105,122,000,000			$ 105,122,000,000			$ 111,070,000,000
Net adjustment resulting from the change in the charge-off rate					$ 330,000,000
Percentage of threshold				50.00%
Goodwill impaired method for fair value determination				We assess qualitative factors to determine whether it is “more-likely-than-not” that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. The “more-likely-than-not” threshold is defined as having a likelihood of more than 50 percent.
Option to exercise clean-up call and purchase education loans from trust of original loan balance				10 percent or less of the original loan balance
Percentage of trust's asset balance needed to trigger clean-up call				10.00%
Option to purchase education loan of the trust's initial pool balance				up to 10 percent of the trust’s initial pool balance
Description of post employment benefits				The Company administers the Navient Corporation Employee Severance Plan and the Navient Corporation Executive Severance Plan for Senior Officers (collectively, “the Severance Plan”). The Severance Plan provides severance benefits in the event of termination of the Company’s full-time employees and part-time employees who work at least 24 hours per week.
Restructuring/other reorganization expenses	29,000,000		$ 29,000,000	$ 29,000,000	32,000,000
Adjustments for New Accounting Pronouncement [Member]
Summary Of Significant Accounting Policies [Line Items]
Reduction to income tax expense				5,000,000
Default Aversion Service [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred asset recovery revenue recognized		$ 47,000,000
Securitization Trust [Member]
Summary Of Significant Accounting Policies [Line Items]
Assets	25,000,000			25,000,000
Residual interests				11,000,000
Securitization Trust [Member] \| Earnest [Member]
Summary Of Significant Accounting Policies [Line Items]
Assets	14,000,000			$ 14,000,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Delinquency period (in days)				212 days
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of aggregate education loan to purchase				10.00%
FFELP Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, Fair Value	82,271,000,000			$ 82,271,000,000			86,626,000,000
Uncollected contractual principal and interest payments	67,853,000,000			67,853,000,000	73,838,000,000		70,557,000,000
Loans, net	81,703,000,000			81,703,000,000			87,730,000,000
Loans receivable, discount	$ 43,000,000			43,000,000		$ 47,000,000
Allowance for loans acquired				$ 0
FFELP Loans [Member] \| After October 1 1993 and before July 1 2006 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage reimbursement on all qualifying default claims period	98.00%			98.00%
FFELP Loans [Member] \| On or After July 1 2006 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage reimbursement on all qualifying default claims period	97.00%			97.00%
FFELP Loans [Member] \| Prior to October 1 1993 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage reimbursement on all qualifying default claims period	100.00%			100.00%
Loans Acquired With Non-Deteriorated Credit Quality [Member] \| FFELP Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, principal amount	$ 3,500,000,000			$ 3,500,000,000
Private Education Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, Fair Value	24,421,000,000			24,421,000,000			23,191,000,000
Uncollected contractual principal and interest payments	22,924,000,000			22,924,000,000	24,502,000,000		22,150,000,000
Estimated accretable yield						108,000,000
Loans, net	23,419,000,000			23,419,000,000			23,340,000,000
Valuation allowance	0			0		0
Loans receivable, discount	392,000,000			392,000,000		424,000,000
Allowance for loans acquired				$ 0
Allowance for credit losses factors influenced managements judgment				Our model is based upon the most recent twelve months of actual collection experience as the starting point for the non-TDR portfolio and the most recent approximate 10 years for the TDR portfolio and applies expected macroeconomic changes and collection procedure changes to estimate expected losses caused by loss events incurred as of the balance sheet date. Our model for the non-TDR portfolio places a greater emphasis on the more recent default experience rather than the default experience for older historical periods, as we believe the more recent default experience is more indicative of the probable losses incurred in the loan portfolio today that will default over the next two years. The TDR portfolio uses a longer historical default experience since we are projecting life of loan remaining losses. Similar to estimating defaults, we use historical customer payment behavior to estimate the timing and amount of future recoveries on charged-off loans. We use judgment in determining whether historical performance is representative of what we expect to collect in the future. We then apply the default and collection rate projections to each category of loans. Once the quantitative calculation is performed, we review the adequacy of the allowance for loan losses and determine if qualitative adjustments need to be considered. Additionally, we consider changes in laws and regulations that could potentially impact the allowance for loan losses. More judgment has been required over the last several years, compared with years prior, in light of the U.S. economy and its effect on our customers’ ability to pay their obligations. We believe that our model reflects recent customer behavior, loan performance, and collection performance, as well as expectations about economic factors.
Net adjustment resulting from the change in the charge-off rate					330,000,000
Loans default recovery rate			21.00%
Private Education Loans [Member] \| Loans Receivable For Partially Charged Off Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans, net	760,000,000			$ 760,000,000	881,000,000		$ 815,000,000	$ 1,245,000,000
Net adjustment resulting from the change in the charge-off rate			$ 330,000,000		$ 330,000,000
Private Education Loans [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Portion of loan amount charged off at default			73.00%		73.00%
Private Education Loans [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Portion of loan amount charged off at default			79.00%		79.00%
Private Education Loans [Member] \| Loans With Deteriorated Credit Quality [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, principal amount						261,000,000
Loans receivable, Fair Value						101,000,000
Uncollected contractual principal and interest payments						$ 411,000,000
Loans, net	97,000,000			97,000,000
Private Education Loans [Member] \| Loans Acquired With Non-Deteriorated Credit Quality [Member]
Summary Of Significant Accounting Policies [Line Items]
Loans receivable, principal amount	$ 2,800,000,000			$ 2,800,000,000

Education Loans - Additional In

Education Loans - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
Education Loans - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Percentage of education loan portfolio in repayment	86.00%	86.00%	83.00%
Amount of loan sold	$ 0		$ 0
FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Amount of loan sold				$ 412,000,000
Gain (loss) on sale of loans				12,000,000
After October 1 1993 and before July 1 2006 [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Percentage reimbursement on all qualifying default claims period	98.00%	98.00%
On or After July 1 2006 [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Percentage reimbursement on all qualifying default claims period	97.00%	97.00%
Stafford Loans [Member] \| Minimum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		5 years
Stafford Loans [Member] \| Maximum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		10 years
Plus Loans [Member] \| Minimum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		5 years
Plus Loans [Member] \| Maximum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		10 years
Stafford Loans [Member] \| Minimum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		12 years
Stafford Loans [Member] \| Maximum [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		30 years
Plus Loans [Member] \| Weighted Average [Member]
Accounts Notes And Loans Receivable [Line Items]
Estimated weighted average life of education loans		7 years	7 years
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Amount of loan sold				178,000,000
Gain (loss) on sale of loans				$ (21,000,000)
Private Education Loans [Member] \| Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		10 years
Private Education Loans [Member] \| Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Repayment term		15 years

Education Loans - Education Loa

Education Loans - Education Loan Portfolio by Program (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]
Loans, net	$ 105,122	$ 111,070
Percentage to total education loans	100.00%	100.00%
Average Balance education loans	$ 108,751	$ 117,858
Average Effective Interest Rate of education loans	3.98%	3.49%
FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, net	$ 81,703	$ 87,730
Stafford And Other Education Loans [Member] \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, net	$ 28,409	$ 32,319
Percentage to total education loans	27.00%	29.00%
Average Balance education loans	$ 30,462	$ 34,710
Average Effective Interest Rate of education loans	2.94%	2.31%
Consolidation Loans Member \| FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, net	$ 53,294	$ 55,411
Percentage to total education loans	51.00%	50.00%
Average Balance education loans	$ 54,527	$ 57,787
Average Effective Interest Rate of education loans	3.30%	2.98%
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans, net	$ 23,419	$ 23,340
Percentage to total education loans	22.00%	21.00%
Average Balance education loans	$ 23,762	$ 25,361
Average Effective Interest Rate of education loans	6.88%	6.26%

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2015USD ($)	Dec. 31, 2017USD ($)Loan	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate				$ 330
Percentage of loans granted forbearance that migrated to TDR classification		61.00%	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		$ 2.7	$ 2.6
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
Loans default recovery rate	21.00%
Net adjustment resulting from the change in the charge-off rate				330
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	$ 330			$ 330
Private Education Loans [Member] \| Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	73.00%			73.00%
Private Education Loans [Member] \| Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	79.00%			79.00%

Allowance for Loan Losses - All

Allowance for Loan Losses - Allowance for Credit Losses and Recorded Investments in Loans (Detail) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan	Dec. 31, 2015USD ($)SecurityLoan
Allowance for Loan Losses
Beginning balance				$ 1,433				$ 1,564	$ 1,433	$ 1,564	$ 2,033
Provisions for losses	$ 109	$ 105	$ 105	107	$ 102	$ 106	$ 110	111	426	429	581
Net charge-offs remaining											(726)
Net adjustment resulting from the change in the charge-off rate											(330)
Total net charge-offs									(499)	(570)	(1,056)
Reclassification of interest reserve									7	10	11
Loan sales											(5)
Ending balance	1,367				1,433				1,367	1,433	1,564
Allowance Ending Balance:
Ending balance: individually evaluated for impairment - TDR	1,180				1,201				1,180	1,201	1,221
Ending balance: collectively evaluated for impairment					232					232	343
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	187								187
Ending balance	1,367				1,433				1,367	1,433	1,564
Loans Ending Balance:
Ending balance: individually evaluated for impairment - TDR	10,951				11,197				10,951	11,197	11,002
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	89,761								89,761
Purchased Non-Credit Impaired Loans acquired at a discount	5,847								5,847
Purchased Credit Impaired Loans	248								248
Collectively evaluated for impairment					101,033					101,033	112,873
Ending total loans	106,807				112,230				106,807	112,230	123,875
Ending balance	1,367				1,433				1,367	1,433	1,564
FFELP Loans [Member]
Allowance for Loan Losses
Beginning balance				67				78	67	78	93
Provisions for losses									42	43	46
Net charge-offs remaining											(61)
Total net charge-offs									(49)	(54)	(61)
Ending balance	60				67				60	67	78
Allowance Ending Balance:
Ending balance: collectively evaluated for impairment					67					67	78
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	60								60
Ending balance	60				67				60	67	78
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	77,860								77,860
Purchased Non-Credit Impaired Loans acquired at a discount	3,237								3,237
Collectively evaluated for impairment					86,918					86,918	95,393
Ending total loans	81,097				86,918				$ 81,097	$ 86,918	$ 95,393
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate (annualized)											0.08%
Allowance coverage of net charge-offs, excluding the net adjustment resulting from the change in the charge-off rate (annualized) \| SecurityLoan											1.3
Charge-offs as a percentage of average loans in repayment									0.07%	0.07%
Allowance coverage of charge-offs \| SecurityLoan									1.2	1.2
Allowance as a percentage of the ending total loan balance									0.07%	0.08%	0.08%
Allowance as a percentage of the ending loans in repayment									0.09%	0.09%	0.11%
Average loans in repayment									$ 68,318	$ 72,714	$ 75,925
Ending loans in repayment	67,853				70,557				67,853	70,557	73,838
Ending balance	60				67				60	67	78
Private Education Loans [Member]
Allowance for Loan Losses
Beginning balance				1,351				1,471	1,351	1,471	1,916
Provisions for losses									382	383	538
Net charge-offs remaining											(659)
Net adjustment resulting from the change in the charge-off rate											(330)
Total net charge-offs									(443)	(513)	(989)
Reclassification of interest reserve									7	10	11
Loan sales											(5)
Ending balance	1,297				1,351				1,297	1,351	1,471
Allowance Ending Balance:
Ending balance: individually evaluated for impairment - TDR	1,171				1,190				1,171	1,190	1,209
Ending balance: collectively evaluated for impairment					161					161	262
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	126								126
Ending balance	1,297				1,351				1,297	1,351	1,471
Loans Ending Balance:
Ending balance: individually evaluated for impairment - TDR	10,921				11,165				10,921	11,165	10,965
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	11,861								11,861
Purchased Non-Credit Impaired Loans acquired at a discount	2,610								2,610
Purchased Credit Impaired Loans	248								248
Collectively evaluated for impairment					13,983					13,983	17,431
Ending total loans	25,640				25,148				$ 25,640	$ 25,148	$ 28,396
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate (annualized)											2.55%
Net adjustment resulting from the change in the charge-off rate as a percentage of average loans in repayment (annualized)											1.28%
Allowance coverage of net charge-offs, excluding the net adjustment resulting from the change in the charge-off rate (annualized) \| SecurityLoan											2.2
Charge-offs as a percentage of average loans in repayment									1.98%	2.20%
Allowance coverage of charge-offs \| SecurityLoan									2.9	2.6
Allowance as a percentage of the ending total loan balance									5.06%	5.37%	5.18%
Allowance as a percentage of the ending loans in repayment									5.66%	6.10%	6.00%
Average loans in repayment									$ 22,342	$ 23,275	$ 25,802
Ending loans in repayment	22,924				22,150				22,924	22,150	24,502
Ending balance	1,297				1,351				1,297	1,351	1,471
Other Loans [Member]
Allowance for Loan Losses
Beginning balance				$ 15				$ 15	15	15	24
Provisions for losses									2	3	(3)
Net charge-offs remaining											(6)
Total net charge-offs									(7)	(3)	(6)
Ending balance	10				15				10	15	15
Allowance Ending Balance:
Ending balance: individually evaluated for impairment - TDR	9				11				9	11	12
Ending balance: collectively evaluated for impairment					4					4	3
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	1								1
Ending balance	10				15				10	15	15
Loans Ending Balance:
Ending balance: individually evaluated for impairment - TDR	30				32				30	32	37
Collectively evaluated for impairment:
Excluding Purchased Non-Credit Impaired Loans acquired at a discount and Purchased Credit Impaired Loans	40								40
Collectively evaluated for impairment					132					132	49
Ending total loans	70				164				$ 70	$ 164	$ 86
Net charge-offs as a percentage of average loans in repayment, excluding the net adjustment resulting from the change in the charge-off rate (annualized)											6.17%
Allowance coverage of net charge-offs, excluding the net adjustment resulting from the change in the charge-off rate (annualized) \| SecurityLoan											2.5
Charge-offs as a percentage of average loans in repayment									5.39%	2.10%
Allowance coverage of charge-offs \| SecurityLoan									1.5	7
Allowance as a percentage of the ending total loan balance									14.32%	9.35%	17.28%
Allowance as a percentage of the ending loans in repayment									14.32%	9.35%	17.28%
Average loans in repayment									$ 130	$ 104	$ 97
Ending loans in repayment	70				164				70	164	86
Ending balance	$ 10				$ 15				$ 10	$ 15	$ 15

Allowance for Loan Losses - A44

Allowance for Loan Losses - Allowance for Credit Losses and Recorded Investments in Loans (Parenthetical) (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 01, 2017
Accounts Notes And Loans Receivable [Line Items]
Net adjustment resulting from the change in the charge-off rate				$ 330,000,000
JPM Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans purchased, Unpaid principal amount		$ 6,500,000,000
FFELP Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans purchased, Unpaid principal amount		5,700,000,000	$ 3,600,000,000	$ 3,700,000,000
Allowance for loans acquired		0
Loans receivable, discount		$ 43,000,000			$ 47,000,000
Allowance as a percentage of the ending total loan balance		0.07%	0.08%	0.08%
Allowance as a percentage of the ending loans in repayment		0.09%	0.09%	0.11%
FFELP Loans [Member] \| Loans Receivable Excluding Recent Loans Acquired [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance as a percentage of the ending total loan balance		0.08%
Allowance as a percentage of the ending loans in repayment		0.09%
FFELP Loans [Member] \| JPM Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans purchased, Unpaid principal amount		$ 3,500,000,000
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance for loans acquired		0
Loans receivable, discount		$ 392,000,000			$ 424,000,000
Allowance as a percentage of the ending total loan balance		5.06%	5.37%	5.18%
Allowance as a percentage of the ending loans in repayment		5.66%	6.10%	6.00%
Net adjustment resulting from the change in the charge-off rate				$ 330,000,000
Private Education Loans [Member] \| Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Portion of loan amount charged off at default	73.00%			73.00%
Private Education Loans [Member] \| Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Portion of loan amount charged off at default	79.00%			79.00%
Private Education Loans [Member] \| Loans Receivable Excluding Recent Loans Acquired [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance as a percentage of the ending total loan balance		5.69%
Allowance as a percentage of the ending loans in repayment		6.42%
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	$ 330,000,000			$ 330,000,000
Private Education Loans [Member] \| JPM Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans purchased, Unpaid principal amount		$ 3,000,000,000

Allowance for Loan Losses - Age

Allowance for Loan Losses - Age Analysis of Past Due Loans Delinquencies (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans in repayment and percentage of each status:
Loans allowance for losses	$ (1,367)	$ (1,433)	$ (1,564)	$ (2,033)
Loans, net	105,122	111,070
FFELP Loans [Member]
Loans in repayment and percentage of each status:
Total loans in repayment	67,853	70,557	73,838
Loans allowance for losses	(60)	(67)	(78)	$ (93)
Loans, net	81,703	87,730
Credit Concentration Risk [Member] \| Private Education Loans - TDR [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	10,536	10,805	10,642
Loans in repayment and percentage of each status:
Loans current	8,333	8,273	7,887
Total loans in repayment	9,378	9,638	9,242
Total loans, gross	10,536	10,805	10,642
Loans unamortized premium (discount)	(225)	(237)	(243)
Total loans	10,311	10,568	10,399
Loans allowance for losses	(1,171)	(1,190)	(1,209)
Loans, net	9,525	9,738	9,513
Loans receivable for partially charged-off loans	385	360	323
Credit Concentration Risk [Member] \| Private Education Loans - Non-TDR [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	14,344	13,528	16,873
Loans in repayment and percentage of each status:
Total loans in repayment	13,546	12,512	15,260
Total loans, gross	14,344	13,528	16,873
Loans unamortized premium (discount)	(699)	(220)	(288)
Total loans	13,645	13,308	16,585
Loans allowance for losses	(126)	(161)	(262)
Loans, net	13,894	13,602	16,881
Loans receivable for partially charged-off loans	$ 375	$ 455	$ 558
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	100.00%	100.00%	100.00%
Credit Concentration Risk [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	100.00%	100.00%	100.00%
Credit Concentration Risk [Member] \| Financing Receivables, 31 to 60 Days Past Due [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 351	$ 412	$ 414
Credit Concentration Risk [Member] \| Financing Receivables, 31 to 60 Days Past Due [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 120	$ 110	$ 163
Credit Concentration Risk [Member] \| Financing Receivables, 31 to 60 Days Past Due [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	3.70%	4.30%	4.50%
Credit Concentration Risk [Member] \| Financing Receivables, 31 to 60 Days Past Due [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	0.90%	0.90%	1.10%
Credit Concentration Risk [Member] \| Financing Receivables, 61 to 90 Days Past Due [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 207	$ 267	$ 263
Credit Concentration Risk [Member] \| Financing Receivables, 61 to 90 Days Past Due [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 59	$ 54	$ 85
Credit Concentration Risk [Member] \| Financing Receivables, 61 to 90 Days Past Due [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	2.20%	2.80%	2.90%
Credit Concentration Risk [Member] \| Financing Receivables, 61 to 90 Days Past Due [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	0.40%	0.40%	0.60%
Credit Concentration Risk [Member] \| Financing Receivables, 90 Days Past Due [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 487	$ 686	$ 678
Credit Concentration Risk [Member] \| Financing Receivables, 90 Days Past Due [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 110	$ 115	$ 168
Credit Concentration Risk [Member] \| Financing Receivables, 90 Days Past Due [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	5.20%	7.10%	7.30%
Credit Concentration Risk [Member] \| Financing Receivables, 90 Days Past Due [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Loans delinquent, percentage	0.80%	0.90%	1.00%
Credit Concentration Risk [Member] \| Financing Receivables, Current [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Loans current	$ 13,257	$ 12,233	$ 14,844
Credit Concentration Risk [Member] \| Financing Receivables, Current [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	88.90%	85.80%	85.30%
Credit Concentration Risk [Member] \| Financing Receivables, Current [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	97.90%	97.80%	97.30%
Credit Concentration Risk [Member] \| Financing Receivables, Loans In Repayment [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	89.00%	89.20%	86.80%
Credit Concentration Risk [Member] \| Financing Receivables, Loans In Repayment [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	94.40%	92.50%	90.40%
Credit Concentration Risk [Member] \| Financing Receivables, Delinquent Loans in Repayment [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	11.10%	14.20%	14.70%
Credit Concentration Risk [Member] \| Financing Receivables, Delinquent Loans in Repayment [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	2.10%	2.20%	2.70%
Credit Concentration Risk [Member] \| Financing Receivables, Forbearance, Loans In Repayment [Member] \| Accounts Receivable [Member] \| Private Education Loans - TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	6.80%	5.70%	7.00%
Credit Concentration Risk [Member] \| Financing Receivables, Forbearance, Loans In Repayment [Member] \| Accounts Receivable [Member] \| Private Education Loans - Non-TDR [Member]
Loans in repayment and percentage of each status:
Dimensions of concentration risk	1.60%	1.60%	1.80%
Credit Concentration Risk [Member] \| School/Grace/Deferment [Member] \| Private Education Loans - TDR [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	$ 477	$ 579	$ 706
Loans in repayment and percentage of each status:
Total loans, gross	477	579	706
Credit Concentration Risk [Member] \| School/Grace/Deferment [Member] \| Private Education Loans - Non-TDR [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	584	814	1,334
Loans in repayment and percentage of each status:
Total loans, gross	584	814	1,334
Credit Concentration Risk [Member] \| Forbearance [Member] \| Private Education Loans - TDR [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	681	588	694
Loans in repayment and percentage of each status:
Total loans, gross	681	588	694
Credit Concentration Risk [Member] \| Forbearance [Member] \| Private Education Loans - Non-TDR [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	214	202	279
Loans in repayment and percentage of each status:
Total loans, gross	214	202	279
Credit Concentration Risk [Member] \| FFELP Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	81,097	86,918	95,393
Loans in repayment and percentage of each status:
Loans current	59,264	61,977	62,651
Total loans in repayment	67,853	70,557	73,838
Total loans, gross	81,097	86,918	95,393
Loans unamortized premium (discount)	666	879	1,087
Total loans	81,763	87,797	96,480
Loans allowance for losses	(60)	(67)	(78)
Loans, net	$ 81,703	$ 87,730	$ 96,402
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%	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	$ 2,638	$ 2,820	$ 3,285
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	3.90%	4.00%	4.50%
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	$ 1,763	$ 1,325	$ 1,856
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	2.60%	1.90%	2.50%
Credit Concentration Risk [Member] \| FFELP Loans [Member] \| Financing Receivables, 90 Days Past Due [Member]
Loans in repayment and percentage of each status:
Loans delinquent	$ 4,188	$ 4,435	$ 6,046
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	6.20%	6.30%	8.20%
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	87.30%	87.80%	84.80%
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	83.70%	81.20%	77.40%
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	12.70%	12.20%	15.20%
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	11.20%	12.90%	15.30%
Credit Concentration Risk [Member] \| FFELP Loans [Member] \| School/Grace/Deferment [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	$ 4,711	$ 5,871	$ 8,257
Loans in repayment and percentage of each status:
Total loans, gross	4,711	5,871	8,257
Credit Concentration Risk [Member] \| FFELP Loans [Member] \| Forbearance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans, gross	8,533	10,490	13,298
Loans in repayment and percentage of each status:
Total loans, gross	$ 8,533	$ 10,490	$ 13,298

Allowance for Loan Losses - Pri

Allowance for Loan Losses - Private Education Loan Portfolio Stratified by Key Credit Quality Indicators (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Private Education Loans - TDR [Member] \| Original Winning FICO Scores [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 10,536	$ 10,805
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - TDR [Member] \| Original Winning FICO Scores [Member] \| FICO 640 and Above [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 9,647	$ 9,863
Total Private Education Loans Credit Quality Indicators, Percent	92.00%	91.00%
Private Education Loans - TDR [Member] \| Original Winning FICO Scores [Member] \| FICO Below 640 [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 889	$ 942
Total Private Education Loans Credit Quality Indicators, Percent	8.00%	9.00%
Private Education Loans - TDR [Member] \| School Type [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 10,536	$ 10,805
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - TDR [Member] \| School Type [Member] \| Not For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 8,247	$ 8,346
Total Private Education Loans Credit Quality Indicators, Percent	78.00%	77.00%
Private Education Loans - TDR [Member] \| School Type [Member] \| For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 2,289	$ 2,459
Total Private Education Loans Credit Quality Indicators, Percent	22.00%	23.00%
Private Education Loans - TDR [Member] \| Cosigners [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 10,536	$ 10,805
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - TDR [Member] \| Cosigners [Member] \| With Consigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 6,441	$ 6,486
Total Private Education Loans Credit Quality Indicators, Percent	61.00%	60.00%
Private Education Loans - TDR [Member] \| Cosigners [Member] \| Without Consigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 4,095	$ 4,319
Total Private Education Loans Credit Quality Indicators, Percent	39.00%	40.00%
Private Education Loans - TDR [Member] \| Seasoning [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 10,536	$ 10,805
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - TDR [Member] \| Seasoning [Member] \| 1-12 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 506	$ 754
Total Private Education Loans Credit Quality Indicators, Percent	5.00%	7.00%
Private Education Loans - TDR [Member] \| Seasoning [Member] \| 13-24 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 644	$ 927
Total Private Education Loans Credit Quality Indicators, Percent	6.00%	9.00%
Private Education Loans - TDR [Member] \| Seasoning [Member] \| 25-36 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 947	$ 1,289
Total Private Education Loans Credit Quality Indicators, Percent	9.00%	12.00%
Private Education Loans - TDR [Member] \| Seasoning [Member] \| 37-48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 1,271	$ 1,620
Total Private Education Loans Credit Quality Indicators, Percent	12.00%	15.00%
Private Education Loans - TDR [Member] \| Seasoning [Member] \| More than 48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 6,691	$ 5,636
Total Private Education Loans Credit Quality Indicators, Percent	63.00%	52.00%
Private Education Loans - TDR [Member] \| Seasoning [Member] \| Not Yet in Repayment [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 477	$ 579
Total Private Education Loans Credit Quality Indicators, Percent	5.00%	5.00%
Private Education Loans - Non-TDR [Member] \| Original Winning FICO Scores [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,344	$ 13,528
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - Non-TDR [Member] \| Original Winning FICO Scores [Member] \| FICO 640 and Above [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 13,752	$ 13,120
Total Private Education Loans Credit Quality Indicators, Percent	96.00%	97.00%
Private Education Loans - Non-TDR [Member] \| Original Winning FICO Scores [Member] \| FICO Below 640 [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 592	$ 408
Total Private Education Loans Credit Quality Indicators, Percent	4.00%	3.00%
Private Education Loans - Non-TDR [Member] \| School Type [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,344	$ 13,528
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - Non-TDR [Member] \| School Type [Member] \| Not For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 12,431	$ 11,338
Total Private Education Loans Credit Quality Indicators, Percent	87.00%	84.00%
Private Education Loans - Non-TDR [Member] \| School Type [Member] \| For Profit [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 1,913	$ 2,190
Total Private Education Loans Credit Quality Indicators, Percent	13.00%	16.00%
Private Education Loans - Non-TDR [Member] \| Cosigners [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,344	$ 13,528
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - Non-TDR [Member] \| Cosigners [Member] \| With Consigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 9,193	$ 9,124
Total Private Education Loans Credit Quality Indicators, Percent	64.00%	67.00%
Private Education Loans - Non-TDR [Member] \| Cosigners [Member] \| Without Consigner [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 5,151	$ 4,404
Total Private Education Loans Credit Quality Indicators, Percent	36.00%	33.00%
Private Education Loans - Non-TDR [Member] \| Seasoning [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 14,344	$ 13,528
Total Private Education Loans Credit Quality Indicators, Percent	100.00%	100.00%
Private Education Loans - Non-TDR [Member] \| Seasoning [Member] \| 1-12 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 1,424	$ 586
Total Private Education Loans Credit Quality Indicators, Percent	10.00%	4.00%
Private Education Loans - Non-TDR [Member] \| Seasoning [Member] \| 13-24 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 437	$ 344
Total Private Education Loans Credit Quality Indicators, Percent	3.00%	3.00%
Private Education Loans - Non-TDR [Member] \| Seasoning [Member] \| 25-36 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 466	$ 619
Total Private Education Loans Credit Quality Indicators, Percent	3.00%	5.00%
Private Education Loans - Non-TDR [Member] \| Seasoning [Member] \| 37-48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 867	$ 1,103
Total Private Education Loans Credit Quality Indicators, Percent	6.00%	8.00%
Private Education Loans - Non-TDR [Member] \| Seasoning [Member] \| More than 48 Payments [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 10,566	$ 10,062
Total Private Education Loans Credit Quality Indicators, Percent	74.00%	74.00%
Private Education Loans - Non-TDR [Member] \| Seasoning [Member] \| Not Yet in Repayment [Member]
Accounts Notes And Loans Receivable [Line Items]
Total Private Education Loans Credit Quality Indicators	$ 584	$ 814
Total Private Education Loans Credit Quality Indicators, Percent	4.00%	6.00%

Allowance for Loan Losses - Rec

Allowance for Loan Losses - Receivable for Partially Charged-Off Private Education Loans (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Receivable at beginning of period		$ 111,070
Net adjustment resulting from the change in the charge-off rate				$ (330)
Net charge-offs remaining				(726)
Total net charge-offs		(499)	$ (570)	(1,056)
Receivable at end of period		105,122	111,070
Private Education Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Receivable at beginning of period		23,340
Net adjustment resulting from the change in the charge-off rate				(330)
Net charge-offs remaining				(659)
Total net charge-offs		(443)	(513)	(989)
Receivable at end of period		23,419	23,340
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		815	881	1,245
Expected future recoveries of current period defaults		110	128	183
Recoveries		(155)	(181)	(191)
Net adjustment resulting from the change in the charge-off rate	$ (330)			(330)
Net charge-offs remaining		(10)	(13)	(26)
Total net charge-offs		(10)	(13)	(356)
Receivable at end of period		$ 760	$ 815	$ 881

Allowance for Loan Losses - R48

Allowance for Loan Losses - Receivable for Partially Charged-Off Loans (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate		$ 330
Private Education Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Net adjustment resulting from the change in the charge-off rate		330
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	$ 330	$ 330
Private Education Loans [Member] \| Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	73.00%	73.00%
Private Education Loans [Member] \| Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Portion of loan amount charged off at default	79.00%	79.00%

Allowance for Loan Losses - R49

Allowance for Loan Losses - Recorded Investment, Unpaid Principal Balance and Related Allowance for TDR Loans (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Impaired [Line Items]
TDR Loans, Recorded Investment	$ 10,890	$ 11,119
TDR loans, Total Ending Loans	10,921	11,165
TDR Loans, Related Allowance	$ 1,171	$ 1,190

Allowance for Loan Losses - Ave

Allowance for Loan Losses - Average Recorded Investment and Interest Income Recognized for TDR (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Impaired financing receivable, Average Recorded Investment	$ 10,989	$ 11,078	$ 10,770
Impaired financing receivable, Interest Income Recognized	$ 708	$ 667	$ 653

Allowance for Loan Losses - Loa

Allowance for Loan Losses - Loans Modified Accounts for TDR (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Modifications [Line Items]
Modified Loans	$ 816	$ 1,169	$ 1,604
Charge-Offs	346	382	459
Payment-Default	$ 181	$ 265	$ 403

Allowance for Loan Losses - Acc

Allowance for Loan Losses - Accrued Interest Receivable (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	$ 1,965	$ 1,663
Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	383	391	$ 490
Accrued Interest Receivable, Allowance for Uncollectible Interest	26	30	35
Private Education Loans [Member] \| TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	196	192	201
Accrued Interest Receivable, Allowance for Uncollectible Interest	20	23	26
Private Education Loans [Member] \| Non-TDR [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	187	199	289
Accrued Interest Receivable, Allowance for Uncollectible Interest	6	7	9
Accrued Interest Receivable, Greater Than 90 Days Past Due [Member] \| Private Education Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Accrued Interest Receivable	24	33	35
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	20	28	28
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	$ 5	$ 7

Business Combinations, Goodwi53

Business Combinations, Goodwill and Acquired Intangible Assets - Additional Information (Detail) $ in Millions	1 Months Ended				12 Months Ended
	Nov. 30, 2017USD ($)	Jul. 31, 2017USD ($)	Oct. 31, 2015USD ($)	Feb. 28, 2015USD ($)	Dec. 31, 2017USD ($)Segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Oct. 01, 2017USD ($)	Jun. 30, 2016USD ($)	Sep. 30, 2015USD ($)
Indefinite Lived Intangible Assets By Major Class [Line Items]
Goodwill					$ 701	$ 545
Number of reportable segments \| Segment					4
Discount rate					15.00%			13.50%
Amortization of acquired intangible assets					$ 23	$ 29	$ 12
2,018					20
2,019					17
2,020					14
2,021					12
After 2,021					$ 39
Asset Recovery - Xtend Healthcare [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Controlling interest percentage			89.00%
Business acquisition, effective date of acquisition					Oct. 31, 2015
Goodwill			$ 102
Business acquisition, purchase price			$ 164
Business acquisition, definite life intangible assets									$ 65
Estimated fair value of equity in excess of carrying value								19.00%
Carrying value of equity								$ 176
Asset Recovery - Xtend Healthcare [Member] \| Minimum [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Definite life intangible assets, amortization period					10 years
Asset Recovery - Xtend Healthcare [Member] \| Maximum [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Definite life intangible assets, amortization period					15 years
Earnest [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Controlling interest percentage	95.00%
Payments to acquire business, cash	$ 149
Business acquisition, effective date of acquisition					Nov. 30, 2017
Goodwill	$ 87
Duncan Solutions [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Controlling interest percentage		100.00%
Payments to acquire business, cash		$ 86
Business acquisition, effective date of acquisition					Jul. 31, 2017
Goodwill		$ 63
Asset Recovery - Gila [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Controlling interest percentage				98.00%
Business acquisition, effective date of acquisition					Feb. 28, 2015
Goodwill				$ 97
Business acquisition, purchase price				$ 185
Business acquisition, definite life intangible assets										$ 71
Business acquisition, indefinite life intangible asset										$ 13
Estimated fair value of equity in excess of carrying value					9.00%
Carrying value of equity					$ 245
Asset Recovery - Gila [Member] \| Minimum [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Definite life intangible assets, amortization period					7 years
Asset Recovery - Gila [Member] \| Maximum [Member]
Indefinite Lived Intangible Assets By Major Class [Line Items]
Definite life intangible assets, amortization period					16 years

Business Combinations, Goodwi54

Business Combinations, Goodwill and Acquired Intangible Assets - Summary of Goodwill, Accumulated Impairments and Net Goodwill for Each Reporting Units and Reportable Segments (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Nov. 30, 2017	Dec. 31, 2016
Goodwill [Line Items]
Gross	$ 882		$ 726
Accumulated Impairments and Other Adjustments	(181)		(181)
Net	701		545
FFELP Loans Segment [Member]
Goodwill [Line Items]
Gross	194		194
Accumulated Impairments and Other Adjustments	(4)		(4)
Net	190		190
Private Education Loans Segment [Member]
Goodwill [Line Items]
Gross	234		147
Accumulated Impairments and Other Adjustments	(41)		(41)
Net	193		106
Private Education Loans Segment [Member] \| Private Education Loans [Member]
Goodwill [Line Items]
Gross	147		147
Accumulated Impairments and Other Adjustments	(41)		(41)
Net	106		106
Business Services Segment [Member]
Goodwill [Line Items]
Gross	454		385
Accumulated Impairments and Other Adjustments	(136)		(136)
Net	318		249
Business Services Segment [Member] \| Servicing [Member]
Goodwill [Line Items]
Gross	50		50
Net	50		50
Earnest [Member]
Goodwill [Line Items]
Net		$ 87
Earnest [Member] \| Private Education Loans Segment [Member]
Goodwill [Line Items]
Gross	87
Net	87
Asset Recovery - Contingency [Member] \| Business Services Segment [Member]
Goodwill [Line Items]
Gross	136		136
Accumulated Impairments and Other Adjustments	(136)		(136)
Asset Recovery - Gila [Member] \| Business Services Segment [Member]
Goodwill [Line Items]
Gross	160		97
Net	160		97
Asset Recovery - Xtend Healthcare [Member] \| Business Services Segment [Member]
Goodwill [Line Items]
Gross	108		102
Net	$ 108		$ 102

Business Combinations, Goodwi55

Business Combinations, Goodwill and Acquired Intangible Assets - Summary of Goodwill, Accumulated Impairments and Net Goodwill for Each Reporting Units and Reportable Segments (Parenthetical) (Detail) $ in Millions	Apr. 30, 2014USD ($)
SLM BankCo [Member]
Goodwill [Line Items]
Goodwill allocated to consumer banking business	$ 41

Business Combinations, Goodwi56

Business Combinations, Goodwill and Acquired Intangible Assets - Acquired Intangible Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	$ 447	$ 440
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(339)	(316)
Intangible assets subject to amortization, Net	108	124
Customer, Services and Lending Relationships [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	292	292
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(234)	(219)
Intangible assets subject to amortization, Net	58	73
Favorable Lease [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	1	1
Intangible assets subject to amortization, Net	1	1
Non-competes [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	2	2
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(2)	(2)
Software and Technology [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	104	101
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(85)	(82)
Intangible assets subject to amortization, Net	19	19
Trade Names and Trademarks [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, Cost Basis	48	44
Intangible assets subject to amortization, Accumulated Impairment and Amortization	(18)	(13)
Intangible assets subject to amortization, Net	$ 30	$ 31

Borrowings - Company's Borrowin

Borrowings - Company's Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Short-term borrowings	$ 4,771	$ 2,334
Long-term borrowings	105,012	112,368
Total	109,783	114,702
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,327	716
FFELP Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,536
Long-term borrowings	8,400
Private Education Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	684	464
Total Before Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Short-term borrowings	4,750	2,335
Long-term borrowings	105,018	113,119
Total	109,768	115,454
Total Before Hedge Accounting Adjustments [Member] \| Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,306	717
Long-term borrowings	12,624	13,029
Total	13,930	13,746
Total Before Hedge Accounting Adjustments [Member] \| Total Unsecured Borrowings [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,306	717
Long-term borrowings	12,624	13,029
Total	13,930	13,746
Total Before Hedge Accounting Adjustments [Member] \| FFELP Loan Securitizations [Member]
Debt Instrument [Line Items]
Long-term borrowings	71,208	73,522
Total	71,208	73,522
Total Before Hedge Accounting Adjustments [Member] \| Private Education Loan Securitizations [Member]
Debt Instrument [Line Items]
Short-term borrowings	686	548
Long-term borrowings	12,646	14,125
Total	13,332	14,673
Total Before Hedge Accounting Adjustments [Member] \| FFELP Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	1,536
Long-term borrowings	6,830	12,443
Total	8,366	12,443
Total Before Hedge Accounting Adjustments [Member] \| Private Education Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Short-term borrowings	684	464
Long-term borrowings	1,710
Total	2,394	464
Total Before Hedge Accounting Adjustments [Member] \| Other [Member]
Debt Instrument [Line Items]
Short-term borrowings	538	606
Total	538	606
Total Before Hedge Accounting Adjustments [Member] \| Secured Borrowings [Member]
Debt Instrument [Line Items]
Short-term borrowings	3,444	1,618
Long-term borrowings	92,394	100,090
Total	95,838	101,708
Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Short-term borrowings	21	(1)
Long-term borrowings	(6)	(751)
Total	$ 15	$ (752)

Borrowings - Company's Borrow58

Borrowings - Company's Borrowings (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt	$ 105,012	$ 112,368
Short-term Debt	4,771	2,334
Private Education Loan Securitizations Repurchase Facilities [Member]
Debt Instrument [Line Items]
Short-term Debt	686	548
Total Before Hedge Accounting Adjustments [Member]
Debt Instrument [Line Items]
Long-term debt	105,018	113,119
Short-term Debt	4,750	2,335
Total Before Hedge Accounting Adjustments [Member] \| Private Education Loan Securitizations Repurchase Facilities [Member]
Debt Instrument [Line Items]
Long-term debt	1,300	475
Short-term Debt	686	548
Total Before Hedge Accounting Adjustments [Member] \| Other [Member]
Debt Instrument [Line Items]
Short-term Debt	538	606
Securities re-pledged subject to an overnight repurchase transaction	0	193
Total Before Hedge Accounting Adjustments [Member] \| Short Term Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt principal amount	1,300	719
Total Before Hedge Accounting Adjustments [Member] \| Long Term Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt principal amount	$ 12,700	$ 13,100

Borrowings - Outstanding Short-

Borrowings - Outstanding Short-Term Borrowings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 4,771	$ 2,334
Weighted Average Interest Rate	4.16%	2.82%
Short-term borrowings, Average Balance	$ 3,194	$ 2,092
Weighted Average Interest Rate, Average Balance	4.22%	3.03%
Maximum outstanding at any month end	$ 4,771	$ 2,637
Private Education Loan Securitizations Repurchase Facilities [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 686	$ 548
Weighted Average Interest Rate	4.65%	3.72%
Short-term borrowings, Average Balance	$ 706	$ 42
Weighted Average Interest Rate, Average Balance	4.32%	3.81%
FFELP Loan - Other Facilities [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 1,536
Weighted Average Interest Rate	2.11%
Short-term borrowings, Average Balance	$ 261
Weighted Average Interest Rate, Average Balance	1.26%
Private Education Loan - Other Facilities [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 684	$ 464
Weighted Average Interest Rate	2.92%	2.02%
Short-term borrowings, Average Balance	$ 572	$ 389
Weighted Average Interest Rate, Average Balance	2.42%	1.83%
Senior Unsecured Debt [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 1,327	$ 716
Weighted Average Interest Rate	8.06%	4.22%
Short-term borrowings, Average Balance	$ 1,197	$ 1,032
Weighted Average Interest Rate, Average Balance	6.80%	5.01%
Other Interest Bearing Liabilities [Member]
Short-term Debt [Line Items]
Short-term borrowings, Ending Balance	$ 538	$ 606
Weighted Average Interest Rate	1.33%	0.96%
Short-term borrowings, Average Balance	$ 458	$ 629
Weighted Average Interest Rate, Average Balance	1.27%	0.48%

Borrowings - Long-Term Borrowin

Borrowings - Long-Term Borrowings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term borrowings	$ 105,012	$ 112,368
Weighted Average Interest Rate	2.67%	2.14%
Long-term borrowings, Average Balance	$ 109,088	$ 118,973
U.S Dollar Denominated Interest Bearing, Due 2018-2083 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 83,209
Weighted Average Interest Rate	2.31%
Long-term borrowings, Average Balance	$ 86,186
Non-U. S Dollar-Denominated Interest Bearing, Due 2023-2041 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 6,423	$ 7,265
Weighted Average Interest Rate	0.37%	0.28%
Long-term borrowings, Average Balance	$ 7,355	$ 8,761
Floating Rate Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 89,632	$ 95,840
Weighted Average Interest Rate	2.17%	1.54%
Long-term borrowings, Average Balance	$ 93,541	$ 102,642
U.S Dollar Denominated Interest Bearing, Due 2019-2058 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 15,114
Weighted Average Interest Rate	5.60%
Long-term borrowings, Average Balance	$ 15,266
Non-U. S Dollar Denominated Interest Bearing, Due 2034-2035 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 266	$ 257
Weighted Average Interest Rate	2.72%	2.82%
Long-term borrowings, Average Balance	$ 281	$ 281
Fixed Rate Notes [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 15,380	$ 16,528
Weighted Average Interest Rate	5.55%	5.60%
Long-term borrowings, Average Balance	$ 15,547	$ 16,331
U.S Dollar Denominated Interest Bearing, Due 2017-2083 [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 88,575
Weighted Average Interest Rate		1.65%
Long-term borrowings, Average Balance		$ 93,881
U.S Dollar Denominated Interest Bearing, Due 2018-2058 [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 16,271
Weighted Average Interest Rate		5.65%
Long-term borrowings, Average Balance		$ 16,050

Borrowings - Expected Maturitie

Borrowings - Expected Maturities of Long-term Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
2,018	$ 11,900
2,019	12,700
2,020	11,200
2,021	9,000
2,022	8,100
2023-2039	53,000
Total	105,012	$ 112,368
Fixed Maturities [Member]
Debt Instrument [Line Items]
2,018	11,810
2,019	12,645
2,020	11,117
2,021	8,905
2,022	8,057
2023-2039	52,484
Long term debt maturities total	105,018
Hedge accounting adjustments	(6)
Total	105,012
Fixed Maturities [Member] \| Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
2,019	2,369
2,020	2,041
2,021	1,428
2,022	1,731
2023-2039	5,055
Long term debt maturities total	12,624
Hedge accounting adjustments	240
Total	12,864
Fixed Maturities [Member] \| Secured Borrowings [Member]
Debt Instrument [Line Items]
2,018	11,810
2,019	10,276
2,020	9,076
2,021	7,477
2,022	6,326
2023-2039	47,429
Long term debt maturities total	92,394
Hedge accounting adjustments	(246)
Total	$ 92,148

Borrowings - Expected Maturit62

Borrowings - Expected Maturities of Long-term Borrowings (Parenthetical) (Detail) $ in Billions	Dec. 31, 2017USD ($)
Disclosure - Borrowings - Expected Maturities of Long-term Borrowings (Parenthetical) (Detail) [Line Items]
On-balance sheet securitization trust debt included in projected principal paydowns in 2018	$ 11.8
Aggregate principal amount of debt maturing in 2018	11.9
Aggregate principal amount of debt maturing in 2019	12.7
Aggregate principal amount of debt maturing in 2020	11.2
Aggregate principal amount of debt maturing in 2021	9
Aggregate principal amount of debt maturing in 2022	8.1
Aggregate principal amount of debt maturing in 2023-2039	$ 53

Borrowings - Financing VIEs (De

Borrowings - Financing VIEs (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Securities Financing Transaction [Line Items]
Short-term borrowings	$ 4,771	$ 2,334
Long-term borrowings	105,012	112,368
Total	109,783	114,702
Loans	105,122	111,070
Total Before Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	4,750	2,335
Long-term borrowings	105,018	113,119
Total	109,768	115,454
Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	21	(1)
Long-term borrowings	(6)	(751)
Total	15	(752)
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	2,906	1,078
Long-term borrowings	89,317	95,492
Total	92,223	96,570
Loans	98,596	104,008
Cash	3,091	3,434
Other assets, Net	1,160	(11)
Total Carrying Amount of Assets Securing Debt Outstanding	102,847	107,431
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| FFELP Loan Securitizations [Member]
Securities Financing Transaction [Line Items]
Long-term borrowings	71,208	73,522
Total	71,208	73,522
Loans	72,145	74,197
Cash	2,335	2,676
Other assets, Net	1,078	778
Total Carrying Amount of Assets Securing Debt Outstanding	75,558	77,651
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Private Education Loan Securitizations [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	686	548
Long-term borrowings	12,646	14,125
Total	13,332	14,673
Loans	17,739	19,815
Cash	484	455
Other assets, Net	237	260
Total Carrying Amount of Assets Securing Debt Outstanding	18,460	20,530
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	3,999	9,046
Total	5,535	9,046
Loans	5,565	9,232
Cash	204	289
Other assets, Net	156	172
Total Carrying Amount of Assets Securing Debt Outstanding	5,925	9,693
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Private Education Loan - Other Facilities [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	684	464
Long-term borrowings	1,710
Total	2,394	464
Loans	3,147	685
Cash	68	10
Other assets, Net	31	14
Total Carrying Amount of Assets Securing Debt Outstanding	3,246	709
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Total Before Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings	2,906	1,078
Long-term borrowings	89,563	96,693
Total	92,469	97,771
Loans	98,596	104,008
Cash	3,091	3,434
Other assets, Net	1,502	1,224
Total Carrying Amount of Assets Securing Debt Outstanding	103,189	108,666
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Hedge Accounting Adjustments [Member]
Securities Financing Transaction [Line Items]
Long-term borrowings	(246)	(1,201)
Total	(246)	(1,201)
Other assets, Net	(342)	(1,235)
Total Carrying Amount of Assets Securing Debt Outstanding	$ (342)	(1,235)
Assets and Liabilities of Consolidated Variable Interest Entities [Member] \| Other [Member]
Securities Financing Transaction [Line Items]
Short-term borrowings		66
Total		66
Loans		79
Cash		4
Total Carrying Amount of Assets Securing Debt Outstanding		$ 83

Borrowings - Financing VIEs (Pa

Borrowings - Financing VIEs (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Securities Financing Transaction [Line Items]
Long-term debt	$ 105,012	$ 112,368
Short-term Debt	4,771	2,334
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Long-term debt	89,317	95,492
Short-term Debt	2,906	1,078
Restricted cash	3,091	3,434
Private Education Loan Securitizations Repurchase Facilities [Member]
Securities Financing Transaction [Line Items]
Short-term Debt	686	548
Private Education Loan Securitizations Repurchase Facilities [Member] \| Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Securities Financing Transaction [Line Items]
Long-term debt	1,300	475
Short-term Debt	686	548
Restricted cash	$ 96	$ 49

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) - USD ($)	12 Months Ended
Borrowings - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Outstanding borrowings under facility	$ 105,012,000,000	$ 112,368,000,000
Issuance of unsecured debt	$ 1,600,000,000	$ 1,300,000,000	$ 500,000,000
Private Education Loan Securitizations [Member] \| Asset-backed Securities, Securitized Loans and Receivables [Member]
Debt Instrument [Line Items]
Amount of asset-backed securitization repurchase facility			$ 2,500,000,000
Private Education Refinance Loan [Member] \| Private Education Loan Abcp Borrowings [Member]
Debt Instrument [Line Items]
Facility maturity date	2018-10
Maximum unused capacity	$ 328,000,000
Maximum borrowing capacity	750,000,000
FFELP Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Outstanding borrowings under facility	8,400,000,000
Assets securing facility	9,400,000,000
Maximum unused capacity	2,400,000,000
Unencumbered Loans	700,000,000
Private Education Loan Abcp Borrowings [Member]
Debt Instrument [Line Items]
Outstanding borrowings under facility	2,400,000,000
Assets securing facility	3,100,000,000
Maximum unused capacity	925,000,000
Unencumbered Loans	$ 2,500,000,000
Minimum [Member] \| FFELP Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Facility maturity date	2018-11
Minimum [Member] \| Private Education Loan Abcp Borrowings [Member]
Debt Instrument [Line Items]
Facility maturity date	2018-06
Maximum [Member] \| FFELP Loan - Other Facilities [Member]
Debt Instrument [Line Items]
Facility maturity date	2021-01
Maximum [Member] \| Private Education Loan Abcp Borrowings [Member]
Debt Instrument [Line Items]
Facility maturity date	2020-06

Borrowings - Gains (Losses) on

Borrowings - Gains (Losses) on Debt Repurchases (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure - Borrowings - Gains (Losses) on Debt Repurchases (Detail) [Line Items]
Debt principal repurchased	$ 513	$ 1,467	$ 1,744
Gains (losses) on debt repurchases	$ (3)	$ 1	$ 21

Derivative Financial Instrume67

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Net positive exposure related to corporate derivatives	$ 24,000,000	$ 110,000,000
Euro and British Pound Sterling denominated bonds outstanding in securitization trusts	6,700,000,000
Notional of interest rate swaps entered into by the trusts to swap Prime to LIBOR	137,900,000,000	80,700,000,000
Net positive exposure on foreign currency swaps	64,000,000	9,000,000
Decrease in valuation due to net credit risk adjustments	6,000,000	0
Decrease in valuation due to liquidity adjustments	30,000,000	31,000,000
Derivative liability at fair value including accrued interest and premium receivable	659,000,000	1,670,000,000
Counterparty [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liability at fair value including accrued interest and premium receivable	217,000,000
Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional of interest rate swaps entered into by the trusts to swap Prime to LIBOR	108,500,000,000	$ 50,800,000,000
Interest Rate Swaps [Member] \| Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional of interest rate swaps entered into by the trusts to swap Prime to LIBOR	$ 7,800,000,000

Derivative Financial Instrume68

Derivative Financial Instruments - Impact of Derivatives on Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative Assets:
Derivative assets	$ 480	$ 565
Derivative Liabilities:
Derivative liabilities	(735)	(1,701)
Net total derivatives	(255)	(1,136)
Designated as Hedging Instrument [Member] \| Cash Flow [Member]
Derivative Assets:
Derivative assets	95	78
Derivative Liabilities:
Derivative liabilities	(16)	(76)
Net total derivatives	79	2
Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative Assets:
Derivative assets	378	465
Derivative Liabilities:
Derivative liabilities	(512)	(1,305)
Net total derivatives	(134)	(840)
Trading [Member]
Derivative Assets:
Derivative assets	7	22
Derivative Liabilities:
Derivative liabilities	(207)	(320)
Net total derivatives	(200)	(298)
Interest Rate Swaps [Member]
Derivative Assets:
Derivative assets	392	565
Derivative Liabilities:
Derivative liabilities	(189)	(208)
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow [Member]
Derivative Assets:
Derivative assets	95	78
Derivative Liabilities:
Derivative liabilities	(16)	(76)
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative Assets:
Derivative assets	290	465
Derivative Liabilities:
Derivative liabilities	(102)	(62)
Interest Rate Swaps [Member] \| Trading [Member]
Derivative Assets:
Derivative assets	7	22
Derivative Liabilities:
Derivative liabilities	(71)	(70)
Cross-Currency Interest Rate Swaps [Member]
Derivative Assets:
Derivative assets	88
Derivative Liabilities:
Derivative liabilities	(454)	(1,296)
Cross-Currency Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative Assets:
Derivative assets	88
Derivative Liabilities:
Derivative liabilities	(410)	(1,243)
Cross-Currency Interest Rate Swaps [Member] \| Trading [Member]
Derivative Liabilities:
Derivative liabilities	(44)	(53)
Floor Income Contracts [Member]
Derivative Liabilities:
Derivative liabilities	(74)	(184)
Floor Income Contracts [Member] \| Trading [Member]
Derivative Liabilities:
Derivative liabilities	(74)	(184)
Other [Member]
Derivative Liabilities:
Derivative liabilities	(18)	(13)
Other [Member] \| Trading [Member]
Derivative Liabilities:
Derivative liabilities	$ (18)	$ (13)

Derivative Financial Instrume69

Derivative Financial Instruments - Gross Positions without Impact of Master Netting Agreements (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Derivative assets	$ 480	$ 565
Derivative values with impact of master netting agreements (as carried on balance sheet), Assets	438	534
Cash collateral (held) pledged, Assets	(536)	(345)
Derivative liabilities	(735)	(1,701)
Cash collateral (held) pledged, Liabilities	235	319
Other Assets [Member]
Derivatives Fair Value [Line Items]
Derivative assets	480	565
Impact of master netting agreements, Assets	(42)	(31)
Derivative values with impact of master netting agreements (as carried on balance sheet), Assets	438	534
Cash collateral (held) pledged, Assets	(536)	(345)
Net position, Assets	(98)	189
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivative liabilities	(735)	(1,701)
Impact of master netting agreements, Liabilities	42	31
Derivative values with impact of master netting agreements (as carried on balance sheet), Liabilities	(693)	(1,670)
Cash collateral (held) pledged, Liabilities	235	319
Net position, Liabilities	$ (458)	$ (1,351)

Derivative Financial Instrume70

Derivative Financial Instruments - Derivative Notional Values (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Total Derivative Notional Values	$ 137,900,000,000	$ 80,700,000,000
Designated as Hedging Instrument [Member] \| Cash Flow [Member]
Derivative [Line Items]
Total Derivative Notional Values	24,100,000,000	15,200,000,000
Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	19,100,000,000	20,300,000,000
Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	94,700,000,000	45,200,000,000
Interest Rate Swaps [Member]
Derivative [Line Items]
Total Derivative Notional Values	108,500,000,000	50,800,000,000
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow [Member]
Derivative [Line Items]
Total Derivative Notional Values	24,100,000,000	15,200,000,000
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	12,400,000,000	11,800,000,000
Interest Rate Swaps [Member] \| Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	72,000,000,000	23,800,000,000
Floor Income Contracts [Member]
Derivative [Line Items]
Total Derivative Notional Values	21,900,000,000	18,500,000,000
Floor Income Contracts [Member] \| Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	21,900,000,000	18,500,000,000
Cross-Currency Interest Rate Swaps [Member]
Derivative [Line Items]
Total Derivative Notional Values	7,000,000,000	8,800,000,000
Cross-Currency Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative [Line Items]
Total Derivative Notional Values	6,700,000,000	8,500,000,000
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	500,000,000	2,600,000,000
Other [Member] \| Trading [Member]
Derivative [Line Items]
Total Derivative Notional Values	$ 500,000,000	$ 2,600,000,000

Derivative Financial Instrume71

Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Income (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									$ 844	$ (324)	$ (280)
Realized Gain (Loss) on Derivatives									(53)	(88)	(277)
Unrealized Gain (Loss) on Hedged Item									(761)	652	1,061
Total Gain (Loss) on Derivatives, Gross									30	240	504
Realized Gain (Loss) on Derivatives, Net									(61)	(211)	(615)
Total Gain (Loss) On Derivatives, Net	$ 38	$ 25	$ (25)	$ (16)	$ 6	$ 137	$ (28)	$ 1	22	117	166
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain (Loss) on Derivatives									8	123	338
Less: realized gains (losses) recorded in interest expense									8	123	338
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									(761)	652	1,061
Designated as Hedging Instrument [Member] \| Fair Value [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									707	(607)	(909)
Realized Gain (Loss) on Derivatives									57	173	338
Unrealized Gain (Loss) on Hedged Item									(761)	652	1,061
Total Gain (Loss) on Derivatives, Gross									3	218	490
Designated as Hedging Instrument [Member] \| Fair Value [Member] \| Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									(214)	(288)	(115)
Realized Gain (Loss) on Derivatives									175	259	345
Unrealized Gain (Loss) on Hedged Item									193	302	140
Total Gain (Loss) on Derivatives, Gross									154	273	370
Designated as Hedging Instrument [Member] \| Fair Value [Member] \| Cross-Currency Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									921	(319)	(794)
Realized Gain (Loss) on Derivatives									(118)	(86)	(7)
Unrealized Gain (Loss) on Hedged Item									(954)	350	921
Total Gain (Loss) on Derivatives, Gross									(151)	(55)	120
Designated as Hedging Instrument [Member] \| Cash Flow [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain (Loss) on Derivatives									(49)	(50)
Total Gain (Loss) on Derivatives, Gross									(49)	(50)
Designated as Hedging Instrument [Member] \| Cash Flow [Member] \| Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain (Loss) on Derivatives									(49)	(50)
Total Gain (Loss) on Derivatives, Gross									(49)	(50)
Trading [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									137	283	629
Realized Gain (Loss) on Derivatives									(61)	(211)	(615)
Total Gain (Loss) on Derivatives, Gross									76	72	14
Unrealized Gain (Loss) on Derivatives, Net									844	(324)	(280)
Trading [Member] \| Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									(16)	(13)	61
Realized Gain (Loss) on Derivatives									24	42	42
Total Gain (Loss) on Derivatives, Gross									8	29	103
Trading [Member] \| Cross-Currency Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									8	9	2
Realized Gain (Loss) on Derivatives									(6)	(4)	(4)
Total Gain (Loss) on Derivatives, Gross									2	5	(2)
Trading [Member] \| Floor Income Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									150	297	557
Realized Gain (Loss) on Derivatives									(69)	(246)	(650)
Total Gain (Loss) on Derivatives, Gross									81	51	(93)
Trading [Member] \| Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives									(5)	(10)	9
Realized Gain (Loss) on Derivatives									(10)	(3)	(3)
Total Gain (Loss) on Derivatives, Gross									$ (15)	$ (13)	$ 6

Derivative Financial Instrume72

Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Changes in Stockholders' Equity (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) on cash flow hedges	$ 25	$ 26	$ (59)
Total change in stockholders’ equity for unrealized gains (losses) on derivatives	55	57	(60)
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized (gains) losses recognized in interest expense	$ 30	$ 31	$ (1)

Derivative Financial Instrume73

Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Disclosure - Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (Detail) [Line Items]
Amount of after-tax net losses to be reclassified from accumulated other comprehensive income to earnings in the next 12 months	$ 2

Derivative Financial Instrume74

Derivative Financial Instruments - Collateral Held and Pledged (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Collateral held:
Cash (obligation to return cash collateral is recorded in short-term borrowings)	$ 536	$ 345
Securities at fair value — corporate derivatives (not recorded in financial statements)		193
Securities at fair value — on-balance sheet securitization derivatives (not recorded in financial statements)	297	230
Total collateral held	833	768
Derivative asset at fair value including accrued interest	618	689
Collateral pledged to others:
Cash (right to receive return of cash collateral is recorded in investments)	235	319
Total collateral pledged	235	319
Derivative liability at fair value including accrued interest and premium receivable	$ 659	$ 1,670

Other Assets - Schedule of Othe

Other Assets - Schedule of Other Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure - Other Assets - Schedule of Other Assets (Detail) [Line Items]
Accrued interest receivable, net	$ 1,965	$ 1,663
Benefit and insurance-related investments	481	488
Derivatives at fair value	438	534
Income tax asset, net current and deferred	380	725
Fixed assets, net	156	160
Accounts receivable	108	95
Other loans, net	59	148
Other	438	380
Total	$ 4,025	$ 4,193

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class Of Stock [Line Items]
Common stock, shares authorized	1,125,000,000	1,125,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares issued	440,000,000	436,000,000
Common shares unissued but encumbered	28,000,000
Common stock dividend paid	$ 0.64	$ 0.64	$ 0.64
Purchase price of common stock repurchased on open market	$ 440,000,000	$ 755,000,000	$ 945,000,000
Authorized share repurchased program amount		$ 600,000,000
Authorized share repurchased program remaining available amount	$ 160,000,000
Common Stock [Member]
Class Of Stock [Line Items]
Closing price of common stock	$ 13.32
Common Stock Shares Outstanding [Member]
Class Of Stock [Line Items]
Common stock, shares issued	263,000,000
Common shares repurchased	29,646,374	59,625,325	56,043,711

Stockholders' Equity - Common S

Stockholders' Equity - Common Share Repurchases and Issuances (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity, Class of Treasury Stock [Line Items]
Average purchase price per share	$ 14.85	$ 12.68	$ 16.87
Shares repurchased related to employee stock-based compensation plans	1,847,651	3,197,355	2,404,328
Average purchase price per share	$ 15.40	$ 13.21	$ 19.81
Common shares issued	3,680,479	5,476,010	4,924,021
Common Stock Shares Outstanding [Member]
Equity, Class of Treasury Stock [Line Items]
Common shares repurchased	29,646,374	59,625,325	56,043,711
Shares repurchased related to employee stock-based compensation plans	1,847,651	3,197,355	2,404,328
Common shares issued	3,680,479	5,476,010	4,924,021

Earnings (Loss) per Common Sh78

Earnings (Loss) per Common Share - Schedule of Earnings per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Net income attributable to Navient Corporation	$ (84)	$ 176	$ 112	$ 88	$ 145	$ 230	$ 125	$ 181	$ 292	$ 681	$ 984
Denominator:
Weighted average shares used to compute basic EPS									275	316	376
Effect of dilutive securities:
Dilutive effect of stock options, restricted stock, restricted stock units, performance stock units and Employee Stock Purchase Plan (“ESPP”)									6	6	6
Dilutive potential common shares									6	6	6
Weighted average shares used to compute diluted EPS									281	322	382
Basic earnings per common share attributable to Navient Corporation	$ (0.32)	$ 0.65	$ 0.40	$ 0.31	$ 0.49	$ 0.74	$ 0.39	$ 0.53	$ 1.06	$ 2.15	$ 2.62
Diluted earnings per common share attributable to Navient Corporation	$ (0.32)	$ 0.64	$ 0.39	$ 0.30	$ 0.48	$ 0.73	$ 0.38	$ 0.53	$ 1.04	$ 2.12	$ 2.58

Earnings (Loss) per Common Sh79

Earnings (Loss) per Common Share - Schedule of Earnings per Common Share (Parenthetical) (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock awards not included in the computation of diluted earnings per share	5	4	6

Stock-Based Compensation Plan80

Stock-Based Compensation Plans and Arrangements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 35	$ 26	$ 29
Unrecognized compensation cost	$ 17
Weighted average period for total unrecognized compensation cost	1 year 4 months 24 days
Time Vested Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	Most stock options are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date.
Restricted Stock Units, RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	RSUs generally are time-vested, with one-third vesting per year beginning with the first anniversary of the grant date
Performance Stock Units, PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	PSUs vest based on achieving certain corporate performance goals over a three-year performance period
Navient Corporation 2014 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effective date	Apr. 7, 2014
Shares authorized to be issued under plan	55,000,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effective date	May 1, 2014
Shares authorized to be issued under plan	1,000,000
Grants Made since 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term for stock options (in years)	5 years
Grants Made Prior to 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term for stock options (in years)	10 years

Stock-Based Compensation Plan81

Stock-Based Compensation Plans and Arrangements - Black-Scholes Model Assumptions for Calculating Stock Option and ESPP Fair Values (Detail) - Employee Stock Option [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of the option	3 years	3 years	2 years 10 months 24 days
Expected volatility	34.00%	30.00%	22.00%
Risk-free interest rate	1.44%	0.90%	0.95%
Expected dividend rate	4.13%	6.97%	2.99%
Weighted average fair value of options granted and stock purchase rights	$ 2.69	$ 1.01	$ 2.22

Stock-Based Compensation Plan82

Stock-Based Compensation Plans and Arrangements - Stock Option Activity (Detail) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Disclosure - Stock-Based Compensation Plans and Arrangements - Stock Option Activity (Detail) [Line Items]
Number of Options, Outstanding, beginning balance \| shares	14,912,004
Granted, Options \| shares	1,308,167
Exercised, Options \| shares	(1,497,807)
Canceled, Options \| shares	(538,638)
Number of Options, Outstanding, ending balance \| shares	14,183,726
Number of Options, Exercisable, ending balance \| shares	9,653,511
Weighted Average Exercise Price per Share, Outstanding, beginning balance \| $ / shares	$ 12.45
Granted, Weighted Average Exercise Price per Share \| $ / shares	15.48
Exercised, Weighted Average Exercise Price per Share \| $ / shares	9.57
Canceled, Weighted Average Exercise Price per Share \| $ / shares	27.16
Weighted Average Exercise Price per Share, Outstanding, ending balance \| $ / shares	12.48
Weighted Average Exercise Price per Share, Exercisable, ending balance \| $ / shares	$ 12.34
Weighted Average Remaining Contractual Term, Outstanding, ending balance	1 year 10 months 25 days
Weighted Average Remaining Contractual Term, Exercisable, ending balance	1 year 3 months 19 days
Aggregate Intrinsic Value, Outstanding, ending balance \| $	$ 37
Aggregate Intrinsic Value, Exercisable, ending balance \| $	$ 26

Stock-Based Compensation Plan83

Stock-Based Compensation Plans and Arrangements - Stock Option Activity (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 17
Weighted average period for total unrecognized compensation cost	1 year 4 months 24 days
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised	$ 9	$ 13	$ 19
Unrecognized compensation cost	$ 1
Weighted average period for total unrecognized compensation cost	1 year 9 months 18 days

Stock-Based Compensation Plan84

Stock-Based Compensation Plans and Arrangements - Restricted Stock and Performance Stock Unit Activity (Detail)	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Restricted Stock Units and Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Non-vested, beginning balance \| shares	4,372,376
Granted, Shares \| shares	1,817,218
Vested, Shares \| shares	(1,724,568)
Canceled, Shares \| shares	(36,721)
Number of Shares, Non-vested, ending balance \| shares	4,428,305
Weighted Average Grant Date Fair Value, Non-vested, beginning balance \| $ / shares	$ 12.56
Granted, Weighted Average Grant Date Fair Value \| $ / shares	15.41
Vested, Weighted Average Grant Date Fair Value \| $ / shares	13.58
Canceled, Weighted Average Grant Date Fair Value \| $ / shares	12.95
Weighted Average Grant Date Fair Value, Non-vested, ending balance \| $ / shares	$ 13.33
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Shares \| shares	59,124
Vested, Shares \| shares	(50,727)
Canceled, Shares \| shares	(8,397)
Granted, Weighted Average Grant Date Fair Value \| $ / shares	$ 15.39
Vested, Weighted Average Grant Date Fair Value \| $ / shares	15.37
Canceled, Weighted Average Grant Date Fair Value \| $ / shares	$ 15.48

Stock-Based Compensation Plan85

Stock-Based Compensation Plans and Arrangements - Restricted Stock and Performance Stock Unit Activity (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 17
Weighted average period for total unrecognized compensation cost	1 year 4 months 24 days
Restricted Stock Units and Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of restricted stock that vested	$ 23	$ 30	$ 29
Unrecognized compensation cost	$ 16
Weighted average period for total unrecognized compensation cost	1 year 4 months 24 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of restricted stock that vested	$ 1	$ 1	$ 1
Unrecognized compensation cost	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure - Fair Value Measurements - Additional Information (Detail) [Line Items]
Maximum remaining term for investment purchased for estimating at cost	90 days
Decrease in valuation due to net credit risk adjustments	$ 6	$ 0
Decrease in valuation due to liquidity adjustments	$ 30	$ 31

Fair Value Measurements - Valua

Fair Value Measurements - Valuation of Financial Instruments that are Marked-to-Market on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale investments:
Available-for-sale investments	$ 2	$ 3
Derivative assets	480	565
Derivative liabilities	(735)	(1,701)
Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	392	565
Derivative liabilities	(189)	(208)
Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	88
Derivative liabilities	(454)	(1,296)
Floor Income Contracts [Member]
Available-for-sale investments:
Derivative liabilities	(74)	(184)
Other [Member]
Available-for-sale investments:
Derivative liabilities	(18)	(13)
Fair Value Measurements Recurring [Member]
Available-for-sale investments:
Available-for-sale investments	2	3
Derivative assets	480	565
Total	482	568
Derivative liabilities	(735)	(1,701)
Total	(735)	(1,701)
Fair Value Measurements Recurring [Member] \| Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	392	565
Derivative liabilities	(189)	(208)
Fair Value Measurements Recurring [Member] \| Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	88
Derivative liabilities	(454)	(1,296)
Fair Value Measurements Recurring [Member] \| Floor Income Contracts [Member]
Available-for-sale investments:
Derivative liabilities	(74)	(184)
Fair Value Measurements Recurring [Member] \| Other [Member]
Available-for-sale investments:
Derivative liabilities	(18)	(13)
Fair Value Measurements Recurring [Member] \| Agency Residential Mortgage-Backed Securities [Member]
Available-for-sale investments:
Available-for-sale investments		1
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	3
Derivative assets	388	553
Total	390	556
Derivative liabilities	(262)	(387)
Total	(262)	(387)
Fair Value Measurements Recurring [Member] \| Level 2 [Member] \| Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	388	553
Derivative liabilities	(144)	(150)
Fair Value Measurements Recurring [Member] \| Level 2 [Member] \| Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative liabilities	(44)	(53)
Fair Value Measurements Recurring [Member] \| Level 2 [Member] \| Floor Income Contracts [Member]
Available-for-sale investments:
Derivative liabilities	(74)	(184)
Fair Value Measurements Recurring [Member] \| Level 2 [Member] \| Agency Residential Mortgage-Backed Securities [Member]
Available-for-sale investments:
Available-for-sale investments		1
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	92	12
Total	92	12
Derivative liabilities	(473)	(1,314)
Total	(473)	(1,314)
Fair Value Measurements Recurring [Member] \| Level 3 [Member] \| Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	4	12
Derivative liabilities	(45)	(58)
Fair Value Measurements Recurring [Member] \| Level 3 [Member] \| Cross-Currency Interest Rate Swaps [Member]
Available-for-sale investments:
Derivative assets	88
Derivative liabilities	(410)	(1,243)
Fair Value Measurements Recurring [Member] \| Level 3 [Member] \| Other [Member]
Available-for-sale investments:
Derivative liabilities	$ (18)	$ (13)

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	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ (1,302)	$ (949)	$ (216)
Total gains/(losses) (realized and unrealized):
Included in earnings	788	(439)	(751)
Included in other comprehensive income	0	0	0
Settlements	133	94	18
Transfers in and/or out of level 3	0	(8)	0
Balance, end of period	(381)	(1,302)	(949)
Change in unrealized gains/(losses) relating to instruments still held at the reporting date	795	(344)	(737)
Interest Rate Swaps [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	(46)	(44)	(88)
Total gains/(losses) (realized and unrealized):
Included in earnings		3	39
Included in other comprehensive income	0	0	0
Settlements	5	3	5
Transfers in and/or out of level 3	0	(8)	0
Balance, end of period	(41)	(46)	(44)
Change in unrealized gains/(losses) relating to instruments still held at the reporting date	5	7	37
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	(1,243)	(903)	(117)
Total gains/(losses) (realized and unrealized):
Included in earnings	803	(428)	(796)
Included in other comprehensive income	0	0	0
Settlements	118	88	10
Transfers in and/or out of level 3	0		0
Balance, end of period	(322)	(1,243)	(903)
Change in unrealized gains/(losses) relating to instruments still held at the reporting date	795	(340)	(783)
Other [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	(13)	(2)	(11)
Total gains/(losses) (realized and unrealized):
Included in earnings	(15)	(14)	6
Included in other comprehensive income	0	0	0
Settlements	10	3	3
Transfers in and/or out of level 3	0		0
Balance, end of period	(18)	(13)	(2)
Change in unrealized gains/(losses) relating to instruments still held at the reporting date	$ (5)	$ (11)	$ 9

Fair Value Measurements - Inclu

Fair Value Measurements - Included in Earnings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gains (losses) on derivative and hedging activities, net	$ 788	$ (439)	$ (751)
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	906	(351)	(741)
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	$ (118)	$ (88)	$ (10)

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Data Used in Recurring Valuations of Level 3 (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Interest Rate Swaps [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	$ 203	$ 357
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	(366)	(1,296)
Other [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	(18)	$ (13)
Level 3 [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, Fair Value	(381)
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	$ (322)
Discounted cash flow	Discounted Cash Flow, Constant Prepayment Rate
Constant prepayment rate	4.00%
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	$ (18)
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	$ (41)
Discounted cash flow	Discounted Cash Flow, Constant Prepayment Rate
Constant prepayment rate	6.00%
Level 3 [Member] \| Prime/LIBOR Basis Swaps [Member] \| Interest Rate Swaps [Member] \| Minimum [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Bid/ask adjustment to discount rate	0.08%
Level 3 [Member] \| Prime/LIBOR Basis Swaps [Member] \| Interest Rate Swaps [Member] \| Maximum [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Bid/ask adjustment to discount rate	0.08%
Level 3 [Member] \| Prime/LIBOR Basis Swaps [Member] \| Interest Rate Swaps [Member] \| Weighted Average [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Bid/ask adjustment to discount rate	0.08%

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	$ 105,122	$ 111,070
Total earning assets, Carrying Value	110,156	116,273
Short-term borrowings, Carrying Value	4,771	2,334
Long-term borrowings, Carrying Value	105,012	112,368
Total interest-bearing liabilities, Carrying Value	109,783	114,702
Total earning assets, Fair Value	111,726	115,020
Short-term borrowings, Fair Value	4,783	2,346
Long-term borrowings, Fair Value	104,921	109,826
Total interest-bearing liabilities, Fair Value	109,704	112,172
FFELP Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	81,703	87,730
Loans receivable, Fair Value	82,271	86,626
Floor Income Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(74)	(184)
Derivative financial instruments, Fair Value	(74)	(184)
Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	203	357
Derivative financial instruments, Fair Value	203	357
Cross-Currency Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(366)	(1,296)
Derivative financial instruments, Fair Value	(366)	(1,296)
Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial instruments, Carrying Value	(18)	(13)
Derivative financial instruments, Fair Value	(18)	(13)
Private Education Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, Carrying Value	23,419	23,340
Loans receivable, Fair Value	24,421	23,191
Difference [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Excess of net asset fair value over carrying value	1,649	1,277
Total earning assets, Fair Value	1,570	(1,253)
Short-term borrowings, Fair Value	(12)	(12)
Long-term borrowings, Fair Value	91	2,542
Total interest-bearing liabilities, Fair Value	79	2,530
Difference [Member] \| FFELP Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable, Fair Value	568	(1,104)
Difference [Member] \| Private Education Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable, Fair Value	1,002	(149)
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and investments	5,034	5,203
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and investments	$ 5,034	$ 5,203

Fair Value Measurements - Fai92

Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure - Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Parenthetical) (Detail) [Line Items]
Available-for-sale investments, cost basis	$ 2	$ 3
Available-for-sale investments, fair value	$ 2	$ 3

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2017
Loss Contingencies [Line Items]
Total reserves established during year	$ 177,000,000	$ 177,000,000
SLM BankCo [Member] \| Indemnification Matters [Member]
Loss Contingencies [Line Items]
Reserve for estimated amounts and costs incurred			$ 0

Income Taxes - Reconciliations

Income Taxes - Reconciliations of Statutory U.S. Federal Income Tax Rates to Our Effective Tax Rate for Continuing Operations (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Examination [Line Items]
Statutory rate	35.00%	35.00%	35.00%
DTA Remeasurement Loss	27.20%
Net excess tax benefits related to stock-based incentive payments	(0.70%)
State tax, net of federal benefit	0.80%	3.80%	2.60%
Other, net	(0.50%)	(0.30%)	0.10%
Effective tax rate	61.80%	38.50%	37.70%

Income Taxes - Reconciliation95

Income Taxes - Reconciliations of Statutory U.S. Federal Income Tax Rates to Our Effective Tax Rate for Continuing Operations (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Examination [Line Items]
Statutory rate	35.00%	35.00%	35.00%
DTA remeasurement loss	$ 208
Tax Year 2018 [Member]
Income Tax Examination [Line Items]
Statutory rate	21.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Statutory U.S. federal rate	35.00%	35.00%	35.00%
Valuation allowance, Operating loss and credit carryovers	$ 42	$ 7
Foreign tax credit carryforwards	2
Unrecognized tax benefits at end of year	57.4	$ 73	$ 56.3	$ 51.9
Unrecognized tax benefits recognition impact on effective tax rate	$ 45.3
Minimum [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Statute of limitation period for open tax reviews	3 years
Maximum [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Statute of limitation period for open tax reviews	4 years
State [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Valuation allowance, Operating loss and credit carryovers	$ 34
Operating loss carryforwards	$ 576
Operating loss carryforwards, expiration dates	2,021
Tax-effected NOL	$ 39
Federal [Member]
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible [Line Items]
Valuation allowance, Operating loss and credit carryovers	8
Operating loss carryforwards	$ 110
Operating loss carryforwards, expiration dates	2,029
Tax-effected NOL	$ 23

Income Taxes - Components of Pr

Income Taxes - Components of Provision for Income Tax Expense (Benefit) (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current provision/(benefit):
Federal									$ 77	$ 246	$ 136
State									(3)	47	22
Foreign									3	1
Total current provision/(benefit)									77	294	158
Deferred provision/(benefit):
Federal									385	115	398
State									11	18	41
Foreign									(1)
Total deferred provision/(benefit)									395	133	439
Provision for income tax expense/(benefit)	$ 266	$ 93	$ 60	$ 53	$ 96	$ 147	$ 81	$ 103	$ 472	$ 427	$ 597

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Loan reserves	$ 317	$ 581
Education loan premiums and discounts, net	52	74
Operating loss and credit carryovers	22	5
Stock-based compensation plans	18	32
Accrued expenses not currently deductible	24	33
Market value adjustments on education loans, investments and derivatives	9	65
Deferred revenue		37
Other	14	40
Total deferred tax assets	456	867
Deferred tax liabilities:
Unrealized derivatives and investment gains and losses, net	23	3
Original issue discount on borrowings	11	27
Debt repurchases	8
Other	22	35
Total deferred tax liabilities	64	65
Net deferred tax assets	$ 392	$ 802

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes in Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure - Income Taxes - Summary of Changes in Unrecognized Tax Benefits (Detail) [Line Items]
Unrecognized tax benefits at beginning of year	$ 73	$ 56.3	$ 51.9
Increases resulting from tax positions taken during a prior period	0.7	19.9	1.6
Decreases resulting from tax positions taken during a prior period	(1.8)	(5.6)	(1.8)
Increases resulting from tax positions taken during the current period	4.4	4.4	6.9
Decreases related to settlements with taxing authorities	(5.1)	(0.1)
Reductions related to the lapse of statute of limitations	(13.8)	(1.9)	(2.3)
Unrecognized tax benefits at end of year	$ 57.4	$ 73	$ 56.3

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017USD ($)Segment	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)AccountBorrowerClient	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of reportable operating segments \| Segment	4
Loans, net	$ 105,122		$ 105,122	$ 111,070
Servicing revenue			$ 290	304	$ 340
Number of clients for business processing services \| Client			600
Accounts receivable	108		$ 108	95
Total assets	114,991		$ 114,991	121,136
Default Aversion Service [Member]
Segment Reporting Information [Line Items]
Deferred asset recovery revenue recognized		$ 47
Minimum [Member]
Segment Reporting Information [Line Items]
Number of borrowers helped to successfully rehabilitate loans \| Borrower			261,000
Great Lakes [Member]
Segment Reporting Information [Line Items]
Servicing revenue			$ 238	172
Great Lakes [Member] \| Default Aversion Service [Member]
Segment Reporting Information [Line Items]
Deferred asset recovery revenue recognized			47
Consumer Lending Segment [Member]
Segment Reporting Information [Line Items]
Loans, net	23,419		$ 23,419	23,340
Number of years experience			40 years
Total assets	25,268		$ 25,268	25,569
Business Processing [Member]
Segment Reporting Information [Line Items]
Total assets	466		466	373
Business Processing [Member] \| Nonfederal Education Loan [Member]
Segment Reporting Information [Line Items]
Accounts receivable	11,400		11,400	10,100	9,900
Other Segment [Member]
Segment Reporting Information [Line Items]
Total assets	2,100		$ 2,100	1,900
Department of Education [Member] \| Federal Education Loans [Member]
Segment Reporting Information [Line Items]
Number of contracts under ED servicing contract \| Account			6,100,000
Loans under service contract	205,900		$ 205,900
Revenue from servicing contract			150
Earnest [Member] \| Consumer Lending Segment [Member]
Segment Reporting Information [Line Items]
Private education refinance loans originated			900
Private Education Refinance Loan [Member] \| Consumer Lending Segment [Member]
Segment Reporting Information [Line Items]
Loans, net	761		761
Private Education Loans [Member]
Segment Reporting Information [Line Items]
Loans, net	23,419		23,419	23,340
Private Education Loans [Member] \| Consumer Lending Segment [Member]
Segment Reporting Information [Line Items]
Loans, net	$ 23,400		$ 23,400
Loan portfolio amortization period weighted average life			20 years
Amortization period			6 years
Percentage of loans funded through securitization debt	55.00%		55.00%
ED Asset Recovery and Servicing Contracts [Member]
Segment Reporting Information [Line Items]
Allocation methodology description			Since 2009, Navient has been one of four TIVAS that provides loan servicing for federal loans owned by ED. We continually strive to help our customers successfully navigate the repayment of their loans. Under the contract, we seek to improve on the performance metrics that determine the allocation of new accounts under the servicing contract with ED
FFELP Loans [Member]
Segment Reporting Information [Line Items]
Loans, net	$ 81,703		$ 81,703	87,730
Loan portfolio amortization period weighted average life			20 years
Amortization period			7 years
Loans purchased, unpaid principal amount	$ 5,700		$ 5,700	$ 3,600	$ 3,700
Percentage of general guaranty agreements of FFELP loans			97.00%
Percentage of loans funded through securitization debt	84.00%		84.00%

Segment Reporting - Asset Infor

Segment Reporting - Asset Information for Loans Segment (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Loans, net	$ 105,122	$ 111,070
Other	4,025	4,193
Total assets	114,991	121,136
Federal Education Loans [Member]
Segment Reporting Information [Line Items]
Loans, net	81,703	87,730
Cash and investments	2,821	3,299
Other	2,601	2,226
Total assets	87,125	93,255
Consumer Lending Segment [Member]
Segment Reporting Information [Line Items]
Loans, net	23,419	23,340
Cash and investments	706	667
Other	1,143	1,562
Total assets	$ 25,268	$ 25,569

Segment Reporting - Segment Rev

Segment Reporting - Segment Revenue Include Healthcare Services (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Revenue Reconciling Item [Line Items]
Accounts receivable	$ 108	$ 95
Business Processing [Member] \| Nonfederal Education Loan [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	212,000	174,000	$ 99,000
Accounts receivable	11,400	10,100	9,900
Business Processing [Member] \| Government [Member] \| Nonfederal Education Loan [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	134,000	106,000	86,000
Business Processing [Member] \| Healthcare [Member] \| Nonfederal Education Loan [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	$ 78,000	$ 68,000	$ 13,000

Segment Reporting - Segment Res

Segment Reporting - Segment Results and Reconciliations to GAAP (Detail) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Cash and investments										$ 43	$ 22	$ 8
Total interest income										4,383	4,146	4,295
Total interest expense										2,971	2,441	2,074
Net interest income	$ 366	$ 355	$ 351	$ 340	$ 378	$ 412	$ 429	$ 486		1,412	1,705	2,221
Less: provisions for loan losses	109	105	105	107	102	106	110	111		426	429	581
Net interest income after provisions for loan losses	257	250	246	233	276	306	319	375		986	1,276	1,640
Other income (loss):
Servicing revenue										290	304	340
Asset recovery and business processing revenue										475	390	367
Other income										31	124	183
Gains (losses) on sales of loans and investments										3		(9)
Gains (losses) on debt repurchases										(3)	1	21
Total other income										796	819	902
Expenses:
Direct operating expenses										659	664	635
Overhead expenses										307	287	283
Total operating expenses	260	238	230	238	246	228	230	247		966	951	918
Goodwill and acquired intangible asset impairment and amortization	5	6	6	6	13	12	6	4		23	36	12
Restructuring/other reorganization expenses	29								$ 29	29		32
Total expenses										1,018	987	962
Income from continuing operations, before income tax expense										764	1,108	1,580
Income tax expense (benefit)	$ 266	$ 93	$ 60	$ 53	$ 96	$ 147	$ 81	$ 103		472	427	597
Net income from continuing operations										292	681	983
Income from discontinued operations, net of tax expense												1
Net income (loss)										292	681	984
Operating Segments [Member]
Interest income:
Cash and investments										43	22	8
Total interest income										4,369	4,013	3,883
Total interest expense										2,990	2,410	2,037
Net interest income										1,379	1,603	1,846
Less: provisions for loan losses										426	429	581
Net interest income after provisions for loan losses										953	1,174	1,265
Other income (loss):
Servicing revenue										290	304	340
Asset recovery and business processing revenue										475	390	367
Other income										19	14	15
Gains (losses) on sales of loans and investments										3		(9)
Gains (losses) on debt repurchases										(3)	1	21
Total other income										784	709	734
Expenses:
Direct operating expenses										659	664	635
Overhead expenses										307	287	283
Total operating expenses										966	951	918
Restructuring/other reorganization expenses										29
Total expenses										995	951	918
Income from continuing operations, before income tax expense										742	932	1,081
Income tax expense (benefit)										491	345	401
Net income from continuing operations												680
Income from discontinued operations, net of tax expense												1
Net income (loss)										251	587	681
Operating Segments [Member] \| Federal Education Loans [Member]
Interest income:
Cash and investments										29	16	6
Total interest income										2,721	2,420	2,125
Total interest expense										2,022	1,597	1,247
Net interest income										699	823	878
Less: provisions for loan losses										44	46	43
Net interest income after provisions for loan losses										655	777	835
Other income (loss):
Servicing revenue										280	289	319
Asset recovery and business processing revenue										263	216	268
Other income										3		3
Gains (losses) on sales of loans and investments										3		11
Total other income										549	505	601
Expenses:
Direct operating expenses										316	366	401
Total operating expenses										316	366	401
Total expenses										316	366	401
Income from continuing operations, before income tax expense										888	916	1,035
Income tax expense (benefit)										321	338	384
Net income from continuing operations												651
Net income (loss)										567	578	651
Operating Segments [Member] \| Consumer Lending [Member]
Interest income:
Cash and investments										5	2
Total interest income										1,639	1,589	1,756
Total interest expense										825	704	680
Net interest income										814	885	1,076
Less: provisions for loan losses										382	383	538
Net interest income after provisions for loan losses										432	502	538
Other income (loss):
Servicing revenue										10	15	21
Gains (losses) on sales of loans and investments												(21)
Total other income										10	15
Expenses:
Direct operating expenses										156	149	151
Total operating expenses										156	149	151
Total expenses										156	149	151
Income from continuing operations, before income tax expense										286	368	387
Income tax expense (benefit)										103	137	143
Net income from continuing operations												244
Net income (loss)										183	231	244
Operating Segments [Member] \| Business Processing [Member]
Other income (loss):
Asset recovery and business processing revenue										212	174	99
Total other income										212	174	99
Expenses:
Direct operating expenses										187	149	83
Total operating expenses										187	149	83
Total expenses										187	149	83
Income from continuing operations, before income tax expense										25	25	16
Income tax expense (benefit)										9	9	6
Net income from continuing operations												10
Net income (loss)										16	16	10
Operating Segments [Member] \| Other Segment [Member]
Interest income:
Cash and investments										9	4	2
Total interest income										9	4	2
Total interest expense										143	109	110
Net interest income										(134)	(105)	(108)
Net interest income after provisions for loan losses										(134)	(105)	(108)
Other income (loss):
Other income										16	14	12
Gains (losses) on sales of loans and investments												1
Gains (losses) on debt repurchases										(3)	1	21
Total other income										13	15	34
Expenses:
Overhead expenses										307	287	283
Total operating expenses										307	287	283
Restructuring/other reorganization expenses										29
Total expenses										336	287	283
Income from continuing operations, before income tax expense										(457)	(377)	(357)
Income tax expense (benefit)										58	(139)	(132)
Net income from continuing operations												(225)
Income from discontinued operations, net of tax expense												1
Net income (loss)										(515)	(238)	(224)
Adjustments [Member] \| Reclassifications [Member]
Interest income:
Total interest income										69	247	650
Total interest expense										(8)	31	37
Net interest income										77	216	613
Net interest income after provisions for loan losses										77	216	613
Other income (loss):
Other income										(77)	(216)	(613)
Total other income										(77)	(216)	(613)
Adjustments [Member] \| Additions (Subtractions) [Member]
Interest income:
Total interest income										(55)	(114)	(238)
Total interest expense										(11)
Net interest income										(44)	(114)	(238)
Net interest income after provisions for loan losses										(44)	(114)	(238)
Other income (loss):
Other income										89	326	781
Total other income										89	326	781
Expenses:
Goodwill and acquired intangible asset impairment and amortization										23	36	12
Restructuring/other reorganization expenses												32
Total expenses										23	36	44
Income from continuing operations, before income tax expense										22	176	499
Income tax expense (benefit)										(19)	82	196
Net income from continuing operations												303
Net income (loss)										41	94	303
Adjustments [Member] \| Total Adjustments [Member]
Interest income:
Total interest income										14	133	412
Total interest expense										(19)	31	37
Net interest income										33	102	375
Net interest income after provisions for loan losses										33	102	375
Other income (loss):
Other income										12	110	168
Total other income										12	110	168
Expenses:
Goodwill and acquired intangible asset impairment and amortization										23	36	12
Restructuring/other reorganization expenses												32
Total expenses										23	36	44
Income from continuing operations, before income tax expense										22	176	499
Income tax expense (benefit)										(19)	82	196
Net income from continuing operations												303
Net income (loss)										41	94	303
Education Loan Portfolio [Member]
Interest income:
Total interest income										4,327	4,115	4,280
Education Loan Portfolio [Member] \| Operating Segments [Member]
Interest income:
Total interest income										4,313	3,982	3,868
Education Loan Portfolio [Member] \| Operating Segments [Member] \| Federal Education Loans [Member]
Interest income:
Total interest income										2,679	2,395	2,112
Education Loan Portfolio [Member] \| Operating Segments [Member] \| Consumer Lending [Member]
Interest income:
Total interest income										1,634	1,587	1,756
Education Loan Portfolio [Member] \| Adjustments [Member] \| Reclassifications [Member]
Interest income:
Total interest income										69	247	650
Education Loan Portfolio [Member] \| Adjustments [Member] \| Additions (Subtractions) [Member]
Interest income:
Total interest income										(55)	(114)	(238)
Education Loan Portfolio [Member] \| Adjustments [Member] \| Total Adjustments [Member]
Interest income:
Total interest income										14	133	412
Other Loans [Member]
Interest income:
Total interest income										13	9	7
Other Loans [Member] \| Operating Segments [Member]
Interest income:
Total interest income										13	9	7
Other Loans [Member] \| Operating Segments [Member] \| Federal Education Loans [Member]
Interest income:
Total interest income										$ 13	$ 9	$ 7

Segment Reporting - Segment 104

Segment Reporting - Segment Result and Reconciliations to GAAP - Core Earnings Adjustments (Detail) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income after provisions for loan losses	$ 257	$ 250	$ 246	$ 233	$ 276	$ 306	$ 319	$ 375		$ 986	$ 1,276	$ 1,640
Total other income (loss)										796	819	902
Goodwill and acquired intangible asset impairment and amortization	5	6	6	6	13	12	6	4		23	36	12
Restructuring/other reorganization expenses	29								$ 29	29		32
Income tax expense (benefit)	266	93	60	53	96	147	81	103		472	427	597
Net income attributable to Navient Corporation	$ (84)	$ 176	$ 112	$ 88	$ 145	$ 230	$ 125	$ 181		292	681	984
Total Adjustments [Member] \| Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income after provisions for loan losses										33	102	375
Total other income (loss)										12	110	168
Goodwill and acquired intangible asset impairment and amortization										23	36	12
Restructuring/other reorganization expenses												32
Total “Core Earnings” adjustments to GAAP										22	176	499
Income tax expense (benefit)										(19)	82	196
Net income attributable to Navient Corporation										41	94	303
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	36	12
Total “Core Earnings” adjustments to GAAP										(23)	(36)	(12)
Net Impact of Derivative Accounting [Member] \| Total Adjustments [Member] \| Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net interest income after provisions for loan losses										33	102	375
Total other income (loss)										12	110	168
Total “Core Earnings” adjustments to GAAP										$ 45	$ 212	543
Net Impact from Spin-Off of SLM BankCo [Member] \| Total Adjustments [Member] \| Adjustments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Restructuring/other reorganization expenses												32
Total “Core Earnings” adjustments to GAAP												$ (32)

Segment Reporting - Core Earnin

Segment Reporting - Core Earnings Adjustments to GAAP (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
“Core Earnings” adjustments to GAAP:
Net tax effect	$ (266)	$ (93)	$ (60)	$ (53)	$ (96)	$ (147)	$ (81)	$ (103)	$ (472)	$ (427)	$ (597)
Net income attributable to Navient Corporation	$ (84)	$ 176	$ 112	$ 88	$ 145	$ 230	$ 125	$ 181	292	681	984
Total Adjustments [Member] \| Adjustments [Member]
“Core Earnings” adjustments to GAAP:
Core Earnings adjustments to GAAP									22	176	499
Net tax effect									19	(82)	(196)
Net income attributable to Navient Corporation									41	94	303
Net Impact from Spin-Off of SLM BankCo [Member] \| Total Adjustments [Member] \| Adjustments [Member]
“Core Earnings” adjustments to GAAP:
Core Earnings adjustments to GAAP											(32)
Net Impact of Derivative Accounting [Member] \| Total Adjustments [Member] \| Adjustments [Member]
“Core Earnings” adjustments to GAAP:
Core Earnings adjustments to GAAP									45	212	543
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)	$ (36)	$ (12)

Segment Reporting - Core Ear106

Segment Reporting - Core Earnings Adjustments to GAAP (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)
Segment Reporting [Abstract]
Amount that will be equal to cumulative net unrealized gain or loss over the life of the contract	$ 0

Quarterly Financial Informat107

Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure - Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) [Line Items]
Net interest income	$ 366	$ 355	$ 351	$ 340	$ 378	$ 412	$ 429	$ 486		$ 1,412	$ 1,705	$ 2,221
Less: provisions for loan losses	109	105	105	107	102	106	110	111		426	429	581
Net interest income after provisions for loan losses	257	250	246	233	276	306	319	375		986	1,276	1,640
Other income	181	238	187	168	218	174	151	159
Gains (losses) on derivative and hedging activities, net	38	25	(25)	(16)	6	137	(28)	1		22	117	166
Operating expenses	260	238	230	238	246	228	230	247		966	951	918
Goodwill and acquired intangible asset impairment and amortization expense	5	6	6	6	13	12	6	4		23	36	12
Restructuring/other reorganization expenses	29								$ 29	29		32
Income tax expense	266	93	60	53	96	147	81	103		472	427	597
Net income attributable to Navient Corporation	$ (84)	$ 176	$ 112	$ 88	$ 145	$ 230	$ 125	$ 181		$ 292	$ 681	$ 984
Basic earnings per common share attributable to Navient Corporation	$ (0.32)	$ 0.65	$ 0.40	$ 0.31	$ 0.49	$ 0.74	$ 0.39	$ 0.53		$ 1.06	$ 2.15	$ 2.62
Diluted earnings per common share attributable to Navient Corporation	$ (0.32)	$ 0.64	$ 0.39	$ 0.30	$ 0.48	$ 0.73	$ 0.38	$ 0.53		$ 1.04	$ 2.12	$ 2.58