Ally Financial (ALLY) 10-K 25 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 21, 2020	Jun. 28, 2019
Entity Information [Line Items]
Document Annual Report	true
Entity Public Float			$ 12.2
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-3754
Entity Registrant Name	ALLY FINANCIAL INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	38-0572512
Entity Address, Address Description	Ally Detroit Center
Entity Address, Address Line One	500 Woodward Ave.
Entity Address, Address Line Two	Floor 10
Entity Address, City or Town	Detroit
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	48226
City Area Code	866
Local Phone Number	710-4623
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		375,074,939
Entity Central Index Key	0000040729
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Common stock
Entity Information [Line Items]
Security Exchange Name	NYSE
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	ALLY
Trust Preferred Securities Subject to Mandatory Redemption
Entity Information [Line Items]
Security Exchange Name	NYSE
Title of 12(b) Security	8.125% Fixed Rate/Floating Rate Trust Preferred Securities, Series 2 of GMAC Capital Trust I
Trading Symbol	ALLY PRA

Consolidated Statement of Incom

Consolidated Statement of Income Consolidated Statement of Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Revenue and Other Income [Abstract]
Interest and fees on finance receivables and loans									$ 7,337	$ 6,688	$ 5,819
Interest on loans held-for-sale									17	15	0
Interest and dividends on investment securities and other earning assets									955	788	599
Interest on cash and cash equivalents									78	72	37
Operating leases									1,470	1,489	1,867
Total financing revenue and other interest income									9,857	9,052	8,322
Interest Expense [Abstract]
Interest on deposits									2,538	1,735	1,077
Interest on short-term borrowings									135	149	127
Interest on long-term debt									1,570	1,753	1,653
Total interest expense									4,243	3,637	2,857
Net depreciation expense on operating lease assets									981	1,025	1,244
Net financing revenue and other interest income	$ 1,156	$ 1,188	$ 1,157	$ 1,132	$ 1,140	$ 1,107	$ 1,094	$ 1,049	4,633	4,390	4,221
Other revenue [Abstract]
Insurance premiums and service revenue earned									1,087	1,022	973
Gain on mortgage and automotive loans, net									28	25	68
Other gain on investments, net									243	(50)	102
Other income, net of losses									403	417	401
Total other revenue	487	413	395	466	298	398	364	354	1,761	1,414	1,544
Total net revenue	1,643	1,601	1,552	1,598	1,438	1,505	1,458	1,403	6,394	5,804	5,765
Provision for loan losses	276	263	177	282	266	233	158	261	998	918	1,148
Noninterest Expense [Abstract]
Compensation and benefits expense									1,222	1,155	1,095
Insurance losses and loss adjustment expenses									321	295	332
Other operating expenses									1,886	1,814	1,683
Total noninterest expense	880	838	881	830	804	807	839	814	3,429	3,264	3,110
Income from continuing operations before income tax expense	487	500	494	486	368	465	461	328	1,967	1,622	1,507
Statement [Abstract]
Income tax expense from continuing operations	106	119	(90)	111	79	91	113	76	246	359	581
Net income from continuing operations	381	381	584	375	289	374	348	252	1,721	1,263	926
Loss from discontinued operations, net of tax	(3)	0	(2)	(1)	1	0	1	(2)	(6)	0	3
Net income	$ 378	$ 381	$ 582	$ 374	$ 290	$ 374	$ 349	$ 250	$ 1,715	$ 1,263	$ 929
Earnings Per Share, Basic [Abstract]
Net income from continuing operations, basic earnings per common share	$ 1	$ 0.98	$ 1.47	$ 0.93	$ 0.70	$ 0.89	$ 0.81	$ 0.58	$ 4.38	$ 2.97	$ 2.04
Loss from discontinued operations, net of tax, basic earnings per common share									(0.02)	0	0.01
Net income, basic earnings per common share	0.99	0.97	1.46	0.93	0.70	0.89	0.81	0.57	4.36	2.97	2.05
Earnings Per Share, Diluted [Abstract]
Net income from continuing operations, diluted earnings per common share	0.99	0.97	1.46	0.92	0.70	0.88	0.80	0.57	4.35	2.95	2.03
Loss from discontinued operations, net of tax, diluted earnings per common share									(0.02)	0	0.01
Net income, diluted earnings per common share	0.99	0.97	1.46	0.92	0.70	0.88	0.81	0.57	4.34	2.95	2.04
Cash dividends declared per common share	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.15	$ 0.15	$ 0.13	$ 0.13	$ 0.68	$ 0.56	$ 0.40

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 1,715	$ 1,263	$ 929
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent [Abstract]
Other comprehensive income (loss), investment securities, net unrealized gains (losses) arising during the period, after tax	741	(287)	192
Other comprehensive income (loss), investment securities, net realized gains reclassified to income from continuing operations, after tax	60	8	92
Other comprehensive income (loss), investment securities, net change, after tax	681	(295)	100
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Other comprehensive income (loss), translation adjustments, net unrealized gains (losses) arising during the period, after tax	5	(11)	8
Other Comprehensive Income (loss), net investment hedges, net unrealized gains (losses) arising during the period	(4)	9	(6)
Other comprehensive income (loss), translation adjustments and net investment hedges, net change	1	(2)	2
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Other comprehensive income (loss), cash flow hedges, net unrealized gains (losses) arising during the period	(7)	10	3
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification, after tax	10	2	0
Other comprehensive income (loss), cash flow hedge, gain (loss), after reclassification and tax	(17)	8	3
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, after tax	(11)	0	1
Other Comprehensive Income (Loss), net of tax	654	(289)	106
Comprehensive Income	$ 2,369	$ 974	$ 1,035

Condensed Consolidated Balance

Condensed Consolidated Balance Sheet & Mini Balance Sheet - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets [Abstract]
Cash and cash equivalents, noninterest-bearing	$ 619	$ 810
Cash and cash equivalents, interest-bearing	2,936	3,727
Total cash and cash equivalents	3,555	4,537
Equity securities	616	773
Available-for-sale securities	30,284	25,303
Held-to-maturity securities	1,568	2,362
Loans held-for-sale, net	158	314
Finance receivables and loans, net [Abstract]
Finance receivables and loans, net	128,231	129,926
Allowance for loan losses	1,263	1,242
Total finance receivables and loans, net	126,968	128,684
Investment in operating leases, net	8,864	8,417
Premiums receivable and other insurance assets	2,558	2,326
Other assets	6,073	6,153
Total assets	180,644	178,869
Liabilities and Equity [Abstract]
Deposit liabilities, noninterest-bearing	119	142
Deposit liabilities, interest-bearing	120,633	106,036
Total deposit liabilities	120,752	106,178
Short-term borrowings	5,531	9,987
Long-term debt	34,027	44,193
Interest payable	641	523
Unearned insurance premiums and service revenue	3,305	3,044
Accrued expenses and other liabilities	1,972	1,676
Total liabilities	166,228	165,601
Equity [Abstract]
Common Stocks, Including Additional Paid in Capital	21,438	21,345
Accumulated deficit	(4,057)	(5,489)
Accumulated other comprehensive income (loss)	123	(539)
Treasury stock, at cost	(3,088)	(2,049)
Total equity	14,416	13,268
Total liabilities and equity	180,644	178,869
Variable interest entity
Finance receivables and loans, net [Abstract]
Finance receivables and loans, net	18,710	18,086
Allowance for loan losses	153	114
Total finance receivables and loans, net	18,557	17,972
Investment in operating leases, net	0	164
Other assets	787	767
Total assets	19,344	18,903
Liabilities and Equity [Abstract]
Long-term debt	9,087	10,482
Accrued expenses and other liabilities	11	12
Total liabilities	$ 9,098	$ 10,494

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheet & Mini Balance Sheet (Paranthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	1,100,000,000	1,100,000,000
Common stock, shares issued	496,957,805	492,797,409
Common stock, shares outstanding	374,331,998	404,899,599
Treasury stock, shares	122,625,807	87,897,810
Held-to-maturity securities, fair value	$ 1,600	$ 2,307

Condensed Consolidated Statemen

Condensed Consolidated Statement of Changes in Equity - USD ($) $ in Millions	Total	Common stock and paid-in capital	Accumulated Deficit	Accumulated other comprehensive (loss) income	Treasury stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity	$ 13,494	$ 21,245	$ (6,406)	$ (235)	$ (1,110)
Common stock dividends, amount per share	$ 0.56
Net income	$ 1,263		1,263
Share-based compensation	100	100
Other comprehensive income (loss)	289			289
Common stock repurchases	(939)				(939)
Common stock dividends	(242)		(242)
Equity	$ 13,268	21,345	(5,489)	(539)	(2,049)
Common stock dividends, amount per share	$ 0.68
Net income	$ 1,715		1,715
Share-based compensation	93	93
Other comprehensive income (loss)	(654)			(654)
Common stock repurchases	(1,039)				(1,039)
Common stock dividends	(273)		(273)
Equity	$ 14,416	$ 21,438	$ (4,057)	$ 123	$ (3,088)

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Statement of Cash Flows [Abstract]
Net income	$ 1,715	$ 1,263	$ 929
Net Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization	1,555	1,649	1,859
Provision for loan losses	998	918	1,148
Gain on mortgage and automotive loans, net	(28)	(25)	(68)
Other loss (gain) on investments, net	(243)	50	(102)
Originations and purchases of loans held-for-sale	(1,276)	(1,016)	(414)
Proceeds from sales and repayments of loans held-for-sale	1,288	948	310
Increase (decrease) in deferred income taxes	179	330	534
Increase (decrease) in interest payable	118	148	24
Increase (decrease) in other assets	(28)	(87)	(153)
Increase (decrease) in other liabilities	(177)	2	(69)
Increase (decrease) in other assets and liabilities, net	(51)	(30)	81
Net cash provided by operating activities	4,050	4,150	4,079
Net Cash (Used in) Provided by Investing Activities [Abstract]
Purchases of equity securities	(498)	(1,076)	(899)
Proceeds from sales of equity securities	814	787	1,049
Purchases of available-for-sale securities	15,199	7,868	10,335
Proceeds from sales of available-for-sale securities	7,079	852	3,584
Proceeds from repayments of available-for-sale securities	5,154	3,215	2,899
Purchases of held-to-maturity securities	(514)	(578)	(1,026)
Proceeds from repayments of held-to-maturity securities	302	147	68
Purchases of finance receivables and loans held-for-investment	(4,439)	(5,693)	(5,452)
Proceeds from sales of finance receivables and loans initially held-for-investment	1,038	91	1,339
Originations and repayments of finance receivables and loans held-for-investment and other, net	4,252	(3,245)	(1,063)
Purchases of operating lease assets	(4,023)	(3,709)	(4,052)
Disposals of operating lease assets	2,625	3,089	5,567
Acquisitions, net of acquired cash	(171)	0	0
Net change in nonmarketable equity investments	190	(181)	(187)
Payments for (proceeds from) other, net	(379)	(340)	(219)
Net cash used in investing activities	(3,769)	(14,509)	(8,727)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Net change in short-term borrowings	(4,456)	(1,426)	(1,263)
Net increase in deposits	14,547	12,867	14,172
Proceeds from issuance of long-term debt	6,915	18,401	17,969
Repayments of long-term debt	(17,224)	(17,940)	(27,908)
Repurchase of common stock	(1,039)	(939)	(753)
Dividends paid	(273)	(242)	(184)
Net cash provided by financing activities	(1,530)	10,721	2,033
Effect of exchange-rate changes on cash and cash equivalents and restricted cash	3	(5)	3
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net increase (decrease) in cash and cash equivalents and restricted cash	(1,246)	357	(2,612)
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash	5,626	5,269	7,881
Cash and cash equivalents and restricted cash	4,380	5,626	5,269
Supplemental Cash Flow Information [Abstract]
Cash paid for interest	4,034	3,380	2,829
Cash paid for income taxes	64	36	51
Held-to-maturity securities received in consideration for loans sold	0	26	56
Loans held-for-sale transferred to finance receivables and loans held-for-investment	242	0	0
Finance receivables and loans transferred to loans held-for-sale, noncash	960	815	1,339
Held-to-maturity securities transferred to available-for-sale	943	0	$ 0
Restricted Cash [Abstract]
Cash and cash equivalents as disclosed on the Condensed Consolidated Balance Sheet	3,555	4,537
Restricted cash included in other assets on the Condensed Consolidated Balance Sheet	$ 825	$ 1,089

Description of Business, Basis

Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]	Description of Business, Basis of Presentation, and Significant Accounting Policies Ally Financial Inc. (together with its consolidated subsidiaries unless the context otherwise requires, Ally, the Company, or we, us, or our) is a leading digital financial-services company . As a customer-centric company with passionate customer service and innovative financial solutions, we are relentlessly focused on “Doing It Right” and being a trusted financial-services provider to our consumer, commercial, and corporate customers. We are one of the largest full-service automotive finance operations in the country and offer a wide range of financial services and insurance products to automotive dealerships and consumers. Our award-winning online bank (Ally Bank, Member FDIC and Equal Housing Lender) offers mortgage lending, personal lending, and a variety of deposit and other banking products, including savings, money-market, and checking accounts, certificates of deposit (CDs), and individual retirement accounts (IRAs). Additionally, we offer securities-brokerage and investment-advisory services through Ally Invest. Our robust corporate-finance business offers capital for equity sponsors and middle-market companies. We are a Delaware corporation and are registered as a bank holding company (BHC) under the Bank Holding Company Act of 1956, as amended , and a financial holding company (FHC) under the Gramm-Leach-Bliley Act of 1999, as amended . Consolidation and Basis of Presentation The Consolidated Financial Statements include the accounts of the parent and its consolidated subsidiaries, of which it is deemed to possess control, after eliminating intercompany balances and transactions, and include all variable interest entities (VIEs) in which we are the primary beneficiary. Refer to Note 11 for further details on our VIEs. Other entities in which we have invested and have the ability to exercise significant influence over operating and financial policies of the investee, but upon which we do not possess control, are accounted for by the equity method of accounting within the financial statements and they are therefore not consolidated. Our accounting and reporting policies conform to accounting principles generally accepted in the United States of America (GAAP). Additionally, where applicable, the policies conform to the accounting and reporting guidelines prescribed by bank regulatory authorities. Certain reclassifications may have been made to the prior periods’ financial statements and notes to conform to the current period’s presentation, which did not have a material impact on our Consolidated Financial Statements. In the past, we have operated our international subsidiaries in a similar manner as we operate in the United States of America (U.S. or United States), subject to local laws or other circumstances that may cause us to modify our procedures accordingly. The financial statements of subsidiaries that operate outside of the United States generally are measured using the local currency as the functional currency. All assets and liabilities of foreign subsidiaries are translated into U.S. dollars at year-end exchange rates. The resulting translation adjustments are recorded in accumulated other comprehensive income until the foreign subsidiaries are sold or substantially liquidated at which point the accumulated translation adjustments are recognized directly in earnings as part of the gain or loss on sale or liquidation. Income and expense items are translated at average exchange rates prevailing during the reporting period. Other than our Canadian Insurance operations, the majority of our international operations have ceased and are included in discontinued operations. Use of Estimates and Assumptions 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 that affect income and expenses during the reporting period and related disclosures. In developing the estimates and assumptions, management uses all available evidence; however, actual results could differ because of uncertainties associated with estimating the amounts, timing, and likelihood of possible outcomes. Our most significant estimates pertain to the allowance for loan losses, valuations of automotive operating lease assets and residuals, fair value of financial instruments, and the determination of the provision for income taxes.
Significant Accounting Policies	Significant Accounting Policies Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash on deposit at other financial institutions, cash items in process of collection, and certain highly liquid investments with original maturities of three months or less from the date of purchase. The book value of cash equivalents approximates fair value because of the short maturities of these instruments and the insignificant risk they present to changes in value with respect to changes in interest rates. Certain securities with original maturities of three months or less from the date of purchase that are held as a portion of longer-term investment portfolios, primarily held by our Insurance operations, are classified as investment securities. Cash and cash equivalents with legal restrictions limiting our ability to withdraw and use the funds are considered restricted cash and restricted cash equivalents and are presented as other assets on our Consolidated Balance Sheet. Investments Our investment portfolio includes various debt and equity securities. Our debt securities include government securities, corporate bonds, asset-backed securities (ABS), and mortgage-backed securities (MBS). Debt securities are classified based on management’s intent to sell or hold the security. We classify debt securities as held-to-maturity only when we have both the intent and ability to hold the securities to maturity. We classify debt securities as trading when the securities are acquired for the purpose of selling or holding them for a short period of time. Debt securities not classified as either held-to-maturity or trading are classified as available-for-sale. Our portfolio includes debt securities classified as available-for-sale and held-to-maturity. Our available-for-sale debt securities are carried at fair value with unrealized gains and losses included in accumulated other comprehensive income and are assessed for potential impairment. Our held-to-maturity debt securities are carried at amortized cost and are assessed for potential impairment. We assess our available-for-sale and held-to-maturity debt securities for potential other-than-temporary impairment. We employ a methodology that considers available evidence in evaluating potential other-than-temporary impairment of our debt securities. If the cost of an investment exceeds its fair value, we evaluate, among other factors, the magnitude and duration of the decline in fair value. We also evaluate the financial health of and business outlook for the issuer, the performance of the underlying assets for interests in securitized assets, and, for debt securities classified as available-for-sale, our intent and ability to hold the investment through recovery of its amortized cost basis. Once a decline in fair value of a debt security is determined to be other-than-temporary, an impairment charge for the credit component is recorded to other gain on investments, net, in our Consolidated Statement of Income, and a new cost basis in the investment is established. The noncredit loss component of a debt security continues to be recorded in other comprehensive income when we do not intend to sell the security and it is not more likely than not that we will have to sell the security prior to the security’s anticipated recovery. Both the credit and noncredit loss components are recorded in earnings when we intend to sell the security or it is more likely than not that we will have to sell the security prior to the security’s anticipated recovery. Subsequent increases and decreases to the fair value of available-for-sale debt securities are included in other comprehensive income, so long as they are not attributable to another other-than-temporary impairment. Premiums on debt securities that have noncontingent call features that are callable at fixed prices on preset dates are amortized to the earliest call date as an adjustment to investment yield. All other premiums and discounts on debt securities are amortized over the stated maturity of the security as an adjustment to investment yield. Our investments in equity securities include securities that are recognized at fair value with changes in the fair value recorded in earnings, and equity securities that are recognized using other measurement principles. Effective January 1, 2018, equity securities that have a readily determinable fair value are recorded at fair value with changes in fair value recorded in earnings and reported in other gain on investments, net in our Consolidated Statement of Income. These investments, which are primarily attributable to the investment portfolio of our Insurance operations, are included in equity securities on our Consolidated Balance Sheet. We also hold certain equity investments that do not have a readily determinable fair value and are not eligible to be recognized using other measurement principles that are held at fair value. Refer to Note 8 for further information on these equity securities that have a readily determinable market value. Our equity securities recognized using other measurement principles include investments in Federal Home Loan Bank (FHLB) and Federal Reserve Bank (FRB) stock held to meet regulatory requirements, equity investments related to low-income housing tax credits and the Community Reinvestment Act (CRA), which do not have a readily determinable fair value, and other equity investments that do not have a readily determinable fair value. Our low-income housing tax credit investments are accounted for using the proportional amortization method of accounting for qualified affordable housing investments. Our obligations related to unfunded commitments for our low-income housing tax credit investments are included in other liabilities. The majority of our other CRA investments are accounted for using the equity method of accounting. Our investments in low-income housing tax credits and other CRA investments are included in investments in qualified affordable housing projects and equity-method investments, respectively, in other assets on our Consolidated Balance Sheet. Our investments in FHLB and FRB stock are carried at cost, less impairment. Our remaining investment in equity securities are recorded at cost, less impairment and adjusted for observable price changes under the measurement alternative provided under GAAP. These investments, along with our investments in FHLB and FRB stock, are included in nonmarketable equity investments in other assets on our Consolidated Balance Sheet. Investments recorded under the measurement alternative are also reviewed at each reporting period to determine if any adjustments are required for observable price changes in identical or similar securities of the same issuer. As conditions warrant, we review these investments for impairment and adjust the carrying value of the investment if it is deemed to be impaired. Realized gains and losses on the sale of securities are determined using the specific identification method and are reported in other gain on investments, net in our Consolidated Statement of Income. Finance Receivables and Loans We initially classify finance receivables and loans as either loans held-for-sale or loans held-for-investment based on management’s assessment of our intent and ability to hold the loans for the foreseeable future or until maturity. Management’s view of the foreseeable future is based on the longest reasonably reliable net income, liquidity, and capital forecast period. Management’s intent and ability with respect to certain loans may change from time to time depending on a number of factors, for example economic, liquidity, and capital conditions. In order to reclassify loans to held-for-sale, management must have the intent to sell the loans and reasonably identify the specific loans to be sold. Loans classified as held-for-sale are presented as loans held-for-sale, net on our Consolidated Balance Sheet and are carried at the lower of their net carrying value or fair value, unless the fair value option was elected, in which case those loans are carried at fair value. Loan origination fees and costs are included in the initial carrying value of loans originated as held-for-sale for which we have not elected the fair value option. Loan origination fees and costs are recognized in earnings when earned or incurred, respectively, for loans classified as held-for-sale for which we have elected the fair value option. We have elected the fair value option for conforming mortgage direct-to-consumer originations for which we have a commitment to sell. The interest rate lock commitment that we enter into for a mortgage loan originated as held-for-sale and certain forward commitments to sell mortgage loans are considered derivative instruments, which are carried at fair value on our Consolidate Balance Sheet. We have elected the fair value option to measure our non-derivative forward commitments. Changes in the fair value of our interest rate lock commitments, derivative forward commitments, and non-derivative forward commitments related to mortgage loans originated as held-for-sale, as well as changes in the carrying value of loans classified as held-for-sale, are reported through gain on mortgage and automotive loans, net in our Consolidated Statement of Income . Interest income on our loans classified as held-for-sale is recognized based upon the contractual rate of interest on the loan and the unpaid principal balance. We report accrued interest receivable on our loans classified as held-for-sale in other assets on the Consolidated Balance Sheet. We have also elected the fair value option for certain loans acquired within our consumer other portfolio segment. Changes in fair value related to these loans are reported through other income, net of losses in our Consolidated Statement of Income . Loans classified as held-for-investment are presented as finance receivables and loans, net on our Consolidated Balance Sheet. Finance receivables and loans are reported at their gross carrying value, which includes the principal amount outstanding, net of unamortized deferred fees and costs on originated loans, unamortized premiums and discounts on purchased loans, unamortized basis adjustments arising from the designation of finance receivables and loans as the hedged item in qualifying fair value hedge relationships, and cumulative principal charge-offs. We refer to the gross carrying value less the allowance for loan loss as the net carrying value in finance receivables and loans. Unearned rate support received from an automotive manufacturer on certain automotive loans, deferred origination fees and costs, and premiums and discounts on purchased loans, are amortized over the contractual life of the related finance receivable or loan using the effective interest method. We make various incentive payments for consumer automotive loan originations to automotive dealers and account for these payments as direct loan origination costs. Additionally, we make incentive payments to certain commercial automobile wholesale borrowers and account for these payments as a reduction to interest income in the period they are earned. Interest income on our finance receivables and loans is recognized based on the contractual rate of interest plus the amortization of deferred amounts using the effective interest method. We report accrued interest receivable on our finance receivables and loans in other assets on our Consolidated Balance Sheet. Loan commitment fees are generally deferred and amortized over the commitment period. For information on finance receivables and loans, refer to Note 9 . Our portfolio segments are based on the level at which we develop and document our methodology for determining the allowance for loan losses. Additionally, the classes of finance receivables are based on several factors including the method for monitoring and assessing credit risk, the method of measuring carrying value, and the risk characteristics of the finance receivable. Based on an evaluation of our process for developing the allowance for loan losses including the nature and extent of exposure to credit risk arising from finance receivables, we have determined our portfolio segments to be consumer automotive, consumer mortgage, consumer other, and commercial. • Consumer automotive — Consists of retail automotive financing for new and used vehicles. • Consumer mortgage — Consists of the following classes of finance receivables. • Mortgage Finance — Consists of consumer first-lien mortgages from our ongoing mortgage operations including bulk acquisitions, direct-to-consumer originations, and refinancing of high-quality jumbo mortgages and low-to-moderate income (LMI) mortgages. • Mortgage — Legacy — Consists of consumer mortgage assets originated prior to January 1, 2009, including first-lien mortgages, subordinate-lien mortgages, and home equity mortgages. • Consumer other — Consists of unsecured consumer lending from point-of-sale financing. • Commercial — Consists of the following classes of finance receivables. • Commercial and Industrial • Automotive — Consists of financing operations to fund dealer purchases of new and used vehicles through wholesale floorplan financing. Additional commercial offerings include automotive dealer term loans, revolving lines, and dealer fleet financing. • Other — Consists primarily of senior secured leveraged cash flow and asset-based loans related to our Corporate-Finance business. • Commercial Real Estate — Consists of term loans primarily secured by dealership land and buildings, and other commercial lending secured by real estate. Nonaccrual Loans Generally, we recognize loans of all classes as past due when they are 30 days delinquent on making a contractually required payment, and loans are placed on nonaccrual status when principal or interest has been delinquent for at least 90 days, or when full collection is not expected . Interest income recognition is suspended when finance receivables and loans are placed on nonaccrual status. Additionally, amortization of premiums and discounts and deferred fees and costs ceases when finance receivables and loans are placed on nonaccrual. Exceptions include commercial real estate loans that are placed on nonaccrual status when delinquent for 60 days or when full collection is not probable, if sooner. Additionally, our policy is to generally place all loans that have been modified in troubled debt restructurings (TDRs) on nonaccrual status until the loan has been brought fully current, the collection of contractual principal and interest is reasonably assured, and six consecutive months of repayment performance is achieved. In certain cases, if a borrower has been current up to the time of the modification and repayment of the debt subsequent to the modification is reasonably assured, we may choose to continue to accrue interest on the loan. Loans on nonaccrual status are reported as nonperforming loans in Note 9 . The receivable for interest income that is accrued, but not collected, at the date finance receivables and loans are placed on nonaccrual status is reversed against interest income and subsequently recognized only to the extent it is received in cash or until it qualifies for return to accrual status. However, where there is doubt regarding the ultimate collectability of loan principal, all cash received is applied to reduce the carrying value of such loans. Generally, finance receivables and loans are restored to accrual status only when contractually current and the collection of future payments is reasonably assured. Impaired Loans Loans of all classes are considered impaired when we determine it is probable that we will be unable to collect all amounts due (both principal and interest) according to the terms of the loan agreement. For all classes of consumer loans, impaired loans include all loans that have been modified in TDRs. Commercial loans of all classes are considered impaired on an individual basis and reported as impaired when we determine it is probable that we will be unable to collect all amounts due according to the terms of the loan agreement. With the exception of certain consumer TDRs that have been returned to accruing status, for all classes of impaired loans, income recognition is consistent with that of nonaccrual loans discussed above. Impaired loans may return to accrual status as discussed in the preceding nonaccrual loan section at which time, the normal accrual of interest income resumes. For collateral dependent loans, if the recorded investment in the impaired loans exceeds the fair value of the collateral, a charge-off is recorded consistent with the TDR discussion below. Troubled Debt Restructurings When the terms of finance receivables or loans are modified, consideration must be given as to whether or not the modification results in a TDR. A modification is considered to be a TDR when both the borrower is experiencing financial difficulty and we grant a concession to the borrower. These considerations require significant judgment and vary by portfolio segment. In all cases, the cumulative impacts of all modifications are considered at the time of the most recent modification. For consumer loans of all classes, various qualitative factors are utilized for assessing the financial difficulty of the borrower. These include, but are not limited to, the borrower’s default status on any of its debts, bankruptcy and recent changes in financial circumstances (loss of job, etc.). A concession has been granted when as a result of the modification we do not expect to collect all amounts due under the original loan terms, including interest accrued at the original contract rate. Types of modifications that may be considered concessions include, but are not limited to, extensions of terms at a rate that does not constitute a market rate, a reduction, deferral or forgiveness of principal or interest owed and loans that have been discharged in a Chapter 7 Bankruptcy and have not been reaffirmed by the borrower. In addition to the modifications noted above, in our consumer automotive portfolio segment of loans we also provide extensions or deferrals of payments to borrowers whom we deem to be experiencing only temporary financial difficulty. In these cases, there are limits within our operational policies to minimize the number of times a loan can be extended, as well as limits to the length of each extension, including a cumulative cap over the life of the loan. If these limits are breached, the modification is considered a TDR as noted in the following paragraph. Before offering an extension or deferral, we evaluate the capacity of the customer to make the scheduled payments after the deferral period. During the deferral period, we continue to accrue and collect interest on the loan as part of the deferral agreement. We grant these extensions or deferrals when we expect to collect all amounts due including interest accrued at the original contract rate. A restructuring that results in only a delay in payment that is deemed to be insignificant is not a concession and the modification is not considered to be a TDR. In order to assess whether a restructuring that results in a delay in payment is insignificant, we consider the amount of the restructured payments subject to delay in conjunction with the unpaid principal balance or the collateral value of the loan, whether or not the delay is significant with respect to the frequency of payments under the original contract, or the loan’s original expected duration. In the cases where payment extensions on our automotive loan portfolio cumulatively extend beyond 90 days and are more than 10% of the original contractual term or where the cumulative payment extension is beyond 180 days, we deem the delay in payment to be more than insignificant, and as such, classify these types of modifications as TDRs. Otherwise, we believe that the modifications do not represent a concessionary modification and accordingly, they are not classified as TDRs. For commercial loans of all classes, similar qualitative factors are considered when assessing the financial difficulty of the borrower. In addition to the factors noted above, consideration is also given to the borrower’s forecasted ability to service the debt in accordance with the contractual terms, possible regulatory actions, and other potential business disruptions (for example, the loss of a significant customer or other revenue stream). Consideration of a concession is also similar for commercial loans. In addition to the factors noted above, consideration is also given to whether additional guarantees or collateral have been provided. For all loans, TDR classification typically results from our loss mitigation activities. For loans held-for-investment that are not carried at fair value and are TDRs, impairment is typically measured based on the difference between the gross carrying value of the loan and the present value of the expected future cash flows of the loan. The loan may also be measured for impairment based on the fair value of the underlying collateral less costs to sell for loans that are collateral dependent. We recognize impairment by either establishing a valuation allowance or recording a charge-off. The financial impacts of modifications that meet the definition of a TDR are reported in the period in which they are identified as TDRs. Additionally, if a loan that is classified as a TDR redefaults within 12 months of the modification, we are required to disclose the instances of redefault. For the purpose of this disclosure, we have determined that a loan is considered to have redefaulted when the loan meets the requirements for evaluation under our charge-off policy except for commercial loans where redefault is defined as 90 days past due. Impaired loans may return to accrual status as discussed in the preceding nonaccrual loan section at which time, the normal accrual of interest income resumes. Net Charge-offs We disclose the measurement of net charge-offs as the amount of gross charge-offs recognized less recoveries received. Gross charge-offs reflect the amount of the gross carrying value directly written-off. Generally, we recognize recoveries when they are received and record them as an increase to the allowance for loan losses. As a general rule, consumer automotive loans are written down to estimated collateral value, less costs to sell, once a loan becomes 120 days past due. In our consumer mortgage portfolio segment, first-lien mortgages and a subset of our home equity portfolio that are secured by real estate in a first-lien position are written down to the estimated fair value of the collateral, less costs to sell, once a mortgage loan becomes 180 days past due. Consumer mortgage loans that represent second-lien positions are charged off at 180 days past due. Loans in our consumer other segment are charged off at 120 days past due. Within 60 days of receipt of notification of filing from the bankruptcy court, or within the time frames noted above, consumer automotive and first-lien consumer mortgage loans in bankruptcy are written down to their expected future cash flows, which is generally fair value of the collateral, less costs to sell, and second-lien consumer mortgage loans and consumer other loans are fully charged-off, unless it can be clearly demonstrated that repayment is likely to occur. Regardless of other timelines noted within this policy, loans are considered collateral dependent once foreclosure or repossession proceedings begin and are charged-off to the estimated fair value of the underlying collateral, less costs to sell at that time. Commercial loans are individually evaluated and written down to the estimated fair value of the collateral less costs to sell when collectability of the recorded balance is in doubt. Generally, all commercial loans are charged-off when it becomes unlikely that the borrower is willing or able to repay the remaining balance of the loan and any underlying collateral is not sufficient to recover the outstanding principal. Collateral dependent loans are charged-off to the fair market value of collateral less costs to sell when appropriate. Noncollateral dependent loans are fully written-off. Allowance for Loan Losses The allowance for loan losses (the allowance) is management’s estimate of incurred losses in the lending portfolios. We determine the amount of the allowance required for each of our portfolio segments based on its relative risk characteristics. The evaluation of these factors for both consumer and commercial finance receivables and loans involves quantitative analysis combined with sound management judgment. Additions to the allowance are charged to current period earnings through the provision for loan losses; amounts determined to be uncollectible are charged directly against the allowance, net of amounts recovered on previously charged-off accounts. The allowance is composed of two components: specific reserves established for individual loans evaluated as impaired and portfolio-level reserves established for large groups of typically smaller balance homogeneous loans that are collectively evaluated for impairment. We evaluate the adequacy of the allowance based on the combined total of these two components. Determining the appropriateness of the allowance is complex and requires judgment by management about the effect of matters that are inherently uncertain. It is possible that others, given the same information, may at any point in time reach different reasonable conclusions. Measurement of impairment for specific reserves is generally determined on a loan-by-loan basis. Loans determined to be specifically impaired are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate, an observable market price, or the estimated fair value of the collateral less estimated costs to sell when appropriate, whichever is determined to be the most appropriate. When these measurement values are lower than the net carrying value of that loan, impairment is recognized. Loans that are not identified as individually impaired are pooled with other loans with similar risk characteristics for evaluation of impairment for the portfolio-level allowance. For the purpose of calculating portfolio-level reserves, we have grouped our loans into four portfolio segments: consumer automotive, consumer mortgage, consumer other, and commercial. The allowance consists of the combination of a quantitative assessment component based on statistical models for consumer automotive, consumer mortgage, and commercial, and a vintage analysis for consumer other, a retrospective evaluation of actual loss information to loss forecasts, and includes a qualitative component based on management judgment. Management takes into consideration relevant qualitative factors, including external and internal trends such as the impacts of changes in underwriting standards, collections and account management effectiveness, geographic concentrations, and economic events, among other factors, that have occurred but are not yet reflected in the quantitative assessment component. Qualitative adjustments are documented, reviewed, and approved through our established risk governance processes and follow regulatory guidance. Management also considers the need for a reserve on unfunded non-derivative loan commitments across our portfolio segments, including lines of credit and standby letters of credit, using similar procedures and methodologies used to determine the allowance for loan losses while also considering historical loss ratios and potential usage levels. The reserve for unfunded loan commitments is recorded within other liabilities on our Consolidated Balance Sheet and the related expense is reported as other noninterest expense in our Consolidated Statement of Income . Refer to Note 28 for information on our unfunded loan commitments. During 2019, we did not substantively change any material aspect of our overall approach used to determine the allowance for loan losses for our portfolio segments. There were no material changes in criteria or estimation techniques as compared to prior periods that impacted the determination of the current period allowance for loan losses for our portfolio segments. However, during 2019, we acquired Health Credit Services and assumed their lending operations, which created our consumer other portfolio segment. The methodology used for the consumer other portfolio segment is described below. Refer to Note 9 for information on the allowance for loan losses. Consumer Loans Our consumer automotive, consumer mortgage, and consumer other portfolio segments are reviewed for impairment based on an analysis of loans that are grouped into common risk categories. We perform periodic and systematic detailed reviews of our lending portfolios to identify inherent risks and to assess the overall collectability of those portfolios. Loss models are utilized for these portfolios, which consider a variety of credit quality indicators including, but not limited to, historical loss experience, current economic conditions, credit scores, and expected loss factors by loan type. Consumer Automotive Portfolio Segment The allowance for loan losses within the consumer automotive portfolio segment is calculated using proprietary statistical models and other risk indicators applied to pools of loans with similar risk characteristics, including credit bureau score and loan-to-value (LTV) ratios to arrive at an estimate of incurred losses in the portfolio. These statistical loss forecasting models are utilized to estimate incurred losses and consider a variety of factors including, but not limited to, historical loss experience, estimated defaults based on portfolio trends, and general economic and business trends. These statistical models predict forecasted losses inherent in the portfolio. The forecasted losses consider historical factors such as frequency (the number of contracts that we expect to default) and loss severity (the loss amount of contracts we expect to default). The loss severity within the consumer automotive portfolio segment is impacted by the market values of vehicles that are repossessed. Vehicle market values are affected by numerous factors including vehicle supply, the condition of the vehicle upon repossession, the overall price and volatility of gasoline or diesel fuel, consumer preference related to specific vehicle segments, and other factors. The quantitative assessment component of the allowance may be supplemented with qualitative reserves based on management’s determination that such adjustments provide a better estimate of credit losses. This qualitative assessment takes into consideration relevant internal and external factors that have occurred, but are not yet reflected in the forecasted losses, and may affect the performance of the portfolio. Consumer Mortgage Portfolio Segment The allowance for loan losses within the consumer mortgage portfolio segment is calculated by using statistical models based on pools of loans with similar risk characteristics, including credit score, LTV, loan age, documentation type, product type, and loan purpose, to arrive at an estimate of incurred losses in the portfolio. These statistical loss forecasting models are utilized to estimate incurred losses and consider a variety of factors including, but not limited to, historical loss experience, estimated foreclosures or defaults based on portfolio trends, delinquencies, and general economic and business trends. The forecasted losses are statistically derived based on a suite of behavioral based transition models. This transition framework predicts various stages of delinquency, default, and voluntary prepayment over the course of the life of the loan. The transition probability is a function of the loan and borrower characteristics and economic variables and considers historical factors such as frequency and loss severity. When a default event is predicted, a severity model is applied to estimate future loan losses. Loss severity within the consumer mortgage portfolio segment is impacted by the market values of foreclosed properties, which is affected by numerous factors, including geographic considerations and the condition of the foreclosed property. The quantitative assessment component of the allowance may be supplemented with qualitative reserves based on management’s determination that such adjustments provide a be

Acquisitions Acquistions (Notes

Acquisitions Acquistions (Notes)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Acquisitions On October 1, 2019 , we acquired 100% of the equity of Credit Services Corporation, LLC, including its wholly owned subsidiary, Health Credit Services LLC (collectively Health Credit Services), a digital point-of-sale payment provider that offers financing to consumers for various healthcare procedures or services, for $177 million in cash. Health Credit Services operates as a wholly owned subsidiary of Ally. We applied the acquisition method of accounting to this transaction, which generally requires the initial recognition of assets acquired, including identifiable intangible assets, and liabilities assumed at their respective fair value. Goodwill is recognized as the excess of the acquisition price after the recognition of the net assets, including the identifiable intangible assets. Beginning in October 2019, financial information related to Health Credit Services, which we renamed Ally Lending, is included within Corporate and Other. The following table summarizes the allocation of cash consideration paid for Health Credit Services and the amounts of the identifiable assets acquired and liabilities assumed recognized at the acquisition date. ($ in millions) Purchase price Cash consideration $ 177 Allocation of purchase price to net assets acquired Finance receivables and loans 75 Intangible assets (a) 23 Cash and short-term investments 6 Other assets 6 Debt (62 ) Employee compensation and benefits (5 ) Other liabilities (19 ) Goodwill $ 153 (a) The weighted average amortization period on the acquired intangible assets was 3 years. Refer to Note 1 for further information on our intangible assets. The goodwill of $153 million arising from the acquisition consists largely of expected growth of the business as we leverage the Ally brand and our marketing capabilities to scale the acquired point-of-sale payment provider and expand the suite of financial products we offer to our existing growing customer base. The goodwill recognized is expected to be amortized for income tax purposes over a 15 -year period. Refer to Note 13 for the carrying amount of goodwill at the beginning and end of the reporting period.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers Our primary revenue sources, which include financing revenue and other interest income, are addressed by other GAAP and are not in the scope of ASC Topic 606, Revenue from Contracts with Customers. As part of our Insurance operations, we recognize revenue from insurance contracts, which are addressed by other GAAP and are not included in the scope of this standard. Certain noninsurance contracts within our Insurance operations, including vehicle service contracts (VSCs), guaranteed asset protection (GAP) contracts, and vehicle maintenance contracts (VMCs), are included in the scope of this standard. All revenue associated with noninsurance contracts is recognized over the contract term on a basis proportionate to the anticipated cost emergence. Further, commissions and sales expense incurred to obtain these contracts are amortized over the terms of the related policies and service contracts on the same basis as premiums and service revenue are earned, and all advertising costs are recognized as expense when incurred. The following is a description of our primary revenue sources that are derived from contracts with customers. Revenue from contracts with customers is recognized when control of the promised goods or services is transferred to our customers, and in an amount that reflects the consideration that we expect to receive in exchange for those goods or services. For information regarding our revenue recognition policies outside the scope of the amendments to the revenue recognition principles of ASC Topic 606, Revenue from Contracts with Customers , refer to Note 1. • Noninsurance contracts — We sell VSCs that offer owners mechanical repair protection and roadside assistance for new and used vehicles beyond the manufacturer’s new vehicle limited warranty. We sell GAP contracts that protect the customer against having to pay certain amounts to a lender above the fair market value of their vehicle if the vehicle is damaged and declared a total loss or stolen. We also sell VMCs that provide coverage for certain agreed-upon services, such as oil changes and tire rotations, over the coverage period. We receive payment in full at the inception of each of these contracts. Our performance obligation for these contracts is satisfied over the term of the contract and we recognize revenue over the contract term on a basis proportionate to the anticipated incurrence of costs, as we believe this is the most appropriate method to measure progress towards satisfaction of the performance obligation. • Sale of off-lease vehicles — When a customer’s vehicle lease matures, the customer has the option of purchasing or returning the vehicle. If the vehicle is returned to us, we obtain possession with the intent to sell through SmartAuction—our online auction platform, our dealer channel, or through various other physical auctions. Our performance obligation is satisfied and the remarketing gain or loss is recognized when control of the vehicle has passed to the buyer, which coincides with the sale date. Our actual sales proceeds from remarketing the vehicle may be higher or lower than the estimated residual value resulting in a gain or loss on remarketing recorded through depreciation expense on operating lease assets in our Consolidated Statement of Income. • Remarketing fee income — In addition to using SmartAuction as a remarketing channel for our returned lease vehicles, we maintain the internet auction site and administer the auction process for third-party use. We earn a service fee from dealers for every third-party vehicle sold through SmartAuction. Our performance obligation is to provide the online marketplace for used vehicle transactions to be consummated. This obligation is satisfied and revenue is recognized when control of the vehicle has passed to the buyer, which coincides with the sale date. This revenue is recorded as remarketing fees within other income in our Consolidated Statement of Income. • Brokerage commissions and other revenues through Ally Invest — We charge fees to customers related to their use of certain services on our Ally Invest digital wealth management and online brokerage platform. These fees include commissions on low-priced securities, option contracts, other security types, account service fees, account management fees on professional portfolio management services, and other ancillary fees. Commissions on customer-directed trades and account service fees are based on published fee schedules and are generated from a customer option to purchase the services offered under the contract. These options do not represent a material right and are only considered a contract when the customer executes their option to purchase these services. Based on this, the term of the contract does not extend beyond services provided, and as such revenue is recognized upon the completion of our performance obligation, which we view as the successful execution of the trade or service. Revenue on professional portfolio management services is calculated monthly based upon a fixed percentage of the client’s assets under management. Due to the fact that this revenue stream is composed of variable consideration that is based on factors outside of our control, we have deemed this revenue as constrained and we are unable to estimate the initial transaction price at the inception of the contract. We have elected to use the practical expedient under GAAP to recognize revenue monthly based on the amount we are able to invoice the customer. We also earn revenue from a fee-sharing agreement with our clearing broker related to the interest income the clearing broker earns on customer cash balances and margin loans made to our customers. We concluded the initial transaction price is exclusively variable consideration and, based on the nature of our performance obligation to allow the clearing broker to collect interest income from cash deposits and customer loans from our customers, we are unable to determine the amount of revenue to be recognized until the total customer cash balance or the total interest income recognized on margin loans has been determined, which occurs monthly. These revenue streams are recorded as other income in our Consolidated Statement of Income. • Brokered/agent commissions through Insurance operations — We have agreements with third parties to offer various vehicle protection products to consumers. We also have agreements with third-party insurers to offer various insurance coverages to dealers. Our performance obligation for these arrangements is satisfied when a customer or dealer has purchased a vehicle protection product or an insurance policy through the third-party provider. In determining the initial transaction price for these agreements, we noted that revenue on brokered/agent commissions is based on the volume of vehicle protection product contracts sold or a percentage of insurance premium written, which is not known to us at the inception of the agreements with these third-party providers. As such, we believe the initial transaction price is exclusively variable consideration and, based on the nature of the performance obligation, we are unable to determine the amount of revenue we will record until the customer purchases a vehicle protection product or a dealer purchases an insurance policy from the third-party provider. Once we are notified of vehicle protection product sales or insurance policies issued by the third-party providers, we record the commission earned as insurance premiums and service revenues earned in our Consolidated Statement of Income. • Deposit account and other banking fees — We charge depositors various account service fees including those for outgoing wires, excessive transactions, overdrafts, stop payments, and returned deposits. These fees are generated from a customer option to purchase services offered under the contract. These options do not represent a material right and are only considered a contract in accordance with the amendments to the revenue recognition principles when the customer exercises their option to purchase these account services. Based on this, the term for our contracts with customers is considered day-to-day, and the contract does not extend beyond the services already provided. Revenue derived from deposit account fees is recorded at the point in time we perform the requested service, and is recorded as other income in our Consolidated Statement of Income. As a debit card issuer, we also generate interchange fee income from merchants during debit card transactions and incur certain corresponding charges from merchant card networks. Our performance obligation is satisfied when we have initiated the payment of funds from a customer’s account to a merchant through our contractual agreements with the merchant card networks. Interchange fees are reported on a net basis as other income in our Consolidated Statement of Income. • Other revenue — Other revenue primarily includes service revenue related to various account management functions and fee income derived from third-party loans arranged through Clearlane—our online automotive lender exchange. These revenue streams are recorded as other income in our Consolidated Statement of Income. The following table presents a disaggregated view of our revenue from contracts with customers included in other revenue that falls within the scope of the revenue recognition principles of ASC Topic 606, Revenue from Contracts with Customers. Year ended December 31, ($ in millions) Automotive Finance operations Insurance operations Mortgage Finance operations Corporate Finance operations Corporate and Other Consolidated 2019 Revenue from contracts with customers Noninsurance contracts (a) (b) (c) $ — $ 542 $ — $ — $ — $ 542 Remarketing fee income 74 — — — — 74 Brokerage commissions and other revenue — — — — 61 61 Deposit account and other banking fees — — — — 16 16 Brokered/agent commissions — 14 — — — 14 Other 19 1 — — — 20 Total revenue from contracts with customers 93 557 — — 77 727 All other revenue 156 717 22 45 94 1,034 Total other revenue (d) $ 249 $ 1,274 $ 22 $ 45 $ 171 $ 1,761 2018 Revenue from contracts with customers Noninsurance contracts (a) (b) (c) $ — $ 506 $ — $ — $ — $ 506 Remarketing fee income 79 — — — — 79 Brokerage commissions and other revenue — — — — 62 62 Deposit account and other banking fees — — — — 13 13 Brokered/agent commissions — 15 — — — 15 Other 13 1 — — — 14 Total revenue from contracts with customers 92 522 — — 75 689 All other revenue 177 459 7 38 44 725 Total other revenue (d) $ 269 $ 981 $ 7 $ 38 $ 119 $ 1,414 (a) We had opening balances of $2.6 billion and $2.5 billion in unearned revenue associated with outstanding contracts at January 1, 2019, and January 1, 2018 , respectively, and $816 million and $786 million of these balances were recognized as insurance premiums and service revenue earned in our Consolidated Statement of Income during the year ended December 31, 2019 , and December 31, 2018 . (b) At December 31, 2019 , we had unearned revenue of $2.9 billion associated with outstanding contracts, and with respect to this balance we expect to recognize revenue of $768 million in 2020 , $682 million in 2021 , $569 million in 2022 , $433 million in 2023 , and $417 million thereafter. At December 31, 2018 , we had unearned revenue of $2.6 billion associated with outstanding contracts. (c) We had deferred insurance assets of $1.5 billion and $1.7 billion at January 1, 2019, and December 31, 2019 , respectively, and recognized $463 million of expense during the year ended December 31, 2019 . We had deferred insurance assets of $1.4 billion and $1.5 billion at January 1, 2018, and December 31, 2018 , respectively, and recognized $427 million of expense during the year ended December 31, 2018 . (d) Represents a component of total net revenue. Refer to Note 26 for further information on our reportable operating segments. In addition to the components of other revenue presented above, as part of our Automotive Finance operations, we recognized net remarketing gains of $69 million for the year ended December 31, 2019 , and $90 million for the year ended December 31, 2018 , on the sale of off-lease vehicles. These gains are included in depreciation expense on operating lease assets in our Consolidated Statement of Income .

Insurance Premiums and Service

Insurance Premiums and Service Revenue Insurance Premiums and Service Revenue (Notes)	12 Months Ended
	Dec. 31, 2019
Insurance Premiums and Service Revenue [Abstract]
Premiums Receivable Note	Insurance Premiums and Service Revenue The following table is a summary of insurance premiums and service revenue written and earned. 2019 2018 2017 Year ended December 31, ($ in millions) Written Earned Written Earned Written Earned Insurance premiums Direct $ 491 $ 464 $ 420 $ 414 $ 384 $ 364 Assumed — 2 — 4 2 5 Gross insurance premiums 491 466 420 418 386 369 Ceded (232 ) (209 ) (219 ) (197 ) (254 ) (188 ) Net insurance premiums 259 257 201 221 132 181 Service revenue 1,051 830 973 801 864 792 Insurance premiums and service revenue written and earned $ 1,310 $ 1,087 $ 1,174 $ 1,022 $ 996 $ 973 Premiums Receivable and Other Insurance Assets Premiums receivable and other insurance assets consisted of the following. December 31, ($ in millions) 2019 2018 Prepaid reinsurance premiums $ 551 $ 527 Reinsurance recoverable on unpaid losses 88 96 Reinsurance recoverable on paid losses 23 22 Premiums receivable 105 88 Deferred policy acquisition costs 1,791 1,593 Total premiums receivable and other insurance assets $ 2,558 $ 2,326

Other Income, Net of Losses

Other Income, Net of Losses	12 Months Ended
	Dec. 31, 2019
Other Nonoperating Income (Expense) [Abstract]
Other Income and Other Expense Disclosure	Other Income, Net of Losses Details of other income, net of losses, were as follows. Year ended December 31, ($ in millions) 2019 2018 2017 Late charges and other administrative fees $ 114 $ 110 $ 102 Remarketing fees 74 79 104 Income from equity-method investments 62 46 14 Servicing fees 17 27 51 Other, net 136 155 130 Total other income, net of losses $ 403 $ 417 $ 401

Reserves for Insurance Losses a

Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses	12 Months Ended
	Dec. 31, 2019
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Reserves for Insurance Losses and Loss Adjustment Expenses	Reserves for Insurance Losses and Loss Adjustment Expenses The following table shows incurred claims and allocated loss adjustment expenses, net of reinsurance. For the years ended December 31, ($ in millions) December 31, 2019 ($ in millions) Accident year (a) 2012 (b) 2013 (b) 2014 (b) 2015 (b) 2016 2017 2018 2019 Total of incurred-but-not-reported liabilities plus expected development on reported claims (c) Cumulative number of reported claims (c) 2012 $ 435 $ 430 $ 423 $ 423 $ 423 $ 422 422 $ 421 $ — 772,549 2013 376 365 370 370 369 368 368 — 672,278 2014 390 389 388 388 388 388 — 525,298 2015 274 271 272 272 272 — 342,267 2016 326 327 328 328 — 476,034 2017 310 314 315 — 481,646 2018 271 272 — 505,982 2019 303 23 515,689 Total $ 2,667 (a) Due to the discontinuation of various product lines and sale of certain international operations, information prior to 2012 has been excluded from the table in order to appropriately reflect the number of years for which claims are typically outstanding. In addition, given the short tail of our insurance contracts, the table above reflects the combined presentation of all business lines. (b) Information presented for the years 2012 through 2015 is unaudited supplementary information. (c) Claims are reported on a claimant basis. Claimant is defined as one vehicle for GAP products, one repair for VSCs and VMCs, one dealership for dealer inventory products, and per individual/coverage for run-off personal automotive products. The following table shows cumulative paid claims and allocated loss adjustment expenses, net of reinsurance. For the years ended December 31, ($ in millions) Accident year (a) 2012 (b) 2013 (b) 2014 (b) 2015 (b) 2016 2017 2018 2019 2012 $ 391 $ 412 $ 416 $ 418 $ 419 $ 421 $ 421 $ 421 2013 347 364 366 368 368 368 368 2014 369 388 388 388 388 388 2015 252 272 272 272 272 2016 302 327 328 328 2017 289 315 315 2018 245 273 2019 278 Total $ 2,643 All outstanding liabilities for loss and allocated loss adjustment expenses before 2012, net of reinsurance 8 Reserves for insurance losses and allocated loss adjustment expenses, net of reinsurance $ 32 (a) Due to the discontinuation of various product lines and sale of certain international operations, information prior to 2012 has been excluded from the table in order to appropriately reflect the number of years for which claims are typically outstanding. In addition, given the short tail of our insurance contracts, the table above reflects the combined presentation of all business lines. (b) Information presented for the years 2012 through 2015 is unaudited supplementary information. The following table shows the average annual percentage payout of incurred claims by age, net of reinsurance. The information presented is unaudited supplementary information. Year 1 2 3 4 5 6 7 8 Percentage payout of incurred claims 92.6 % 6.6 % 0.4 % 0.2 % 0.1 % 0.1 % 0.1 % — % The following table shows a reconciliation of the disclosures of incurred and paid claims development to the reserves for insurance losses and loss adjustment expenses. December 31, ($ in millions) 2019 2018 2017 Reserves for insurance losses and loss adjustment expenses, net of reinsurance $ 32 $ 35 $ 30 Total reinsurance recoverable on unpaid claims 88 96 108 Unallocated loss adjustment expenses 2 3 2 Total gross reserves for insurance losses and loss adjustment expenses $ 122 $ 134 $ 140 The following table shows a rollforward of our reserves for insurance losses and loss adjustment expenses. ($ in millions) 2019 2018 2017 Total gross reserves for insurance losses and loss adjustment expenses at January 1, $ 134 $ 140 $ 149 Less: Reinsurance recoverable 96 108 108 Net reserves for insurance losses and loss adjustment expenses at January 1, 38 32 41 Net insurance losses and loss adjustment expenses incurred related to: Current year 321 291 332 Prior years (a) — 4 — Total net insurance losses and loss adjustment expenses incurred 321 295 332 Net insurance losses and loss adjustment expenses paid or payable related to: Current year (295 ) (263 ) (309 ) Prior years (30 ) (26 ) (32 ) Total net insurance losses and loss adjustment expenses paid or payable (325 ) (289 ) (341 ) Net reserves for insurance losses and loss adjustment expenses at December 31, 34 38 32 Plus: Reinsurance recoverable 88 96 108 Total gross reserves for insurance losses and loss adjustment expenses at December 31, $ 122 $ 134 $ 140 (a) There have been no material adverse changes to the reserve for prior years.

Other Operating Expenses

Other Operating Expenses	12 Months Ended
	Dec. 31, 2019
Operating Expenses [Abstract]
Other Operating Income and Expense	Other Operating Expenses Details of other operating expenses were as follows. Year ended December 31, ($ in millions) 2019 2018 2017 Insurance commissions $ 475 $ 440 $ 415 Technology and communications 311 299 284 Advertising and marketing 180 172 133 Lease and loan administration 172 164 159 Professional services 126 133 113 Regulatory and licensing fees 115 121 113 Vehicle remarketing and repossession 105 111 110 Property and equipment depreciation 96 87 89 Occupancy 57 45 46 Non-income taxes 34 29 21 Amortization of intangible assets 13 11 11 Other 202 202 189 Total other operating expenses $ 1,886 $ 1,814 $ 1,683

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure	Investment Securities Our investment portfolio includes various debt and equity securities. Our debt securities, which are classified as available-for-sale or held-to-maturity, include government securities, corporate bonds, asset-backed securities, and mortgage-backed securities. The cost, fair value, and gross unrealized gains and losses on available-for-sale and held-to-maturity debt securities were as follows. 2019 2018 Amortized cost Gross unrealized Fair value Amortized cost Gross unrealized Fair value December 31, ($ in millions) gains losses gains losses Available-for-sale securities Debt securities U.S. Treasury and federal agencies $ 2,059 $ 6 $ (17 ) $ 2,048 $ 1,911 $ — $ (60 ) $ 1,851 U.S. States and political subdivisions 623 19 (1 ) 641 816 3 (17 ) 802 Foreign government 184 3 (1 ) 186 145 1 (1 ) 145 Agency mortgage-backed residential (a) 21,183 257 (36 ) 21,404 17,486 47 (395 ) 17,138 Mortgage-backed residential 2,841 20 (11 ) 2,850 2,796 1 (111 ) 2,686 Agency mortgage-backed commercial 1,344 44 (6 ) 1,382 3 — — 3 Mortgage-backed commercial 41 1 — 42 715 1 (2 ) 714 Asset-backed 365 3 — 368 723 2 (2 ) 723 Corporate debt 1,327 37 (1 ) 1,363 1,286 1 (46 ) 1,241 Total available-for-sale securities (b) (c) (d) $ 29,967 $ 390 $ (73 ) $ 30,284 $ 25,881 $ 56 $ (634 ) $ 25,303 Held-to-maturity securities Debt securities Agency mortgage-backed residential (a) (e) $ 1,547 $ 38 $ (6 ) $ 1,579 $ 2,319 $ 6 $ (61 ) $ 2,264 Asset-backed retained notes 21 — — 21 43 — — 43 Total held-to-maturity securities $ 1,568 $ 38 $ (6 ) $ 1,600 $ 2,362 $ 6 $ (61 ) $ 2,307 (a) During the year ended December 31, 2019 , agency mortgage-backed residential securities with an amortized cost of $943 million and a fair value of $945 million were transferred from held-to-maturity to available-for-sale, which resulted in the establishment of a $2 million net unrealized gain at the time of transfer. The transfer was made following the issuance of the final rules by banking agencies implementing provisions of the Economic Growth, Regulatory Relief, and Consumer Protection Act (EGRRCP Act) as further described in the section titled Regulation and Supervision in Part I, Item 1, of this report. Under the final rules, Ally is no longer subject to liquidity coverage ratio requirements. (b) Certain entities related to our Insurance operations are required to deposit securities with state regulatory authorities. These deposited securities totaled $12 million at both December 31, 2019 , and December 31, 2018 . (c) Certain available-for-sale securities are included in fair value hedging relationships. Refer to Note 21 for additional information. (d) Available-for-sale securities with a fair value of $1.9 billion and $9.2 billion at December 31, 2019 , and December 31, 2018 , respectively, were pledged to secure advances from the FHLB, short-term borrowings or repurchase agreements, or for other purposes as required by contractual obligation or law. Under these agreements, we granted the counterparty the right to sell or pledge $118 million and $821 million of the underlying investment securities at December 31, 2019 , and December 31, 2018 , respectively. (e) Held-to-maturity securities with a fair value of $915 million and $1.2 billion at December 31, 2019 , and December 31, 2018 , respectively, were pledged to secure advances from the FHLB. The maturity distribution of debt securities outstanding is summarized in the following tables based upon contractual maturities. Call or prepayment options may cause actual maturities to differ from contractual maturities. Total Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years ($ in millions) Amount Yield Amount Yield Amount Yield Amount Yield Amount Yield December 31, 2019 Fair value of available-for-sale securities (a) U.S. Treasury and federal agencies $ 2,048 1.5 % $ 65 2.1 % $ 1,590 1.4 % $ 393 1.7 % $ — — % U.S. States and political subdivisions 641 3.1 22 2.7 75 2.3 159 2.8 385 3.4 Foreign government 186 1.9 35 0.4 65 2.3 86 2.3 — — Agency mortgage-backed residential 21,404 3.2 — — — — 47 2.0 21,357 3.2 Mortgage-backed residential 2,850 3.2 — — — — — — 2,850 3.2 Agency mortgage-backed commercial 1,382 2.9 — — 3 3.2 1,109 3.0 270 2.4 Mortgage-backed commercial 42 3.5 — — — — — — 42 3.5 Asset-backed 368 3.5 — — 317 3.6 5 2.7 46 3.0 Corporate debt 1,363 3.2 125 2.9 580 3.0 649 3.4 9 3.3 Total available-for-sale securities $ 30,284 3.1 $ 247 2.3 $ 2,630 2.1 $ 2,448 2.8 $ 24,959 3.2 Amortized cost of available-for-sale securities $ 29,967 $ 246 $ 2,624 $ 2,378 $ 24,719 Amortized cost of held-to-maturity securities Agency mortgage-backed residential $ 1,547 3.2 % $ — — % $ — — % $ — — % $ 1,547 3.2 % Asset-backed retained notes 21 2.2 — — 21 2.2 — — — — Total held-to-maturity securities $ 1,568 3.2 $ — — $ 21 2.2 $ — — $ 1,547 3.2 December 31, 2018 Fair value of available-for-sale securities (a) U.S. Treasury and federal agencies $ 1,851 1.9 % $ 12 1.0 % $ 1,277 1.8 % $ 562 2.0 % $ — — % U.S. States and political subdivisions 802 3.0 49 1.9 43 2.3 252 2.6 458 3.4 Foreign government 145 2.4 18 3.1 60 2.3 67 2.4 — — Agency mortgage-backed residential 17,138 3.3 — — — — 54 1.9 17,084 3.3 Mortgage-backed residential 2,686 3.3 — — — — — — 2,686 3.3 Agency mortgage-backed commercial 3 3.1 — — 3 3.1 — — — — Mortgage-backed commercial 714 3.8 — — — — 46 3.9 668 3.8 Asset-backed 723 3.5 — — 478 3.4 121 4.0 124 3.3 Corporate debt 1,241 3.1 144 2.8 496 2.9 581 3.3 20 5.5 Total available-for-sale securities $ 25,303 3.2 $ 223 2.6 $ 2,357 2.4 $ 1,683 2.8 $ 21,040 3.3 Amortized cost of available-for-sale securities $ 25,881 $ 224 $ 2,405 $ 1,743 $ 21,509 Amortized cost of held-to-maturity securities Agency mortgage-backed residential $ 2,319 3.2 % $ — — % $ — — % $ — — % $ 2,319 3.2 % Asset-backed retained notes 43 2.0 — — 42 2.0 1 3.3 — — Total held-to-maturity securities $ 2,362 3.2 $ — — $ 42 2.0 $ 1 3.3 $ 2,319 3.2 (a) Yield is calculated using the effective yield of each security at the end of the period, weighted based on the market value. The effective yield considers the contractual coupon and amortized cost, and excludes expected capital gains and losses. The balances of cash equivalents were $73 million and $35 million at December 31, 2019 , and December 31, 2018 , respectively, and were composed primarily of money-market accounts and short-term securities, including U.S. Treasury bills. The following table presents interest and dividends on investment securities. Year ended December 31, ($ in millions) 2019 2018 2017 Taxable interest $ 858 $ 690 $ 534 Taxable dividends 14 14 12 Interest and dividends exempt from U.S. federal income tax 15 25 22 Interest and dividends on investment securities $ 887 $ 729 $ 568 The following table presents gross gains and losses realized upon the sales of available-for-sale securities, and net gains or losses on equity securities held during the period. There were no other-than-temporary impairments of available-for-sale securities for the periods presented. Year ended December 31, ($ in millions) 2019 2018 2017 Available-for-sale securities Gross realized gains $ 82 $ 12 $ 106 Gross realized losses (a) (4 ) (1 ) (4 ) Net realized gains on available-for-sale securities 78 11 102 Net realized gain on equity securities 73 60 Net unrealized gain (loss) on equity securities 92 (121 ) Other gain (loss) on investments, net $ 243 $ (50 ) $ 102 (a) Certain available-for-sale securities were sold at a loss in 2019 , 2018 , and 2017 as a result of identifiable market or credit events, or a loss was realized based on corporate actions outside of our control (such as a call by the issuer). Any such sales were made in accordance with our risk-management policies and practices. The table below summarizes available-for-sale and held-to-maturity securities in an unrealized loss position, which we evaluated for other than temporary impairment. For additional information on our methodology, refer to Note 1 . As of December 31, 2019 , we did not have the intent to sell the available-for-sale or held-to-maturity securities with an unrealized loss position and we do not believe it is more likely than not that we will be required to sell these securities before recovery of their amortized cost basis. As a result of this evaluation, we believe that the securities with an unrealized loss position are not considered to be other-than-temporarily impaired at December 31, 2019 . 2019 2018 Less than 12 months 12 months or longer Less than 12 months 12 months or longer December 31, ($ in millions) Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss Available-for-sale securities Debt securities U.S. Treasury and federal agencies $ 1,267 $ (11 ) $ 279 $ (6 ) $ 31 $ — $ 1,758 $ (60 ) U.S. States and political subdivisions 72 (1 ) 5 — 259 (3 ) 317 (14 ) Foreign government 40 (1 ) 3 — 6 — 74 (1 ) Agency mortgage-backed residential 4,606 (23 ) 908 (13 ) 5,537 (94 ) 7,808 (301 ) Mortgage-backed residential 613 (4 ) 203 (7 ) 1,024 (20 ) 1,360 (91 ) Agency mortgage-backed commercial 335 (6 ) — — — — — — Mortgage-backed commercial — — — — 347 (1 ) 36 (1 ) Asset-backed 8 — 11 — 294 (1 ) 124 (1 ) Corporate debt 71 — 41 (1 ) 576 (19 ) 569 (27 ) Total temporarily impaired available-for-sale securities $ 7,012 $ (46 ) $ 1,450 $ (27 ) $ 8,074 $ (138 ) $ 12,046 $ (496 ) Held-to-maturity securities Debt securities Agency mortgage-backed residential $ 283 $ (6 ) $ — $ — $ 457 $ (6 ) $ 1,376 $ (55 ) Asset-backed retained notes — — 3 — 16 — 19 — Total held-to-maturity debt securities $ 283 $ (6 ) $ 3 $ — $ 473 $ (6 ) $ 1,395 $ (55 )

Finance Receivables and Loans,

Finance Receivables and Loans, Net	12 Months Ended
	Dec. 31, 2019
Loans and Leases Receivable, Net Amount [Abstract]
Loans, Notes, Trade and Other Receivables Disclosure	Finance Receivables and Loans, Net The composition of finance receivables and loans reported at gross carrying value was as follows. December 31, ($ in millions) 2019 2018 Consumer automotive (a) $ 72,390 $ 70,539 Consumer mortgage Mortgage Finance (b) 16,181 15,155 Mortgage — Legacy (c) 1,141 1,546 Total consumer mortgage 17,322 16,701 Consumer other (d) 212 — Total consumer 89,924 87,240 Commercial Commercial and industrial Automotive 28,332 33,672 Other 5,014 4,205 Commercial real estate 4,961 4,809 Total commercial 38,307 42,686 Total finance receivables and loans (e) $ 128,231 $ 129,926 (a) Certain finance receivables and loans are included in fair value hedging relationships. Refer to Note 21 for additional information. (b) Includes loans originated as interest-only mortgage loans of $11 million and $18 million at December 31, 2019 , and December 31, 2018 , respectively, 47% of which are expected to start principal amortization in 2020 . The remainder of these loans have exited the interest-only period. (c) Includes loans originated as interest-only mortgage loans of $212 million and $341 million at December 31, 2019 , and December 31, 2018 , respectively, of which 99% have exited the interest-only period. (d) Includes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option. (e) Totals include net unearned income, unamortized premiums and discounts, and deferred fees and costs of $503 million and $587 million at December 31, 2019 , and December 31, 2018 , respectively. The following tables present an analysis of the activity in the allowance for loan losses on finance receivables and loans. ($ in millions) Consumer automotive Consumer mortgage Consumer other (a) Commercial Total Allowance at January 1, 2019 $ 1,048 $ 53 $ — $ 141 $ 1,242 Charge-offs (b) (1,423 ) (13 ) (5 ) (49 ) (1,490 ) Recoveries 493 21 — — 514 Net charge-offs (930 ) 8 (5 ) (49 ) (976 ) Provision for loan losses 957 (13 ) 14 40 998 Other — (2 ) — 1 (1 ) Allowance at December 31, 2019 $ 1,075 $ 46 $ 9 $ 133 $ 1,263 Allowance for loan losses at December 31, 2019 Individually evaluated for impairment $ 38 $ 18 $ — $ 33 $ 89 Collectively evaluated for impairment 1,037 28 9 100 1,174 Finance receivables and loans at gross carrying value Ending balance $ 72,390 $ 17,322 $ 201 $ 38,307 $ 128,220 Individually evaluated for impairment 538 208 — 215 961 Collectively evaluated for impairment 71,852 17,114 201 38,092 127,259 (a) Excludes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option. (b) Represents the amount of the gross carrying value directly written off. For consumer and commercial loans, the loss from a charge-off is measured as the difference between the gross carrying value of a loan and the fair value of the collateral, less costs to sell. Refer to Note 1 for more information regarding our charge-off policies. ($ in millions) Consumer automotive Consumer mortgage Commercial Total Allowance at January 1, 2018 $ 1,066 $ 79 $ 131 $ 1,276 Charge-offs (a) (1,383 ) (35 ) (15 ) (1,433 ) Recoveries 456 25 7 488 Net charge-offs (927 ) (10 ) (8 ) (945 ) Provision for loan losses 911 (15 ) 22 918 Other (b) (2 ) (1 ) (4 ) (7 ) Allowance at December 31, 2018 $ 1,048 $ 53 $ 141 $ 1,242 Allowance for loan losses at December 31, 2018 Individually evaluated for impairment $ 44 $ 23 $ 56 $ 123 Collectively evaluated for impairment 1,004 30 85 1,119 Finance receivables and loans at gross carrying value Ending balance $ 70,539 $ 16,701 $ 42,686 $ 129,926 Individually evaluated for impairment 495 231 349 1,075 Collectively evaluated for impairment 70,044 16,470 42,337 128,851 (a) Represents the amount of the gross carrying value directly written off. For consumer and commercial loans, the loss from a charge-off is measured as the difference between the gross carrying value of a loan and the fair value of the collateral, less costs to sell. Refer to Note 1 for more information regarding our charge-off policies. (b) Primarily related to the transfer of finance receivables and loans from held-for-investment to held-for-sale. The following table presents information about significant sales of finance receivables and loans and transfers of finance receivables and loans from held-for-investment to held-for-sale based on net carrying value. Year ended December 31, ($ in millions) 2019 2018 Consumer automotive $ 20 $ 578 Consumer mortgage 940 10 Commercial — 238 Total sales and transfers (a) $ 960 $ 826 (a) During the year ended December 31, 2019 , we also sold $131 million of loans held-for-sale that were initially classified as finance receivables and loans held-for-investment and were transferred to held-for-sale during 2018, and transferred $79 million of finance receivables from held-for-sale to held-for-investment, both relating to equipment finance receivables from our commercial automotive business. The following table presents information about significant purchases of finance receivables and loans based on unpaid principal balance at the time of purchase. Year ended December 31, ($ in millions) 2019 2018 Consumer automotive $ 531 $ 896 Consumer mortgage 3,451 4,446 Consumer other (a) 117 — Commercial 46 15 Total purchases of finance receivables and loans $ 4,145 $ 5,357 (a) During the year ended December 31, 2019 , we also obtained $75 million of finance receivables and loans from our acquisition of Health Credit Services. For additional information on our acquisition, refer to Note 2 . The following table presents an analysis of our past-due finance receivables and loans recorded at gross carrying value. December 31, ($ in millions) 30–59 days past due 60–89 days past due 90 days or more past due Total past due Current Total finance receivables and loans 2019 Consumer automotive $ 2,185 $ 590 $ 367 $ 3,142 $ 69,248 $ 72,390 Consumer mortgage Mortgage Finance 56 11 9 76 16,105 16,181 Mortgage — Legacy 25 8 28 61 1,080 1,141 Total consumer mortgage 81 19 37 137 17,185 17,322 Consumer other (a) 3 2 2 7 194 201 Total consumer 2,269 611 406 3,286 86,627 89,913 Commercial Commercial and industrial Automotive 34 — 28 62 28,270 28,332 Other — — 17 17 4,997 5,014 Commercial real estate — — 4 4 4,957 4,961 Total commercial 34 — 49 83 38,224 38,307 Total consumer and commercial $ 2,303 $ 611 $ 455 $ 3,369 $ 124,851 $ 128,220 2018 Consumer automotive $ 2,107 $ 537 $ 296 $ 2,940 $ 67,599 $ 70,539 Consumer mortgage Mortgage Finance 67 5 4 76 15,079 15,155 Mortgage — Legacy 30 10 42 82 1,464 1,546 Total consumer mortgage 97 15 46 158 16,543 16,701 Total consumer 2,204 552 342 3,098 84,142 87,240 Commercial Commercial and industrial Automotive — 1 31 32 33,640 33,672 Other — 4 16 20 4,185 4,205 Commercial real estate — — 1 1 4,808 4,809 Total commercial — 5 48 53 42,633 42,686 Total consumer and commercial $ 2,204 $ 557 $ 390 $ 3,151 $ 126,775 $ 129,926 (a) Excludes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option. The following table presents the gross carrying value of our finance receivables and loans on nonaccrual status. December 31, ($ in millions) 2019 2018 Consumer automotive $ 762 $ 664 Consumer mortgage Mortgage Finance 17 9 Mortgage — Legacy 40 70 Total consumer mortgage 57 79 Consumer other 2 — Total consumer 821 743 Commercial Commercial and industrial Automotive 73 203 Other 138 142 Commercial real estate 4 4 Total commercial 215 349 Total consumer and commercial finance receivables and loans $ 1,036 $ 1,092 Management performs a quarterly analysis of the consumer automotive, consumer mortgage, consumer other, and commercial portfolios using a range of credit quality indicators to assess the adequacy of the allowance for loan losses based on historical and current trends. The following tables present the population of loans by quality indicators for our consumer automotive, consumer mortgage, and commercial portfolios. The following table presents performing and nonperforming credit quality indicators in accordance with our internal accounting policies for our consumer finance receivables and loans recorded at gross carrying value. Nonperforming loans include finance receivables and loans on nonaccrual status when the principal or interest has been delinquent for 90 days or more, or when full collection is not expected. Refer to Note 1 for additional information. 2019 2018 December 31, ($ in millions) Performing Nonperforming Total Performing Nonperforming Total Consumer automotive $ 71,628 $ 762 $ 72,390 $ 69,875 $ 664 $ 70,539 Consumer mortgage Mortgage Finance 16,164 17 16,181 15,146 9 15,155 Mortgage — Legacy 1,101 40 1,141 1,476 70 1,546 Total consumer mortgage 17,265 57 17,322 16,622 79 16,701 Consumer other (a) 199 2 201 — — — Total consumer $ 89,092 $ 821 $ 89,913 $ 86,497 $ 743 $ 87,240 (a) Excludes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option. The following table presents pass and criticized credit quality indicators based on regulatory definitions for our commercial finance receivables and loans recorded at gross carrying value. 2019 2018 December 31, ($ in millions) Pass Criticized (a) Total Pass Criticized (a) Total Commercial and industrial Automotive $ 25,235 $ 3,097 $ 28,332 $ 30,799 $ 2,873 $ 33,672 Other 4,225 789 5,014 3,373 832 4,205 Commercial real estate 4,620 341 4,961 4,538 271 4,809 Total commercial $ 34,080 $ 4,227 $ 38,307 $ 38,710 $ 3,976 $ 42,686 (a) Includes loans classified as special mention, substandard, or doubtful. These classifications are based on regulatory definitions and generally represent loans within our portfolio that have a higher default risk or have already defaulted. Impaired Loans and Troubled Debt Restructurings Impaired Loans Loans are considered impaired when we determine it is probable that we will be unable to collect all amounts due according to the terms of the loan agreement. For more information on our impaired finance receivables and loans, refer to Note 1 . The following table presents information about our impaired finance receivables and loans. December 31, ($ in millions) Unpaid principal balance (a) Gross carrying value Impaired with no allowance Impaired with an allowance Allowance for impaired loans 2019 Consumer automotive $ 553 $ 538 $ 113 $ 425 $ 38 Consumer mortgage Mortgage Finance 14 14 6 8 — Mortgage — Legacy 199 194 64 130 18 Total consumer mortgage 213 208 70 138 18 Total consumer 766 746 183 563 56 Commercial Commercial and industrial Automotive 73 73 1 72 12 Other 170 138 73 65 21 Commercial real estate 4 4 4 — — Total commercial 247 215 78 137 33 Total consumer and commercial finance receivables and loans $ 1,013 $ 961 $ 261 $ 700 $ 89 2018 Consumer automotive $ 503 $ 495 $ 105 $ 390 $ 44 Consumer mortgage Mortgage Finance 15 15 6 9 1 Mortgage — Legacy 221 216 65 151 22 Total consumer mortgage 236 231 71 160 23 Total consumer 739 726 176 550 67 Commercial Commercial and industrial Automotive 203 203 112 91 10 Other 159 142 40 102 46 Commercial real estate 4 4 4 — — Total commercial 366 349 156 193 56 Total consumer and commercial finance receivables and loans $ 1,105 $ 1,075 $ 332 $ 743 $ 123 (a) Adjusted for charge-offs. The following table presents average balance and interest income for our impaired finance receivables and loans. 2019 2018 2017 Year ended December 31, ($ in millions) Average balance Interest income Average balance Interest income Average balance Interest income Consumer automotive $ 510 $ 35 $ 478 $ 28 $ 391 $ 21 Consumer mortgage Mortgage Finance 14 1 11 1 8 — Mortgage — Legacy 206 9 218 10 234 10 Total consumer mortgage 220 10 229 11 242 10 Total consumer 730 45 707 39 633 31 Commercial Commercial and industrial Automotive 113 2 93 4 49 2 Other 121 — 84 — 69 9 Commercial real estate 5 — 5 1 5 — Total commercial 239 2 182 5 123 11 Total consumer and commercial finance receivables and loans $ 969 $ 47 $ 889 $ 44 $ 756 $ 42 Troubled Debt Restructurings TDRs are loan modifications where concessions were granted to borrowers experiencing financial difficulties. For consumer automotive loans, we may offer several types of assistance to aid our customers, including payment extensions and rewrites of the loan terms. Additionally, for mortgage loans, as part of certain programs, we offer mortgage loan modifications to qualified borrowers. These programs are in place to provide support to our mortgage customers in financial distress, including principal forgiveness, maturity extensions, delinquent interest capitalization, and changes to contractual interest rates. Total TDRs recorded at gross carrying value were $867 million , $812 million , and $712 million at December 31, 2019 , 2018, and 2017, respectively. Total commitments to lend additional funds to borrowers whose terms had been modified in a TDR were $17 million , $4 million , and $6 million at December 31, 2019 , 2018, and 2017, respectively. Refer to Note 1 for additional information. The following tables present information related to finance receivables and loans recorded at gross carrying value modified in connection with a TDR during the period. Year ended December 31, ($ in millions) Number of loans Pre-modification gross carrying value Post-modification gross carrying value 2019 Consumer automotive 27,623 $ 476 $ 413 Consumer mortgage Mortgage Finance 8 1 1 Mortgage — Legacy 61 8 8 Total consumer mortgage 69 9 9 Total consumer finance receivables and loans 27,692 $ 485 $ 422 2018 Consumer automotive 26,748 $ 426 $ 378 Consumer mortgage Mortgage Finance 23 9 9 Mortgage — Legacy 204 30 29 Total consumer mortgage 227 39 38 Total consumer finance receivables and loans 26,975 $ 465 $ 416 2017 Consumer automotive 26,156 $ 380 $ 333 Consumer mortgage Mortgage Finance 4 1 1 Mortgage — Legacy 122 21 21 Total consumer mortgage 126 22 22 Total consumer finance receivables and loans 26,282 $ 402 $ 355 Year ended December 31, ($ in millions) Number of loans Pre-modification gross carrying value Post-modification gross carrying value 2019 Commercial and industrial Automotive 7 $ 46 $ 46 Other 3 82 46 Total commercial finance receivables and loans 10 $ 128 $ 92 2018 Commercial and industrial Automotive 3 $ 4 $ 4 Other 3 85 82 Total commercial finance receivables and loans 6 $ 89 $ 86 2017 Commercial and industrial Automotive 4 $ 16 $ 15 Other — 44 44 Commercial real estate 2 3 3 Total commercial finance receivables and loans 6 $ 63 $ 62 The following table presents information about finance receivables and loans recorded at gross carrying value that have redefaulted during the reporting period and were within 12 months or less of being modified as a TDR. Redefault is when finance receivables and loans meet the requirements for evaluation under our charge-off policy (refer to Note 1 for additional information) except for commercial finance receivables and loans, where redefault is defined as 90 days past due. Year ended December 31, ($ in millions) Number of loans Gross carrying value Charge-off amount 2019 Consumer automotive 7,215 $ 81 $ 52 Total consumer finance receivables and loans 7,215 $ 81 $ 52 2018 Consumer automotive 9,711 $ 111 $ 73 Consumer mortgage Mortgage — Legacy 2 — — Total consumer finance receivables and loans 9,713 $ 111 $ 73 2017 Consumer automotive 8,829 $ 102 $ 71 Consumer mortgage Mortgage Finance 1 1 — Mortgage — Legacy 2 — — Total consumer finance receivables and loans 8,832 $ 103 $ 71 Concentration Risk Consumer We monitor our consumer loan portfolio for concentration risk across the states in which we lend. The highest concentrations of consumer loans are in California and Texas, which represented an aggregate of 24.9% and 25.4% of our total outstanding consumer finance receivables and loans at December 31, 2019 , and December 31, 2018 , respectively. The following table shows the percentage of consumer automotive and consumer mortgage finance receivables and loans by state concentration based on gross carrying value. 2019 (a) 2018 December 31, Consumer automotive Consumer mortgage Consumer automotive Consumer mortgage California 8.5 % 35.1 % 8.4 % 36.9 % Texas 12.4 6.5 12.8 6.2 Florida 8.8 5.1 8.8 4.7 Pennsylvania 4.6 1.9 4.5 1.4 Illinois 4.1 2.6 4.1 3.0 Georgia 3.9 2.8 4.1 2.8 North Carolina 4.0 2.0 3.9 1.7 New York 3.1 3.0 3.1 2.4 Ohio 3.6 0.5 3.5 0.4 New Jersey 2.8 2.3 2.7 2.1 Other United States 44.2 38.2 44.1 38.4 Total consumer loans 100.0 % 100.0 % 100.0 % 100.0 % (a) Presentation is in descending order as a percentage of total consumer finance receivables and loans at December 31, 2019. Commercial Real Estate The commercial real estate portfolio consists of finance receivables and loans issued primarily to automotive dealers. The following table presents the percentage of total commercial real estate finance receivables and loans by state concentration based on gross carrying value. December 31, 2019 2018 Texas 15.0 % 15.5 % Florida 11.6 11.6 Michigan 8.2 6.8 California 7.2 8.3 New York 5.9 4.8 North Carolina 4.6 3.6 Georgia 3.5 4.0 New Jersey 2.9 3.1 South Carolina 2.8 3.4 Illinois 2.4 2.0 Other United States 35.9 36.9 Total commercial real estate finance receivables and loans 100.0 % 100.0 % Commercial Criticized Exposure Finance receivables and loans classified as special mention, substandard, or doubtful are reported as criticized. These classifications are based on regulatory definitions and generally represent finance receivables and loans within our portfolio that have a higher default risk or have already defaulted. These finance receivables and loans require additional monitoring and review including specific actions to mitigate our potential loss. The following table presents the percentage of total commercial criticized finance receivables and loans by industry concentration based on gross carrying value. December 31, 2019 2018 Automotive 81.7 % 80.6 % Services 5.4 5.0 Electronics 3.7 2.3 Other 9.2 12.1 Total commercial criticized finance receivables and loans 100.0 % 100.0 %

Leasing

Leasing	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leasing On January 1, 2019, we adopted the amendments to the lease accounting principles. Refer to the section titled Recently Adopted Accounting Standards in Note 1 for additional information. Ally as the Lessee We have operating leases for our corporate facilities, which have remaining lease terms of 8 months to 12 years. Most of the property leases have fixed payment terms with annual fixed-escalation clauses and include options to extend the leases for periods that range from 3 months to 15 years. Some of those lease agreements also include options to terminate the leases in periods that range from 2 to 6 years after the commencement of the leases. We have not included any of these term extensions or termination provisions in our estimates of the lease term, as we do not consider it reasonably certain that the options will be exercised. We also have operating leases for a fleet of vehicles that is used by our sales force for business purposes, with noncancelable lease terms of 367 days. Thereafter, the leases are month-to-month, up to a maximum of 48 months from inception. The following table details our total investment in operating leases. ($ in millions) December 31, 2019 January 1, 2019 (a) Assets Operating lease right-of-use assets (b) $ 168 $ 161 Liabilities Operating lease liabilities (c) $ 196 $ 190 (a) Date of adoption. (b) Included in other assets on our Consolidated Balance Sheet . (c) Included in accrued expenses and other liabilities on our Consolidated Balance Sheet . During the year ended December 31, 2019 , we paid $49 million , in cash for amounts included in the measurement of lease liabilities at December 31, 2019 . This amount is included in net cash provided by operating activities in the Consolidated Statement of Cash Flows . During the year ended December 31, 2019 , we obtained $52 million of ROU assets in exchange for new operating lease liabilities. As of December 31, 2019 , the weighted-average remaining lease term of our operating lease portfolio was 7 years, and the weighted-average discount rate was 2.85% . The following table presents future minimum rental payments we are required to make under operating leases that have commenced as of December 31, 2019 , and that have noncancelable lease terms expiring after December 31, 2019 . Year ended December 31, ($ in millions) 2020 $ 50 2021 43 2022 29 2023 18 2024 14 2025 and thereafter 62 Total undiscounted cash flows 216 Difference between undiscounted cash flows and discounted cash flows (20 ) Total lease liability $ 196 In addition to the above, we entered into a forward-starting lease agreement in September 2017, for a new corporate facility in Charlotte, North Carolina, where we plan to consolidate several existing facilities into that location. The lessor and their agents are currently constructing the facilities at this location, with the lease scheduled to commence in April 2021 after construction is completed. The lease agreement will have a total of $290 million in undiscounted future lease payments over the 15 -year term of the lease. We also have an option to purchase this facility after construction is completed, subject to certain terms and conditions. Future minimum rental payments required under operating leases as of December 31, 2018, prior to the date of adoption and as defined by the previous lease accounting guidance, with noncancelable lease terms expiring after December 31, 2018, were as follows. Year ended December 31, ($ in millions) 2019 $ 48 2020 47 2021 46 2022 37 2023 31 2024 and thereafter 294 Total minimum payments required $ 503 The following table details the components of total net operating lease expense. Year ended December 31, ($ in millions) 2019 2018 2017 Operating lease expense $ 45 $ 43 $ 42 Variable lease expense 8 7 7 Total lease expense, net (a) $ 53 $ 50 $ 49 (a) Included in other operating expenses in our Consolidated Statement of Income Ally as the Lessor Investment in Operating Leases We purchase consumer operating lease contracts and the associated vehicles from dealerships after those contracts are executed by the dealers and the consumers. The amount we pay a dealer for an operating lease contract is based on the negotiated price for the vehicle less vehicle trade-in, down payment from the consumer, and available automotive manufacturer incentives. Under the operating lease, the consumer is obligated to make payments in amounts equal to the amount by which the negotiated purchase price of the vehicle (less any trade-in value, down payment, or available manufacturer incentives) exceeds the contract residual value (including residual support) of the vehicle at lease termination, plus operating lease rental charges. The customer can terminate the lease at any point after commencement, subject to additional charges and fees. Both the consumer and the dealership have the option to purchase the vehicle at the end of the lease term, which can range from 24 to 60 months, at the residual value of the vehicle, however it is not reasonably certain this option will be exercised and accordingly our consumer leases are classified as operating leases. In addition to the charges described above, the consumer is generally responsible for certain charges related to excess mileage or excessive wear and tear on the vehicle. These charges are deemed variable lease payments and, as these payments are not based on a rate or index, they are recognized as net depreciation expense on operating lease assets in our Consolidated Statement of Income as incurred. When we acquire a consumer operating lease, we assume ownership of the vehicle from the dealer. We require that property damage, bodily injury, collision, and comprehensive insurance be obtained by the lessee on all consumer operating leases. Neither the consumer nor the dealer is responsible for the value of the vehicle at the time of lease termination. When vehicles are not purchased by customers or the receiving dealer at scheduled lease termination, the vehicle is returned to us for remarketing. We generally bear the risk of loss to the extent the value of a leased vehicle upon remarketing is below the expected residual value. At termination, our actual sales proceeds from remarketing the vehicle may be higher or lower than the estimated residual value resulting in a gain or loss on remarketing, which is included in net depreciation expense on operating lease assets in our Consolidated Statement of Income . Excessive mileage or excessive wear and tear on the vehicle during the lease may impact the sales proceeds received upon remarketing. As of December 31, 2019 , consumer operating leases with a carrying value, net of accumulated depreciation, of $352 million were covered by a residual value guarantee of 15% of the manufacturer’s suggested retail price. The following table details our investment in operating leases. Year ended December 31, ($ in millions) 2019 2018 Vehicles $ 10,426 $ 9,995 Accumulated depreciation (1,562 ) (1,578 ) Investment in operating leases, net $ 8,864 $ 8,417 The following table presents future minimum rental payments we have the right to receive under operating leases with noncancelable lease terms expiring after December 31, 2019 . Year ended December 31, ($ in millions) 2020 $ 1,339 2021 851 2022 383 2023 86 2024 6 2025 and thereafter — Total lease payments from operating leases $ 2,665 We recognized operating lease revenue of $1.5 billion for both the years ended December 31, 2019, and 2018, and $1.9 billion for the year ended December 31, 2017. Depreciation expense on operating lease assets includes remarketing gains and losses recognized on the sale of operating lease assets. The following table summarizes the components of depreciation expense on operating lease assets. Year ended December 31, ($ in millions) 2019 2018 2017 Depreciation expense on operating lease assets (excluding remarketing gains) (a) $ 1,050 $ 1,115 $ 1,368 Remarketing gains, net (69 ) (90 ) (124 ) Net depreciation expense on operating lease assets $ 981 $ 1,025 $ 1,244 (a) Includes variable lease payments related to excess mileage and excessive wear and tear on vehicles of $19 million during the year ended December 31, 2019, $24 million during the year ended December 31, 2018, and $32 million during the year ended December 31, 2017. Finance Leases Our total gross investment in finance leases, which is included in finance receivables and loans, net, on our Consolidated Balance Sheet was $472 million and $439 million as of December 31, 2019 , and December 31, 2018 , respectively. This includes lease payment receivables of $459 million and $425 million at December 31, 2019 , and December 31, 2018 , respectively, and unguaranteed residual assets of $13 million and $ 14 million at December 31, 2019 , and December 31, 2018 , respectively. Interest income on finance lease receivables was $25 million for the year ended December 31, 2019 , $22 million for the year ended December 31, 2018 , and $22 million for the year ended December 31, 2017, and is included in interest and fees on finance receivables and loans in our Consolidated Statement of Income . The following table presents future minimum rental payments we have the right to receive under finance leases with noncancelable lease terms expiring after December 31, 2019 . Year ended December 31, ($ in millions) 2020 $ 167 2021 142 2022 94 2023 60 2024 32 2025 and thereafter 19 Total undiscounted cash flows 514 Difference between undiscounted cash flows and discounted cash flows (55 ) Present value of lease payments recorded as lease receivable $ 459

Securitizations and Variable In

Securitizations and Variable Interest Entities	12 Months Ended
	Dec. 31, 2019
Securitizations And Variable Interest Entities [Abstract]
Variable Interest Entity Disclosure	Securitizations and Variable Interest Entities Overview We securitize, transfer, and service consumer and commercial automotive loans, and operating leases. We often securitize these loans and notes secured by operating leases (collectively referred to as financial assets) using special purpose entities (SPEs). SPEs are often VIEs and may or may not be included on our Consolidated Balance Sheet . Securitizations In executing a securitization, we typically sell pools of financial assets to a wholly owned, bankruptcy-remote SPE, which then transfers the financial assets to a separate, transaction-specific SPE for cash, and typically, other retained interests. The SPE is funded through the issuance of beneficial interests, which could take the form of notes or residual interests and can be sold to investors or retained by us. We typically hold retained beneficial interests in our securitizations including, but not limited to, retained notes, certificated residual interests, as well as certain noncertificated interests retained from the sale of automotive finance receivables. If sold, the beneficial interests only entitle the investors to specified cash flows generated from the underlying securitized assets. If retained, the interests provide credit enhancement to the SPE as they may absorb credit losses or other cash shortfalls and may represent a form of significant continuing economic interests. In addition to providing a source of liquidity and cost-efficient funding, securitizing these financial assets also reduces our credit exposure to the borrowers beyond any economic interest we may retain. The SPEs are limited to specific activities by their respective legal documents, but are generally allowed to acquire the financial assets, to issue beneficial interests to investors to fund the acquisition of the financial assets, and to enter into interest rate hedges to mitigate certain risks related to the financial assets or beneficial interests of the entity. A servicer, who is generally us, is appointed pursuant to the underlying legal documents to service the assets the SPE holds and the beneficial interests it issues. Servicing functions include, but are not limited to, general collections activity on current and noncurrent accounts, loss mitigation efforts including repossession and sale of collateral, as well as preparing and furnishing statements summarizing the asset and beneficial interest performance. These servicing responsibilities constitute continued involvement in the transferred financial assets. Cash flows from the securitized financial assets represent the sole source for payment of distributions on the beneficial interests issued by the SPE and for payments to the parties that perform services for the SPE, such as the servicer or the trustee. We generally hold certain conditional repurchase options specific to securitizations that allow us to repurchase assets from the securitization entity. The majority of the securitizations provide us, as servicer, with a call option that allows us to repurchase the remaining transferred financial assets or redeem outstanding beneficial interests at our discretion once the asset pool reaches a predefined level, which represents the point where servicing becomes administratively burdensome (a clean-up call option). The repurchase price is typically the discounted securitization balance of the assets plus accrued interest when applicable. We generally have discretion regarding when or if we will exercise these options, but we would do so only when it is in our best interest. Other than our customary representation, warranty, and covenant provisions, these securitizations are nonrecourse to us, thereby transferring the risk of future credit losses to the extent the beneficial interests in the SPEs are held by third parties. Representation, warranty, and certain covenant provisions generally require us to repurchase assets or indemnify the investor or other party for incurred losses to the extent it is determined that the assets were ineligible or were otherwise defective at the time of sale, or otherwise not in compliance with the ongoing covenant obligations. We did not provide any non-contractual financial support to any of these entities during 2019, 2018, or 2017. Variable Interest Entities The VIEs included on the Consolidated Balance Sheet represent separate entities where we are deemed to be the primary beneficiary, primarily due to our servicing activities and our beneficial interests in the VIE that could be potentially significant. We determine whether we have a potentially significant beneficial interest in the VIE based on the consideration of both qualitative and quantitative factors regarding the nature, size, and form of our involvement in the VIE. The third-party investors in the obligations of consolidated VIEs have legal recourse only to the assets of the VIEs and do not have such recourse to us, except for the customary representation, warranty, and covenant provisions. In addition, the cash flows from the assets are restricted only to pay such liabilities. Thus, our economic exposure to loss from outstanding third-party financing related to consolidated VIEs is limited to the carrying value of the consolidated VIE assets. Generally, all assets of consolidated VIEs are restricted for the beneficial interest holders. For additional information regarding our significant accounting policies for consolidated VIEs, refer to the Securitizations and Variable Interest Entities section of Note 1 . The nature, purpose, and activities of nonconsolidated SPEs are similar to those of our consolidated SPEs with the primary difference being the nature and extent of our continuing involvement. For nonconsolidated SPEs, the transferred financial assets are removed from our balance sheet provided the conditions for sale accounting are met. The financial assets obtained from the securitization are primarily reported as cash or retained interests (if applicable). Liabilities incurred as part of these securitizations, are recorded at fair value at the time of sale and are reported as accrued expenses and other liabilities on our Consolidated Balance Sheet . Upon the sale of the loans, we recognize a gain or loss on sale for the difference between the assets recognized, the assets derecognized, and the liabilities recognized as part of the transaction. With respect to our ongoing right to service the assets we sell, the servicing fee we receive represents adequate compensation, and consequently, we do not recognize a servicing asset or liability. There were no sales of financial assets into nonconsolidated VIEs for the year ended December 31, 2019 . There was a pretax gain of $1 million for the year ended December 31, 2018 , and a pretax gain of $2 million for the year ended December 31, 2017, from sales of financial assets into nonconsolidated VIEs. For additional information regarding the company’s significant accounting policies for nonconsolidated VIEs, refer to the Variable Interest Entities and Securitizations section of Note 1 . We provide long-term guarantee contracts to investors in certain nonconsolidated affordable housing entities and have extended a line of credit to provide liquidity. Since we do not have control over the entities or the power to make decisions, we do not consolidate the entities and our involvement is limited to the guarantee and the line of credit. We are involved with various other nonconsolidated equity investments, including affordable housing entities and venture capital funds and loan funds. We do not consolidate these entities and our involvement is limited to our outstanding investment, additional capital committed to these funds plus any previously recognized low-income housing tax credits that are subject to recapture. The following table presents our involvement in consolidated and nonconsolidated VIEs in which we hold variable interests. For additional detail related to the assets and liabilities of consolidated variable interest entities refer to the Consolidated Balance Sheet . December 31, ($ in millions) Carrying value of total assets Carrying value of total liabilities Assets sold to nonconsolidated VIEs (a) Maximum exposure to loss in nonconsolidated VIEs 2019 On-balance sheet variable interest entities Consumer automotive $ 20,376 (b) $ 6,070 (c) Commercial automotive 8,009 3,049 Off-balance-sheet variable interest entities Consumer automotive (d) 23 (e) — $ 417 $ 440 (f) Commercial other 1,079 (g) 378 (h) — 1,397 (i) Total $ 29,487 $ 9,497 $ 417 $ 1,837 2018 On-balance sheet variable interest entities Consumer automotive $ 16,255 (b) $ 6,573 (c) Commercial automotive 11,089 3,946 Off-balance-sheet variable interest entities Consumer automotive 45 (e) — $ 1,235 $ 1,280 (f) Commercial other 806 (g) 326 (h) — 1,054 (i) Total $ 28,195 $ 10,845 $ 1,235 $ 2,334 (a) Asset values represent the current unpaid principal balance of outstanding consumer finance receivables and loans within the VIEs. (b) Includes $9.0 billion and $8.4 billion of assets that were not encumbered by VIE beneficial interests held by third parties at December 31, 2019 , and December 31, 2018 , respectively. Ally or consolidated affiliates hold the interests in these assets. (c) Includes $21 million and $25 million of liabilities that were not obligations to third-party beneficial interest holders at December 31, 2019 , and December 31, 2018 , respectively. (d) During the year ended December 31, 2019 , we indicated our intent to exercise clean-up call option related to a nonconsolidated securitization-related VIE. The option enables us to repurchase the remaining transferred financial assets at our discretion once the asset pool declines to a predefined level and redeem the related outstanding debt. As a result of this event, we became the primary beneficiary of the VIE, which included $48 million of consumer automotive loans and $45 million of related debt, and the VIE was consolidated on our Consolidated Balance Sheet. The related amounts were removed from assets sold to nonconsolidated VIEs and maximum exposure to loss in nonconsolidated VIEs. (e) Represents retained notes and certificated residual interests, of which $21 million and $43 million were classified as held-to-maturity securities at December 31, 2019 , and December 31, 2018 , respectively, and $2 million were classified as other assets at both December 31, 2019 , and December 31, 2018 . These assets represent our five percent interest in the credit risk of the assets underlying asset-backed securitizations. (f) Maximum exposure to loss represents the current unpaid principal balance of outstanding loans, retained notes, certificated residual interests, as well as certain noncertificated interests retained from the sale of automotive finance receivables. This measure is based on the very unlikely event that all of our sold loans have defects that would trigger a representation, warranty, and covenant provision and the underlying collateral supporting the loans becomes worthless. This required disclosure is not an indication of our expected loss. (g) Amounts are classified as other assets. (h) Amounts are classified as accrued expenses and other liabilities. (i) For certain nonconsolidated affordable housing entities, maximum exposure to loss represents the yield we guaranteed investors through long-term guarantee contracts. The amount disclosed is based on the unlikely event that the yield delivered to investors in the form of low-income tax housing credits is recaptured. For nonconsolidated equity investments, maximum exposure to loss represents our outstanding investment, additional committed capital, and low-income housing tax credits subject to recapture. The amount disclosed is based on the unlikely event that our committed capital is funded, our investments become worthless, and the tax credits previously delivered to us are recaptured. This required disclosure is not an indication of our expected loss. On-balance Sheet Variable Interest Entities The assets of consolidated VIEs that can be used only to settle obligations of the consolidated VIEs and the liabilities of those entities for which creditors or beneficial interest holders do not have recourse to our general credit were as follows. December 31, ($ in millions) 2019 2018 Assets Finance receivables and loans, net Consumer $ 10,791 $ 7,282 Commercial 7,919 10,804 Allowance for loan losses (153 ) (114 ) Total finance receivables and loans, net 18,557 17,972 Investment in operating leases, net — 164 Other assets 787 767 Total assets $ 19,344 $ 18,903 Liabilities Long-term debt $ 9,087 $ 10,482 Accrued expenses and other liabilities 11 12 Total liabilities $ 9,098 $ 10,494 Cash Flows with Off-Balance-Sheet Securitization Entities The following table summarizes cash flows received and paid related to SPEs and asset-backed financings where the transfer is accounted for as a sale and we have a continuing involvement with the transferred consumer automotive assets (for example, servicing) that were outstanding during the years ended December 31, 2019 , 2018 , and 2017 . Additionally, this table contains information regarding cash flows received from and paid to nonconsolidated SPEs that existed during each period. Year ended December 31, ($ in millions) Consumer automotive Consumer mortgage 2019 Cash flows received on retained interests in securitization entities $ 23 $ — Servicing fees 10 — Cash disbursements for repurchases during the period (2 ) — 2018 Cash proceeds from transfers completed during the period $ 24 $ — Cash flows received on retained interests in securitization entities 20 — Servicing fees 18 — Cash disbursements for repurchases during the period (4 ) — Representation and warranty recoveries — 2 2017 Cash proceeds from transfers completed during the period $ 1,187 $ — Cash disbursements for repurchases during the period (a) (491 ) — Servicing fees 31 — Cash flows received on retained interests in securitization entities 21 — Other cash flows 4 — (a) During the second quarter of 2017, we elected to not renew a consumer automotive credit conduit facility and also purchased the related consumer automotive loans and settled associated retained interests. Delinquencies and Net Credit Losses The following tables present quantitative information about delinquencies and net credit losses for off-balance-sheet securitizations and whole-loan sales where we have continuing involvement. Total amount Amount 60 days or more past due December 31, ($ in millions) 2019 2018 2019 2018 Off-balance-sheet securitization entities Consumer automotive $ 417 $ 1,235 $ 6 $ 13 Whole-loan sales (a) Consumer automotive 207 634 2 3 Total $ 624 $ 1,869 $ 8 $ 16 (a) Whole-loan sales are not part of a securitization transaction, but represent consumer automotive pools of loans sold to third-party investors. Net credit losses Year ended December 31, ($ in millions) 2019 2018 Off-balance-sheet securitization entities Consumer automotive $ 6 $ 10 Whole-loan sales (a) Consumer automotive 1 2 Total $ 7 $ 12 (a) Whole-loan sales are not part of a securitization transaction, but represent consumer automotive pools of loans sold to third-party investors. Affordable Housing Investments We have investments in various limited partnerships that sponsor affordable housing projects, which meet the definition of a VIE. The purpose of these investments is to achieve a satisfactory return on capital through the receipt of low-income housing tax credits (LIHTC) and to assist us in achieving goals associated with the CRA. Our affordable housing investments are accounted for using the proportional amortization method of accounting, which recognizes the amortized cost of the investment as a component of income tax expense. The following table summarizes information about our affordable housing investments. Year ended December 31, ($ in millions) 2019 2018 2017 Affordable housing tax credits and other tax benefits (a) $ 86 $ 61 $ 43 Tax credit amortization expense recognized as a component of income tax expense 72 51 44 (a) There were no impairment losses recognized during the years ended December 31, 2019 , 2018 , and 2017 , resulting from the forfeiture or ineligibility of tax credits or other circumstances. Our investment in qualified affordable housing projects was $830 million and $649 million at December 31, 2019 , and 2018 , respectively, and is included within other assets on our Consolidated Balance Sheet . Additionally, unfunded commitments to provide additional capital to investees in qualified affordable housing projects were $372 million and $319 million at December 31, 2019 , and 2018 , respectively, and are included within accrued expenses and other liabilities on our Consolidated Balance Sheet . Substantially all of the unfunded commitments at December 31, 2019 , are expected to be paid out within the next five years.

Premiums Receivable and Other I

Premiums Receivable and Other Insurance Assets Premiums Receivable and Other Insurance Assets (Notes)	12 Months Ended
	Dec. 31, 2019
Premiums and Other Receivables, Net [Abstract]
Premiums Receivable Note	Insurance Premiums and Service Revenue The following table is a summary of insurance premiums and service revenue written and earned. 2019 2018 2017 Year ended December 31, ($ in millions) Written Earned Written Earned Written Earned Insurance premiums Direct $ 491 $ 464 $ 420 $ 414 $ 384 $ 364 Assumed — 2 — 4 2 5 Gross insurance premiums 491 466 420 418 386 369 Ceded (232 ) (209 ) (219 ) (197 ) (254 ) (188 ) Net insurance premiums 259 257 201 221 132 181 Service revenue 1,051 830 973 801 864 792 Insurance premiums and service revenue written and earned $ 1,310 $ 1,087 $ 1,174 $ 1,022 $ 996 $ 973 Premiums Receivable and Other Insurance Assets Premiums receivable and other insurance assets consisted of the following. December 31, ($ in millions) 2019 2018 Prepaid reinsurance premiums $ 551 $ 527 Reinsurance recoverable on unpaid losses 88 96 Reinsurance recoverable on paid losses 23 22 Premiums receivable 105 88 Deferred policy acquisition costs 1,791 1,593 Total premiums receivable and other insurance assets $ 2,558 $ 2,326

Other Assets

Other Assets	12 Months Ended
	Dec. 31, 2019
Other Assets [Abstract]
Other Assets Disclosure	Other Assets The components of other assets were as follows. December 31, ($ in millions) 2019 2018 Property and equipment at cost $ 1,332 $ 1,250 Accumulated depreciation (686 ) (686 ) Net property and equipment 646 564 Nonmarketable equity investments (a) 1,232 1,410 Investment in qualified affordable housing projects 830 649 Restricted cash held for securitization trusts (b) 738 965 Accrued interest, fees, and rent receivables 589 599 Goodwill (c) 393 240 Equity-method investments (d) 358 262 Other accounts receivable 117 203 Restricted cash and cash equivalents (e) 87 124 Net intangible assets (f) 69 59 Fair value of derivative contracts in receivable position (g) 64 41 Net deferred tax assets 58 317 Other assets 892 720 Total other assets $ 6,073 $ 6,153 (a) Includes investments in FHLB stock of $701 million and $903 million at December 31, 2019 , and 2018 , respectively; FRB stock of $449 million and $448 million at December 31, 2019 , and 2018 , respectively; and equity securities without a readily determinable fair value of $82 million and $59 million at December 31, 2019 , and 2018 , respectively, measured at cost with adjustments for impairment and observable changes in price. During the year ended December 31, 2019 , we recorded $9 million of upward adjustments and $3 million of impairments and downward adjustments related to equity securities without a readily determinable fair value. Through December 31, 2019 , we recorded $10 million of cumulative upward adjustments and $6 million of cumulative impairments and downward adjustments related to equity securities without a readily determinable fair value. (b) Includes restricted cash collected from customer payments on securitized receivables, which are distributed by us to investors as payments on the related secured debt, and cash reserve deposits utilized as a form of credit enhancement for various securitization transactions. (c) Includes goodwill of $27 million within our Insurance operations at both December 31, 2019 , and 2018 ; $20 million within Automotive Finance operations at both December 31, 2019 , and 2018 ; and $346 million and $193 million within Corporate and Other at December 31, 2019 , and 2018 , respectively. The increase in goodwill within Corporate and Other of $153 million was attributable to our acquisition of Health Credit Services, as further described in Note 2. No other changes to the carrying amount of goodwill were recorded during the years ended December 31, 2019 , and 2018 . (d) Primarily relates to investments made in connection with our CRA program. (e) Primarily represents a number of arrangements with third parties where certain restrictions are placed on balances we hold due to collateral agreements associated with operational processes with a third-party bank, or letter of credit arrangements and corresponding collateral requirements. (f) Includes gross intangible assets of $111 million and $88 million at December 31, 2019 , and 2018 , respectively, and accumulated depreciation of $42 million and $29 million at December 31, 2019 , and 2018 . (g) For additional information on derivative instruments and hedging activities, refer to Note 21 .

Deposit Liabilities

Deposit Liabilities	12 Months Ended
	Dec. 31, 2019
Deposits [Abstract]
Deposit Liabilities Disclosures	Deposit Liabilities Deposit liabilities consisted of the following. December 31, ($ in millions) 2019 2018 Noninterest-bearing deposits $ 119 $ 142 Interest-bearing deposits Savings and money-market checking accounts 62,486 56,050 Certificates of deposit 58,146 49,985 Other deposits 1 1 Total deposit liabilities $ 120,752 $ 106,178 At December 31, 2019 , and December 31, 2018 , certificates of deposit included $25.6 billion and $21.0 billion , respectively, of those in denominations of $100 thousand or more. At December 31, 2019 , and December 31, 2018 , certificates of deposit included $8.2 billion and $6.1 billion , respectively, of those in denominations in excess of $250 thousand federal insurance limits. The following table presents the scheduled maturity of total certificates of deposit at December 31, 2019 . ($ in millions) Due in 2020 $ 41,419 Due in 2021 10,541 Due in 2022 4,061 Due in 2023 996 Due in 2024 1,129 Total certificates of deposit $ 58,146

Debt

Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt Disclosure	Debt Short-term Borrowings The following table presents the composition of our short-term borrowings portfolio. 2019 2018 December 31, ($ in millions) Unsecured Secured (a) Total Unsecured Secured (a) Total Demand notes $ 2,581 $ — $ 2,581 $ 2,477 $ — $ 2,477 Federal Home Loan Bank — 2,950 2,950 — 6,825 6,825 Securities sold under agreements to repurchase — — — — 685 685 Total short-term borrowings $ 2,581 $ 2,950 $ 5,531 $ 2,477 $ 7,510 $ 9,987 Weighted average interest rate (b) 1.8 % 2.5 % (a) Refer to the section below titled Long-term Debt for further details on assets restricted as collateral for payment of the related debt. (b) Based on the debt outstanding and the interest rate at December 31 of each year. We periodically enter into term repurchase agreements—short-term borrowing agreements in which we sell securities to one or more investors while simultaneously committing to repurchase them at a specified future date, at the stated price plus accrued interest. As of December 31, 2019 , Ally had no securities sold under agreements to repurchase. Refer to Note 8 and Note 25 for further details. The primary risk associated with these repurchase agreements is that the counterparty will be unable to perform under the terms of the contract. As the borrower, we are exposed to the excess market value of the securities pledged over the amount borrowed. Daily mark-to-market collateral management is designed to limit this risk to the initial margin. However, should a counterparty declare bankruptcy or become insolvent, we may incur additional delays and costs. In some instances, we may place or receive cash collateral with counterparties under collateral arrangements associated with our repurchase agreements. At December 31, 2019 , we placed no cash collateral and did not receive cash or noncash collateral . At December 31, 2018 , we did not place any collateral, and we received cash collateral totaling $8 million and noncash collateral totaling $4 million . Long-term Debt The following tables present the composition of our long-term debt portfolio. December 31, ($ in millions) Amount Interest rate Weighted average stated interest rate (a) Due date range 2019 Unsecured debt Fixed rate (b) $ 8,566 Variable rate 1 Trust preferred securities (c) 2,575 Hedge basis adjustment (d) 62 Total unsecured debt 11,204 1.71–8.00% 6.34 % 2020–2049 Secured debt Fixed rate 21,477 Variable rate (e) 1,384 Hedge basis adjustment (d) (38 ) Total secured debt (f) (g) (h) 22,823 1.35–4.03% 2.44 % 2020–2027 Total long-term debt $ 34,027 2018 Unsecured debt Fixed rate (b) $ 9,406 Variable rate 1 Trust preferred securities (c) 2,572 Hedge basis adjustment (d) 128 Total unsecured debt 12,107 2.42–8.40% 6.29 % 2019–2049 Secured debt Fixed rate 23,514 Variable rate (e) 8,633 Hedge basis adjustment (d) (61 ) Total secured debt (f) (g) (h) 32,086 1.26–4.50% 2.54 % 2019–2037 Total long-term debt $ 44,193 (a) Based on the debt outstanding and the interest rate at December 31 of each year excluding any impacts of interest rate hedges. (b) Includes subordinated debt of $1.0 billion at both December 31, 2019 , and 2018 . (c) Refer to the section below titled Trust Preferred Securities for further information. (d) Represents the basis adjustment associated with the application of hedge accounting on certain of our long-term debt positions. Refer to Note 21 for additional information. (e) Includes $92 million and $5 million at December 31, 2019 , and 2018 , respectively, of long-term debt that does not have a stated interest rate. (f) Includes $9.1 billion and $10.5 billion of VIE secured debt at December 31, 2019 , and 2018 , respectively. (g) Includes $450 million and $6.7 billion of debt outstanding from our committed secured credit facilities at December 31, 2019 , and 2018 , respectively. (h) Includes advances from the FHLB of Pittsburgh of $13.3 billion and $14.9 billion at December 31, 2019 , and 2018 , respectively. 2019 2018 December 31, ($ in millions) Unsecured Secured Total Unsecured Secured Total Long-term debt (a) Due within one year $ 2,214 $ 7,005 $ 9,219 $ 1,663 $ 7,313 $ 8,976 Due after one year 8,990 15,818 24,808 10,444 24,773 35,217 Total long-term debt (b) (c) $ 11,204 $ 22,823 $ 34,027 $ 12,107 $ 32,086 $ 44,193 (a) Includes basis adjustments related to the application of hedge accounting. To achieve the desired balance between fixed- and variable-rate debt, we may utilize interest rate swap agreements. The use of these derivative financial instruments had the effect of converting $7.0 billion of our fixed-rate debt into variable-rate obligations at December 31, 2019 . We did not have any derivative financial instruments that converted fixed-rate debt into variable-rate obligations or variable-rate debt into fixed rate obligations at December 31, 2018. The following table presents the scheduled remaining maturity of long-term debt at December 31, 2019 , assuming no early redemptions will occur. The amounts below include adjustments to the carrying value resulting from the application of hedge accounting. The actual payment of secured debt may vary based on the payment activity of the related pledged assets. ($ in millions) 2020 2021 2022 2023 2024 2025 and thereafter Total Unsecured Long-term debt $ 2,258 $ 697 $ 1,121 $ (9 ) $ 1,470 $ 6,767 $ 12,304 Original issue discount (44 ) (47 ) (52 ) (59 ) (65 ) (833 ) (1,100 ) Total unsecured 2,214 650 1,069 (68 ) 1,405 5,934 11,204 Secured Long-term debt 7,005 9,530 5,552 627 107 2 22,823 Total long-term debt $ 9,219 $ 10,180 $ 6,621 $ 559 $ 1,512 $ 5,936 $ 34,027 The following summarizes assets restricted as collateral for the payment of the related debt obligation, primarily arising from securitization transactions accounted for as secured borrowings and repurchase agreements. 2019 2018 December 31, ($ in millions) Total (a) Ally Bank Total (a) Ally Bank Investment securities (b) $ 2,698 $ 2,698 $ 10,280 $ 9,564 Mortgage assets held-for-investment and lending receivables 17,135 17,135 16,498 16,498 Consumer automotive finance receivables 13,481 11,534 17,015 9,715 Commercial automotive finance receivables 12,890 12,890 15,563 15,563 Operating leases — — 170 — Total assets restricted as collateral (c) (d) $ 46,204 $ 44,257 $ 59,526 $ 51,340 Secured debt $ 25,773 (e) $ 24,069 $ 39,596 (e) $ 32,072 (a) Ally Bank is a component of the total column. (b) A portion of the restricted investment securities at December 31, 2018 , was restricted under repurchase agreements. Refer to the section above titled Short-term Borrowings for information on the repurchase agreements. (c) Ally Bank has an advance agreement with the FHLB, and had assets pledged to secure borrowings that were restricted as collateral to the FHLB totaling $24.8 billion and $30.8 billion at December 31, 2019 , and December 31, 2018 , respectively. These assets were composed primarily of consumer mortgage finance receivables and loans and investment securities. Ally Bank has access to the FRB Discount Window and had assets pledged and restricted as collateral to the FRB totaling $2.4 billion at both December 31, 2019 , and December 31, 2018 . These assets were composed of consumer automotive finance receivables and loans. Availability under these programs is only for the operations of Ally Bank and cannot be used to fund the operations or liabilities of Ally or its subsidiaries. (d) Excludes restricted cash and cash reserves for securitization trusts recorded within other assets on the Consolidated Balance Sheet . Refer to Note 13 for additional information. (e) Includes $3.0 billion and $7.5 billion of short-term borrowings at December 31, 2019 , and December 31, 2018 , respectively. Trust Preferred Securities At both December 31, 2019 , and December 31, 2018 , we had issued and outstanding approximately $2.6 billion in aggregate liquidation preference of 8.125% Fixed Rate/Floating Rate Trust Preferred Securities, Series 2 (Series 2 TRUPS). Each Series 2 TRUPS security has a liquidation amount of $25 . Distributions are cumulative and are payable until redemption at the applicable coupon rate. Distributions are payable at an annual rate equal to three-month London interbank offered rate plus 5.785% payable quarterly in arrears. Ally has the right to defer payments of interest for a period not exceeding 20 consecutive quarters. The Series 2 TRUPS have no stated maturity date, but must be redeemed upon the redemption or maturity of the related debentures (Debentures), which mature on February 15, 2040. Ally at any time may redeem the Series 2 TRUPS at a redemption price equal to 100% of the principal amount being redeemed, plus accrued and unpaid interest through the date of redemption. The Series 2 TRUPS are generally nonvoting, other than with respect to certain limited matters. During any period in which any Series 2 TRUPS remain outstanding but in which distributions on the Series 2 TRUPS have not been fully paid, none of Ally or its subsidiaries will be permitted to (i) declare or pay dividends on, make any distributions with respect to, or redeem, purchase, acquire or otherwise make a liquidation payment with respect to, any of Ally’s capital stock or make any guarantee payment with respect thereto; or (ii) make any payments of principal, interest, or premium on, or repay, repurchase or redeem, any debt securities or guarantees that rank on a parity with or junior in interest to the Debentures with certain specified exceptions in each case. The Series 2 TRUPS were issued prior to October 4, 2010, under the Emergency Economic Stabilization Act of 2008 and are not subject to phase-out from additional Tier 1 capital into Tier 2 capital. The amount of Series 2 TRUPS included in Ally’s Tier 1 capital was $2.5 billion at December 31, 2019 . The amount represents the carrying amount of the Series 2 TRUPS less our common stock investment in the trust. Covenants and Other Requirements In secured funding transactions, there are trigger events that could cause the debt to be prepaid at an accelerated rate or could cause our usage of the committed secured credit facility to be discontinued. The triggers are generally based on the financial health and performance of the servicer as well as performance criteria for the pool of receivables, such as delinquency ratios, loss ratios, and commercial payment rates. During 2019, there were no trigger events that resulted in the repayment of debt at an accelerated rate or impacted the usage of our facilities. Funding Facilities We utilize both committed secured credit facilities and other collateralized funding vehicles. The debt outstanding under our various funding facilities is included on our Consolidated Balance Sheet . The total capacity in our credit facilities is provided by banks through private transactions. The facilities can be revolving in nature, generally having an original tenor ranging from 364 days to two years, and allow for additional funding during the commitment period, or they can be amortizing and not allow for any further funding after the commitment period. At December 31, 2019 , all of our $2.5 billion of capacity was revolving and of this balance, $1.1 billion was from facilities with a remaining tenor greater than 364 days. Committed Secured Credit Facilities Outstanding Unused capacity (a) Total capacity December 31, ($ in millions) 2019 2018 2019 2018 2019 2018 Bank funding Secured $ — $ 3,500 $ — $ 1,300 $ — $ 4,800 Parent funding Secured 450 3,165 2,050 635 2,500 3,800 Total committed secured credit facilities $ 450 $ 6,665 $ 2,050 $ 1,935 $ 2,500 $ 8,600 (a) Funding from committed secured credit facilities is available on request in the event excess collateral resides in certain facilities or the extent incremental collateral is available and contributed to the facilities.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2019
Accounts Payable and Accrued Liabilities [Abstract]
Accounts Payable and Accrued Liabilities Disclosure	Accrued Expenses and Other Liabilities The components of accrued expenses and other liabilities were as follows. December 31, ($ in millions) 2019 2018 Accounts payable $ 535 $ 516 Unfunded commitments for investment in qualified affordable housing projects 372 319 Employee compensation and benefits 296 255 Reserves for insurance losses and loss adjustment expenses 122 134 Net deferred tax liabilities 67 17 Cash collateral received from counterparties 48 41 Deferred revenue 36 27 Fair value of derivative contracts in payable position (a) 5 37 Other liabilities 491 330 Total accrued expenses and other liabilities $ 1,972 $ 1,676 (a) For additional information on derivative instruments and hedging activities, refer to Note 21 .

Equity Equity (Notes)

Equity Equity (Notes)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stockholders' Equity Note Disclosure	Equity Common Stock The following table presents changes in the number of shares issued and outstanding. (shares in thousands) (a) 2019 2018 2017 Common stock Total issued at January 1, 492,797 489,884 485,708 New issuances Employee benefits and compensation plans 4,160 2,914 4,176 Total issued at December 31, 496,958 492,797 489,884 Treasury balance at January 1, (87,898 ) (52,830 ) (18,707 ) Repurchase of common stock (b) (34,728 ) (35,068 ) (34,122 ) Total treasury stock at December 31, (122,626 ) (87,898 ) (52,830 ) Total outstanding at December 31, 374,332 404,900 437,054 (a) Figures in the table may not recalculate exactly due to rounding. Number of shares issued, in treasury, and outstanding are calculated based on unrounded numbers. (b) Includes shares of common stock withheld to cover income taxes owed by participants in our share-based incentive plans. Refer to the section titled Capital Planning and Stress Tests in Note 20 for additional information regarding our common-stock-repurchase program.

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	12 Months Ended
	Dec. 31, 2019
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss) Note	Accumulated Other Comprehensive Income (Loss) The following table presents changes, net of tax, in each component of accumulated other comprehensive income (loss). ($ in millions) Unrealized (losses) gains on investment securities (a) Translation adjustments and net investment hedges (b) Cash flow hedges (b) Defined benefit pension plans Accumulated other comprehensive income (loss) Balance at January 1, 2017 $ (273 ) $ 14 $ 8 $ (90 ) $ (341 ) Net change 100 2 3 1 106 Balance at December 31, 2017 (173 ) 16 11 (89 ) (235 ) Cumulative effect of changes in accounting principles, net of tax Adoption of Accounting Standards Update 2016-01 27 — — — 27 Adoption of Accounting Standards Update 2018-02 (40 ) 4 — (6 ) (42 ) Balance at January 1, 2018 (186 ) 20 11 (95 ) (250 ) Net change (295 ) (2 ) 8 — (289 ) Balance at December 31, 2018 (481 ) 18 19 (95 ) (539 ) Cumulative effect of changes in accounting principles, net of tax (c) Adoption of Accounting Standards Update 2017-08 8 — — — 8 Balance at January 1, 2019 (473 ) 18 19 (95 ) (531 ) Net change 681 1 (17 ) (11 ) 654 Balance at December 31, 2019 $ 208 $ 19 $ 2 $ (106 ) $ 123 (a) Represents the after-tax difference between the fair value and amortized cost of our available-for-sale securities portfolio. (b) For additional information on derivative instruments and hedging activities, refer to Note 21 . (c) Refer to the section titled Recently Adopted Accounting Standards in Note 1 for additional information. The following tables present the before- and after-tax changes in each component of accumulated other comprehensive income (loss). Year ended December 31, 2019 ($ in millions) Before tax Tax effect After tax Investment securities Net unrealized gains arising during the period $ 968 $ (227 ) $ 741 Less: Net realized gains reclassified to income from continuing operations 78 (a) (18 ) (b) 60 Net change 890 (209 ) 681 Translation adjustments Net unrealized gains arising during the period 7 (2 ) 5 Net investment hedges (c) Net unrealized losses arising during the period (6 ) 2 (4 ) Cash flow hedges (c) Net unrealized losses arising during the period (11 ) 4 (7 ) Less: Net realized gains reclassified to income from continuing operations 12 (d) (2 ) (b) 10 Net change (23 ) 6 (17 ) Defined benefit pension plans Net unrealized losses arising during the period (14 ) 3 (11 ) Other comprehensive income $ 854 $ (200 ) $ 654 (a) Includes gains reclassified to other gain on investments, net in our Consolidated Statement of Income . (b) Includes amounts reclassified to income tax expense from continuing operations in our Consolidated Statement of Income . (c) For additional information on derivative instruments and hedging activities, refer to Note 21 . (d) Includes gains reclassified to interest on deposits and interest on long-term debt in our Consolidated Statement of Income . Year ended December 31, 2018 ($ in millions) Before tax Tax effect After tax Investment securities Net unrealized losses arising during the period $ (375 ) $ 88 $ (287 ) Less: Net realized gains reclassified to income from continuing operations 11 (a) (3 ) (b) 8 Net change (386 ) 91 (295 ) Translation adjustments Net unrealized losses arising during the period (14 ) 3 (11 ) Net investment hedges (c) Net unrealized gains arising during the period 12 (3 ) 9 Cash flow hedges (c) Net unrealized gains arising during the period 12 (2 ) 10 Less: Net realized gains reclassified to income from continuing operations 2 (d) — 2 Net change 10 (2 ) 8 Defined benefit pension plans Net unrealized gains arising during the period 1 (1 ) — Other comprehensive loss $ (377 ) $ 88 $ (289 ) (a) Includes gains reclassified to other gain on investments, net in our Consolidated Statement of Income . (b) Includes amounts reclassified to income tax expense from continuing operations in our Consolidated Statement of Income . (c) For additional information on derivative instruments and hedging activities, refer to Note 21 . (d) Includes gains reclassified to interest on deposits and interest on long-term debt in our Consolidated Statement of Income . Year ended December 31, 2017 ($ in millions) Before tax Tax effect After tax Investment securities Net unrealized gains arising during the period $ 237 $ (45 ) $ 192 Less: Net realized gains reclassified to income from continuing operations 105 (a) (13 ) (b) 92 Net change 132 (32 ) 100 Translation adjustments Net unrealized gains arising during the period 12 (4 ) 8 Net investment hedges (c) Net unrealized losses arising during the period (10 ) 4 (6 ) Cash flow hedges (c) Net unrealized gains arising during the period 5 (2 ) 3 Defined benefit pension plans Net unrealized gains arising during the period 1 — 1 Other comprehensive income $ 140 $ (34 ) $ 106 (a) Includes gains reclassified to other gain on investments, net in our Consolidated Statement of Income . (b) Includes amounts reclassified to income tax expense from continuing operations in our Consolidated Statement of Income . (c) For additional information on derivative instruments and hedging activities, refer to Note 21 .

Earnings per Common Share

Earnings per Common Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings per Common Share The following table presents the calculation of basic and diluted earnings per common share. Year ended December 31, ($ in millions, except per share data; shares in thousands) (a) 2019 2018 2017 Net income from continuing operations $ 1,721 $ 1,263 $ 926 (Loss) income from discontinued operations, net of tax (6 ) — 3 Net income attributable to common stockholders $ 1,715 $ 1,263 $ 929 Basic weighted-average common shares outstanding (b) 393,234 425,165 453,704 Diluted weighted-average common shares outstanding (b) 395,395 427,680 455,350 Basic earnings per common share Net income from continuing operations $ 4.38 $ 2.97 $ 2.04 (Loss) income from discontinued operations, net of tax (0.02 ) — 0.01 Net income 4.36 2.97 2.05 Diluted earnings per common share Net income from continuing operations 4.35 2.95 2.03 (Loss) income from discontinued operations, net of tax (0.02 ) — 0.01 Net income $ 4.34 $ 2.95 $ 2.04 (a) Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers. (b) Includes shares related to share-based compensation that vested but were not yet issued .

Regulatory Capital and Other Re

Regulatory Capital and Other Regulatory Matters	12 Months Ended
	Dec. 31, 2019
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Regulatory Capital Requirements under Banking Regulations	Regulatory Capital and Other Regulatory Matters Basel Capital Framework The FRB and other U.S. banking agencies have adopted risk-based and leverage capital standards that establish minimum capital-to-asset ratios for BHCs, like Ally, and depository institutions, like Ally Bank. The risk-based capital ratios are based on a banking organization’s risk-weighted assets (RWAs), which are generally determined under the standardized approach applicable to Ally and Ally Bank by (1) assigning on-balance-sheet exposures to broad risk-weight categories according to the counterparty or, if relevant, the guarantor or collateral (with higher risk weights assigned to categories of exposures perceived as representing greater risk), and (2) multiplying off-balance-sheet exposures by specified credit conversion factors to calculate credit equivalent amounts and assigning those credit equivalent amounts to the relevant risk-weight categories. The leverage ratio, in contrast, is based on an institution’s average unweighted on-balance-sheet exposures. Ally and Ally Bank are subject to capital requirements issued by U.S. banking regulators that require us to maintain risk-based and leverage capital ratios above minimum levels. As of January 1, 2015, Ally and Ally Bank became subject to the rules implementing the 2010 Basel III capital framework in the United States (U.S. Basel III), which generally reflects higher capital requirements, capital buffers, and changes to regulatory capital definitions, deductions, and adjustments, relative to the predecessor requirements implementing the Basel I capital framework in the United States. Certain aspects of U.S. Basel III, including the capital buffers, were subject to a phase-in period through December 31, 2018. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary action by regulators that, if undertaken, could have a direct material effect on the Consolidated Financial Statements or the results of operations and financial condition of Ally and Ally Bank. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, Ally and Ally Bank must meet specific capital guidelines that involve quantitative measures of capital, assets, and certain off-balance-sheet items. These measures and related classifications, which are used in the calculation of our risk-based and leverage capital ratios and those of Ally Bank, are also subject to qualitative judgments by the regulators about the components of capital, the risk weightings of assets and other exposures, and other factors. The FRB also uses these ratios and guidelines as part of the capital planning and stress testing processes. In addition, in order for Ally to maintain its status as an FHC, Ally and its bank subsidiary, Ally Bank, must remain well capitalized and well managed, as defined under applicable laws. The well capitalized standard for insured depository institutions, such as Ally Bank, reflects the capital requirements under U.S. Basel III. Under U.S. Basel III, Ally and Ally Bank must maintain a minimum Common Equity Tier 1 risk-based capital ratio of 4.5% , a minimum Tier 1 risk-based capital ratio of 6% , and a minimum total risk-based capital ratio of 8% . In addition to these minimum risk-based capital ratios, Ally and Ally Bank are subject to a capital conservation buffer of more than 2.5% . Failure to maintain the full amount of the buffer would result in restrictions on the ability of Ally and Ally Bank to make capital distributions, including dividend payments and stock repurchases and redemptions, and to pay discretionary bonuses to executive officers. U.S. Basel III also subjects Ally and Ally Bank to a minimum Tier 1 leverage ratio of 4% . U.S. Basel III also revised the eligibility criteria for regulatory capital instruments and provides for the phase-out of instruments that had previously been recognized as capital but that do not satisfy these criteria. For example, subject to certain exceptions (for example, certain debt or equity issued to the U.S. government under the Emergency Economic Stabilization Act), trust preferred and other hybrid securities were excluded from a BHC’s Tier 1 capital as of January 1, 2016. Also, subject to a phase-in schedule, certain items are deducted from Common Equity Tier 1 capital under U.S. Basel III that had not previously been deducted from regulatory capital, and certain other deductions from regulatory capital have been modified. Among other things, U.S. Basel III requires significant investments in the common stock of unconsolidated financial institutions, mortgage servicing assets (MSAs) , and certain deferred tax assets (DTAs) that exceed specified individual and aggregate thresholds to be deducted from Common Equity Tier 1 capital. U.S. Basel III also revised the standardized approach for calculating RWAs by, among other things, modifying certain risk weights and the methods for calculating RWAs for certain types of assets and exposures. Ally and Ally Bank are subject to the U.S. Basel III standardized approach for counterparty credit risk, but not to the U.S. Basel III advanced approaches for credit risk or operational risk. Ally is also not subject to the U.S. market-risk capital rule, which applies only to banking organizations with significant trading assets and liabilities. The following table summarizes our capital ratios under the U.S. Basel III capital framework. December 31, 2019 December 31, 2018 Required minimum (a) Well-capitalized minimum ($ in millions) Amount Ratio Amount Ratio Capital ratios Common Equity Tier 1 (to risk-weighted assets) Ally Financial Inc. $ 13,837 9.54 % $ 13,397 9.14 % 4.50 % (b) Ally Bank 16,627 12.30 16,552 12.61 4.50 6.50 % Tier 1 (to risk-weighted assets) Ally Financial Inc. $ 16,271 11.22 % $ 15,831 10.80 % 6.00 % 6.00 % Ally Bank 16,627 12.30 16,552 12.61 6.00 8.00 Total (to risk-weighted assets) Ally Financial Inc. $ 18,506 12.76 % $ 18,046 12.31 % 8.00 % 10.00 % Ally Bank 17,854 13.21 17,620 13.42 8.00 10.00 Tier 1 leverage (to adjusted quarterly average assets) (c) Ally Financial Inc. $ 16,271 9.08 % $ 15,831 9.00 % 4.00 % (b) Ally Bank 16,627 10.01 16,552 10.69 4.00 5.00 % (a) In addition to the minimum risk-based capital requirements for the Common Equity Tier 1 capital, Tier 1 capital, and total capital ratios, Ally and Ally Bank were required to maintain a minimum capital conservation buffer of 2.5% and 1.875% at December 31, 2019 , and December 31, 2018 , respectively. (b) Currently, there is no ratio component for determining whether a BHC is “well-capitalized.” (c) Federal regulatory reporting guidelines require the calculation of adjusted quarterly average assets using a daily average methodology. At December 31, 2019 , and 2018, Ally and Ally Bank were “well-capitalized” and met all applicable capital requirements to which each was subject. Recent Regulatory Developments In October 2019, the FRB and other U.S. banking agencies issued final rules implementing targeted amendments to the Dodd-Frank Act and other financial-services laws that had been enacted in May 2018 through the EGRRCP Act. The final rules establish four risk-based categories of prudential standards and capital and liquidity requirements for banking organizations with $100 billion or more in total consolidated assets. The most stringent standards and requirements apply to U.S. global systemically important BHCs, which are assigned to Category I. The assignment of other banking organizations to the remaining three categories is based on measures of size and four other risk-based indicators: cross-jurisdictional activity, weighted short-term wholesale funding (wSTWF), nonbank assets, and off-balance-sheet exposure. Under the final rules, Ally is designated as a Category IV firm and, as such, is (1) made subject to supervisory stress testing on a two-year cycle rather than the previously required one-year cycle, (2) required to continue submitting an annual capital plan to the FRB, (3) allowed to continue excluding accumulated other comprehensive income from regulatory capital, (4) required to continue maintaining a buffer of unencumbered highly liquid assets to meet projected net stressed cash outflows over a 30-day planning horizon, (5) required to conduct liquidity stress tests on a quarterly basis rather than the previously required monthly basis, (6) allowed to engage in more tailored liquidity risk management, including monthly rather than weekly calculations of collateral positions, the elimination of limits for activities that are not relevant to the firm, and fewer required elements of monitoring of intraday liquidity exposures, (7) exempted from company-run capital stress testing, (8) exempted from the modified liquidity coverage ratio (LCR) and the proposed modified net stable funding ratio provided that wSTWF remains under $50 billion , and (9) allowed to remain exempted from the supplementary leverage ratio, the countercyclical capital buffer, and single-counterparty credit limits. The final rules went in effect on December 31, 2019. Relatedly, in April 2019, the Federal Deposit Insurance Corporation (FDIC) extended the date by which all covered insured depository institutions (CIDIs), including Ally Bank, must submit their next resolution plans to the date or dates specified by the FDIC in the future in connection with its final determination on amendments to the rule governing CIDI resolution planning, which have not yet been issued. At this time, the impacts that such a potential future proposal may have on us are not clear. In July 2019, the FRB and other U.S. banking agencies issued a final rule to simplify the capital treatment for MSAs, certain DTAs, and investments in the capital instruments of unconsolidated financial institutions (collectively, threshold items). Under the current capital rule, a banking organization must deduct from capital amounts of threshold items that individually exceed 10% of Common Equity Tier 1 capital. The aggregate amount of threshold items not deducted under the 10% threshold deduction but that nonetheless exceeds 15% of Common Equity Tier 1 capital minus certain deductions from and adjustments to Common Equity Tier 1 capital must also be deducted. Any amount of these MSAs and certain DTAs not deducted from Common Equity Tier 1 capital are currently risk weighted at 100% . The final rule removes the individual and aggregate deduction thresholds for threshold items and adopts a single 25% Common Equity Tier 1 capital deduction threshold for each item individually, and requires that any of the threshold items not deducted be risk weighted at 250% . The final rule also simplifies the calculation methodology for minority interests. These provisions will take effect for us on April 1, 2020. We do not expect these provisions to have a material impact on our capital position. In December 2018, the FRB and other U.S. banking agencies approved a final rule to address the impact of CECL on regulatory capital by allowing BHCs and banks, including Ally, the option to phase in the day-one impact of CECL. For regulatory capital purposes, this permitted us to phase in 25% of the capital impact of CECL on January 1, 2020, with an additional 25% to be phased in at the beginning of each subsequent year until fully phased in by the first quarter of 2023. In addition, the FRB announced that, in order to reduce uncertainty, the FRB will maintain its current modeling framework for the allowance for loan losses in supervisory stress tests through the 2021 cycle. In April 2018, the FRB issued a proposal to more closely align forward-looking stress testing results with the FRB’s non-stress regulatory capital requirements for banking organizations with $50 billion or more in total consolidated assets. The proposal would introduce a stress capital buffer based on firm-specific stress test performance, which would effectively replace the non-stress capital conservation buffer. The proposal would also make several changes to the CCAR process, such as eliminating the CCAR quantitative objection, narrowing the set of planned capital actions assumed to occur in the stress scenario, and eliminating the 30% dividend payout ratio as a criterion for heightened scrutiny of a firm’s capital plan. In December 2017, the Basel Committee approved revisions to the global Basel III capital framework (commonly known as Basel IV), many of which—if adopted in the United States—could heighten regulatory capital standards. At this time, how the FRB proposal and the Basel Committee revisions will be harmonized and finalized in the United States is not clear or predictable , and we continue to evaluate the impacts these proposals and revisions may have on us. Compliance with capital requirements is a strategic priority for Ally. We expect to be in compliance with all applicable requirements within the established timeframes. Capital Planning and Stress Tests Under the final rules implementing the EGRRCP Act , we are (1) made subject to supervisory stress testing on a two-year cycle rather than the previously required one-year cycle, (2) required to continue submitting an annual capital plan to the FRB, (3) allowed to continue excluding accumulated other comprehensive income from regulatory capital, (4) exempted from company-run capital stress testing, and (5) allowed to remain exempted from the supplementary leverage ratio and the countercyclical capital buffer. Our annual capital plan must include an assessment of our expected uses and sources of capital and a description of all planned capital actions over a nine-quarter planning horizon, including any issuance of a debt or equity capital instrument, any dividend or other capital distribution, and any similar action that the FRB determines could have an impact on our capital. The plan must also include a discussion of how we, under expected and stressful conditions, will maintain capital commensurate with its risks and above the minimum regulatory capital ratios, and will serve as a source of strength to Ally Bank. The FRB will either object to the plan, in whole or in part, or provide a notice of non-objection. If the FRB objects to the plan, or if certain material events occur after submission of the plan, we must submit a revised plan to the FRB within 30 days. Even if the FRB does not object to the plan, we may be precluded from or limited in paying dividends or other capital distributions without the FRB’s approval under certain circumstances—for example, when we would not meet minimum regulatory capital ratios and capital buffers after giving effect to the distributions. In October 2019, the FRB noted its intent to propose changes to the capital-plan rule, including for the purpose of providing Category IV firms like us with additional flexibility in developing their annual capital plans. At this time, the impacts that such a potential future proposal may have on us are not clear. The following table presents information related to our common stock and distributions to our common stockholders over the last eight quarters. Common stock repurchased during period (a) Number of common shares outstanding Cash dividends declared per common share (b) ($ in millions, except per share data; shares in thousands) Approximate dollar value Number of shares Beginning of period End of period 2018 First quarter $ 185 6,473 437,054 432,691 $ 0.13 Second quarter 195 7,280 432,691 425,752 0.13 Third quarter 250 9,194 425,752 416,591 0.15 Fourth quarter 309 12,121 416,591 404,900 0.15 2019 First quarter $ 211 8,113 404,900 399,761 $ 0.17 Second quarter 229 7,775 399,761 392,775 0.17 Third quarter 300 9,287 392,775 383,523 0.17 Fourth quarter 299 9,554 383,523 374,332 0.17 (a) Includes shares of common stock withheld to cover income taxes owed by participants in our share-based incentive plans. (b) On January 13, 2020 , the Ally Board of Directors (our Board) declared a quarterly cash dividend of $0.19 per share on all common stock, payable on February 14, 2020 . Refer to Note 31 for further information regarding this common stock dividend. We received a non-objection to our 2018 capital plan in June 2018. We were not required to submit an annual capital plan to the FRB, participate in the supervisory stress test or CCAR, or conduct company-run capital stress tests during the 2019 cycle. Instead, our capital actions during this cycle are largely based on the results from our 2018 supervisory stress test. On April 1, 2019, our Board authorized an increase in our stock-repurchase program, permitting us to repurchase up to $1.25 billion of our common stock from time to time from the third quarter of 2019 through the second quarter of 2020, representing a 25% increase over our previously announced program. Additionally, on January 13, 2020 , our Board declared a quarterly cash dividend of $0.19 per share of our common stock. Refer to Note 31 for further information on the most recent dividend. Our ability to make capital distributions, including our ability to pay dividends or repurchase shares of our common stock, will continue to be subject to the FRB’s review and internal governance requirements, including approval by our Board. The amount and size of any future dividends and share repurchases also will be subject to various factors, including Ally’s capital and liquidity positions, regulatory considerations, any accounting standards that affect capital or liquidity (including CECL), financial and operational performance, alternative uses of capital, common-stock price, and general market conditions, and may be suspended at any time. Depository Institutions Ally Bank is a member of the Federal Reserve System and is subject to regulation, supervision, and examination by the FRB and the UDFI. Ally Bank’s deposits are insured by the FDIC, and Ally Bank is required to file periodic reports with the FDIC concerning its financial condition. Total assets of Ally Bank were $167.5 billion and $159.0 billion at December 31, 2019, and 2018, respectively. Federal and Utah law place a number of conditions, restrictions, and limitations on dividends and other capital distributions that may be paid by Ally Bank to Ally. Dividends or other distributions made by Ally Bank to Ally were $2.0 billion and $2.6 billion in 2019 and 2018, respectively. The FRB requires banks to maintain minimum average reserve balances. The amount of the required reserve balance for Ally Bank was $416 million and $279 million at December 31, 2019, and 2018, respectively. Ally Bank is required to satisfy regulatory net worth requirements. Failure to meet minimum capital requirements can initiate certain mandatory actions by federal, state, and foreign agencies that could have a material effect on our results of operations and financial condition. Ally Bank was in compliance with these requirements at December 31, 2019. Insurance Companies Certain of our Insurance operations are subject to certain minimum aggregate capital requirements, net asset and dividend restrictions under applicable state and foreign insurance laws, and the rules and regulations promulgated by various U.S. and foreign regulatory agencies. Under various state and foreign insurance regulations, dividend distributions may be made only from statutory unassigned surplus, with approvals required from the regulatory authorities for dividends in excess of certain statutory limitations. At December 31, 2019, the maximum dividend that could be paid by the U.S. insurance subsidiaries over the next 12 months without prior statutory approval was $129 million .

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure	Derivative Instruments and Hedging Activities We enter into derivative instruments, which may include interest rate swaps, foreign-currency forwards, equity options, futures, and interest rate options in connection with our risk-management activities. Our primary objective for utilizing derivative financial instruments is to manage interest rate risk associated with our fixed- and variable-rate assets and liabilities, foreign exchange risks related to our foreign-currency denominated assets and liabilities, and other market risks related to our investment portfolio. Interest Rate Risk We monitor our mix of fixed- and variable-rate assets and liabilities and may enter into interest rate swaps, forwards, futures, options, and swaptions to achieve our desired mix of fixed- and variable-rate assets and liabilities. We execute these trades to modify our exposure to interest rate risk by converting certain fixed-rate instruments to a variable-rate and certain variable-rate instruments to a fixed-rate. We use a mix of both derivatives that qualify for hedge accounting treatment and economic hedges (which do not qualify for hedge accounting treatment). Derivatives qualifying for hedge accounting treatment can include receive-fixed swaps designated as fair value hedges of specific fixed-rate unsecured debt obligations, receive-fixed swaps designated as fair value hedges of specific fixed-rate FHLB advances, pay-fixed swaps designated as fair value hedges of securities within our available-for-sale portfolio, and pay-fixed swaps designated as fair value hedges of closed portfolios of fixed-rate held-for-investment consumer automotive loan assets in which the hedged item is the last layer expected to be remaining at the end of the hedging relationship. Other derivatives qualifying for hedge accounting consist of pay-fixed swaps designated as cash flow hedges of the expected future cash flows in the form of interest payments on certain variable-rate borrowings and deposit liabilities, receive-fixed swaps designated as cash flow hedges of the expected future cash flows in the form of interest receipts on certain securities within our available-for-sale portfolio, as well as interest rate floor contracts designated as cash flow hedges of the expected future cash flows in the form of interest receipts on a portion of our dealer floorplan commercial loans. We execute economic hedges, which may consist of interest rate swaps, interest rate caps, forwards, futures, options, and swaptions to mitigate interest rate risk. We also enter into interest rate lock commitments and forward-sale commitments that are executed as part of our mortgage business that meet the accounting definition of a derivative. Foreign Exchange Risk We enter into derivative financial instrument contracts to mitigate the risk associated with variability in cash flows related to our various foreign-currency exposures. We enter into foreign-currency forwards with external counterparties as net investment hedges of foreign exchange exposure on our investment in foreign subsidiaries. Our equity is impacted by the cumulative translation adjustments resulting from the translation of foreign subsidiary results; this impact is reflected in our accumulated other comprehensive income (loss). We also periodically enter into foreign-currency forwards to economically hedge any foreign-denominated debt, centralized lending, and foreign-denominated third-party loans. These foreign-currency forwards that are used as economic hedges are recorded at fair value with changes recorded as income or expense offsetting the gains and losses on the associated foreign-currency transactions. Investment Risk We enter into equity options to mitigate the risk associated with our exposure to the equity markets. Counterparty Credit Risk Derivative financial instruments contain an element of credit risk if counterparties are unable to meet the terms of the agreements. Credit risk associated with derivative financial instruments is measured as the net replacement cost should the counterparties that owe us under the contract completely fail to perform under the terms of those contracts, assuming no recoveries of underlying collateral as measured by the market value of the derivative financial instrument. We manage our risk to financial counterparties through internal credit analysis, limits, and monitoring. Additionally, derivatives and repurchase agreements are entered into with approved counterparties using industry standard agreements. We execute certain over-the-counter (OTC) derivatives such as interest rate caps and floors using bilateral agreements with financial counterparties. Bilateral agreements generally require both parties to post collateral in the event the fair values of the derivative financial instruments meet posting thresholds established under the agreements. In the event that either party defaults on the obligation, the secured party may seize the collateral. Payments related to the exchange of collateral for OTC derivatives are recognized as collateral. We also execute certain derivatives such as interest rate swaps with clearinghouses, which requires us to post and receive collateral. For these clearinghouse derivatives, these payments are recognized as settlements rather than collateral. Certain derivative instruments contain provisions that require us to either post additional collateral or immediately settle any outstanding liability balances upon the occurrence of a specified credit-risk-related event. No such specified credit-risk-related events occurred during the years ended December 31, 2019 , 2018 , or 2017 . We placed noncash collateral totaling $118 million supporting our derivative positions at December 31, 2019 , compared to $26 million and $105 million of cash and noncash collateral, respectively, at December 31, 2018 , in accounts maintained by counterparties. These amounts include collateral placed at clearinghouses and exclude cash and noncash collateral pledged under repurchase agreements. Refer to Note 15 for details on the repurchase agreements. The receivables for cash collateral placed are included on our Consolidated Balance Sheet in other assets. We received cash and noncash collateral from counterparties totaling $40 million and $29 million , respectively, in accounts maintained by counterparties at December 31, 2019 , compared to $30 million and $3 million of cash and noncash collateral at December 31, 2018 . These amounts include collateral received from clearinghouses and exclude cash and noncash collateral pledged under repurchase agreements. Refer to Note 15 for details on repurchase agreements. The payables for cash collateral received are included on our Consolidated Balance Sheet in accrued expenses and other liabilities. Included in these amounts is noncash collateral where we have been granted the right to sell or pledge the underlying assets. We have not sold or pledged any of the noncash collateral received under these agreements. Balance Sheet Presentation The following table summarizes the amounts of derivative instruments reported on our Consolidated Balance Sheet . The amounts are presented on a gross basis, are segregated by derivatives that are designated and qualifying as hedging instruments or those that are not, and are further segregated by type of contract within those two categories. Derivative contracts in a receivable and payable position exclude open trade equity on derivatives cleared through central clearing counterparties. Any associated collateral exchanged with our central clearing counterparties are treated as settlements of the derivative exposure, rather than collateral. Such payments are recognized as settlements of the derivatives contracts in a receivable and payable position on our Consolidated Balance Sheet . Notional amounts are reference amounts from which contractual obligations are derived and are not recorded on the balance sheet. In our view, derivative notional is not an accurate measure of our derivative exposure when viewed in isolation from other factors, such as market rate fluctuations and counterparty credit risk. 2019 2018 Derivative contracts in a Notional amount Derivative contracts in a Notional amount December 31, ($ in millions) receivable position payable position receivable position payable position Derivatives designated as accounting hedges Interest rate contracts Swaps $ — $ — $ 17,101 $ — $ — $ 24,203 Purchased options 62 — 14,100 — — — Foreign exchange contracts Forwards — 3 157 1 — 136 Total derivatives designated as accounting hedges 62 3 31,358 1 — 24,339 Derivatives not designated as accounting hedges Interest rate contracts Futures and forwards — — 81 — — 11 Written options 2 — 522 — 37 6,793 Purchased options — — 416 37 — 6,742 Total interest rate risk 2 — 1,019 37 37 13,546 Foreign exchange contracts Futures and forwards — 2 112 3 — 181 Total foreign exchange risk — 2 112 3 — 181 Total derivatives not designated as accounting hedges 2 2 1,131 40 37 13,727 Total derivatives $ 64 $ 5 $ 32,489 $ 41 $ 37 $ 38,066 The following table presents amounts recorded on our Consolidated Balance Sheet related to cumulative basis adjustments for fair value hedges. December 31, ($ in millions) Carrying amount of the hedged items Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged items Total Discontinued (a) 2019 2018 2019 2018 2019 2018 Assets Available-for-sale securities (b) (c) $ 1,217 $ 1,485 $ 18 $ — $ 18 $ (5 ) Finance receivables and loans, net (d) 33,312 40,850 135 24 44 5 Liabilities Long-term debt $ 11,995 $ 13,001 $ 24 $ 67 $ 127 $ 67 (a) Represents the fair value hedging adjustment on qualifying hedges for which the hedging relationship was discontinued. This represents a subset of the amounts reported in the total hedging adjustment. (b) The carrying amount of hedged available-for-sale securities is presented above using amortized cost. Refer to Note 8 for a reconciliation of the amortized cost and fair value of available-for-sale securities. (c) Includes the amortized cost basis of closed portfolios used to designate hedging relationships in which the hedged item is the last layer expected to be remaining at the end of the hedging relationship. At December 31, 2019 , the amortized cost basis of the closed portfolios used in these hedging relationships was $230 million , the amount identified as the last of layer in the discontinued hedge relationship was $200 million , and the basis adjustment associated with the discontinued last-of-layer relationships was a $2 million asset, which was allocated across the entire remaining pool upon termination of the hedge relationship. There were no open last-of-layer relationships at December 31, 2019. At December 31, 2018 , the amortized cost basis of the closed portfolios used in these hedging relationships was $47 million , the amount identified as the last of layer in the hedge relationship was $28 million , and there was no basis adjustment associated with the last-of-layer relationships. (d) The hedged item represents the carrying value of the hedged portfolio of assets. The amount identified as the last of layer in the open hedge relationship was $10.2 billion as of December 31, 2019 , and $21.4 billion as of December 31, 2018 . The basis adjustment associated with the open last-of-layer relationship was a $91 million asset as of December 31, 2019 , and a $19 million asset as of December 31, 2018 , which would be allocated across the entire remaining closed pool upon termination or maturity of the hedge relationship. The amount that is identified as the last of layer in the discontinued hedge relationship was $12.8 billion at December 31, 2019 . The basis adjustment associated with the discontinued last-of-layer relationship was a $43 million asset as of December 31, 2019 , which was allocated across the entire remaining pool upon termination of the hedge relationship. Statement of Income Presentation The following table summarizes the location and amounts of gains and losses on derivative instruments not designated as accounting hedges reported in our Consolidated Statement of Income . Year ended December 31, ($ in millions) 2019 2018 2017 Gain (loss) recognized in earnings Interest rate contracts Gain on mortgage and automotive loans, net $ 1 $ — $ 1 Other income, net of losses (11 ) — (3 ) Total interest rate contracts (10 ) — (2 ) Foreign exchange contracts Other income, net of losses — 13 (7 ) Other operating expenses (4 ) — — Total foreign exchange contracts (4 ) 13 (7 ) Total (loss) gain recognized in earnings $ (14 ) $ 13 $ (9 ) The following table summarizes the location and amounts of gains and losses on derivative instruments designated as fair value and cash flow hedges reported in our Consolidated Statement of Income . Interest and fees on finance receivables and loans Interest and dividends on investment securities and other earning assets Interest on deposits Interest on long-term debt Year ended December 31, ($ in millions) 2019 2018 2017 2019 2018 2017 2019 2018 2017 2019 2018 2017 Gain (loss) on fair value hedging relationships Interest rate contracts Hedged fixed-rate unsecured debt $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 41 $ 62 $ 8 Derivatives designated as hedging instruments on fixed-rate unsecured debt — — — — — — — — — (41 ) (61 ) (3 ) Hedged fixed-rate FHLB advances — — — — — — — — — — 47 22 Derivatives designated as hedging instruments on fixed-rate FHLB advances — — — — — — — — — — (47 ) (22 ) Hedged available-for-sale securities — — — 28 (3 ) (1 ) — — — — — — Derivatives designated as hedging instruments on available-for-sale securities — — — (28 ) 3 1 — — — — — — Hedged fixed-rate consumer automotive loans 138 19 (3 ) — — — — — — — — — Derivatives designated as hedging instruments on fixed-rate consumer automotive loans (138 ) (19 ) 1 — — — — — — — — — Total (loss) gain on fair value hedging relationships — — (2 ) — — — — — — — 1 5 (Loss) gain on cash flow hedging relationships Interest rate contracts Hedged deposit liabilities Reclassified from accumulated other comprehensive income into income — — — — — — (4 ) 1 — — — — Hedged variable-rate borrowings Reclassified from accumulated other comprehensive income into income — — — — — — — — — 15 1 — Total (loss) gain on cash flow hedging relationships $ — $ — $ — $ — $ — $ — $ (4 ) $ 1 $ — $ 15 $ 1 $ — Total amounts presented in the Consolidated Statement of Income $ 7,337 $ 6,688 $ 5,819 $ 955 $ 788 $ 599 $ 2,538 $ 1,735 $ 1,077 $ 1,570 $ 1,753 $ 1,653 During the next 12 months, we estimate $19 million of losses will be reclassified into pretax earnings from derivatives designated as cash flow hedges. The following table summarizes the location and amounts of gains and losses related to interest and amortization on derivative instruments designated as fair value and cash flow hedges reported in our Consolidated Statement of Income . Interest and fees on finance receivables and loans Interest and dividends on investment securities and other earning assets Interest on deposits Interest on long-term debt Year ended December 31, ($ in millions) 2019 2018 2017 2019 2018 2017 2019 2018 2017 2019 2018 2017 Gain (loss) on fair value hedging relationships Interest rate contracts Amortization of deferred unsecured debt basis adjustments $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 25 $ 51 $ 77 Interest for qualifying accounting hedges of unsecured debt — — — — — — — — — — 8 24 Amortization of deferred secured debt basis adjustments (FHLB advances) — — — — — — — — — (23 ) (17 ) (2 ) Interest for qualifying accounting hedges of secured debt (FHLB advances) — — — — — — — — — — 6 3 Amortization of deferred basis adjustments of available-for-sale securities — — — (3 ) — — — — — — — — Interest for qualifying accounting hedges of available-for-sale securities — — — 2 (1 ) — — — — — — — Amortization of deferred loan basis adjustments (28 ) (14 ) (21 ) — — — — — — — — — Interest for qualifying accounting hedges of consumer automotive loans held-for-investment 22 16 (1 ) — — — — — — — — — Total (loss) gain on fair value hedging relationships (6 ) 2 (22 ) (1 ) (1 ) — — — — 2 48 102 Gain (loss) on cash flow hedging relationships Interest rate contracts Interest for qualifying accounting hedges of variable-rate borrowings — — — — — — — — — — 8 (1 ) Interest for qualifying accounting hedges of deposit liabilities — — — — — — (1 ) 3 — — — — Interest for qualifying accounting hedges of variable-rate commercial loans 1 — — — — — — — — — — — Total gain (loss) on cash flow hedging relationships $ 1 $ — $ — $ — $ — $ — $ (1 ) $ 3 $ — $ — $ 8 $ (1 ) The following table summarizes the effect of cash flow hedges on accumulated other comprehensive income (loss). Year ended December 31, ($ in millions) 2019 2018 2017 Interest rate contracts (Loss) gain recognized in other comprehensive income (loss) $ (23 ) $ 10 $ 5 The following table summarizes the effect of net investment hedges on accumulated other comprehensive income (loss) and the Consolidated Statement of Income . Year ended December 31, ($ in millions) 2019 2018 2017 Foreign exchange contracts (a) (b) (Loss) gain recognized in other comprehensive income (loss) $ (6 ) $ 12 $ (10 ) (a) There were no amounts excluded from effectiveness testing for the years ended December 31, 2019 , 2018 , or 2017 . (b) Gains and losses reclassified from accumulated other comprehensive income (loss) are reported as other income, net of losses, in the Consolidated Statement of Income . There were no amounts reclassified for the years ended December 31, 2019 , 2018 , or 2017 .

Income Taxes Income Taxes

Income Taxes Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax Disclosure	Income Taxes The significant components of income tax expense from continuing operations were as follows. Year ended December 31, ($ in millions) 2019 2018 2017 Current income tax (benefit) expense U.S. federal $ (2 ) $ (12 ) $ (17 ) Foreign 4 5 6 State and local 65 35 53 Total current expense 67 28 42 Deferred income tax expense (benefit) U.S. federal 178 328 566 Foreign 2 — — State and local (1 ) 3 (27 ) Total deferred expense 179 331 539 Total income tax expense from continuing operations $ 246 $ 359 $ 581 A reconciliation of income tax expense from continuing operations with the amounts at the statutory U.S. federal income tax rate is shown in the following table. Year ended December 31, ($ in millions) 2019 2018 2017 Statutory U.S. federal tax expense (a) $ 413 $ 340 $ 527 Change in tax resulting from Valuation allowance change, excluding expirations (219 ) (8 ) (49 ) State and local income taxes, net of federal income tax benefit (b) 50 26 7 Nondeductible expenses 29 28 4 Tax credits, excluding expirations (27 ) (20 ) (12 ) Changes in unrecognized tax benefits 5 22 1 Tax law enactment (1 ) (23 ) 119 Other, net (4 ) (6 ) (16 ) Total income tax expense from continuing operations $ 246 $ 359 $ 581 (a) The statutory U.S. federal tax rate was 21% for both the years ended December 31, 2019 , and 2018 , and 35% for year ended December 31, 2017 . (b) Amount for 2017 includes state deferred tax adjustments primarily offset in the valuation allowance change caption. For the year ended December 31, 2019 , consolidated income tax expense from continuing operations was driven by tax attributable to pretax earnings for the year, partially offset by a release of valuation allowance on foreign tax credit carryforwards during the second quarter of 2019. The valuation allowance release was primarily driven by our current capacity to engage in certain foreign securitization transactions and the market demand from investors related to these transactions, coupled with the anticipated timing of the forecasted expiration of certain foreign tax credit carryforwards. For the year ended December 31, 2018 , consolidated income tax expense from continuing operations was largely driven by tax attributable to pretax earnings for the year. For the year ended December 31, 2017 , consolidated income tax expense from continuing operations was largely driven by tax attributable to pretax earnings for the year and income tax expense attributable to changes to our net deferred tax assets as a result of the Tax Cuts and Jobs Act of 2017 (Tax Act), partially offset by changes to our valuation allowance balances related to capital-in-nature deferred tax assets and foreign tax credit carryforwards. As of each reporting date, we consider existing evidence, both positive and negative, that could impact our view with regard to future realization of deferred tax assets. We continue to believe it is more likely than not that the benefit for certain foreign tax credit carryforwards and state net operating loss carryforwards will not be realized. In recognition of this risk, we continue to provide a partial valuation allowance on the deferred tax assets relating to these carryforwards and it is reasonably possible that the valuation allowance may change in the next 12 months. The significant components of deferred tax assets and liabilities are reflected in the following table. December 31, ($ in millions) 2019 2018 Deferred tax assets Tax credit carryforwards $ 1,784 $ 1,796 Adjustments to loan value 448 366 State and local taxes 153 168 Unearned insurance premiums 98 90 Other 214 257 Gross deferred tax assets 2,697 2,677 Valuation allowance (837 ) (1,057 ) Deferred tax assets, net of valuation allowance 1,860 1,620 Deferred tax liabilities Lease transactions 1,325 850 Deferred acquisition costs 366 321 Debt transactions 91 93 Other 87 56 Gross deferred tax liabilities 1,869 1,320 Net deferred tax (liabilities) assets (a) $ (9 ) $ 300 (a) Amounts include $58 million and $317 million of net deferred tax assets included in other assets on our Consolidated Balance Sheet for tax jurisdictions in a total net deferred tax asset position at December 31, 2019 , and 2018 , respectively, and $67 million and $17 million included in accrued expenses and other liabilities on our Consolidated Balance Sheet for tax jurisdictions in a total net deferred tax liability position. The following table summarizes net deferred tax assets including related valuation allowances at December 31, 2019 . ($ in millions) Deferred tax asset (liability) Valuation allowance Net deferred tax asset (liability) Years of expiration Tax credit carryforwards Foreign tax credits $ 1,433 $ (737 ) $ 696 2022–2029 General business credits 351 — 351 2025–2039 Total tax credit carryforwards 1,784 (737 ) 1,047 Tax loss carryforwards Net operating losses — federal 7 (a) — 7 2027–2036 Net operating losses — state 176 (b) (100 ) 76 2020–2039 Total federal and state tax loss carryforwards 183 (100 ) 83 Other net deferred tax liabilities (1,139 ) — (1,139 ) n/a Net deferred tax assets (liabilities) $ 828 $ (837 ) $ (9 ) (a) Federal net operating loss carryforwards are included in the other assets total disclosed in our deferred inventory table above. (b) State net operating loss carryforwards are included in the state and local taxes and other liabilities totals disclosed in our deferred inventory table above. As of December 31, 2019 , we continue to not assert that foreign earnings are indefinitely reinvested outside of the United States. Deferred tax liabilities for incremental U.S. tax that stem from temporary differences related to investment in foreign subsidiaries or corporate joint ventures are negligible and have been recognized as of December 31, 2019 . The following table provides a reconciliation of the beginning and ending amount of unrecognized tax benefits. ($ in millions) 2019 2018 2017 Balance at January 1, $ 44 $ 15 $ 14 Additions based on tax positions related to the current year — — — Additions for tax positions of prior years 11 29 3 Reductions for tax positions of prior years (5 ) — (1 ) Settlements (2 ) — — Expiration of statute of limitations — — (1 ) Balance at December 31, $ 48 $ 44 $ 15 Included in the unrecognized tax benefits balances are some items, the recognition of which would not affect the effective tax rate, such as the tax effect of certain temporary differences and the portion of gross state unrecognized tax benefits that would be offset by the tax benefit of the associated federal deduction. At December 31, 2019 , 2018 , and 2017 , the balance of unrecognized tax benefits that, if recognized, would affect our effective tax rate were $38 million , $34 million , and $12 million , respectively. We recognize accrued interest and penalties related to uncertain income tax positions in interest expense and other operating expenses, respectively. For the years ended December 31, 2019 , 2018 , and 2017 , the cumulative accrued balance for interest and penalties was less than $1 million and interest and penalties of $1 million or less were accrued each year. It is reasonably possible that the unrecognized tax benefits will decrease by up to $36 million over the next 12 months if certain tax matters ultimately settle with the applicable taxing jurisdictions. We file tax returns in the U.S. federal jurisdiction and various states and foreign jurisdictions. Our most significant operations are in the United States and Canada. The oldest tax years that remain subject to examination for those jurisdictions are 2016 and 2011, respectively.

Share-based Compensation Plans

Share-based Compensation Plans Share-based Compensation Plans (Notes)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Compensation and Employee Benefit Plans [Text Block]	23 . Share-based Compensation Plans We grant Restricted Stock Units or Awards (RSUs) and Performance Stock Units or Awards (PSUs) to certain employees under the Ally Financial Inc. Incentive Compensation Plan (AICP). The AICP allows us to grant an array of equity-based and other incentive awards to our named executive officers and other employees. These awards are structured to align with long-term value creation for our stockholders, to provide appropriate incentives for participating employees, and to achieve the other objectives of our compensation philosophy. At December 31, 2019 , we had 30,703,972 shares available for future grants of equity-based awards remaining under the AICP. Our equity-based awards generally settle in Ally common stock and are classified as equity awards under GAAP. The cost of the awards is ratably charged to compensation and benefits expense in our Consolidated Statement of Income over their applicable service period and are based on the grant date fair value of Ally common stock. The awards typically include retirement eligibility and qualifying termination provisions, which fully vest as of the date upon meeting the eligibility requirements and are paid on the original settlement date. PSUs and RSUs PSUs are payable contingent upon Ally achieving certain predefined performance objectives over a three- year measurement period for 2019 granted awards, or a two-year measurement period for 2018, 2017, and 2016 granted awards. All PSUs granted have a three-year service condition. The number of awards payable upon vesting can range from zero to 150% of the grant amount. The PSUs settle in the form of Ally common stock. We accrue dividend equivalents for our PSUs that are paid upon vesting and based on the number of awards payable. RSUs are awarded to employees at no cost to the recipient upon their grant. The compensation costs related to these awards are ratably charged to expense over the applicable service period. The majority of the existing RSUs settle in the form of Ally common stock. RSUs generally vest one third ratably each year over a three-year period starting on the date the award was issued and are converted into shares of common stock as of the vesting date. We accrue dividend equivalents for our RSUs that are paid upon vesting. Ally has awards that vested but were not yet distributed for the years ended December 31, 2019 , 2018 , and 2017 . The following table presents the changes in outstanding non-vested PSUs and RSUs activity during 2019 . (in thousands, except per share data) Number of units Weighted-average grant date fair value per share RSUs and PSUs Outstanding non-vested at January 1, 2019 4,864 $ 23.71 Granted 3,007 26.29 Vested (3,411 ) 22.37 Forfeited (93 ) 26.28 Outstanding non-vested at December 31, 2019 4,367 26.48 We recognized expense related to PSUs and RSUs of $67 million , $72 million , and $60 million for the years ended December 31, 2019 , 2018 , and 2017 , respectively.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Fair Value Fair Value Measurements For purposes of this disclosure, fair value is defined as the exchange price that would be received to sell an asset or paid to transfer a liability (exit price) in the principal or most advantageous market in an orderly transaction between market participants at the measurement date under current market conditions. Fair value is based on the assumptions we believe market participants would use when pricing an asset or liability. Additionally, entities are required to consider all aspects of nonperformance risk, including the entity’s own credit standing, when measuring the fair value of a liability. Judgment is used in estimating inputs to our internal valuation models used to estimate our Level 3 fair value measurements. Level 3 inputs such as interest rate movements, prepayment speeds, credit losses, and discount rates are inherently difficult to estimate. Changes to these inputs can have a significant effect on fair value measurements and amounts that could be realized. GAAP specifies a three-level hierarchy that is used when measuring and disclosing fair value. The fair value hierarchy gives the highest priority to quoted prices available in active markets (i.e., observable inputs) and the lowest priority to data lacking transparency (i.e., unobservable inputs). An instrument’s categorization within the fair value hierarchy is based on the lowest level of significant input to its valuation. The following is a description of the three hierarchy levels. Level 1 Inputs are quoted prices in active markets for identical assets or liabilities at the measurement date. Additionally, the entity must have the ability to access the active market, and the quoted prices cannot be adjusted by the entity. Level 2 Inputs are other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices in active markets for similar assets or liabilities; quoted prices in inactive markets for identical or similar assets or liabilities; or inputs that are observable or can be corroborated by observable market data by correlation or other means for substantially the full term of the assets or liabilities. Level 3 Unobservable inputs are supported by little or no market activity. The unobservable inputs represent management’s best assumptions of how market participants would price the assets or liabilities. Generally, Level 3 assets and liabilities are valued using pricing models, discounted cash flow methodologies, or similar techniques that require significant judgment or estimation. The following are descriptions of the valuation methodologies used to measure material assets and liabilities at fair value and details of the valuation models, key inputs to those models, and significant assumptions utilized. • Equity Securities — We hold various marketable equity securities measured at fair value with changes in fair value recognized in net income. Measurements based on observable market prices are classified as Level 1. • Available-for-sale securities — We carry our available-for-sale securities at fair value based on external pricing sources. We classify our securities as Level 1 when fair value is determined using quoted prices available for the same instruments trading in active markets. We classify our securities as Level 2 when fair value is determined using prices for similar instruments trading in active markets. We perform pricing validation procedures for our available-for-sale securities. • Interests retained in financial asset sales — We retain certain noncertificated interests retained from the sale of automotive finance receivables. Due to inactivity in the market, valuations are based on internally developed discounted cash flow models (an income approach) that use a market-based discount rate; therefore, we classified these assets as Level 3. The valuation considers recent market transactions, experience with similar assets, current business conditions, and analysis of the underlying collateral, as available. To estimate cash flows, we utilize various significant assumptions, including market observable inputs (for example, forward interest rates) and internally developed inputs (for example, prepayment speeds, delinquency levels, and credit losses). • Derivative instruments — We enter into a variety of derivative financial instruments as part of our risk-management strategies. Certain of these derivatives are exchange traded, such as equity options. To determine the fair value of these instruments, we utilize the quoted market prices for those particular derivative contracts; therefore, we classified these contracts as Level 1. We also execute OTC and centrally cleared derivative contracts, such as interest rate swaps, swaptions, foreign-currency denominated forward contracts, caps, floors, and agency to-be-announced securities. We utilize third-party-developed valuation models that are widely accepted in the market to value these derivative contracts. The specific terms of the contract and market observable inputs (such as interest rate forward curves, interpolated volatility assumptions, or equity pricing) are used in the model. We classified these derivative contracts as Level 2 because all significant inputs into these models were market observable. We also enter into interest rate lock commitments and forward-sale commitments that are executed as part of our mortgage business, certain of which meet the accounting definition of a derivative and therefore are recorded as derivatives on our Consolidated Balance Sheet . Because these derivatives are valued using internal pricing models with unobservable inputs, they are classified as Level 3. We are required to consider all aspects of nonperformance risk, including our own credit standing, when measuring fair value of a liability. We reduce credit risk on the majority of our derivatives by entering into legally enforceable agreements that enable the posting and receiving of collateral associated with the fair value of our derivative positions on an ongoing basis. In the event that we do not enter into legally enforceable agreements that enable the posting and receiving of collateral, we will consider our credit risk and the credit risk of our counterparties in the valuation of derivative instruments through a credit valuation adjustment (CVA), if warranted. The CVA calculation would utilize the credit default swap spreads of the counterparty. Recurring Fair Value The following tables display the assets and liabilities measured at fair value on a recurring basis including financial instruments elected for the fair value option. We often economically hedge the fair value change of our assets or liabilities with derivatives and other financial instruments. The tables below display the hedges separately from the hedged items; therefore, they do not directly display the impact of our risk-management activities. Recurring fair value measurements December 31, 2019 ($ in millions) Level 1 Level 2 Level 3 Total Assets Investment securities Equity securities (a) $ 608 $ — $ 8 $ 616 Available-for-sale securities Debt securities U.S. Treasury and federal agencies 2,047 1 — 2,048 U.S. States and political subdivisions — 639 2 641 Foreign government 15 171 — 186 Agency mortgage-backed residential — 21,404 — 21,404 Mortgage-backed residential — 2,850 — 2,850 Agency mortgage-backed commercial — 1,382 — 1,382 Mortgage-backed commercial — 42 — 42 Asset-backed — 368 — 368 Corporate debt — 1,363 — 1,363 Total available-for-sale securities 2,062 28,220 2 30,284 Mortgage loans held-for-sale (b) — — 30 30 Finance receivables and loans, net Consumer other (b) — — 11 11 Interests retained in financial asset sales — — 2 2 Derivative contracts in a receivable position Interest rate — 62 2 64 Total derivative contracts in a receivable position — 62 2 64 Total assets $ 2,670 $ 28,282 $ 55 $ 31,007 Liabilities Accrued expenses and other liabilities Derivative contracts in a payable position Foreign currency $ — $ 5 $ — $ 5 Total derivative contracts in a payable position — 5 — 5 Total liabilities $ — $ 5 $ — $ 5 (a) Our investment in any one industry did not exceed 13% . (b) Carried at fair value due to fair value option elections. Recurring fair value measurements December 31, 2018 ($ in millions) Level 1 Level 2 Level 3 Total Assets Investment securities Equity securities (a) $ 766 $ — $ 7 $ 773 Available-for-sale securities Debt securities U.S. Treasury and federal agencies 1,850 1 — 1,851 U.S. States and political subdivisions — 802 — 802 Foreign government 7 138 — 145 Agency mortgage-backed residential — 17,138 — 17,138 Mortgage-backed residential — 2,686 — 2,686 Agency mortgage-backed commercial — 3 — 3 Mortgage-backed commercial — 714 — 714 Asset-backed — 723 — 723 Corporate debt — 1,241 — 1,241 Total available-for-sale securities 1,857 23,446 — 25,303 Mortgage loans held-for-sale (b) — — 8 8 Interests retained in financial asset sales — — 4 4 Derivative contracts in a receivable position Interest rate — 37 — 37 Foreign currency — 4 — 4 Total derivative contracts in a receivable position — 41 — 41 Total assets $ 2,623 $ 23,487 $ 19 $ 26,129 Liabilities Accrued expenses and other liabilities Derivative contracts in a payable position Interest rate $ — $ 37 $ — $ 37 Total derivative contracts in a payable position — 37 — 37 Total liabilities $ — $ 37 $ — $ 37 (a) Our investment in any one industry did not exceed 9% . (b) Carried at fair value due to fair value option elections. The following tables present the reconciliation for all Level 3 assets and liabilities measured at fair value on a recurring basis. There were no transfers into or out of Level 3 in the periods presented. We often economically hedge the fair value change of our assets or liabilities with derivatives and other financial instruments. The Level 3 items presented below may be hedged by derivatives and other financial instruments that are classified as Level 1 or Level 2. Thus, the following tables do not fully reflect the impact of our risk-management activities. Level 3 recurring fair value measurements Net realized/unrealized gains Fair value at Dec. 31, 2019 Net unrealized gains still held at December 31, 2019 ($ in millions) Fair value at Jan. 1, 2019 included in earnings included in OCI Purchases Sales Issuances Settlements included in earnings included in OCI Assets Investment securities Equity securities $ 7 $ 5 (a) $ — $ — $ — $ — $ (4 ) $ 8 $ 5 $ — Available-for-sale securities — — — 2 — — — 2 — — Mortgage loans held-for-sale (b) 8 12 (c) — 742 (732 ) — — 30 — — Finance receivables and loans, net (b) — 1 (d) — 15 — — (5 ) 11 — — Other assets Interests retained in financial asset sales 4 — — — — — (2 ) 2 — — Derivative assets, net of derivative liabilities — 2 (c) — — — — — 2 2 — Total assets $ 19 $ 20 $ — $ 759 $ (732 ) $ — $ (11 ) $ 55 $ 7 $ — (a) Reported as other gain on investments, net, in the Consolidated Statement of Income . (b) Carried at fair value due to fair value option elections. (c) Reported as gain on mortgage and automotive loans, net, in the Consolidated Statement of Income . (d) Reported as interest and fees on finance receivables and loans in the Consolidated Statement of Income . Level 3 recurring fair value measurements Fair value at Jan. 1, 2018 Net realized/unrealized (losses) gains Purchases Sales Issuances Settlements Fair value at Dec. 31, 2018 Net unrealized losses still held at December 31, 2018 ($ in millions) included in earnings included in OCI included in earnings included in OCI Assets Equity securities $ 19 $ (7 ) (a) $ — $ — $ — $ — $ (5 ) $ 7 $ (10 ) $ — Mortgage loans held-for-sale (b) 13 5 (c) — 303 (313 ) — — 8 — — Other assets Interests retained in financial asset sales 5 — — — — — (1 ) 4 — — Derivative assets 1 (1 ) (c) — — — — — — — — Total assets $ 38 $ (3 ) $ — $ 303 $ (313 ) $ — $ (6 ) $ 19 $ (10 ) $ — (a) Reported as other gain on investments, net, in the Consolidated Statement of Income . (b) Carried at fair value due to fair value option elections. (c) Reported as gain on mortgage and automotive loans, net, in the Consolidated Statement of Income . Nonrecurring Fair Value We may be required to measure certain assets and liabilities at fair value from time to time. These periodic fair value measures typically result from the application of lower-of-cost or fair value accounting or certain impairment measures. These items would constitute nonrecurring fair value measures. The following tables display assets and liabilities measured at fair value on a nonrecurring basis and still held at December 31, 2019 , and December 31, 2018 , respectively. The amounts are as of the end of each period presented, which approximate the fair value measurements that occurred during each period. Nonrecurring fair value measurements Lower-of-cost or fair value reserve, valuation reserve, or cumulative adjustments Total gain (loss) included in earnings December 31, 2019 ($ in millions) Level 1 Level 2 Level 3 Total Assets Loans held-for-sale, net $ — $ — $ 128 $ 128 $ — n/m (a) Commercial finance receivables and loans, net (b) Automotive — — 64 64 (12 ) n/m (a) Other — — 45 45 (21 ) n/m (a) Total commercial finance receivables and loans, net — — 109 109 (33 ) n/m (a) Other assets Nonmarketable equity investments — 5 7 12 — n/m (a) Equity-method investments — — 4 4 (6 ) n/m (a) Repossessed and foreclosed assets (c) — — 12 12 (1 ) n/m (a) Total assets $ — $ 5 $ 260 $ 265 $ (40 ) n/m n/m = not meaningful (a) We consider the applicable valuation allowance, loan loss allowance, or cumulative impairment to be the most relevant indicator of the impact on earnings caused by the fair value measurement. Accordingly, the table above excludes total gains and losses included in earnings for these items. The carrying values are inclusive of the respective valuation allowance, loan loss allowance, or cumulative impairment. (b) Represents the portion of the portfolio specifically impaired during 2019 . The related valuation allowance represents the cumulative adjustment to fair value of those specific receivables. (c) The allowance provided for repossessed and foreclosed assets represents any cumulative valuation adjustment recognized to adjust the assets to fair value. Nonrecurring fair value measurements Lower-of-cost or fair value reserve, valuation reserve, or cumulative adjustments Total gain (loss) included in earnings December 31, 2018 ($ in millions) Level 1 Level 2 Level 3 Total Assets Loans held-for-sale, net Automotive (a) $ — $ — $ 210 $ 210 $ (2 ) n/m (b) Other — — 96 96 — n/m (b) Total loans held-for-sale, net — — 306 306 (2 ) n/m (b) Commercial finance receivables and loans, net (c) Automotive — — 84 84 (10 ) n/m (b) Other — — 55 55 (46 ) n/m (b) Total commercial finance receivables and loans, net — — 139 139 (56 ) n/m (b) Other assets Nonmarketable equity investments — — 1 1 (1 ) n/m (b) Equity-method investments — — 3 3 — n/m (b) Repossessed and foreclosed assets (d) — — 13 13 (1 ) n/m (b) Total assets $ — $ — $ 462 $ 462 $ (60 ) n/m n/m = not meaningful (a) Represents loans within our commercial automotive portfolio. Of this amount, $104 million was valued based upon a sales price for a transaction that closed in January 2019, and $106 million was valued using a discounted cash flow analysis, with a spread over forward interest rates as a significant unobservable input utilizing a range of 0.08 – 1.09% and weighted average of 0.72% . (b) We consider the applicable valuation allowance, loan loss allowance, or cumulative impairment to be the most relevant indicator of the impact on earnings caused by the fair value measurement. Accordingly, the table above excludes total gains and losses included in earnings for these items. The carrying values are inclusive of the respective valuation allowance, loan loss allowance, or cumulative impairment. (c) Represents the portion of the portfolio specifically impaired during 2018 . The related valuation allowance represents the cumulative adjustment to fair value of those specific receivables. (d) The allowance provided for repossessed and foreclosed assets represents any cumulative valuation adjustment recognized to adjust the assets to fair value. Fair Value Option for Financial Assets We elected the fair value option for an insignificant amount of conforming mortgage loans held-for-sale and certain acquired unsecured consumer finance receivables. We elected the fair value option for conforming mortgage loans held-for-sale to mitigate earnings volatility by better matching the accounting for the assets with the related derivatives. We elected the fair value option for certain acquired unsecured consumer finance receivables to mitigate the complexities of recording these loans at amortized cost. Our intent in electing fair value measurement was to mitigate a divergence between accounting gains or losses and economic exposure for certain assets and liabilities. Fair Value of Financial Instruments The following table presents the carrying and estimated fair value of financial instruments, except for those recorded at fair value on a recurring basis presented in the previous section of this note titled Recurring Fair Value. When possible, we use quoted market prices to determine fair value. Where quoted market prices are not available, the fair value is internally derived based on appropriate valuation methodologies with respect to the amount and timing of future cash flows and estimated discount rates. However, considerable judgment is required in interpreting current market data to develop the market assumptions and inputs necessary to estimate fair value. As such, the actual amount received to sell an asset or the amount paid to settle a liability could differ from our estimates. Fair value information presented herein was based on information available at December 31, 2019 , and December 31, 2018 . Estimated fair value ($ in millions) Carrying value Level 1 Level 2 Level 3 Total December 31, 2019 Financial assets Held-to-maturity securities $ 1,568 $ — $ 1,600 $ — $ 1,600 Loans held-for-sale, net 128 — — 128 128 Finance receivables and loans, net 126,957 — — 130,837 130,837 FHLB/FRB stock (a) 1,150 — 1,150 — 1,150 Financial liabilities Deposit liabilities $ 60,146 $ — $ — $ 60,678 $ 60,678 Short-term borrowings 5,531 — — 5,532 5,532 Long-term debt 34,027 — 22,789 14,138 36,927 December 31, 2018 Financial assets Held-to-maturity securities $ 2,362 $ — $ 2,307 $ — $ 2,307 Loans held-for-sale, net 306 — — 306 306 Finance receivables and loans, net 128,684 — — 130,878 130,878 FHLB/FRB stock (a) 1,351 — 1,351 — 1,351 Financial liabilities Deposit liabilities $ 51,985 $ — $ — $ 51,997 $ 51,997 Short-term borrowings 9,987 — — 9,992 9,992 Long-term debt 44,193 — 23,846 21,800 45,646 (a) Included in other assets on our Consolidated Balance Sheet .

Offsetting Assets and Liabiliti

Offsetting Assets and Liabilities	12 Months Ended
	Dec. 31, 2019
Offsetting [Abstract]
Offsetting Assets and Liabilities	Offsetting Assets and Liabilities Our derivative contracts and repurchase/reverse repurchase transactions are supported by qualifying master netting and master repurchase agreements. These agreements are legally enforceable bilateral agreements that (i) create a single legal obligation for all individual transactions covered by the agreement to the nondefaulting entity upon an event of default of the counterparty, including bankruptcy, insolvency, or similar proceeding, and (ii) provide the nondefaulting entity the right to accelerate, terminate, and close-out on a net basis all transactions under the agreement and to liquidate or set off collateral promptly upon an event of default of the counterparty. To further mitigate the risk of counterparty default related to derivative instruments, we maintain collateral agreements with certain counterparties. The agreements require both parties to maintain collateral in the event the fair values of the derivative financial instruments meet established thresholds. In the event that either party defaults on the obligation, the secured party may seize the collateral. Generally, our collateral arrangements are bilateral such that we and the counterparty post collateral for the obligation. Contractual terms provide for standard and customary exchange of collateral based on changes in the market value of the outstanding derivatives. A party posts additional collateral when their obligation rises or removes collateral when it falls, such that the net replacement cost of the nondefaulting party is covered in the event of counterparty default. In certain instances, as it relates to our derivative instruments, we have the option to report derivative assets and liabilities as well as assets and liabilities associated with cash collateral received or delivered that is governed by a master netting agreement on a net basis as long as certain qualifying criteria are met. Similarly, for our repurchase/reverse repurchase transactions, we have the option to report recognized assets and liabilities subject to a master netting agreement on a net basis if certain qualifying criteria are met. At December 31, 2019 , these instruments are reported as gross assets and gross liabilities on the Consolidated Balance Sheet . The composition of offsetting derivative instruments, financial assets, and financial liabilities was as follows. Gross amounts of recognized assets/liabilities Gross amounts offset on the Consolidated Balance Sheet Net amounts of assets/liabilities presented on the Consolidated Balance Sheet Gross amounts not offset on the Consolidated Balance Sheet December 31, ($ in millions) Financial instruments Collateral (a) (b) (c) Net amount 2019 Assets Derivative assets in net asset positions (d) $ 62 $ — $ 62 $ — $ (36 ) $ 26 Derivative assets with no offsetting arrangements 2 — 2 — — 2 Total assets $ 64 $ — $ 64 $ — $ (36 ) $ 28 Liabilities Derivative liabilities in net liability positions (d) $ 5 $ — $ 5 $ — $ (4 ) $ 1 Total liabilities $ 5 $ — $ 5 $ — $ (4 ) $ 1 2018 Assets Derivative assets in net asset positions $ 41 $ — $ 41 $ — $ (4 ) $ 37 Total assets (d) $ 41 $ — $ 41 $ — $ (4 ) $ 37 Liabilities Derivative liabilities in net liability positions (d) $ 37 $ — $ 37 $ — $ — $ 37 Securities sold under agreements to repurchase (e) 685 — 685 — (685 ) — Total liabilities $ 722 $ — $ 722 $ — $ (685 ) $ 37 (a) Financial collateral received/pledged shown as a balance based on the sum of all net asset and liability positions between Ally and each individual derivative counterparty. (b) Amounts disclosed are limited to the financial asset or liability balance and, accordingly, exclude excess collateral received or pledged and noncash collateral received. There was $29 million and $3 million of noncash derivative collateral pledged to us that was excluded at December 31, 2019 , and 2018 , respectively, and $4 million of noncash collateral associated with our repurchase agreements pledged to us that was excluded at December 31, 2018 . We do not record such collateral received on our Consolidated Balance Sheet unless certain conditions are met. (c) Certain agreements grant us the right to sell or pledge the noncash assets we receive as collateral. Noncash collateral pledged to us where the agreement grants us the right to sell or pledge the underlying assets had a fair value of $29 million and $7 million at December 31, 2019 , and 2018 , respectively. We have not sold or pledged any of the noncash collateral received under these agreements as of both December 31, 2019 , and December 31, 2018 . (d) For additional information on derivative instruments and hedging activities, refer to Note 21 . (e) For additional information on securities sold under agreements to repurchase, refer to Note 15 .

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Reporting Disclosure	Segment Information Operating segments are defined as components of an enterprise that engage in business activity from which revenues are earned and expenses incurred for which discrete financial information is available that is evaluated regularly by our chief operating decision maker in deciding how to allocate resources and in assessing performance. We report our results of operations on a business-line basis through four operating segments: Automotive Finance operations, Insurance operations, Mortgage Finance operations, and Corporate Finance operations, with the remaining activity reported in Corporate and Other. The operating segments are determined based on the products and services offered, and reflect the manner in which financial information is currently evaluated by management. The following is a description of each of our reportable operating segments. Automotive Finance operations — One of the largest full-service automotive finance operations in the United States providing automotive financing services to consumers, automotive dealers, companies, and municipalities. Our automotive finance services include providing retail installment sales contracts, loans and operating leases, offering term loans to dealers, financing dealer floorplans and other lines of credit to dealers, warehouse lines to automotive retailers, fleet financing, providing financing to companies and municipalities for the purchase or lease of vehicles, and vehicle-remarketing services. Insurance operations — A complementary automotive-focused business offering both consumer finance protection and insurance products sold primarily through the automotive dealer channel, and commercial insurance products sold directly to dealers. As part of our focus on offering dealers a broad range of consumer financial and insurance products, we provide VSCs, VMCs, and GAP products. We also underwrite select commercial insurance coverages, which primarily insure dealers’ vehicle inventory. Mortgage Finance operations — Consists of the management of held-for-investment and held-for sale consumer mortgage loan portfolios. Our held-for-investment loan portfolio includes bulk purchases of high-quality jumbo and LMI mortgage loans originated by third parties. Our direct-to-consumer mortgage offering, referred to as Ally Home, consists of a variety of jumbo and conforming fixed- and adjustable-rate mortgage products with the assistance of a third-party fulfillment provider. Jumbo mortgage loans are generally held on our balance sheet and are accounted for as held-for-investment. Conforming mortgage loans are generally originated as held-for-sale and then sold to the fulfillment provider , and we retain no mortgage servicing rights associated with those loans that are sold. Corporate Finance operations — Primarily provides senior secured leveraged cash flow and asset-based loans to mostly U.S.-based middle-market companies, with a focus on businesses owned by private equity sponsors. These loans are typically used for leveraged buyouts, mergers and acquisitions, debt refinancing, restructurings, and working capital. We also provide non-bank wholesale-funded managers with partial funding for their direct-lending activities, which is principally leveraged loans. Additionally, we offer a commercial real estate product to serve companies in the healthcare industry. Corporate and Other primarily consists of centralized corporate treasury activities such as management of the cash and corporate investment securities and loan portfolios, short- and long-term debt, retail and brokered deposit liabilities, derivative instruments, original issue discount, and the residual impacts of our corporate funds-transfer pricing (FTP) and treasury asset liability management (ALM) activities. Corporate and Other also includes certain equity investments, which primarily consist of FHLB and FRB stock, the management of our legacy mortgage portfolio, which primarily consists of loans originated prior to January 1, 2009, and reclassifications and eliminations between the reportable operating segments. Financial results related to Ally Invest, our online brokerage operations, are currently included within Corporate and Other. Additionally, beginning in October 2019 with the acquisition of Health Credit Services, financial information related to Ally Lending, our point-of-sale financing business, is included within Corporate and Other. We utilize an FTP methodology for the majority of our business operations. The FTP methodology assigns charge rates and credit rates to classes of assets and liabilities based on expected duration and the benchmark rate curve plus an assumed credit spread. Matching duration allocates interest income and interest expense to these reportable segments so their respective results are insulated from interest rate risk. This methodology is consistent with our ALM practices, which includes managing interest rate risk centrally at a corporate level. The net residual impact of the FTP methodology is included within the results of Corporate and Other. The information presented in our reportable operating segments is based in part on internal allocations, which involve management judgment. Financial information for our reportable operating segments is summarized as follows. Year ended December 31, ($ in millions) Automotive Finance operations Insurance operations Mortgage Finance operations Corporate Finance operations Corporate and Other Consolidated (a) 2019 Net financing revenue and other interest income $ 4,141 $ 54 $ 171 $ 239 $ 28 $ 4,633 Other revenue 249 1,274 22 45 171 1,761 Total net revenue 4,390 1,328 193 284 199 6,394 Provision for loan losses 962 — 5 36 (5 ) 998 Total noninterest expense 1,810 1,013 148 95 363 3,429 Income (loss) from continuing operations before income tax expense $ 1,618 $ 315 $ 40 $ 153 $ (159 ) $ 1,967 Total assets $ 113,863 $ 8,547 $ 16,279 $ 5,787 $ 36,168 $ 180,644 2018 Net financing revenue and other interest income $ 3,769 $ 54 $ 179 $ 204 $ 184 $ 4,390 Other revenue 269 981 7 38 119 1,414 Total net revenue 4,038 1,035 186 242 303 5,804 Provision for loan losses 920 — 1 12 (15 ) 918 Total noninterest expense 1,750 955 140 86 333 3,264 Income (loss) from continuing operations before income tax expense $ 1,368 $ 80 $ 45 $ 144 $ (15 ) $ 1,622 Total assets $ 117,304 $ 7,734 $ 15,211 $ 4,670 $ 33,950 $ 178,869 2017 Net financing revenue and other interest income $ 3,713 $ 59 $ 132 $ 167 $ 150 $ 4,221 Other revenue 355 1,059 4 45 81 1,544 Total net revenue 4,068 1,118 136 212 231 5,765 Provision for loan losses 1,134 — 8 22 (16 ) 1,148 Total noninterest expense 1,714 950 108 76 262 3,110 Income (loss) from continuing operations before income tax expense $ 1,220 $ 168 $ 20 $ 114 $ (15 ) $ 1,507 Total assets $ 114,089 $ 7,464 $ 11,708 $ 3,979 $ 29,908 $ 167,148 (a) Net financing revenue and other interest income after the provision for loan losses totaled $3.6 billion , $3.5 billion , and $3.1 billion for the years ended December 31, 2019 , 2018 , and 2017 , respectively.

Parent and Guarantor Condensed

Parent and Guarantor Condensed Consolidating Financial Statements	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Financial Statements	Parent and Guarantor Consolidating Financial Statements Certain of our senior notes issued by the parent are guaranteed by 100% directly owned subsidiaries of Ally (the Guarantors). As of December 31, 2019 , the Guarantors include Ally US LLC and IB Finance Holding Company, LLC (IB Finance), each of which fully and unconditionally guarantee the senior notes on a joint and several basis. The following financial statements present condensed consolidating financial data for (i) Ally Financial Inc. (on a parent company-only basis); (ii) the Guarantors; (iii) the nonguarantor subsidiaries (all other subsidiaries); and (iv) a column for adjustments to arrive at (v) the information for the parent company, the Guarantors, and nonguarantors on a consolidated basis. Investment in subsidiaries is accounted for by the parent company and the Guarantors using the equity method for this presentation. Results of operations of subsidiaries are therefore classified in the parent company’s and Guarantors’ investment in subsidiaries accounts. The elimination entries set forth in the following condensed consolidating financial statements eliminate distributed and undistributed income of subsidiaries, investment in subsidiaries, and intercompany balances and transactions between the parent, the Guarantors, and nonguarantors. Condensed Consolidating Statements of Comprehensive Income Year ended December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Financing revenue and other interest income Interest and fees on finance receivables and loans $ (225 ) $ — $ 7,570 $ (8 ) $ 7,337 Interest and fees on finance receivables and loans — intercompany 11 6 (17 ) — Interest on loans held-for-sale — 17 — 17 Interest and dividends on investment securities and other earning assets — — 955 — 955 Interest on cash and cash equivalents 10 — 68 — 78 Interest on cash and cash equivalents — intercompany 14 — 17 (31 ) — Operating leases 2 — 1,468 — 1,470 Total financing (loss) revenue and other interest income (188 ) — 10,101 (56 ) 9,857 Interest expense Interest on deposits — — 2,538 — 2,538 Interest on short-term borrowings 53 — 82 — 135 Interest on long-term debt 849 — 721 — 1,570 Interest on intercompany debt 23 — 25 (48 ) — Total interest expense 925 — 3,366 (48 ) 4,243 Net depreciation expense on operating lease assets 3 — 978 — 981 Net financing (loss) revenue and other interest income (1,116 ) — 5,757 (8 ) 4,633 Cash dividends from subsidiaries Bank subsidiary 1,950 1,950 — (3,900 ) — Nonbank subsidiaries 436 — — (436 ) — Other revenue Insurance premiums and service revenue earned — — 1,087 — 1,087 Gain on mortgage and automotive loans, net 4 — 24 — 28 Other gain on investments, net 2 — 241 — 243 Other income, net of losses 337 — 611 (545 ) 403 Total other revenue 343 — 1,963 (545 ) 1,761 Total net revenue 1,613 1,950 7,720 (4,889 ) 6,394 Provision for loan losses 35 — 981 (18 ) 998 Noninterest expense Compensation and benefits expense 36 — 1,186 — 1,222 Insurance losses and loss adjustment expenses — — 321 — 321 Other operating expenses 590 — 1,841 (545 ) 1,886 Total noninterest expense 626 — 3,348 (545 ) 3,429 Income from continuing operations before income tax expense and undistributed income of subsidiaries 952 1,950 3,391 (4,326 ) 1,967 Income tax (benefit) expense from continuing operations (566 ) — 812 — 246 Net income from continuing operations 1,518 1,950 2,579 (4,326 ) 1,721 Loss from discontinued operations, net of tax (6 ) — — — (6 ) Undistributed income of subsidiaries Bank subsidiary 210 210 — (420 ) — Nonbank subsidiaries (7 ) — — 7 — Net income 1,715 2,160 2,579 (4,739 ) 1,715 Other comprehensive income, net of tax 654 492 685 (1,177 ) 654 Comprehensive income $ 2,369 $ 2,652 $ 3,264 $ (5,916 ) $ 2,369 Year ended December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Financing revenue and other interest income Interest and fees on finance receivables and loans $ (40 ) $ — $ 6,728 $ — $ 6,688 Interest and fees on finance receivables and loans — intercompany 12 — 5 (17 ) — Interest on loans held-for-sale — — 15 — 15 Interest and dividends on investment securities and other earning assets — — 789 (1 ) 788 Interest on cash and cash equivalents 8 — 64 — 72 Interest on cash and cash equivalents — intercompany 8 — 9 (17 ) — Operating leases 5 — 1,484 — 1,489 Total financing (loss) revenue and other interest income (7 ) — 9,094 (35 ) 9,052 Interest expense Interest on deposits — — 1,735 — 1,735 Interest on short-term borrowings 44 — 105 — 149 Interest on long-term debt 1,009 — 744 — 1,753 Interest on intercompany debt 15 — 20 (35 ) — Total interest expense 1,068 — 2,604 (35 ) 3,637 Net depreciation expense on operating lease assets 8 — 1,017 — 1,025 Net financing (loss) revenue and other interest income (1,083 ) — 5,473 — 4,390 Cash dividends from subsidiaries Bank subsidiary 2,600 2,600 — (5,200 ) — Nonbank subsidiaries 443 — — (443 ) — Other revenue Insurance premiums and service revenue earned — — 1,022 — 1,022 Gain on mortgage and automotive loans, net 70 — 9 (54 ) 25 Other loss on investments, net — — (50 ) — (50 ) Other income, net of losses 411 — 770 (764 ) 417 Total other revenue 481 — 1,751 (818 ) 1,414 Total net revenue 2,441 2,600 7,224 (6,461 ) 5,804 Provision for loan losses 176 — 796 (54 ) 918 Noninterest expense Compensation and benefits expense 83 — 1,072 — 1,155 Insurance losses and loss adjustment expenses — — 295 — 295 Other operating expenses 681 — 1,897 (764 ) 1,814 Total noninterest expense 764 — 3,264 (764 ) 3,264 Income from continuing operations before income tax (benefit) expense and undistributed (loss) income of subsidiaries 1,501 2,600 3,164 (5,643 ) 1,622 Income tax (benefit) expense from continuing operations (300 ) — 659 — 359 Net income from continuing operations 1,801 2,600 2,505 (5,643 ) 1,263 (Loss) income from discontinued operations, net of tax (2 ) — 2 — — Undistributed (loss) income of subsidiaries Bank subsidiary (614 ) (614 ) — 1,228 — Nonbank subsidiaries 78 — — (78 ) — Net income 1,263 1,986 2,507 (4,493 ) 1,263 Other comprehensive loss, net of tax (289 ) (243 ) (308 ) 551 (289 ) Comprehensive income $ 974 $ 1,743 $ 2,199 $ (3,942 ) $ 974 Year ended December 31, 2017 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Financing revenue and other interest income Interest and fees on finance receivables and loans $ (27 ) $ — $ 5,846 $ — $ 5,819 Interest and fees on finance receivables and loans — intercompany 12 — 6 (18 ) — Interest and dividends on investment securities and other earning assets — — 601 (2 ) 599 Interest on cash and cash equivalents 7 — 30 — 37 Interest on cash and cash equivalents — intercompany 4 — 7 (11 ) — Operating leases 11 — 1,856 — 1,867 Total financing revenue and other interest income 7 — 8,346 (31 ) 8,322 Interest expense Interest on deposits 3 — 1,078 (4 ) 1,077 Interest on short-term borrowings 60 — 67 — 127 Interest on long-term debt 1,101 — 552 — 1,653 Interest on intercompany debt 15 — 12 (27 ) — Total interest expense 1,179 — 1,709 (31 ) 2,857 Net depreciation expense on operating lease assets 11 — 1,233 — 1,244 Net financing (loss) revenue and other interest income (1,183 ) — 5,404 — 4,221 Cash dividends from subsidiaries Bank subsidiary 3,300 3,300 — (6,600 ) — Nonbank subsidiaries 752 — — (752 ) — Other revenue Insurance premiums and service revenue earned — — 973 — 973 Gain on mortgage and automotive loans, net 40 — 28 — 68 Other gain on investments, net — — 102 — 102 Other income, net of losses 675 — 834 (1,108 ) 401 Total other revenue 715 — 1,937 (1,108 ) 1,544 Total net revenue 3,584 3,300 7,341 (8,460 ) 5,765 Provision for loan losses 465 — 683 — 1,148 Noninterest expense Compensation and benefits expense 180 — 915 — 1,095 Insurance losses and loss adjustment expenses — — 332 — 332 Other operating expenses 899 — 1,892 (1,108 ) 1,683 Total noninterest expense 1,079 — 3,139 (1,108 ) 3,110 Income from continuing operations before income tax expense and undistributed (loss) income of subsidiaries 2,040 3,300 3,519 (7,352 ) 1,507 Income tax expense from continuing operations 337 — 244 — 581 Net income from continuing operations 1,703 3,300 3,275 (7,352 ) 926 Income (loss) from discontinued operations, net of tax 7 — (4 ) — 3 Undistributed (loss) income of subsidiaries Bank subsidiary (1,168 ) (1,168 ) — 2,336 — Nonbank subsidiaries 387 — — (387 ) — Net income 929 2,132 3,271 (5,403 ) 929 Other comprehensive income, net of tax 106 65 104 (169 ) 106 Comprehensive income $ 1,035 $ 2,197 $ 3,375 $ (5,572 ) $ 1,035 Condensed Consolidating Balance Sheet December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Assets Cash and cash equivalents Noninterest-bearing $ 49 $ — $ 570 $ — $ 619 Interest-bearing 5 — 2,931 — 2,936 Interest-bearing — intercompany 2,051 — 1,087 (3,138 ) — Total cash and cash equivalents 2,105 — 4,588 (3,138 ) 3,555 Equity securities — — 616 — 616 Available-for-sale securities — — 30,284 — 30,284 Held-to-maturity securities — — 1,578 (10 ) 1,568 Loans held-for-sale, net — — 158 — 158 Finance receivables and loans, net Finance receivables and loans, net 2,167 — 126,054 10 128,231 Intercompany loans to Nonbank subsidiaries 161 — 110 (271 ) — Allowance for loan losses (22 ) — (1,241 ) — (1,263 ) Total finance receivables and loans, net 2,306 — 124,923 (261 ) 126,968 Investment in operating leases, net 1 — 8,863 — 8,864 Intercompany receivables from Bank subsidiary 94 — — (94 ) — Nonbank subsidiaries 50 — 77 (127 ) — Investment in subsidiaries Bank subsidiary 16,954 16,954 — (33,908 ) — Nonbank subsidiaries 6,535 — — (6,535 ) — Premiums receivable and other insurance assets — — 2,558 — 2,558 Other assets 2,193 — 5,690 (1,810 ) 6,073 Total assets $ 30,238 $ 16,954 $ 179,335 $ (45,883 ) $ 180,644 Liabilities and equity Deposit liabilities Noninterest-bearing $ — $ — $ 119 $ — $ 119 Interest-bearing 1 — 120,632 — 120,633 Interest-bearing — intercompany — — 2,051 (2,051 ) — Total deposit liabilities 1 — 122,802 (2,051 ) 120,752 Short-term borrowings 2,581 — 2,950 — 5,531 Long-term debt 11,389 — 22,638 — 34,027 Intercompany debt to Bank subsidiary 10 — — (10 ) — Nonbank subsidiaries 1,197 — 161 (1,358 ) — Intercompany payables to Bank subsidiary 18 — — (18 ) — Nonbank subsidiaries 98 — 133 (231 ) — Interest payable 145 — 496 — 641 Unearned insurance premiums and service revenue — — 3,305 — 3,305 Accrued expenses and other liabilities 383 — 3,371 (1,782 ) 1,972 Total liabilities 15,822 — 155,856 (5,450 ) 166,228 Total equity 14,416 16,954 23,479 (40,433 ) 14,416 Total liabilities and equity $ 30,238 $ 16,954 $ 179,335 $ (45,883 ) $ 180,644 December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Assets Cash and cash equivalents Noninterest-bearing $ 55 $ — $ 755 $ — $ 810 Interest-bearing 5 — 3,722 — 3,727 Interest-bearing — intercompany 1,249 — 521 (1,770 ) — Total cash and cash equivalents 1,309 — 4,998 (1,770 ) 4,537 Equity securities — — 773 — 773 Available-for-sale securities — — 25,303 — 25,303 Held-to-maturity securities — — 2,382 (20 ) 2,362 Loans held-for-sale, net — — 314 — 314 Finance receivables and loans, net Finance receivables and loans, net 2,349 — 127,577 — 129,926 Intercompany loans to Nonbank subsidiaries 882 — 397 (1,279 ) — Allowance for loan losses (55 ) — (1,187 ) — (1,242 ) Total finance receivables and loans, net 3,176 — 126,787 (1,279 ) 128,684 Investment in operating leases, net 5 — 8,412 — 8,417 Intercompany receivables from Bank subsidiary 158 — — (158 ) — Nonbank subsidiaries 45 — 129 (174 ) — Investment in subsidiaries Bank subsidiary 16,213 16,213 — (32,426 ) — Nonbank subsidiaries 6,928 — — (6,928 ) — Premiums receivable and other insurance assets — — 2,326 — 2,326 Other assets 2,226 — 5,453 (1,526 ) 6,153 Total assets $ 30,060 $ 16,213 $ 176,877 $ (44,281 ) $ 178,869 Liabilities and equity Deposit liabilities Noninterest-bearing $ — $ — $ 142 $ — $ 142 Interest-bearing 1 — 106,035 — 106,036 Interest-bearing — intercompany — — 1,249 (1,249 ) — Total deposit liabilities 1 — 107,426 (1,249 ) 106,178 Short-term borrowings 2,477 — 7,510 — 9,987 Long-term debt 12,774 — 31,419 — 44,193 Intercompany debt to Bank subsidiary 20 — — (20 ) — Nonbank subsidiaries 918 — 882 (1,800 ) — Intercompany payables to Bank subsidiary 45 — — (45 ) — Nonbank subsidiaries 124 — 129 (253 ) — Interest payable 159 — 364 — 523 Unearned insurance premiums and service revenue — — 3,044 — 3,044 Accrued expenses and other liabilities 274 — 2,962 (1,560 ) 1,676 Total liabilities 16,792 — 153,736 (4,927 ) 165,601 Total equity 13,268 16,213 23,141 (39,354 ) 13,268 Total liabilities and equity $ 30,060 $ 16,213 $ 176,877 $ (44,281 ) $ 178,869 Condensed Consolidating Statement of Cash Flows Year ended December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Operating activities Net cash provided by operating activities $ 1,818 $ 1,950 $ 4,628 $ (4,346 ) $ 4,050 Investing activities Purchases of equity securities — — (498 ) — (498 ) Proceeds from sales of equity securities — — 814 — 814 Purchases of available-for-sale securities — — (15,199 ) — (15,199 ) Proceeds from sales of available-for-sale securities — — 7,079 — 7,079 Proceeds from repayments of available-for-sale securities — — 5,154 — 5,154 Purchases of held-to-maturity securities — — (514 ) — (514 ) Proceeds from repayments of held-to-maturity securities — — 302 — 302 Net change in investment securities — intercompany — — 10 (10 ) — Purchases of finance receivables and loans held-for-investment — — (4,974 ) 535 (4,439 ) Proceeds from sales of finance receivables and loans initially held-for-investment 548 — 1,025 (535 ) 1,038 Originations and repayments of finance receivables and loans held-for-investment and other, net (253 ) — 4,497 8 4,252 Net change in loans — intercompany 718 — 284 (1,002 ) — Purchases of operating lease assets — — (4,023 ) — (4,023 ) Disposals of operating lease assets 3 — 2,622 — 2,625 Acquisitions, net of cash acquired — — (171 ) — (171 ) Capital contributions to subsidiaries (2 ) — — 2 — Returns of contributed capital 259 — — (259 ) — Net change in nonmarketable equity investments (13 ) — 203 — 190 Other, net (4 ) — (375 ) — (379 ) Net cash provided by (used in) investing activities 1,256 — (3,764 ) (1,261 ) (3,769 ) Financing activities Net change in short-term borrowings — third party 104 — (4,560 ) — (4,456 ) Net increase in deposits — — 15,349 (802 ) 14,547 Proceeds from issuance of long-term debt — third party 801 — 6,114 — 6,915 Repayments of long-term debt — third party (2,173 ) — (15,051 ) — (17,224 ) Net change in debt — intercompany 271 — (718 ) 447 — Repurchase of common stock (1,039 ) — — — (1,039 ) Dividends paid — third party (273 ) — — — (273 ) Dividends paid and returns of contributed capital — intercompany — (1,950 ) (2,646 ) 4,596 — Capital contributions from parent — — 2 (2 ) — Net cash used in financing activities (2,309 ) (1,950 ) (1,510 ) 4,239 (1,530 ) Effect of exchange-rate changes on cash and cash equivalents and restricted cash — — 3 — 3 Net increase (decrease) in cash and cash equivalents and restricted cash 765 — (643 ) (1,368 ) (1,246 ) Cash and cash equivalents and restricted cash at beginning of year 1,398 — 5,998 (1,770 ) 5,626 Cash and cash equivalents and restricted cash at end of year $ 2,163 $ — $ 5,355 $ (3,138 ) $ 4,380 The following table provides a reconciliation of cash and cash equivalents and restricted cash from the Condensed Consolidating Balance Sheet to the Condensed Consolidating Statement of Cash Flows. December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Cash and cash equivalents on the Condensed Consolidating Balance Sheet $ 2,105 $ — $ 4,588 $ (3,138 ) $ 3,555 Restricted cash included in other assets on the Condensed Consolidating Balance Sheet (a) 58 — 767 — 825 Total cash and cash equivalents and restricted cash in the Condensed Consolidating Statement of Cash Flows $ 2,163 $ — $ 5,355 $ (3,138 ) $ 4,380 (a) Restricted cash balances relate primarily to Ally securitization arrangements. Refer to Note 13 for additional details describing the nature of restricted cash balances. Year ended December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Operating activities Net cash provided by operating activities $ 1,659 $ 2,600 $ 5,536 $ (5,645 ) $ 4,150 Investing activities Purchases of equity securities — — (1,076 ) — (1,076 ) Proceeds from sales of equity securities — — 787 — 787 Purchases of available-for-sale securities — — (7,868 ) — (7,868 ) Proceeds from sales of available-for-sale securities — — 852 — 852 Proceeds from repayments of available-for-sale securities — — 3,215 — 3,215 Purchases of held-to-maturity securities — — (578 ) — (578 ) Proceeds from repayments of held-to-maturity securities — — 147 — 147 Net change in investment securities — intercompany — — 54 (54 ) — Purchases of finance receivables and loans held-for-investment (131 ) — (7,101 ) 1,539 (5,693 ) Proceeds from sales of finance receivables and loans initially held-for-investment 1,596 — 34 (1,539 ) 91 Originations and repayments of finance receivables and loans held-for-investment and other, net 3,489 — (6,734 ) — (3,245 ) Net change in loans — intercompany (20 ) — (2 ) 22 — Purchases of operating lease assets — — (3,709 ) — (3,709 ) Disposals of operating lease assets 10 — 3,079 — 3,089 Capital contributions to subsidiaries (61 ) (6 ) — 67 — Returns of contributed capital 266 — — (266 ) — Net change in nonmarketable equity investments (16 ) — (165 ) — (181 ) Other, net — — (340 ) — (340 ) Net cash provided by (used in) investing activities 5,133 (6 ) (19,405 ) (231 ) (14,509 ) Financing activities Net change in short-term borrowings — third party (694 ) — (732 ) — (1,426 ) Net (decrease) increase in deposits (11 ) — 12,989 (111 ) 12,867 Proceeds from issuance of long-term debt — third party 69 — 18,332 — 18,401 Repayments of long-term debt — third party (4,774 ) — (13,166 ) — (17,940 ) Net change in debt — intercompany (198 ) — (10 ) 208 — Repurchase of common stock (939 ) — — — (939 ) Dividends paid — third party (242 ) — — — (242 ) Dividends paid and returns of contributed capital — intercompany — (2,600 ) (3,309 ) 5,909 — Capital contributions from parent — 6 61 (67 ) — Net cash (used in) provided by financing activities (6,789 ) (2,594 ) 14,165 5,939 10,721 Effect of exchange-rate changes on cash and cash equivalents and restricted cash — — (5 ) — (5 ) Net increase in cash and cash equivalents and restricted cash 3 — 291 63 357 Cash and cash equivalents and restricted cash at beginning of year 1,395 — 5,707 (1,833 ) 5,269 Cash and cash equivalents and restricted cash at end of year $ 1,398 $ — $ 5,998 $ (1,770 ) $ 5,626 The following table provides a reconciliation of cash and cash equivalents and restricted cash from the Condensed Consolidating Balance Sheet to the Condensed Consolidating Statement of Cash Flows. December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Cash and cash equivalents on the Condensed Consolidating Balance Sheet $ 1,309 $ — $ 4,998 $ (1,770 ) $ 4,537 Restricted cash included in other assets on the Condensed Consolidating Balance Sheet (a) 89 — 1,000 — 1,089 Total cash and cash equivalents and restricted cash in the Condensed Consolidating Statement of Cash Flows $ 1,398 $ — $ 5,998 $ (1,770 ) $ 5,626 (a) Restricted cash balances relate primarily to Ally securitization arrangements. Refer to Note 13 for additional details describing the nature of restricted cash balances. Year ended December 31, 2017 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Operating activities Net cash provided by operating activities $ 4,591 $ 3,300 $ 3,466 $ (7,278 ) $ 4,079 Investing activities Purchases of equity securities — — (899 ) — (899 ) Proceeds from sales of equity securities — — 1,049 — 1,049 Purchases of available-for-sale securities — — (10,335 ) — (10,335 ) Proceeds from sales of available-for-sale securities — — 3,584 — 3,584 Proceeds from repayments of available-for-sale securities — — 2,899 — 2,899 Purchases of held-to-maturity securities — — (1,026 ) — (1,026 ) Proceeds from repayments of held-to-maturity securities — — 68 — 68 Net change in investment securities — intercompany 7 — 291 (298 ) — Purchases of finance receivables and loans held-for-investment (35 ) — (5,417 ) — (5,452 ) Proceeds from sales of finance receivables and loans initially held-for-investment 106 — 1,233 — 1,339 Originations and repayments of finance receivables and loans held-for-investment and other, net 860 — 33 (1,956 ) (1,063 ) Net change in loans — intercompany 2,068 — 217 (2,285 ) — Purchases of operating lease assets — — (4,052 ) — (4,052 ) Disposals of operating lease assets 13 — 5,554 — 5,567 Capital contributions to subsidiaries (1,212 ) (5 ) — 1,217 — Returns of contributed capital 1,567 — — (1,567 ) — Net change in nonmarketable equity investments — — (187 ) — (187 ) Other, net (31 ) — (99 ) (89 ) (219 ) Net cash provided by (used in) investing activities 3,343 (5 ) (7,087 ) (4,978 ) (8,727 ) Financing activities Net change in short-term borrowings — third party (453 ) — (810 ) — (1,263 ) Net (decrease) increase in deposits (156 ) — 15,466 (1,138 ) 14,172 Proceeds from issuance of long-term debt — third party 354 — 15,654 1,961 17,969 Repayments of long-term debt — third party (6,111 ) — (21,797 ) — (27,908 ) Net change in debt — intercompany (225 ) — (2,074 ) 2,299 — Repurchase of common stock (753 ) — — — (753 ) Dividends paid — third party (184 ) — — — (184 ) Dividends paid and returns of contributed capital — intercompany — (3,300 ) (5,619 ) 8,919 — Capital contributions from parent — 5 1,212 (1,217 ) — Net cash (used in) provided by financing activities (7,528 ) (3,295 ) 2,032 10,824 2,033 Effect of exchange-rate changes on cash and cash equivalents and restricted cash — — 3 — 3 Net increase (decrease) in cash and cash equivalents and restricted cash 406 — (1,586 ) (1,432 ) (2,612 ) Cash and cash equivalents and restricted cash at beginning of year 989 — 7,293 (401 ) 7,881 Cash and cash equivalents and restricted cash at end of year $ 1,395 $ — $ 5,707 $ (1,833 ) $ 5,269

Guarantees and Commitments Guar

Guarantees and Commitments Guarantees and Commitments (Notes)	12 Months Ended
	Dec. 31, 2019
Guarantees and Commitments [Abstract]
Guarantees [Text Block]	Guarantees and Commitments Guarantees Guarantees are defined as contracts or indemnification agreements that contingently require us to make payments to third parties based on changes in the underlying agreements with the guaranteed parties. The following summarizes our outstanding guarantees, including those of our discontinued operations, made to third parties on our Consolidated Balance Sheet , for the periods shown. 2019 2018 December 31, ($ in millions) Maximum liability Carrying value of liability Maximum liability Carrying value of liability Standby letters of credit and other guarantees $ 249 $ 6 $ 218 $ 7 Our Corporate Finance operations has exposure to standby letters of credit that represent irrevocable guarantees of payment of specified financial obligations. Third-party beneficiaries primarily accept standby letters of credit as insurance in the event of nonperformance by our borrowers. Our borrowers may request letters of credit under their revolving loan facility up to a certain sub-limit amount. We may also require collateral to be posted by our borrowers. We received no cash collateral related to these letters of credit at December 31, 2019 . Expiration dates on letters of credit range from certain ongoing commitments that will expire during the upcoming year to terms of several years for certain letters of credit. If the beneficiary draws under a letter of credit, we will be liable to the beneficiary for payment of the amount drawn under such letter of credit, with our recourse being a charge to the borrower’s loan facility or transfer of ownership to us of the related collateral. As many of these commitments are subject to borrowing base agreements and other restrictive covenants or may expire without being fully drawn, the stated amounts of the letters of credit are not necessarily indicative of future cash requirements. In connection with our Ally Invest wealth management business, we introduce customer securities accounts to a clearing broker, which clears and maintains custody of all customer assets and account activity. We are responsible for obtaining from each customer such funds or securities as are required to be deposited or maintained in their accounts. As a result, we are liable for any loss, liability, damage, cost, or expense incurred or sustained by the clearing broker as a result of the failure of any customer to timely make payments or deposits of securities to satisfy their contractual obligations. In addition, customer securities activities are transacted on either a cash or margin basis. In margin transactions, we may extend credit to the customer, through our clearing broker, subject to various regulatory rules and margin lending practices, collateralized by cash and securities in the customer’s account. In connection with these activities, we also execute customer transactions involving the sale of securities not yet purchased. Such transactions may expose us to credit risk in the event the customer’s assets are not sufficient to fully cover losses, which the customer may incur. In the event the customer fails to satisfy its obligations, we will purchase or sell financial instruments in the customer’s account in order to fulfill the customer’s obligations. The maximum potential exposure under these arrangements is difficult to estimate; however, the potential for us to incur material losses pursuant to these arrangements is remote. Commitments Financing Commitments The contractual commitments were as follows. December 31, ($ in millions) 2019 2018 Unused revolving credit line commitments and other (a) $ 4,384 $ 3,435 Commitments to provide capital to investees (b) 504 394 Mortgage loan origination commitments (c) 314 171 Home equity lines of credit (d) 226 253 Construction-lending commitments (e) 127 85 (a) The unused portion of revolving lines of credit reset at prevailing market rates and, as such, approximate market value. (b) We are committed to contribute capital to certain investees. (c) Commitments with mortgage loan applicants in which the loan terms, including interest rate and price, are guaranteed for a designated period of time subject to the completion of underwriting procedures. (d) We are committed to fund the remaining unused balances on home equity lines of credit. (e) We are committed to fund the remaining unused balance while loans are in the construction period. Revolving credit line commitments contain an element of credit risk. We manage the credit risk for unused revolving credit line commitments by applying the same credit policies in making commitments as we do for extending loans. Lease Commitments For details about our future minimum payments under operating leases with noncancelable lease terms, refer to Note 10 . Contractual Commitments We have entered into multiple agreements for sponsorship, information technology, voice and communication technology, and related maintenance. Many of the agreements are subject to variable price provisions, fixed or minimum price provisions, and termination or renewal provisions. Year ended December 31, ($ in millions) 2020 $ 68 2021 38 2022 40 2023 37 2024 14 2025 and thereafter 27 Total future payment obligations $ 224

Contingencies and Other Risks

Contingencies and Other Risks	12 Months Ended
	Dec. 31, 2019
Loss Contingency [Abstract]
Contingencies Disclosure	Contingencies and Other Risks Concentration with GM and Chrysler While we are continuing to diversify our automotive finance and insurance businesses and to expand into other financial services, General Motors Company (GM) and Fiat Chrysler Automobiles US LLC (Chrysler) dealers and their retail customers continue to constitute a significant portion of our customer base. GM, Chrysler, and their captive finance companies compete vigorously with us and could take further actions that negatively impact the amount of business that we do with GM and Chrysler dealers and their customers. Further, a significant adverse change in GM’s or Chrysler’s business—including, for example, in the production or sale of GM or Chrysler vehicles, the quality or resale value of GM or Chrysler vehicles, GM’s or Chrysler’s relationships with its key suppliers, or the rate or volume of recalls of GM or Chrysler vehicles—could negatively impact our GM and Chrysler dealer and retail customer bases and the value of collateral securing our extensions of credit to them. Any future reductions in GM and Chrysler business that we are not able to offset could adversely affect our business and financial results. Legal Matters and Other Contingencies Ally and its subsidiaries, including Ally Bank, are or may be subject to potential liability in connection with pending or threatened legal proceedings and other matters. These legal matters may be formal or informal and include litigation and arbitration with one or more identified claimants, certified or purported class actions with yet-to-be-identified claimants, and regulatory or other governmental information-gathering requests, examinations, investigations, and enforcement proceedings. Our legal matters exist in varying stages of adjudication, arbitration, negotiation, or investigation and span our business lines and operations. Claims may be based in law or equity—such as those arising under contracts or in tort and those involving banking, consumer-protection, securities, tax, employment, and other laws—and some can present novel legal theories and allege substantial or indeterminate damages. Ally and its subsidiaries, including Ally Bank, also are or may be subject to potential liability under other contingent exposures, including indemnification, tax, self-insurance, and other miscellaneous contingencies. We accrue for a legal matter or other contingent exposure when a loss becomes probable and the amount of loss can be reasonably estimated. Accruals are evaluated each quarter and may be adjusted, upward or downward, based on our best judgment after consultation with counsel. No assurance exists that our accruals will not need to be adjusted in the future. When a probable or reasonably possible loss on a legal matter or other contingent exposure could be material to our consolidated financial condition, results of operations, or cash flows, we provide disclosure in this note as prescribed by ASC Topic 450, Contingencies . Refer to Note 1 to the Consolidated Financial Statements for additional information on our policy for establishing accruals. The course and outcome of legal matters are inherently unpredictable. This is especially so when a matter is still in its early stages, the damages sought are indeterminate or unsupported, significant facts are unclear or disputed, novel questions of law or other meaningful legal uncertainties exist, a request to certify a proceeding as a class action is outstanding or granted, multiple parties are named, or regulatory or other governmental entities are involved. Other contingent exposures and their ultimate resolution are similarly unpredictable for reasons that can vary based on the circumstances. As a result, we often are unable to determine how or when threatened or pending legal matters and other contingent exposures will be resolved and what losses may be incrementally and ultimately incurred. Actual losses may be higher or lower than any amounts accrued or estimated for those matters and other exposures, possibly to a significant degree. Subject to the foregoing, based on our current knowledge and after consultation with counsel, we do not believe that the ultimate outcomes of currently threatened or pending legal matters and other contingent exposures are likely to be material to our consolidated financial condition after taking into account existing accruals. In light of the uncertainties inherent in these matters and other exposures, however, one or more of them could be material to our results of operations or cash flows during a particular reporting period, depending on factors such as the amount of the loss or liability and the level of our income for that period. Descriptions of our potentially material legal matters follow. We do not believe, however, that an estimate of reasonably possible losses or a range of reasonably possible losses—whether in excess of any related accrual or where no accrual exists—can be made for any of these matters for some or all of the reasons identified in the preceding paragraphs. Purported and Certified Class Actions In March 2016, Ally filed an action against two buyers of a motor vehicle— Ally Financial Inc. v. Alberta Haskins and David Duncan , Case No. 16JE-AC01713-01 in the Circuit Court of Jefferson County, Missouri—for the purpose of collecting the deficiency that remained due under the retail installment sales contract after the buyers had defaulted and the vehicle had been repossessed and disposed of. In March 2017, the buyers filed a second amended answer and counterclaim on behalf of nationwide and Missouri classes, arguing that Ally’s pre- and post-disposition notices had violated Article 9 of the Uniform Commercial Code as adopted in each jurisdiction. The request for relief includes an indeterminate amount of actual, statutory, and punitive damages as well as fees, costs, interest, and other remedies. In May 2018, the circuit court certified the nationwide and Missouri classes and denied Ally’s motion for partial summary judgment. In September 2018, the case was reassigned to a different circuit-court judge, and in February 2019, Ally filed a motion to decertify the nationwide and Missouri classes. In November 2019, the circuit court denied Ally’s motion to decertify. In December 2019, Ally filed a petition with the Missouri Court of Appeals for a writ prohibiting the circuit court from taking further action other than vacating the order denying decertification— State of Missouri, ex. rel. Ally Financial Inc. v. Hon. Katherine Hardy Senkel , Case No. ED 108501—which was denied that same month. Later in December 2019, Ally filed a petition with the Missouri Supreme Court for an equivalent writ of prohibition— State of Missouri, ex rel. Ally Financial Inc. v. Hon. Katherine Hardy Senkel , Case No. SC 98285—which remains pending. We intend to vigorously defend against this counterclaim.

Quarterly Financial Statements

Quarterly Financial Statements (unaudited) Quarterly Financial Statements (unaudited) (Notes)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Quarterly Financial Statements (unaudited) ($ in millions) First quarter Second quarter Third quarter Fourth quarter 2019 Net financing revenue and other interest income $ 1,132 $ 1,157 $ 1,188 $ 1,156 Other revenue 466 395 413 487 Total net revenue 1,598 1,552 1,601 1,643 Provision for loan losses 282 177 263 276 Total noninterest expense 830 881 838 880 Income from continuing operations before income tax expense 486 494 500 487 Income tax expense (benefit) from continuing operations 111 (90 ) 119 106 Net income from continuing operations 375 584 381 381 Loss from discontinued operations, net of tax (1 ) (2 ) — (3 ) Net income $ 374 $ 582 $ 381 $ 378 Basic earnings per common share (a) Net income from continuing operations $ 0.93 $ 1.47 $ 0.98 $ 1.00 Net income 0.93 1.46 0.97 0.99 Diluted earnings per common share (a) Net income from continuing operations 0.92 1.46 0.97 0.99 Net income 0.92 1.46 0.97 0.99 Cash dividends declared per common share $ 0.17 $ 0.17 $ 0.17 $ 0.17 2018 Net financing revenue and other interest income $ 1,049 $ 1,094 $ 1,107 $ 1,140 Other revenue 354 364 398 298 Total net revenue 1,403 1,458 1,505 1,438 Provision for loan losses 261 158 233 266 Total noninterest expense 814 839 807 804 Income from continuing operations before income tax expense 328 461 465 368 Income tax expense from continuing operations 76 113 91 79 Net income from continuing operations 252 348 374 289 (Loss) income from discontinued operations, net of tax (2 ) 1 — 1 Net income $ 250 $ 349 $ 374 $ 290 Basic earnings per common share (a) Net income from continuing operations $ 0.58 $ 0.81 $ 0.89 $ 0.70 Net income 0.57 0.81 0.89 0.70 Diluted earnings per common share (a) Net income from continuing operations 0.57 0.80 0.88 0.70 Net income 0.57 0.81 0.88 0.70 Cash dividends declared per common share $ 0.13 $ 0.13 $ 0.15 $ 0.15 (a) Earnings per share is calculated quarterly on an independent basis, therefore the total of the amounts presented for each year above may not reconcile to the annual amounts presented in Note 19 .

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Declaration of Quarterly Dividend On January 13, 2020 , our Board declared a quarterly cash dividend of $0.19 per share on all common stock, a $0.02 per share increase relative to our prior quarterly cash dividend. The dividend was paid on February 14, 2020 , to stockholders of record at the close of business on January 31, 2020 . CardWorks Acquisition On February 18, 2020 , Ally announced its execution of a definitive agreement to acquire Cardholder Management Services, Inc. and its subsidiaries, including CardWorks, Inc. and Merrick Bank Corporation (collectively, CardWorks). CardWorks is a nonprime credit-card and consumer-finance provider in the United States with servicing and merchant-service capabilities across the credit spectrum. The acquisition is valued at approximately $2.65 billion , with approximately $1.35 billion in cash and approximately $1.30 billion in common stock of Ally. The consideration is subject to closing equity and other adjustments and to “fill or kill” rights. A possible “fill or kill” adjustment may arise if Ally’s stock price declines by more than 15%, a “fill or kill” termination right is exercised, and Ally elects to “fill” by issuing additional stock. The acquisition is expected to close in the third quarter of 2020 and is subject to the receipt of customary regulatory approvals and the satisfaction of other closing conditions. We filed a copy of the definitive agreement with the SEC on February 20, 2020.

Description of Business, Basi_2

Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Consolidation	The Consolidated Financial Statements include the accounts of the parent and its consolidated subsidiaries, of which it is deemed to possess control, after eliminating intercompany balances and transactions, and include all variable interest entities (VIEs) in which we are the primary beneficiary. Refer to Note 11
Basis of Accounting	Our accounting and reporting policies conform to accounting principles generally accepted in the United States of America (GAAP). Additionally, where applicable, the policies conform to the accounting and reporting guidelines prescribed by bank regulatory authorities. Certain reclassifications may have been made to the prior periods’ financial statements and notes to conform to the current period’s presentation, which did not have a material impact on our Consolidated Financial Statements.
Use of Estimates and Assumptions	Use of Estimates and Assumptions 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 that affect income and expenses during the reporting period and related disclosures. In developing the estimates and assumptions, management uses all available evidence; however, actual results could differ because of uncertainties associated with estimating the amounts, timing, and likelihood of possible outcomes. Our most significant estimates pertain to the allowance for loan losses, valuations of automotive operating lease assets and residuals, fair value of financial instruments, and the determination of the provision for income taxes.
Cash and Cash Equivalents, Policy	Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash on deposit at other financial institutions, cash items in process of collection, and certain highly liquid investments with original maturities of three months or less from the date of purchase. The book value of cash equivalents approximates fair value because of the short maturities of these instruments and the insignificant risk they present to changes in value with respect to changes in interest rates. Certain securities with original maturities of three months or less from the date of purchase that are held as a portion of longer-term investment portfolios, primarily held by our Insurance operations, are classified as investment securities. Cash and cash equivalents with legal restrictions limiting our ability to withdraw and use the funds are considered restricted cash and restricted cash equivalents and are presented as other assets on our Consolidated Balance Sheet.
Investments	Investments Our investment portfolio includes various debt and equity securities. Our debt securities include government securities, corporate bonds, asset-backed securities (ABS), and mortgage-backed securities (MBS). Debt securities are classified based on management’s intent to sell or hold the security. We classify debt securities as held-to-maturity only when we have both the intent and ability to hold the securities to maturity. We classify debt securities as trading when the securities are acquired for the purpose of selling or holding them for a short period of time. Debt securities not classified as either held-to-maturity or trading are classified as available-for-sale. Our portfolio includes debt securities classified as available-for-sale and held-to-maturity. Our available-for-sale debt securities are carried at fair value with unrealized gains and losses included in accumulated other comprehensive income and are assessed for potential impairment. Our held-to-maturity debt securities are carried at amortized cost and are assessed for potential impairment. We assess our available-for-sale and held-to-maturity debt securities for potential other-than-temporary impairment. We employ a methodology that considers available evidence in evaluating potential other-than-temporary impairment of our debt securities. If the cost of an investment exceeds its fair value, we evaluate, among other factors, the magnitude and duration of the decline in fair value. We also evaluate the financial health of and business outlook for the issuer, the performance of the underlying assets for interests in securitized assets, and, for debt securities classified as available-for-sale, our intent and ability to hold the investment through recovery of its amortized cost basis. Once a decline in fair value of a debt security is determined to be other-than-temporary, an impairment charge for the credit component is recorded to other gain on investments, net, in our Consolidated Statement of Income, and a new cost basis in the investment is established. The noncredit loss component of a debt security continues to be recorded in other comprehensive income when we do not intend to sell the security and it is not more likely than not that we will have to sell the security prior to the security’s anticipated recovery. Both the credit and noncredit loss components are recorded in earnings when we intend to sell the security or it is more likely than not that we will have to sell the security prior to the security’s anticipated recovery. Subsequent increases and decreases to the fair value of available-for-sale debt securities are included in other comprehensive income, so long as they are not attributable to another other-than-temporary impairment. Premiums on debt securities that have noncontingent call features that are callable at fixed prices on preset dates are amortized to the earliest call date as an adjustment to investment yield. All other premiums and discounts on debt securities are amortized over the stated maturity of the security as an adjustment to investment yield. Our investments in equity securities include securities that are recognized at fair value with changes in the fair value recorded in earnings, and equity securities that are recognized using other measurement principles. Effective January 1, 2018, equity securities that have a readily determinable fair value are recorded at fair value with changes in fair value recorded in earnings and reported in other gain on investments, net in our Consolidated Statement of Income. These investments, which are primarily attributable to the investment portfolio of our Insurance operations, are included in equity securities on our Consolidated Balance Sheet. We also hold certain equity investments that do not have a readily determinable fair value and are not eligible to be recognized using other measurement principles that are held at fair value. Refer to Note 8 for further information on these equity securities that have a readily determinable market value. Our equity securities recognized using other measurement principles include investments in Federal Home Loan Bank (FHLB) and Federal Reserve Bank (FRB) stock held to meet regulatory requirements, equity investments related to low-income housing tax credits and the Community Reinvestment Act (CRA), which do not have a readily determinable fair value, and other equity investments that do not have a readily determinable fair value. Our low-income housing tax credit investments are accounted for using the proportional amortization method of accounting for qualified affordable housing investments. Our obligations related to unfunded commitments for our low-income housing tax credit investments are included in other liabilities. The majority of our other CRA investments are accounted for using the equity method of accounting. Our investments in low-income housing tax credits and other CRA investments are included in investments in qualified affordable housing projects and equity-method investments, respectively, in other assets on our Consolidated Balance Sheet. Our investments in FHLB and FRB stock are carried at cost, less impairment. Our remaining investment in equity securities are recorded at cost, less impairment and adjusted for observable price changes under the measurement alternative provided under GAAP. These investments, along with our investments in FHLB and FRB stock, are included in nonmarketable equity investments in other assets on our Consolidated Balance Sheet. Investments recorded under the measurement alternative are also reviewed at each reporting period to determine if any adjustments are required for observable price changes in identical or similar securities of the same issuer. As conditions warrant, we review these investments for impairment and adjust the carrying value of the investment if it is deemed to be impaired. Realized gains and losses on the sale of securities are determined using the specific identification method and are reported in other gain on investments, net in our Consolidated Statement of Income.
Finance Receivables and Loans	Finance Receivables and Loans We initially classify finance receivables and loans as either loans held-for-sale or loans held-for-investment based on management’s assessment of our intent and ability to hold the loans for the foreseeable future or until maturity. Management’s view of the foreseeable future is based on the longest reasonably reliable net income, liquidity, and capital forecast period. Management’s intent and ability with respect to certain loans may change from time to time depending on a number of factors, for example economic, liquidity, and capital conditions. In order to reclassify loans to held-for-sale, management must have the intent to sell the loans and reasonably identify the specific loans to be sold. Loans classified as held-for-sale are presented as loans held-for-sale, net on our Consolidated Balance Sheet and are carried at the lower of their net carrying value or fair value, unless the fair value option was elected, in which case those loans are carried at fair value. Loan origination fees and costs are included in the initial carrying value of loans originated as held-for-sale for which we have not elected the fair value option. Loan origination fees and costs are recognized in earnings when earned or incurred, respectively, for loans classified as held-for-sale for which we have elected the fair value option. We have elected the fair value option for conforming mortgage direct-to-consumer originations for which we have a commitment to sell. The interest rate lock commitment that we enter into for a mortgage loan originated as held-for-sale and certain forward commitments to sell mortgage loans are considered derivative instruments, which are carried at fair value on our Consolidate Balance Sheet. We have elected the fair value option to measure our non-derivative forward commitments. Changes in the fair value of our interest rate lock commitments, derivative forward commitments, and non-derivative forward commitments related to mortgage loans originated as held-for-sale, as well as changes in the carrying value of loans classified as held-for-sale, are reported through gain on mortgage and automotive loans, net in our Consolidated Statement of Income . Interest income on our loans classified as held-for-sale is recognized based upon the contractual rate of interest on the loan and the unpaid principal balance. We report accrued interest receivable on our loans classified as held-for-sale in other assets on the Consolidated Balance Sheet. We have also elected the fair value option for certain loans acquired within our consumer other portfolio segment. Changes in fair value related to these loans are reported through other income, net of losses in our Consolidated Statement of Income . Loans classified as held-for-investment are presented as finance receivables and loans, net on our Consolidated Balance Sheet. Finance receivables and loans are reported at their gross carrying value, which includes the principal amount outstanding, net of unamortized deferred fees and costs on originated loans, unamortized premiums and discounts on purchased loans, unamortized basis adjustments arising from the designation of finance receivables and loans as the hedged item in qualifying fair value hedge relationships, and cumulative principal charge-offs. We refer to the gross carrying value less the allowance for loan loss as the net carrying value in finance receivables and loans. Unearned rate support received from an automotive manufacturer on certain automotive loans, deferred origination fees and costs, and premiums and discounts on purchased loans, are amortized over the contractual life of the related finance receivable or loan using the effective interest method. We make various incentive payments for consumer automotive loan originations to automotive dealers and account for these payments as direct loan origination costs. Additionally, we make incentive payments to certain commercial automobile wholesale borrowers and account for these payments as a reduction to interest income in the period they are earned. Interest income on our finance receivables and loans is recognized based on the contractual rate of interest plus the amortization of deferred amounts using the effective interest method. We report accrued interest receivable on our finance receivables and loans in other assets on our Consolidated Balance Sheet. Loan commitment fees are generally deferred and amortized over the commitment period. For information on finance receivables and loans, refer to Note 9 . Our portfolio segments are based on the level at which we develop and document our methodology for determining the allowance for loan losses. Additionally, the classes of finance receivables are based on several factors including the method for monitoring and assessing credit risk, the method of measuring carrying value, and the risk characteristics of the finance receivable. Based on an evaluation of our process for developing the allowance for loan losses including the nature and extent of exposure to credit risk arising from finance receivables, we have determined our portfolio segments to be consumer automotive, consumer mortgage, consumer other, and commercial. • Consumer automotive — Consists of retail automotive financing for new and used vehicles. • Consumer mortgage — Consists of the following classes of finance receivables. • Mortgage Finance — Consists of consumer first-lien mortgages from our ongoing mortgage operations including bulk acquisitions, direct-to-consumer originations, and refinancing of high-quality jumbo mortgages and low-to-moderate income (LMI) mortgages. • Mortgage — Legacy — Consists of consumer mortgage assets originated prior to January 1, 2009, including first-lien mortgages, subordinate-lien mortgages, and home equity mortgages. • Consumer other — Consists of unsecured consumer lending from point-of-sale financing. • Commercial — Consists of the following classes of finance receivables. • Commercial and Industrial • Automotive — Consists of financing operations to fund dealer purchases of new and used vehicles through wholesale floorplan financing. Additional commercial offerings include automotive dealer term loans, revolving lines, and dealer fleet financing. • Other — Consists primarily of senior secured leveraged cash flow and asset-based loans related to our Corporate-Finance business. • Commercial Real Estate — Consists of term loans primarily secured by dealership land and buildings, and other commercial lending secured by real estate. Nonaccrual Loans Generally, we recognize loans of all classes as past due when they are 30 days delinquent on making a contractually required payment, and loans are placed on nonaccrual status when principal or interest has been delinquent for at least 90 days, or when full collection is not expected . Interest income recognition is suspended when finance receivables and loans are placed on nonaccrual status. Additionally, amortization of premiums and discounts and deferred fees and costs ceases when finance receivables and loans are placed on nonaccrual. Exceptions include commercial real estate loans that are placed on nonaccrual status when delinquent for 60 days or when full collection is not probable, if sooner. Additionally, our policy is to generally place all loans that have been modified in troubled debt restructurings (TDRs) on nonaccrual status until the loan has been brought fully current, the collection of contractual principal and interest is reasonably assured, and six consecutive months of repayment performance is achieved. In certain cases, if a borrower has been current up to the time of the modification and repayment of the debt subsequent to the modification is reasonably assured, we may choose to continue to accrue interest on the loan. Loans on nonaccrual status are reported as nonperforming loans in Note 9 . The receivable for interest income that is accrued, but not collected, at the date finance receivables and loans are placed on nonaccrual status is reversed against interest income and subsequently recognized only to the extent it is received in cash or until it qualifies for return to accrual status. However, where there is doubt regarding the ultimate collectability of loan principal, all cash received is applied to reduce the carrying value of such loans. Generally, finance receivables and loans are restored to accrual status only when contractually current and the collection of future payments is reasonably assured. Impaired Loans Loans of all classes are considered impaired when we determine it is probable that we will be unable to collect all amounts due (both principal and interest) according to the terms of the loan agreement. For all classes of consumer loans, impaired loans include all loans that have been modified in TDRs. Commercial loans of all classes are considered impaired on an individual basis and reported as impaired when we determine it is probable that we will be unable to collect all amounts due according to the terms of the loan agreement. With the exception of certain consumer TDRs that have been returned to accruing status, for all classes of impaired loans, income recognition is consistent with that of nonaccrual loans discussed above. Impaired loans may return to accrual status as discussed in the preceding nonaccrual loan section at which time, the normal accrual of interest income resumes. For collateral dependent loans, if the recorded investment in the impaired loans exceeds the fair value of the collateral, a charge-off is recorded consistent with the TDR discussion below. Troubled Debt Restructurings When the terms of finance receivables or loans are modified, consideration must be given as to whether or not the modification results in a TDR. A modification is considered to be a TDR when both the borrower is experiencing financial difficulty and we grant a concession to the borrower. These considerations require significant judgment and vary by portfolio segment. In all cases, the cumulative impacts of all modifications are considered at the time of the most recent modification. For consumer loans of all classes, various qualitative factors are utilized for assessing the financial difficulty of the borrower. These include, but are not limited to, the borrower’s default status on any of its debts, bankruptcy and recent changes in financial circumstances (loss of job, etc.). A concession has been granted when as a result of the modification we do not expect to collect all amounts due under the original loan terms, including interest accrued at the original contract rate. Types of modifications that may be considered concessions include, but are not limited to, extensions of terms at a rate that does not constitute a market rate, a reduction, deferral or forgiveness of principal or interest owed and loans that have been discharged in a Chapter 7 Bankruptcy and have not been reaffirmed by the borrower. In addition to the modifications noted above, in our consumer automotive portfolio segment of loans we also provide extensions or deferrals of payments to borrowers whom we deem to be experiencing only temporary financial difficulty. In these cases, there are limits within our operational policies to minimize the number of times a loan can be extended, as well as limits to the length of each extension, including a cumulative cap over the life of the loan. If these limits are breached, the modification is considered a TDR as noted in the following paragraph. Before offering an extension or deferral, we evaluate the capacity of the customer to make the scheduled payments after the deferral period. During the deferral period, we continue to accrue and collect interest on the loan as part of the deferral agreement. We grant these extensions or deferrals when we expect to collect all amounts due including interest accrued at the original contract rate. A restructuring that results in only a delay in payment that is deemed to be insignificant is not a concession and the modification is not considered to be a TDR. In order to assess whether a restructuring that results in a delay in payment is insignificant, we consider the amount of the restructured payments subject to delay in conjunction with the unpaid principal balance or the collateral value of the loan, whether or not the delay is significant with respect to the frequency of payments under the original contract, or the loan’s original expected duration. In the cases where payment extensions on our automotive loan portfolio cumulatively extend beyond 90 days and are more than 10% of the original contractual term or where the cumulative payment extension is beyond 180 days, we deem the delay in payment to be more than insignificant, and as such, classify these types of modifications as TDRs. Otherwise, we believe that the modifications do not represent a concessionary modification and accordingly, they are not classified as TDRs. For commercial loans of all classes, similar qualitative factors are considered when assessing the financial difficulty of the borrower. In addition to the factors noted above, consideration is also given to the borrower’s forecasted ability to service the debt in accordance with the contractual terms, possible regulatory actions, and other potential business disruptions (for example, the loss of a significant customer or other revenue stream). Consideration of a concession is also similar for commercial loans. In addition to the factors noted above, consideration is also given to whether additional guarantees or collateral have been provided. For all loans, TDR classification typically results from our loss mitigation activities. For loans held-for-investment that are not carried at fair value and are TDRs, impairment is typically measured based on the difference between the gross carrying value of the loan and the present value of the expected future cash flows of the loan. The loan may also be measured for impairment based on the fair value of the underlying collateral less costs to sell for loans that are collateral dependent. We recognize impairment by either establishing a valuation allowance or recording a charge-off. The financial impacts of modifications that meet the definition of a TDR are reported in the period in which they are identified as TDRs. Additionally, if a loan that is classified as a TDR redefaults within 12 months of the modification, we are required to disclose the instances of redefault. For the purpose of this disclosure, we have determined that a loan is considered to have redefaulted when the loan meets the requirements for evaluation under our charge-off policy except for commercial loans where redefault is defined as 90 days past due. Impaired loans may return to accrual status as discussed in the preceding nonaccrual loan section at which time, the normal accrual of interest income resumes. Net Charge-offs We disclose the measurement of net charge-offs as the amount of gross charge-offs recognized less recoveries received. Gross charge-offs reflect the amount of the gross carrying value directly written-off. Generally, we recognize recoveries when they are received and record them as an increase to the allowance for loan losses. As a general rule, consumer automotive loans are written down to estimated collateral value, less costs to sell, once a loan becomes 120 days past due. In our consumer mortgage portfolio segment, first-lien mortgages and a subset of our home equity portfolio that are secured by real estate in a first-lien position are written down to the estimated fair value of the collateral, less costs to sell, once a mortgage loan becomes 180 days past due. Consumer mortgage loans that represent second-lien positions are charged off at 180 days past due. Loans in our consumer other segment are charged off at 120 days past due. Within 60 days of receipt of notification of filing from the bankruptcy court, or within the time frames noted above, consumer automotive and first-lien consumer mortgage loans in bankruptcy are written down to their expected future cash flows, which is generally fair value of the collateral, less costs to sell, and second-lien consumer mortgage loans and consumer other loans are fully charged-off, unless it can be clearly demonstrated that repayment is likely to occur. Regardless of other timelines noted within this policy, loans are considered collateral dependent once foreclosure or repossession proceedings begin and are charged-off to the estimated fair value of the underlying collateral, less costs to sell at that time. Commercial loans are individually evaluated and written down to the estimated fair value of the collateral less costs to sell when collectability of the recorded balance is in doubt. Generally, all commercial loans are charged-off when it becomes unlikely that the borrower is willing or able to repay the remaining balance of the loan and any underlying collateral is not sufficient to recover the outstanding principal. Collateral dependent loans are charged-off to the fair market value of collateral less costs to sell when appropriate. Noncollateral dependent loans are fully written-off.
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses (the allowance) is management’s estimate of incurred losses in the lending portfolios. We determine the amount of the allowance required for each of our portfolio segments based on its relative risk characteristics. The evaluation of these factors for both consumer and commercial finance receivables and loans involves quantitative analysis combined with sound management judgment. Additions to the allowance are charged to current period earnings through the provision for loan losses; amounts determined to be uncollectible are charged directly against the allowance, net of amounts recovered on previously charged-off accounts. The allowance is composed of two components: specific reserves established for individual loans evaluated as impaired and portfolio-level reserves established for large groups of typically smaller balance homogeneous loans that are collectively evaluated for impairment. We evaluate the adequacy of the allowance based on the combined total of these two components. Determining the appropriateness of the allowance is complex and requires judgment by management about the effect of matters that are inherently uncertain. It is possible that others, given the same information, may at any point in time reach different reasonable conclusions. Measurement of impairment for specific reserves is generally determined on a loan-by-loan basis. Loans determined to be specifically impaired are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate, an observable market price, or the estimated fair value of the collateral less estimated costs to sell when appropriate, whichever is determined to be the most appropriate. When these measurement values are lower than the net carrying value of that loan, impairment is recognized. Loans that are not identified as individually impaired are pooled with other loans with similar risk characteristics for evaluation of impairment for the portfolio-level allowance. For the purpose of calculating portfolio-level reserves, we have grouped our loans into four portfolio segments: consumer automotive, consumer mortgage, consumer other, and commercial. The allowance consists of the combination of a quantitative assessment component based on statistical models for consumer automotive, consumer mortgage, and commercial, and a vintage analysis for consumer other, a retrospective evaluation of actual loss information to loss forecasts, and includes a qualitative component based on management judgment. Management takes into consideration relevant qualitative factors, including external and internal trends such as the impacts of changes in underwriting standards, collections and account management effectiveness, geographic concentrations, and economic events, among other factors, that have occurred but are not yet reflected in the quantitative assessment component. Qualitative adjustments are documented, reviewed, and approved through our established risk governance processes and follow regulatory guidance. Management also considers the need for a reserve on unfunded non-derivative loan commitments across our portfolio segments, including lines of credit and standby letters of credit, using similar procedures and methodologies used to determine the allowance for loan losses while also considering historical loss ratios and potential usage levels. The reserve for unfunded loan commitments is recorded within other liabilities on our Consolidated Balance Sheet and the related expense is reported as other noninterest expense in our Consolidated Statement of Income . Refer to Note 28 for information on our unfunded loan commitments. During 2019, we did not substantively change any material aspect of our overall approach used to determine the allowance for loan losses for our portfolio segments. There were no material changes in criteria or estimation techniques as compared to prior periods that impacted the determination of the current period allowance for loan losses for our portfolio segments. However, during 2019, we acquired Health Credit Services and assumed their lending operations, which created our consumer other portfolio segment. The methodology used for the consumer other portfolio segment is described below. Refer to Note 9 for information on the allowance for loan losses. Consumer Loans Our consumer automotive, consumer mortgage, and consumer other portfolio segments are reviewed for impairment based on an analysis of loans that are grouped into common risk categories. We perform periodic and systematic detailed reviews of our lending portfolios to identify inherent risks and to assess the overall collectability of those portfolios. Loss models are utilized for these portfolios, which consider a variety of credit quality indicators including, but not limited to, historical loss experience, current economic conditions, credit scores, and expected loss factors by loan type. Consumer Automotive Portfolio Segment The allowance for loan losses within the consumer automotive portfolio segment is calculated using proprietary statistical models and other risk indicators applied to pools of loans with similar risk characteristics, including credit bureau score and loan-to-value (LTV) ratios to arrive at an estimate of incurred losses in the portfolio. These statistical loss forecasting models are utilized to estimate incurred losses and consider a variety of factors including, but not limited to, historical loss experience, estimated defaults based on portfolio trends, and general economic and business trends. These statistical models predict forecasted losses inherent in the portfolio. The forecasted losses consider historical factors such as frequency (the number of contracts that we expect to default) and loss severity (the loss amount of contracts we expect to default). The loss severity within the consumer automotive portfolio segment is impacted by the market values of vehicles that are repossessed. Vehicle market values are affected by numerous factors including vehicle supply, the condition of the vehicle upon repossession, the overall price and volatility of gasoline or diesel fuel, consumer preference related to specific vehicle segments, and other factors. The quantitative assessment component of the allowance may be supplemented with qualitative reserves based on management’s determination that such adjustments provide a better estimate of credit losses. This qualitative assessment takes into consideration relevant internal and external factors that have occurred, but are not yet reflected in the forecasted losses, and may affect the performance of the portfolio. Consumer Mortgage Portfolio Segment The allowance for loan losses within the consumer mortgage portfolio segment is calculated by using statistical models based on pools of loans with similar risk characteristics, including credit score, LTV, loan age, documentation type, product type, and loan purpose, to arrive at an estimate of incurred losses in the portfolio. These statistical loss forecasting models are utilized to estimate incurred losses and consider a variety of factors including, but not limited to, historical loss experience, estimated foreclosures or defaults based on portfolio trends, delinquencies, and general economic and business trends. The forecasted losses are statistically derived based on a suite of behavioral based transition models. This transition framework predicts various stages of delinquency, default, and voluntary prepayment over the course of the life of the loan. The transition probability is a function of the loan and borrower characteristics and economic variables and considers historical factors such as frequency and loss severity. When a default event is predicted, a severity model is applied to estimate future loan losses. Loss severity within the consumer mortgage portfolio segment is impacted by the market values of foreclosed properties, which is affected by numerous factors, including geographic considerations and the condition of the foreclosed property. The quantitative assessment component of the allowance may be supplemented with qualitative reserves based on management’s determination that such adjustments provide a better estimate of credit losses. This qualitative assessment takes into consideration relevant internal and external factors that have occurred, but are not yet reflected in the forecasted losses, and may affect the performance of the portfolio. Consumer Other Portfolio Segment The allowance for loan losses within the consumer other portfolio segment is calculated by using a vintage analysis that analyzes charge-offs in pools where the loans share the same origination period and similar risk characteristics to arrive at an estimate of incurred losses in the portfolio. The forecasted losses consider monthly vintage level historical balance paydown rates, delinquency and roll rate behaviors by risk tier and product type. The risk tier segmentation is based upon borrower risk characteristics at the time of origination. The quantitative assessment component of the allowance may be supplemented by qualitative reserves based on management’s determination that such adjustments provide a better estimate of credit losses. This qualitative assessment takes into consideration relevant internal and external factors that have occurred, but are not yet reflected in the vintage analysis, and may affect the performance of the portfolio. Commercial Loans The allowance for loan losses within the commercial portfolio is composed of reserves established for specific loans evaluated as impaired and portfolio-level reserves based on nonimpaired loans grouped into pools based on similar risk characteristics and collectively evaluated. A commercial loan is considered impaired when it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement based on current information and events. These loans are primarily evaluated individually and are risk-rated based on borrower, collateral, and industry-specific information that management believes is relevant in determining the occurrence of a loss event and measuring impairment. Management establishes specific allowances for commercial loans determined to be individually impaired based on the present value of expected future cash flows, discounted at the loan’s effective interest rate, observable market prices, or the fair value of collateral—whichever is determined to be the most appropriate. Estimated costs to sell or realize the value of the collateral on a discounted basis are included in the impairment measurement, when appropriate. Loans not identified as impaired are grouped into pools based on similar risk characteristics and collectively evaluated. Our risk rating models use historical loss experience, concentrations, current economic conditions, and performance trends. The commercial historical loss experience is updated quarterly to incorporate the most recent data reflective of the current economic environment. The determination of the allowance is influenced by numerous assumptions and many factors that may materially affect estimates of loss, including volatility of loss given default, probability of default, and rating migration. In assessing the risk rating of a particular loan, several factors are considered including an evaluation of historical and current information involving subjective assessments and interpretations. In addition, the allowance related to the commercial portfolio segment could be influenced by situations in which automotive manufacturers may repurchase vehicles used as collateral to secure the loans in default situations. The quantitative assessment component of the allowance may be supplemented with qualitative reserves based on management’s determination that such adjustments provide a better estimate of credit losses. This qualitative assessment takes into consideration relevant internal and external factors that have occurred, but are not yet reflected in the forecasted losses, and may affect the performance of the portfolio.
Variable Interest Entities and Securitizations	Variable Interest Entities and Securitizations VIEs are legal entities that either have an insufficient amount of equity at risk for the entity to finance its activities without additional subordinated financial support or, as a group, the holders of equity investment at risk lack the ability to direct the entity’s activities that most significantly impact economic performance through voting or similar rights, or do not have the obligation to absorb the expected losses or the right to receive expected residual returns of the entity. For all VIEs in which we are involved, we assess whether we are the primary beneficiary of the VIE on an ongoing basis. In circumstances where we have both the power to direct the activities that most significantly impact the VIEs performance and the obligation to absorb losses or the right to receive the benefits of the VIE that could be significant, we would conclude that we are the primary beneficiary of the VIE, and would consolidate the VIE (also referred to as on-balance sheet). In situations where we are not deemed to be the primary beneficiary of the VIE, we do not consolidate the VIE and only recognize our interests in the VIE (also referred to as off-balance sheet). We are involved in securitizations that typically involve the use of VIEs. For information regarding the company’s securitization activities, refer to Note 11 . In the case of a consolidated on-balance-sheet VIE used for a securitization, the underlying assets remain on our Consolidated Balance Sheet with the corresponding obligations to third party beneficial interest holders reflected as debt. We recognize income on the assets, interest expense on the debt issued by the VIE, and losses on the assets as incurred. Consolidation of the VIE precludes us from recording an accounting sale on the transaction. In securitizations where we are not determined to be the primary beneficiary of the VIE, we must determine whether we achieve a sale for accounting purposes. To achieve a sale for accounting purposes, the financial assets being transferred must be legally isolated, not be constrained by restrictions from further transfer, and be deemed to be beyond our control. We would deem the transaction to be an off-balance-sheet securitization if the preceding three criteria for sale accounting are met. If we were to fail any of these three criteria for sale accounting, the transfer would be accounted for as a secured borrowing consistent with the preceding paragraph regarding on-balance sheet VIEs. The gain or loss recognized on off-balance-sheet securitizations take into consideration any assets received or liabilities assumed, including any retained interests, and servicing assets or liabilities (if applicable), which are initially recorded at fair value at the date of sale. Upon the sale of the financial assets, we recognize a gain or loss on sale for the difference between the assets and liabilities recognized, and the assets derecognized. The financial assets obtained from off-balance-sheet securitizations are primarily reported as cash or if applicable, retained interests. Retained interests are classified as securities or as other assets depending on their form and structure. The estimate of the fair value of the retained interests and servicing requires us to exercise significant judgment about the timing and amount of future cash flows from the interests. For a discussion on fair value estimates, refer to Note 24 . Gains or losses on off-balance-sheet securitizations are reported in gain on mortgage and automotive loans, net, in our Consolidated Statement of Income. We retain the right to service our consumer and commercial automotive loan and operating lease securitizations. We may receive servicing fees for off-balance-sheet securitizations based on the securitized asset balances and certain ancillary fees, all of which are reported in servicing fees in the Consolidated Statement of Income. Typically, the fee we are paid for servicing represents adequate compensation, and consequently, does not result in the recognition of a servicing asset or liability.
Repossessed and Foreclosed Assets	Repossessed and Foreclosed Assets Assets securing our finance receivables and loans are classified as repossessed and foreclosed and included in other assets when physical possession of the collateral is taken, which includes the transfer of title through foreclosure or other similar proceedings. Repossessed and foreclosed assets are initially recognized at the lower of the outstanding balance of the loan at the time of repossession or foreclosure or the fair value of the asset less estimated costs to sell. Losses on the initial revaluation of repossessed and foreclosed assets (and generally, declines in value shortly after repossession or foreclosure) are recognized as a charge-off of the allowance for loan losses. Subsequent declines in value are charged to other operating expenses.
Lease Accounting	Lease Accounting On January 1, 2019, we adopted Accounting Standards Update (ASU) 2016-02, Leases , using the modified retrospective approach, as further described in the section below titled Recently Adopted Accounting Standards . At contract inception, we determine whether the contract is or contains a lease based on the terms and conditions of the contract. Refer to Investments in Operating Leases below for leases in which we are the lessor. Lease contracts for which we are the lessee are recognized on our Consolidated Balance Sheet as right-of-use (ROU) assets and lease liabilities. Lease liabilities and their corresponding ROU assets are recorded based on the present value of the future lease payments over the expected lease term. We utilize our incremental borrowing rate, which is the rate we would incur to borrow on a collateralized basis over a similar term on an amount equal to the lease payments in a similar economic environment since the interest rate implicit in the lease contract is typically not readily determinable. The ROU asset also includes initial direct costs paid less lease incentives received from the lessor. Our lease contracts are generally classified as operating and, as a result, we recognize a single lease cost within other operating expenses on the income statement on a straight-line basis over the lease term. Our leases primarily consist of property-leases and fleet vehicle leases. Our property-lease agreements generally contain a lease component, which includes the right to use the real estate, and non-lease components, which generally include utilities and common area maintenance services. We elected the practical expedient to account for the lease and non-lease components in our property leases as a single lease component for recognition and measurement of our ROU assets and lease liabilities. Our property leases include variable-rent payments made during the lease term which are not based on a rate or index and are excluded from the measurement of the ROU assets and lease liabilities are recognized as a component of variable lease expense as incurred. We have elected not to recognize ROU assets and lease liabilities on property-leases with terms of one year or less. Our fleet vehicle leases also include a lease component, which includes the right to use the vehicle, and non-lease components, which include maintenance, fuel, and administrative services. However, we’ve elected to account for the lease and non-lease components in our fleet vehicle leases separately. As such, the non-lease components are excluded from the measurement of the ROU asset and lease liability and are recognized as other operating expenses as incurred. Investment in Operating Leases Investment in operating leases, net, represents the vehicles that are underlying our automotive operating lease contracts and is reported at cost, less accumulated depreciation and net of impairment charges and origination fees or costs. Depreciation of vehicles is recorded on a straight-line basis to an estimated residual value over the lease term. Manufacturer support payments that we receive upfront are treated as a reduction to the cost-basis in the underlying operating lease asset, which has the effect of reducing depreciation expense over the life of the contract. We periodically evaluate our depreciation rate for leased vehicles based on expected residual values and adjust depreciation expense over the remaining life of the lease if deemed necessary. Income from operating lease assets that includes lease origination fees, net of lease origination costs, is recognized as operating lease revenue on a straight-line basis over the scheduled lease term. We have elected to exclude sales taxes collected from the lessee from our consideration in the lease contract and from variable lease payments not included in contract consideration. We have significant investments in the residual values of the assets in our operating lease portfolio. The residual values represent an estimate of the values of the assets at the end of the lease contracts. At contract inception, we determine pricing based on the projected residual value of the leased vehicle. This evaluation is primarily based on a proprietary model, which includes variables such as age, expected mileage, seasonality, segment factors, vehicle type, economic indicators, production cycle, automotive manufacturer incentives, and shifts in used vehicle supply. This internally generated data is compared against third-party, independent data for reasonableness. Realization of the residual values is dependent on our future ability to market the vehicles under the prevailing market conditions. Over the life of the lease, we evaluate the adequacy of our estimate of the residual value and make adjustments to the depreciation rates to the extent the expected value of the vehicle at lease termination changes. In addition to estimating the residual value at lease termination, we also evaluate the current value of the operating lease asset and test for impairment to the extent necessary when there is an indication of impairment based on market considerations and portfolio characteristics. Impairment is determined to exist if fair value of the leased asset is less than carrying value and it is determined that the net carrying value is not recoverable. The net carrying value of a leased asset is not recoverable if it exceeds the sum of the undiscounted expected future cash flows expected to result from the operating lease payments and the estimated residual value upon eventual disposition. If our operating lease assets are considered to be impaired, the impairment is measured as the amount by which the carrying amount of the assets exceeds the fair value as estimated by discounted cash flows. No impairment was recognized in 2019 , 2018 , or 2017 . We accrue rental income on our operating leases when collection is reasonably assured. We generally discontinue the accrual of revenue on operating leases at the time an account is determined to be uncollectible, which we determine to be the earliest of (i) the time of repossession, (ii) within 60 days of bankruptcy notification, unless it can be clearly demonstrated that repayment is likely to occur, or (iii) greater than 120 days past due. When a leased vehicle is returned to us, either at the end of the lease term or through repossession, the asset is reclassified from investment in operating leases, net, to other assets and recorded at the lower-of-cost or estimated fair value, less costs to sell, on our Consolidated Balance Sheet. Any losses recognized at this time are recorded as depreciation expense. Subsequent decline in value and any gain or loss recognized at the time of sale is recognized as a remarketing gain or loss and presented as a component of depreciation expense.
Impairment of Long-lived Assets	Impairment of Long-lived Assets The net carrying values of long-lived assets (including property and equipment) are evaluated for impairment whenever events or changes in circumstances indicate that their net carrying values may not be recoverable from the estimated undiscounted future cash flows expected to result from their use and eventual disposition. Recoverability of assets to be held and used is measured by a comparison of their net carrying amount to future net undiscounted cash flows expected to be generated by the assets. If these assets are considered to be impaired, the impairment is measured as the amount by which the net carrying amount of the assets exceeds the fair value estimated using a discounted cash flow method. No material impairment was recognized in 2019 , 2018 , or 2017 . An impairment test on an asset group to be sold or otherwise disposed of is performed upon occurrence of a triggering event or when certain criteria are met (for example, the asset is planned to be disposed of within 12 months, appropriate levels of authority have approved the sale, there is an active program to locate a buyer, etc.), which cause the disposal group to be classified as held-for-sale. Long-lived assets held-for-sale are recorded at the lower of their carrying amount or estimated fair value less cost to sell. If the net carrying value of the assets held-for-sale exceeds the fair value less cost to sell, we recognize an impairment loss based on the excess of the net carrying amount over the fair value of the assets less cost to sell.
Property and Equipment	Property and Equipment Property and equipment stated at cost, net of accumulated depreciation and amortization, are reported in other assets on our Consolidated Balance Sheet. Included in property and equipment are certain buildings, furniture and fixtures, leasehold improvements, IT hardware and software, capitalized software costs, and assets under construction. We begin depreciating these assets when they are ready for their intended use. Depreciation is recorded on a straight-line basis over the estimated useful lives of the assets, which generally ranges from three to thirty years depending on the asset class. Capitalized software is generally amortized on a straight-line basis over its useful life, which generally ranges from three to five years. Capitalized software that is not expected to provide substantive service potential or for which development costs significantly exceed the amount originally expected is considered impaired and written down to fair value. Software expenditures that are considered general, administrative, or of a maintenance nature are expensed as incurred.
Goodwill and Other Intangibles	Goodwill and Other Intangibles Goodwill and intangible assets, net of accumulated amortization, are reported in other assets. Our intangible assets primarily consist of acquired customer relationships and developed technology, and are amortized using a straight-line methodology over their estimated useful lives. We review intangible assets for impairment at least annually, or whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. If it is determined the carrying amount of the asset is not recoverable, an impairment charge is recorded. Goodwill represents the excess of the cost of an acquisition over the fair value of net assets acquired, including identifiable intangibles. We allocate goodwill to applicable reporting units based on the relative fair value of the other net assets allocated to those reporting units at the time of the acquisition. In the event we restructure our business, we may reallocate goodwill. We test goodwill for impairment annually, or more frequently if events and changes in circumstances indicate that it is more likely than not that impairment exists. Our annual goodwill impairment test is performed as of August 31 of each year. In certain situations, we may perform a qualitative assessment to test goodwill for impairment. We may also decide to bypass the qualitative assessment and perform a quantitative assessment. If we perform the qualitative assessment to test goodwill for impairment and conclude that it is more likely than not that the reporting unit’s fair value is greater than its carrying value, then the quantitative assessment is not required. However, if we perform the qualitative assessment and determine that it is more likely than not that a reporting unit’s fair value is less than its carrying value, then we must perform the quantitative assessment. The quantitative assessment uses a two-step process. The first step of the assessment requires us to compare the fair value of each of the reporting units to their respective carrying value. The fair value of the reporting units in our quantitative assessment is determined based on various analyses including discounted cash flow projections using assumptions a market participant would use. If the carrying value is less than the fair value, no impairment exists, and the second step does not need to be completed. If the carrying value is greater than the fair value or there is an indication that impairment may exist, a second step must be performed where we determine the implied value of goodwill based on the individual fair values of the reporting unit’s assets and liabilities, including unrecognized intangibles, to compute the amount of the impairment.
Unearned Insurance Premiums and Service Revenue	Unearned Insurance Premiums and Service Revenue Insurance premiums, net of premiums ceded to reinsurers, and service revenue are earned over the terms of the policies. The portion of premiums and service revenue written applicable to the unexpired terms of the policies is recorded as unearned insurance premiums or unearned service revenue. For vehicle service and maintenance contracts, premiums and service revenues are earned on a basis proportionate to the anticipated cost emergence. For additional information related to these contracts, refer to Note 3 . For other short duration contracts, premiums and service revenue are earned on a pro rata basis. For further information, refer to Note 4 .
Deferred Insurance Policy Acquisition Costs	Deferred Insurance Policy Acquisition Costs Certain incremental direct costs incurred to originate a policy are deferred and recorded in other assets. These costs primarily include commissions paid to dealers to originate these policies and vary with the production of business. Deferred policy acquisition costs are amortized over the terms of the related policies and service contracts on the same basis as premiums and service revenue are earned. We group costs incurred for acquiring like contracts and consider anticipated investment income in determining the recoverability of these costs.
Reserves for Insurance Losses and Loss Adjustment Expenses	Reserves for insurance losses and loss adjustment expenses are reported in accrued expenses and other liabilities on our Consolidated Balance Sheet. They are established for the unpaid cost of insured events that have occurred as of a point in time. More specifically, the reserves for insurance losses and loss adjustment expenses represent the accumulation of estimates for both reported losses and those incurred, but not reported, including loss adjustment expenses relating to direct insurance and assumed reinsurance agreements. We use a combination of methods commonly used in the insurance industry, including the chain ladder development factor, expected loss, Bornhuetter Ferguson (BF), and frequency and severity methods to determine the ultimate losses for an individual business line as well as accident year basis depending on the maturity of the accident period and business-line specifics. These methodologies are based on different assumptions and use various inputs to develop alternative estimates of losses. The chain ladder development factor is used for more mature years while the expected loss, BF, and frequency and severity methods are used for less mature years. Both paid and incurred loss and loss adjustment expenses are reviewed where available and a weighted average of estimates or a single method may be considered in selecting the final estimate for an individual accident period. We did not change our methodology for developing reserves for insurance losses for the year ended December 31, 2019 . Estimates for salvage and subrogation recoverable are recognized at the time losses are incurred and netted against the provision for insurance losses and loss adjustment expenses. Reserves are established for each business at the lowest meaningful level of homogeneous data. Since the reserves are based on estimates, the ultimate liability may vary from such estimates. The estimates are regularly reviewed and adjustments, which can potentially be significant, are included in earnings in the period in which they are deemed necessary.
Legal and Regulatory Reserves	Legal and Regulatory Reserves Reserves for legal and regulatory matters are established when those matters present loss contingencies that are both probable and estimable, with a corresponding amount recorded to other operating expense. In cases where we have an accrual for losses, it is our policy to include an estimate for probable and estimable legal expenses related to the case. If, at the time of evaluation, the loss contingency related to a legal or regulatory matter is not both probable and estimable, we do not establish a liability for the contingency. We continue to monitor legal and regulatory matters for further developments that could affect the requirement to establish a liability or that may impact the amount of a previously established liability. There may be exposure to loss in excess of any amounts recognized. For certain other matters where the risk of loss is determined to be reasonably possible, estimable, and material to the financial statements, disclosure regarding details of the matter and an estimated range of loss is required. The estimated range of possible loss does not represent our maximum loss exposure. We also disclose matters that are deemed probable or reasonably possible, material to the financial statements, but for which an estimated range of loss is not possible to determine. While we believe our reserves are adequate, the outcome of legal and regulatory proceedings is extremely difficult to predict, and we may settle claims or be subject to judgments for amounts that differ from our estimates. For information regarding the nature of all material contingencies, refer to Note 29 .
Earnings per Common Share	Earnings per Common Share We compute basic earnings per common share by dividing net income from continuing operations attributable to common stockholders after deducting dividends on preferred stock by the weighted-average number of common shares outstanding during the period. We compute diluted earnings per common share by dividing net income from continuing operations after deducting dividends on preferred stock by the weighted-average number of common shares outstanding during the period plus the dilution resulting from incremental shares that would have been outstanding if dilutive potential common shares had been issued (assuming it does not have the effect of antidilution), if applicable.
Derivatives Instruments and Hedging Activities	Derivative Instruments and Hedging Activities We use derivative instruments primarily for risk management purposes. We do not use derivative instruments for speculative purposes. Certain of our derivative instruments are designated as accounting hedges in qualifying relationships, whereas other derivative instruments have not been designated as accounting hedges. In accordance with applicable accounting standards, all derivative instruments, whether designated as accounting hedges or not, are recorded on the balance sheet as assets or liabilities and measured at fair value. We have elected to report the fair value of derivative assets and liabilities on a gross basis—including the fair value for the right to reclaim cash collateral or the obligation to return cash collateral—arising from instruments executed with the same counterparty under a master netting arrangement where we do not have the intent to offset. For additional information on derivative instruments and hedging activities, refer to Note 21 . At the inception of a qualifying hedge accounting relationship, we designate each qualifying hedge relationship as a hedge of the fair value of a specifically identified asset or liability (fair value hedge); as a hedge of the variability of cash flows to be received or paid, or forecasted to be received or paid, related to a recognized asset or liability (cash flow hedge); or as a hedge of the foreign-currency exposure of a net investment in a foreign operation (net investment hedge). We formally document all relationships between hedging instruments and hedged items, as well as the risk management objectives for undertaking such hedge transactions. Both at hedge inception and on an ongoing basis, we formally assess whether the derivatives that are used in hedging relationships are highly effective in offsetting changes in fair values or cash flows of hedged items. Changes in the fair value of derivative instruments qualifying as fair value hedges, along with the gain or loss on the hedged asset or liability attributable to the hedged risk, are recorded in current period earnings. For qualifying cash flow hedges, changes in the fair value of the derivative financial instruments are recorded in accumulated other comprehensive income, and recognized in the income statement when the hedged cash flows affect earnings. For a qualifying net investment hedge, the gain or loss is reported in accumulated other comprehensive income as part of the cumulative translation adjustment. Hedge accounting treatment is no longer applied if a derivative financial instrument is terminated, the hedge designation is removed, or the derivative instrument is assessed to be no longer highly effective. For terminated fair value hedges, any changes to the hedged asset or liability remain as part of the basis of the hedged asset or liability and are recognized into income over the remaining life of the asset or liability. For terminated cash flow hedges, unless it is probable that the forecasted cash flows will not occur within a specified period, any changes in fair value of the derivative financial instrument previously recognized remain in accumulated other comprehensive income, and are reclassified into earnings in the same period that the hedged cash flows affect earnings. Any previously recognized gain or loss for a net investment hedge continues to remain in accumulated other comprehensive income until earnings are impacted by sale or liquidation of the associated foreign operation. In all instances, after hedge accounting is no longer applied, any subsequent changes in fair value of the derivative instrument will be recorded into earnings. Changes in the fair value of derivative financial instruments held for risk management purposes that are not designated as accounting hedges under GAAP are reported in current period earnings.
Income Taxes	Income Taxes Our income tax expense, deferred tax assets and liabilities, and reserves for unrecognized tax benefits reflect management’s best assessment of estimated future taxes to be paid. We are subject to income taxes predominantly in the United States. Significant judgments and estimates are required in determining the consolidated income tax expense. Deferred income taxes arise from temporary differences between the tax and financial statement recognition of revenue and expense. In evaluating our ability to recover our deferred tax assets within the jurisdiction from which they arise we consider all available positive and negative evidence including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial operations. In projecting future taxable income, we begin with historical results adjusted for the results of discontinued operations and changes in accounting policies and incorporate assumptions including the amount of future state, federal and foreign pretax operating income, the reversal of temporary differences, and the implementation of feasible and prudent tax planning strategies. We use the portfolio method with respect to reclassification of stranded income tax effects in accumulated other comprehensive income. We recognize the financial statement effects of uncertain income tax positions when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. Also, we recognize accrued interest and penalties related to liabilities for uncertain income tax positions in interest expense and other operating expenses, respectively. For additional information regarding our provision for income taxes, refer to Note 22 .
Share-based Compensation	Share-based Compensation Our compensation and benefits expenses include the cost of share-based awards issued to employees. For equity classified share-based awards, compensation cost is ratably charged to expense based on the grant date fair value of the awards over the applicable service periods. For liability classified share-based awards, the associated liability is measured quarterly at fair value based on our share price and services rendered at the time of measurement until the awards are paid, with changes in fair value charged to compensation expense in the period in which the change occurs. We have made an accounting policy election to account for forfeitures of share-based awards as they occur. Refer to Note 23 for a discussion of our share-based compensation plans.
Foreign Exchange	Foreign Exchange Foreign-denominated assets and liabilities resulting from foreign-currency transactions are valued using period-end foreign-exchange rates and the results of operations and cash flows are determined using approximate weighted average exchange rates for the period. Translation adjustments are related to foreign subsidiaries using local currency as their functional currency and are reported as a separate component of accumulated other comprehensive income. Translation gains or losses are reclassified to earnings upon the substantial sale or liquidation of our investments in foreign operations. We may elect to enter into foreign-currency derivatives to mitigate our exposure to changes in foreign-exchange rates. Refer to the Derivative Instruments and Hedging Activities section above for a discussion of our hedging activities of the foreign-currency exposure of a net investment in a foreign operation.
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements, Policy	Leases (ASU 2016-02) In February 2016, the Financial Accounting Standards Board (FASB) issued ASU 2016-02. The amendments in this update primarily replaced the existing accounting requirements for operating leases for lessees. Lessee accounting requirements for finance leases (previously referred to as capital leases) and lessor accounting requirements for operating leases and sales type and direct financing leases were largely unchanged. The amendments require the lessee of an operating lease to record a balance sheet gross-up upon lease commencement by recognizing a ROU asset and lease liability equal to the present value of the lease payments. The ROU asset and lease liability should be derecognized in a manner that effectively yields a straight-line lease expense over the lease term. In addition to the changes to the lessee operating lease accounting requirements, the amendments also changed the types of costs that can be capitalized related to a lease agreement for both lessees and lessors. The amendments also require additional disclosures for all lease types for both lessees and lessors. The FASB issued additional ASUs to clarify the guidance and provide certain practical expedients and an additional transition option. We adopted ASU 2016-02 and the subsequent ASUs that modified ASU 2016-02 (collectively, the amendments) on January 1, 2019. This includes the early adoption of ASU 2019-01, which was issued in March 2019 to amend certain provisions included in ASU 2016-02. We adopted this guidance using the modified retrospective approach on January 1, 2019, and have not adjusted prior period comparative information and will continue to disclose prior period financial information in accordance with the previous lease accounting guidance. We have elected certain practical expedients permitted within the amendments that allowed us to not reassess (i) current lease classifications, (ii) whether existing contracts meet the definition of a lease under the amendments to the lease guidance, and (iii) whether current initial direct costs meet the new criteria for capitalization, for all existing leases as of the adoption date. We made an accounting policy election to calculate the impact of adoption using the remaining minimum lease payments and remaining lease term for each contract that was identified as a lease, discounted at our incremental borrowing rate as of the adoption date. The adoption of the amendments resulted in a ROU asset of approximately $161 million from operating leases for our various corporate facilities, a $29 million reduction to accrued expenses and other liabilities for accrued rent and unamortized tenant improvement allowances, and a lease liability of approximately $190 million . The adoption did not change our previously reported Consolidated Statements of Comprehensive Income and did not result in a cumulative catch-up adjustment to opening retained earnings.
Accounting Standards Update 2017-08
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements, Policy	Receivables—Nonrefundable Fees and Other Costs: Premium Amortization on Purchased Callable Debt Securities (ASU 2017-08) In March 2017, the FASB issued ASU 2017-08. The amendments in this update require premiums on purchased callable debt securities to be amortized to the security’s earliest call date. Prior to this ASU, premiums and discounts on purchased callable debt securities were generally required to be amortized to the security’s maturity date. The amendments do not require an accounting change for securities held at a discount. We adopted the amendments on January 1, 2019, on a modified retrospective basis, which resulted in an increase to our accumulated deficit of $10 million , net of income taxes, partially offset by an $8 million decrease to accumulated other comprehensive loss, net of income taxes.
Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements, Policy	Financial Instruments — Credit Losses (ASU 2016-13) In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (CECL). The amendments in this update introduce a new accounting model to measure credit losses for financial assets measured at amortized cost. The FASB has also issued additional ASUs to clarify the scope and provide additional guidance for ASU 2016-13. Credit losses for financial assets measured at amortized cost should be determined based on the total current expected credit losses over the life of the financial asset or group of financial assets. In effect, the financial asset or group of financial assets should be presented at the net amount expected to be collected. Credit losses will no longer be recorded under the current incurred loss model for financial assets measured at amortized cost. The amendments also modify the accounting for available-for-sale debt securities whereby credit losses will be recorded through an allowance for credit losses rather than a write-down to the security’s cost basis, which allows for reversals of credit losses when estimated credit losses decline. Credit losses for available-for-sale debt securities should be measured in a manner similar to current GAAP. The amendments are effective on January 1, 2020, and must be applied using a modified retrospective approach with a cumulative-effect adjustment through retained earnings as of the beginning of the fiscal year upon adoption as required. While the standard modifies the measurement of the allowance for credit losses, it does not alter the credit risk of our finance receivables and loan portfolio. Upon adoption of the amendments on January 1, 2020, we expect to recognize a reduction to our opening retained earnings of approximately $1.0 billion , net of income taxes, resulting from a pretax increase to our allowance for credit losses of approximately $1.3 billion , primarily driven by our consumer automotive loan portfolio. The increase is primarily related to the difference between loss emergence periods currently utilized, as compared to estimating lifetime credit losses as required by the CECL standard and we do not expect a material impact to the allowance for loan losses from any of our other lending portfolios. Additionally, we do not expect the adoption of CECL to result in a material impact to our held-to-maturity securities portfolio, which is primarily composed of agency-backed mortgage securities, or our available-for-sale debt securities portfolio. We currently expect to phase in the day-one impact of CECL into regulatory capital as prescribed by regulatory capital rules which permit us to phase in 25% of the capital impact of CECL in 2020 and an additional 25% each subsequent year until fully phased in by the first quarter of 2023. Our quantitative allowance for credit loss estimates under CECL are impacted by certain forecasted economic factors. In order to estimate the quantitative portion of our allowance for credit losses under CECL, our modeling processes rely on a single forecast scenario for each macroeconomic factor incorporated. To derive macroeconomic assumptions in this single scenario, we have elected to forecast these macroeconomic factors over a 12-month period which we have determined to be reasonable and supportable. After the 12-month reasonable and supportable forecast period, we have elected to revert on a straight-line basis over a 24-month period to a historical mean for each macroeconomic factor. The mean is calculated from historical data spanning from January 2008 through the most current period, and as a result, includes data points from the last recessionary period. In addition to our quantitative allowance for credit losses, we also incorporate qualitative adjustments that may relate to idiosyncratic risks, changes in current economic conditions that may not be reflected in quantitatively derived results, or other relevant factors to further inform our estimate of the allowance for credit losses. Additionally, due to the expansion of the time horizon over which we are required to estimate future credit losses, we may experience increased volatility in our future provisions for credit losses. Factors that could contribute to such volatility include, but are not limited to, changes in the composition and credit quality of our financing receivables and loan portfolio and investment securities portfolios, economic conditions and forecasts, the allowance for credit loss models that are used, the data that is included in the models, the associated qualitative allowance framework, and our estimation techniques.

Fair Value Fair Value (Policies

Fair Value Fair Value (Policies)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurement, Policy	GAAP specifies a three-level hierarchy that is used when measuring and disclosing fair value. The fair value hierarchy gives the highest priority to quoted prices available in active markets (i.e., observable inputs) and the lowest priority to data lacking transparency (i.e., unobservable inputs). An instrument’s categorization within the fair value hierarchy is based on the lowest level of significant input to its valuation. The following is a description of the three hierarchy levels. Level 1 Inputs are quoted prices in active markets for identical assets or liabilities at the measurement date. Additionally, the entity must have the ability to access the active market, and the quoted prices cannot be adjusted by the entity. Level 2 Inputs are other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices in active markets for similar assets or liabilities; quoted prices in inactive markets for identical or similar assets or liabilities; or inputs that are observable or can be corroborated by observable market data by correlation or other means for substantially the full term of the assets or liabilities. Level 3 Unobservable inputs are supported by little or no market activity. The unobservable inputs represent management’s best assumptions of how market participants would price the assets or liabilities. Generally, Level 3 assets and liabilities are valued using pricing models, discounted cash flow methodologies, or similar techniques that require significant judgment or estimation.

Acquisitions Acquistions (Table

Acquisitions Acquistions (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table summarizes the allocation of cash consideration paid for Health Credit Services and the amounts of the identifiable assets acquired and liabilities assumed recognized at the acquisition date. ($ in millions) Purchase price Cash consideration $ 177 Allocation of purchase price to net assets acquired Finance receivables and loans 75 Intangible assets (a) 23 Cash and short-term investments 6 Other assets 6 Debt (62 ) Employee compensation and benefits (5 ) Other liabilities (19 ) Goodwill $ 153 (a) The weighted average amortization period on the acquired intangible assets was 3 years. Refer to Note 1 for further information on our intangible assets.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents a disaggregated view of our revenue from contracts with customers included in other revenue that falls within the scope of the revenue recognition principles of ASC Topic 606, Revenue from Contracts with Customers. Year ended December 31, ($ in millions) Automotive Finance operations Insurance operations Mortgage Finance operations Corporate Finance operations Corporate and Other Consolidated 2019 Revenue from contracts with customers Noninsurance contracts (a) (b) (c) $ — $ 542 $ — $ — $ — $ 542 Remarketing fee income 74 — — — — 74 Brokerage commissions and other revenue — — — — 61 61 Deposit account and other banking fees — — — — 16 16 Brokered/agent commissions — 14 — — — 14 Other 19 1 — — — 20 Total revenue from contracts with customers 93 557 — — 77 727 All other revenue 156 717 22 45 94 1,034 Total other revenue (d) $ 249 $ 1,274 $ 22 $ 45 $ 171 $ 1,761 2018 Revenue from contracts with customers Noninsurance contracts (a) (b) (c) $ — $ 506 $ — $ — $ — $ 506 Remarketing fee income 79 — — — — 79 Brokerage commissions and other revenue — — — — 62 62 Deposit account and other banking fees — — — — 13 13 Brokered/agent commissions — 15 — — — 15 Other 13 1 — — — 14 Total revenue from contracts with customers 92 522 — — 75 689 All other revenue 177 459 7 38 44 725 Total other revenue (d) $ 269 $ 981 $ 7 $ 38 $ 119 $ 1,414 (a) We had opening balances of $2.6 billion and $2.5 billion in unearned revenue associated with outstanding contracts at January 1, 2019, and January 1, 2018 , respectively, and $816 million and $786 million of these balances were recognized as insurance premiums and service revenue earned in our Consolidated Statement of Income during the year ended December 31, 2019 , and December 31, 2018 . (b) At December 31, 2019 , we had unearned revenue of $2.9 billion associated with outstanding contracts, and with respect to this balance we expect to recognize revenue of $768 million in 2020 , $682 million in 2021 , $569 million in 2022 , $433 million in 2023 , and $417 million thereafter. At December 31, 2018 , we had unearned revenue of $2.6 billion associated with outstanding contracts. (c) We had deferred insurance assets of $1.5 billion and $1.7 billion at January 1, 2019, and December 31, 2019 , respectively, and recognized $463 million of expense during the year ended December 31, 2019 . We had deferred insurance assets of $1.4 billion and $1.5 billion at January 1, 2018, and December 31, 2018 , respectively, and recognized $427 million of expense during the year ended December 31, 2018 . (d) Represents a component of total net revenue. Refer to Note 26 for further information on our reportable operating segments.

Insurance Premiums and Servic_2

Insurance Premiums and Service Revenue Insurance Premiums and Service Revenue (Tables)	12 Months Ended
	Dec. 31, 2019
Insurance Premiums and Service Revenue [Abstract]
Insurance Premiums and Service Revenue	The following table is a summary of insurance premiums and service revenue written and earned. 2019 2018 2017 Year ended December 31, ($ in millions) Written Earned Written Earned Written Earned Insurance premiums Direct $ 491 $ 464 $ 420 $ 414 $ 384 $ 364 Assumed — 2 — 4 2 5 Gross insurance premiums 491 466 420 418 386 369 Ceded (232 ) (209 ) (219 ) (197 ) (254 ) (188 ) Net insurance premiums 259 257 201 221 132 181 Service revenue 1,051 830 973 801 864 792 Insurance premiums and service revenue written and earned $ 1,310 $ 1,087 $ 1,174 $ 1,022 $ 996 $ 973

Other Income, Net of Losses (Ta

Other Income, Net of Losses (Tables)	12 Months Ended
	Dec. 31, 2019
Other Nonoperating Income (Expense) [Abstract]
Schedule of Other Nonoperating Income, by Component	Details of other income, net of losses, were as follows. Year ended December 31, ($ in millions) 2019 2018 2017 Late charges and other administrative fees $ 114 $ 110 $ 102 Remarketing fees 74 79 104 Income from equity-method investments 62 46 14 Servicing fees 17 27 51 Other, net 136 155 130 Total other income, net of losses $ 403 $ 417 $ 401

Reserves for Insurance Losses_2

Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Short-duration insurance contracts, claims development	The following table shows incurred claims and allocated loss adjustment expenses, net of reinsurance. For the years ended December 31, ($ in millions) December 31, 2019 ($ in millions) Accident year (a) 2012 (b) 2013 (b) 2014 (b) 2015 (b) 2016 2017 2018 2019 Total of incurred-but-not-reported liabilities plus expected development on reported claims (c) Cumulative number of reported claims (c) 2012 $ 435 $ 430 $ 423 $ 423 $ 423 $ 422 422 $ 421 $ — 772,549 2013 376 365 370 370 369 368 368 — 672,278 2014 390 389 388 388 388 388 — 525,298 2015 274 271 272 272 272 — 342,267 2016 326 327 328 328 — 476,034 2017 310 314 315 — 481,646 2018 271 272 — 505,982 2019 303 23 515,689 Total $ 2,667 (a) Due to the discontinuation of various product lines and sale of certain international operations, information prior to 2012 has been excluded from the table in order to appropriately reflect the number of years for which claims are typically outstanding. In addition, given the short tail of our insurance contracts, the table above reflects the combined presentation of all business lines. (b) Information presented for the years 2012 through 2015 is unaudited supplementary information. (c) Claims are reported on a claimant basis. Claimant is defined as one vehicle for GAP products, one repair for VSCs and VMCs, one dealership for dealer inventory products, and per individual/coverage for run-off personal automotive products. The following table shows cumulative paid claims and allocated loss adjustment expenses, net of reinsurance. For the years ended December 31, ($ in millions) Accident year (a) 2012 (b) 2013 (b) 2014 (b) 2015 (b) 2016 2017 2018 2019 2012 $ 391 $ 412 $ 416 $ 418 $ 419 $ 421 $ 421 $ 421 2013 347 364 366 368 368 368 368 2014 369 388 388 388 388 388 2015 252 272 272 272 272 2016 302 327 328 328 2017 289 315 315 2018 245 273 2019 278 Total $ 2,643 All outstanding liabilities for loss and allocated loss adjustment expenses before 2012, net of reinsurance 8 Reserves for insurance losses and allocated loss adjustment expenses, net of reinsurance $ 32 (a) Due to the discontinuation of various product lines and sale of certain international operations, information prior to 2012 has been excluded from the table in order to appropriately reflect the number of years for which claims are typically outstanding. In addition, given the short tail of our insurance contracts, the table above reflects the combined presentation of all business lines. (b) Information presented for the years 2012 through 2015 is unaudited supplementary information.
Short-duration insurance contracts, schedule of historical claims duration	The following table shows the average annual percentage payout of incurred claims by age, net of reinsurance. The information presented is unaudited supplementary information. Year 1 2 3 4 5 6 7 8 Percentage payout of incurred claims 92.6 % 6.6 % 0.4 % 0.2 % 0.1 % 0.1 % 0.1 % — %
Short-duration insurance contracts, reconciliation of claims development to liability	The following table shows a reconciliation of the disclosures of incurred and paid claims development to the reserves for insurance losses and loss adjustment expenses. December 31, ($ in millions) 2019 2018 2017 Reserves for insurance losses and loss adjustment expenses, net of reinsurance $ 32 $ 35 $ 30 Total reinsurance recoverable on unpaid claims 88 96 108 Unallocated loss adjustment expenses 2 3 2 Total gross reserves for insurance losses and loss adjustment expenses $ 122 $ 134 $ 140
Short-duration insurance and deposit contracts	The following table shows a rollforward of our reserves for insurance losses and loss adjustment expenses. ($ in millions) 2019 2018 2017 Total gross reserves for insurance losses and loss adjustment expenses at January 1, $ 134 $ 140 $ 149 Less: Reinsurance recoverable 96 108 108 Net reserves for insurance losses and loss adjustment expenses at January 1, 38 32 41 Net insurance losses and loss adjustment expenses incurred related to: Current year 321 291 332 Prior years (a) — 4 — Total net insurance losses and loss adjustment expenses incurred 321 295 332 Net insurance losses and loss adjustment expenses paid or payable related to: Current year (295 ) (263 ) (309 ) Prior years (30 ) (26 ) (32 ) Total net insurance losses and loss adjustment expenses paid or payable (325 ) (289 ) (341 ) Net reserves for insurance losses and loss adjustment expenses at December 31, 34 38 32 Plus: Reinsurance recoverable 88 96 108 Total gross reserves for insurance losses and loss adjustment expenses at December 31, $ 122 $ 134 $ 140 (a) There have been no material adverse changes to the reserve for prior years.

Other Operating Expenses (Table

Other Operating Expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Operating Expenses [Abstract]
Schedule of Other Operating Cost and Expense, by Component	Details of other operating expenses were as follows. Year ended December 31, ($ in millions) 2019 2018 2017 Insurance commissions $ 475 $ 440 $ 415 Technology and communications 311 299 284 Advertising and marketing 180 172 133 Lease and loan administration 172 164 159 Professional services 126 133 113 Regulatory and licensing fees 115 121 113 Vehicle remarketing and repossession 105 111 110 Property and equipment depreciation 96 87 89 Occupancy 57 45 46 Non-income taxes 34 29 21 Amortization of intangible assets 13 11 11 Other 202 202 189 Total other operating expenses $ 1,886 $ 1,814 $ 1,683

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Our investment portfolio includes various debt and equity securities. Our debt securities, which are classified as available-for-sale or held-to-maturity, include government securities, corporate bonds, asset-backed securities, and mortgage-backed securities. The cost, fair value, and gross unrealized gains and losses on available-for-sale and held-to-maturity debt securities were as follows. 2019 2018 Amortized cost Gross unrealized Fair value Amortized cost Gross unrealized Fair value December 31, ($ in millions) gains losses gains losses Available-for-sale securities Debt securities U.S. Treasury and federal agencies $ 2,059 $ 6 $ (17 ) $ 2,048 $ 1,911 $ — $ (60 ) $ 1,851 U.S. States and political subdivisions 623 19 (1 ) 641 816 3 (17 ) 802 Foreign government 184 3 (1 ) 186 145 1 (1 ) 145 Agency mortgage-backed residential (a) 21,183 257 (36 ) 21,404 17,486 47 (395 ) 17,138 Mortgage-backed residential 2,841 20 (11 ) 2,850 2,796 1 (111 ) 2,686 Agency mortgage-backed commercial 1,344 44 (6 ) 1,382 3 — — 3 Mortgage-backed commercial 41 1 — 42 715 1 (2 ) 714 Asset-backed 365 3 — 368 723 2 (2 ) 723 Corporate debt 1,327 37 (1 ) 1,363 1,286 1 (46 ) 1,241 Total available-for-sale securities (b) (c) (d) $ 29,967 $ 390 $ (73 ) $ 30,284 $ 25,881 $ 56 $ (634 ) $ 25,303 Held-to-maturity securities Debt securities Agency mortgage-backed residential (a) (e) $ 1,547 $ 38 $ (6 ) $ 1,579 $ 2,319 $ 6 $ (61 ) $ 2,264 Asset-backed retained notes 21 — — 21 43 — — 43 Total held-to-maturity securities $ 1,568 $ 38 $ (6 ) $ 1,600 $ 2,362 $ 6 $ (61 ) $ 2,307 (a) During the year ended December 31, 2019 , agency mortgage-backed residential securities with an amortized cost of $943 million and a fair value of $945 million were transferred from held-to-maturity to available-for-sale, which resulted in the establishment of a $2 million net unrealized gain at the time of transfer. The transfer was made following the issuance of the final rules by banking agencies implementing provisions of the Economic Growth, Regulatory Relief, and Consumer Protection Act (EGRRCP Act) as further described in the section titled Regulation and Supervision in Part I, Item 1, of this report. Under the final rules, Ally is no longer subject to liquidity coverage ratio requirements. (b) Certain entities related to our Insurance operations are required to deposit securities with state regulatory authorities. These deposited securities totaled $12 million at both December 31, 2019 , and December 31, 2018 . (c) Certain available-for-sale securities are included in fair value hedging relationships. Refer to Note 21 for additional information. (d) Available-for-sale securities with a fair value of $1.9 billion and $9.2 billion at December 31, 2019 , and December 31, 2018 , respectively, were pledged to secure advances from the FHLB, short-term borrowings or repurchase agreements, or for other purposes as required by contractual obligation or law. Under these agreements, we granted the counterparty the right to sell or pledge $118 million and $821 million of the underlying investment securities at December 31, 2019 , and December 31, 2018 , respectively. (e) Held-to-maturity securities with a fair value of $915 million and $1.2 billion at December 31, 2019 , and December 31, 2018 , respectively, were pledged to secure advances from the FHLB.
Investments Classified by Contractual Maturity Date	The maturity distribution of debt securities outstanding is summarized in the following tables based upon contractual maturities. Call or prepayment options may cause actual maturities to differ from contractual maturities. Total Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years ($ in millions) Amount Yield Amount Yield Amount Yield Amount Yield Amount Yield December 31, 2019 Fair value of available-for-sale securities (a) U.S. Treasury and federal agencies $ 2,048 1.5 % $ 65 2.1 % $ 1,590 1.4 % $ 393 1.7 % $ — — % U.S. States and political subdivisions 641 3.1 22 2.7 75 2.3 159 2.8 385 3.4 Foreign government 186 1.9 35 0.4 65 2.3 86 2.3 — — Agency mortgage-backed residential 21,404 3.2 — — — — 47 2.0 21,357 3.2 Mortgage-backed residential 2,850 3.2 — — — — — — 2,850 3.2 Agency mortgage-backed commercial 1,382 2.9 — — 3 3.2 1,109 3.0 270 2.4 Mortgage-backed commercial 42 3.5 — — — — — — 42 3.5 Asset-backed 368 3.5 — — 317 3.6 5 2.7 46 3.0 Corporate debt 1,363 3.2 125 2.9 580 3.0 649 3.4 9 3.3 Total available-for-sale securities $ 30,284 3.1 $ 247 2.3 $ 2,630 2.1 $ 2,448 2.8 $ 24,959 3.2 Amortized cost of available-for-sale securities $ 29,967 $ 246 $ 2,624 $ 2,378 $ 24,719 Amortized cost of held-to-maturity securities Agency mortgage-backed residential $ 1,547 3.2 % $ — — % $ — — % $ — — % $ 1,547 3.2 % Asset-backed retained notes 21 2.2 — — 21 2.2 — — — — Total held-to-maturity securities $ 1,568 3.2 $ — — $ 21 2.2 $ — — $ 1,547 3.2 December 31, 2018 Fair value of available-for-sale securities (a) U.S. Treasury and federal agencies $ 1,851 1.9 % $ 12 1.0 % $ 1,277 1.8 % $ 562 2.0 % $ — — % U.S. States and political subdivisions 802 3.0 49 1.9 43 2.3 252 2.6 458 3.4 Foreign government 145 2.4 18 3.1 60 2.3 67 2.4 — — Agency mortgage-backed residential 17,138 3.3 — — — — 54 1.9 17,084 3.3 Mortgage-backed residential 2,686 3.3 — — — — — — 2,686 3.3 Agency mortgage-backed commercial 3 3.1 — — 3 3.1 — — — — Mortgage-backed commercial 714 3.8 — — — — 46 3.9 668 3.8 Asset-backed 723 3.5 — — 478 3.4 121 4.0 124 3.3 Corporate debt 1,241 3.1 144 2.8 496 2.9 581 3.3 20 5.5 Total available-for-sale securities $ 25,303 3.2 $ 223 2.6 $ 2,357 2.4 $ 1,683 2.8 $ 21,040 3.3 Amortized cost of available-for-sale securities $ 25,881 $ 224 $ 2,405 $ 1,743 $ 21,509 Amortized cost of held-to-maturity securities Agency mortgage-backed residential $ 2,319 3.2 % $ — — % $ — — % $ — — % $ 2,319 3.2 % Asset-backed retained notes 43 2.0 — — 42 2.0 1 3.3 — — Total held-to-maturity securities $ 2,362 3.2 $ — — $ 42 2.0 $ 1 3.3 $ 2,319 3.2 (a) Yield is calculated using the effective yield of each security at the end of the period, weighted based on the market value. The effective yield considers the contractual coupon and amortized cost, and excludes expected capital gains and losses.
Investment Income	The following table presents interest and dividends on investment securities. Year ended December 31, ($ in millions) 2019 2018 2017 Taxable interest $ 858 $ 690 $ 534 Taxable dividends 14 14 12 Interest and dividends exempt from U.S. federal income tax 15 25 22 Interest and dividends on investment securities $ 887 $ 729 $ 568
Schedule of Realized Gain (Loss)	The following table presents gross gains and losses realized upon the sales of available-for-sale securities, and net gains or losses on equity securities held during the period. There were no other-than-temporary impairments of available-for-sale securities for the periods presented. Year ended December 31, ($ in millions) 2019 2018 2017 Available-for-sale securities Gross realized gains $ 82 $ 12 $ 106 Gross realized losses (a) (4 ) (1 ) (4 ) Net realized gains on available-for-sale securities 78 11 102 Net realized gain on equity securities 73 60 Net unrealized gain (loss) on equity securities 92 (121 ) Other gain (loss) on investments, net $ 243 $ (50 ) $ 102 (a) Certain available-for-sale securities were sold at a loss in 2019 , 2018 , and 2017 as a result of identifiable market or credit events, or a loss was realized based on corporate actions outside of our control (such as a call by the issuer). Any such sales were made in accordance with our risk-management policies and practices.
Schedule of Unrealized Loss on Investments	The table below summarizes available-for-sale and held-to-maturity securities in an unrealized loss position, which we evaluated for other than temporary impairment. For additional information on our methodology, refer to Note 1 . As of December 31, 2019 , we did not have the intent to sell the available-for-sale or held-to-maturity securities with an unrealized loss position and we do not believe it is more likely than not that we will be required to sell these securities before recovery of their amortized cost basis. As a result of this evaluation, we believe that the securities with an unrealized loss position are not considered to be other-than-temporarily impaired at December 31, 2019 . 2019 2018 Less than 12 months 12 months or longer Less than 12 months 12 months or longer December 31, ($ in millions) Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss Available-for-sale securities Debt securities U.S. Treasury and federal agencies $ 1,267 $ (11 ) $ 279 $ (6 ) $ 31 $ — $ 1,758 $ (60 ) U.S. States and political subdivisions 72 (1 ) 5 — 259 (3 ) 317 (14 ) Foreign government 40 (1 ) 3 — 6 — 74 (1 ) Agency mortgage-backed residential 4,606 (23 ) 908 (13 ) 5,537 (94 ) 7,808 (301 ) Mortgage-backed residential 613 (4 ) 203 (7 ) 1,024 (20 ) 1,360 (91 ) Agency mortgage-backed commercial 335 (6 ) — — — — — — Mortgage-backed commercial — — — — 347 (1 ) 36 (1 ) Asset-backed 8 — 11 — 294 (1 ) 124 (1 ) Corporate debt 71 — 41 (1 ) 576 (19 ) 569 (27 ) Total temporarily impaired available-for-sale securities $ 7,012 $ (46 ) $ 1,450 $ (27 ) $ 8,074 $ (138 ) $ 12,046 $ (496 ) Held-to-maturity securities Debt securities Agency mortgage-backed residential $ 283 $ (6 ) $ — $ — $ 457 $ (6 ) $ 1,376 $ (55 ) Asset-backed retained notes — — 3 — 16 — 19 — Total held-to-maturity debt securities $ 283 $ (6 ) $ 3 $ — $ 473 $ (6 ) $ 1,395 $ (55 )

Finance Receivables and Loans_2

Finance Receivables and Loans, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Loans and Leases Receivable, Net Amount [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The composition of finance receivables and loans reported at gross carrying value was as follows. December 31, ($ in millions) 2019 2018 Consumer automotive (a) $ 72,390 $ 70,539 Consumer mortgage Mortgage Finance (b) 16,181 15,155 Mortgage — Legacy (c) 1,141 1,546 Total consumer mortgage 17,322 16,701 Consumer other (d) 212 — Total consumer 89,924 87,240 Commercial Commercial and industrial Automotive 28,332 33,672 Other 5,014 4,205 Commercial real estate 4,961 4,809 Total commercial 38,307 42,686 Total finance receivables and loans (e) $ 128,231 $ 129,926 (a) Certain finance receivables and loans are included in fair value hedging relationships. Refer to Note 21 for additional information. (b) Includes loans originated as interest-only mortgage loans of $11 million and $18 million at December 31, 2019 , and December 31, 2018 , respectively, 47% of which are expected to start principal amortization in 2020 . The remainder of these loans have exited the interest-only period. (c) Includes loans originated as interest-only mortgage loans of $212 million and $341 million at December 31, 2019 , and December 31, 2018 , respectively, of which 99% have exited the interest-only period. (d) Includes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option. (e) Totals include net unearned income, unamortized premiums and discounts, and deferred fees and costs of $503 million and $587 million at December 31, 2019 , and December 31, 2018 , respectively.
Allowance for Credit Losses on Financing Receivables	The following tables present an analysis of the activity in the allowance for loan losses on finance receivables and loans. ($ in millions) Consumer automotive Consumer mortgage Consumer other (a) Commercial Total Allowance at January 1, 2019 $ 1,048 $ 53 $ — $ 141 $ 1,242 Charge-offs (b) (1,423 ) (13 ) (5 ) (49 ) (1,490 ) Recoveries 493 21 — — 514 Net charge-offs (930 ) 8 (5 ) (49 ) (976 ) Provision for loan losses 957 (13 ) 14 40 998 Other — (2 ) — 1 (1 ) Allowance at December 31, 2019 $ 1,075 $ 46 $ 9 $ 133 $ 1,263 Allowance for loan losses at December 31, 2019 Individually evaluated for impairment $ 38 $ 18 $ — $ 33 $ 89 Collectively evaluated for impairment 1,037 28 9 100 1,174 Finance receivables and loans at gross carrying value Ending balance $ 72,390 $ 17,322 $ 201 $ 38,307 $ 128,220 Individually evaluated for impairment 538 208 — 215 961 Collectively evaluated for impairment 71,852 17,114 201 38,092 127,259 (a) Excludes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option. (b) Represents the amount of the gross carrying value directly written off. For consumer and commercial loans, the loss from a charge-off is measured as the difference between the gross carrying value of a loan and the fair value of the collateral, less costs to sell. Refer to Note 1 for more information regarding our charge-off policies. ($ in millions) Consumer automotive Consumer mortgage Commercial Total Allowance at January 1, 2018 $ 1,066 $ 79 $ 131 $ 1,276 Charge-offs (a) (1,383 ) (35 ) (15 ) (1,433 ) Recoveries 456 25 7 488 Net charge-offs (927 ) (10 ) (8 ) (945 ) Provision for loan losses 911 (15 ) 22 918 Other (b) (2 ) (1 ) (4 ) (7 ) Allowance at December 31, 2018 $ 1,048 $ 53 $ 141 $ 1,242 Allowance for loan losses at December 31, 2018 Individually evaluated for impairment $ 44 $ 23 $ 56 $ 123 Collectively evaluated for impairment 1,004 30 85 1,119 Finance receivables and loans at gross carrying value Ending balance $ 70,539 $ 16,701 $ 42,686 $ 129,926 Individually evaluated for impairment 495 231 349 1,075 Collectively evaluated for impairment 70,044 16,470 42,337 128,851 (a) Represents the amount of the gross carrying value directly written off. For consumer and commercial loans, the loss from a charge-off is measured as the difference between the gross carrying value of a loan and the fair value of the collateral, less costs to sell. Refer to Note 1 for more information regarding our charge-off policies. (b) Primarily related to the transfer of finance receivables and loans from held-for-investment to held-for-sale.
Schedule Of Sales Of Financing Receivables And Loans	The following table presents information about significant sales of finance receivables and loans and transfers of finance receivables and loans from held-for-investment to held-for-sale based on net carrying value. Year ended December 31, ($ in millions) 2019 2018 Consumer automotive $ 20 $ 578 Consumer mortgage 940 10 Commercial — 238 Total sales and transfers (a) $ 960 $ 826 (a) During the year ended December 31, 2019 , we also sold $131 million of loans held-for-sale that were initially classified as finance receivables and loans held-for-investment and were transferred to held-for-sale during 2018, and transferred $79 million of finance receivables from held-for-sale to held-for-investment, both relating to equipment finance receivables from our commercial automotive business.
Schedule of Purchases of Financing Receivables and Loans	The following table presents information about significant purchases of finance receivables and loans based on unpaid principal balance at the time of purchase. Year ended December 31, ($ in millions) 2019 2018 Consumer automotive $ 531 $ 896 Consumer mortgage 3,451 4,446 Consumer other (a) 117 — Commercial 46 15 Total purchases of finance receivables and loans $ 4,145 $ 5,357 (a) During the year ended December 31, 2019 , we also obtained $75 million of finance receivables and loans from our acquisition of Health Credit Services. For additional information on our acquisition, refer to Note 2 .
Past Due Financing Receivables	The following table presents an analysis of our past-due finance receivables and loans recorded at gross carrying value. December 31, ($ in millions) 30–59 days past due 60–89 days past due 90 days or more past due Total past due Current Total finance receivables and loans 2019 Consumer automotive $ 2,185 $ 590 $ 367 $ 3,142 $ 69,248 $ 72,390 Consumer mortgage Mortgage Finance 56 11 9 76 16,105 16,181 Mortgage — Legacy 25 8 28 61 1,080 1,141 Total consumer mortgage 81 19 37 137 17,185 17,322 Consumer other (a) 3 2 2 7 194 201 Total consumer 2,269 611 406 3,286 86,627 89,913 Commercial Commercial and industrial Automotive 34 — 28 62 28,270 28,332 Other — — 17 17 4,997 5,014 Commercial real estate — — 4 4 4,957 4,961 Total commercial 34 — 49 83 38,224 38,307 Total consumer and commercial $ 2,303 $ 611 $ 455 $ 3,369 $ 124,851 $ 128,220 2018 Consumer automotive $ 2,107 $ 537 $ 296 $ 2,940 $ 67,599 $ 70,539 Consumer mortgage Mortgage Finance 67 5 4 76 15,079 15,155 Mortgage — Legacy 30 10 42 82 1,464 1,546 Total consumer mortgage 97 15 46 158 16,543 16,701 Total consumer 2,204 552 342 3,098 84,142 87,240 Commercial Commercial and industrial Automotive — 1 31 32 33,640 33,672 Other — 4 16 20 4,185 4,205 Commercial real estate — — 1 1 4,808 4,809 Total commercial — 5 48 53 42,633 42,686 Total consumer and commercial $ 2,204 $ 557 $ 390 $ 3,151 $ 126,775 $ 129,926 (a) Excludes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option.
Schedule of Financing Receivables, Non Accrual Status	The following table presents the gross carrying value of our finance receivables and loans on nonaccrual status. December 31, ($ in millions) 2019 2018 Consumer automotive $ 762 $ 664 Consumer mortgage Mortgage Finance 17 9 Mortgage — Legacy 40 70 Total consumer mortgage 57 79 Consumer other 2 — Total consumer 821 743 Commercial Commercial and industrial Automotive 73 203 Other 138 142 Commercial real estate 4 4 Total commercial 215 349 Total consumer and commercial finance receivables and loans $ 1,036 $ 1,092
Financing Receivable Credit Quality Indicators	The following table presents performing and nonperforming credit quality indicators in accordance with our internal accounting policies for our consumer finance receivables and loans recorded at gross carrying value. Nonperforming loans include finance receivables and loans on nonaccrual status when the principal or interest has been delinquent for 90 days or more, or when full collection is not expected. Refer to Note 1 for additional information. 2019 2018 December 31, ($ in millions) Performing Nonperforming Total Performing Nonperforming Total Consumer automotive $ 71,628 $ 762 $ 72,390 $ 69,875 $ 664 $ 70,539 Consumer mortgage Mortgage Finance 16,164 17 16,181 15,146 9 15,155 Mortgage — Legacy 1,101 40 1,141 1,476 70 1,546 Total consumer mortgage 17,265 57 17,322 16,622 79 16,701 Consumer other (a) 199 2 201 — — — Total consumer $ 89,092 $ 821 $ 89,913 $ 86,497 $ 743 $ 87,240 (a) Excludes $11 million of finance receivables at December 31, 2019 , for which we have elected the fair value option.
Schedule Of Pass And Criticized Credit Quality Indicators Of Finance Receivables	The following table presents pass and criticized credit quality indicators based on regulatory definitions for our commercial finance receivables and loans recorded at gross carrying value. 2019 2018 December 31, ($ in millions) Pass Criticized (a) Total Pass Criticized (a) Total Commercial and industrial Automotive $ 25,235 $ 3,097 $ 28,332 $ 30,799 $ 2,873 $ 33,672 Other 4,225 789 5,014 3,373 832 4,205 Commercial real estate 4,620 341 4,961 4,538 271 4,809 Total commercial $ 34,080 $ 4,227 $ 38,307 $ 38,710 $ 3,976 $ 42,686 (a) Includes loans classified as special mention, substandard, or doubtful. These classifications are based on regulatory definitions and generally represent loans within our portfolio that have a higher default risk or have already defaulted.
Impaired Financing Receivables	The following table presents information about our impaired finance receivables and loans. December 31, ($ in millions) Unpaid principal balance (a) Gross carrying value Impaired with no allowance Impaired with an allowance Allowance for impaired loans 2019 Consumer automotive $ 553 $ 538 $ 113 $ 425 $ 38 Consumer mortgage Mortgage Finance 14 14 6 8 — Mortgage — Legacy 199 194 64 130 18 Total consumer mortgage 213 208 70 138 18 Total consumer 766 746 183 563 56 Commercial Commercial and industrial Automotive 73 73 1 72 12 Other 170 138 73 65 21 Commercial real estate 4 4 4 — — Total commercial 247 215 78 137 33 Total consumer and commercial finance receivables and loans $ 1,013 $ 961 $ 261 $ 700 $ 89 2018 Consumer automotive $ 503 $ 495 $ 105 $ 390 $ 44 Consumer mortgage Mortgage Finance 15 15 6 9 1 Mortgage — Legacy 221 216 65 151 22 Total consumer mortgage 236 231 71 160 23 Total consumer 739 726 176 550 67 Commercial Commercial and industrial Automotive 203 203 112 91 10 Other 159 142 40 102 46 Commercial real estate 4 4 4 — — Total commercial 366 349 156 193 56 Total consumer and commercial finance receivables and loans $ 1,105 $ 1,075 $ 332 $ 743 $ 123 (a) Adjusted for charge-offs.
Schedule of Average Balance And Interest Income Of Impaired Finance Receivables	The following table presents average balance and interest income for our impaired finance receivables and loans. 2019 2018 2017 Year ended December 31, ($ in millions) Average balance Interest income Average balance Interest income Average balance Interest income Consumer automotive $ 510 $ 35 $ 478 $ 28 $ 391 $ 21 Consumer mortgage Mortgage Finance 14 1 11 1 8 — Mortgage — Legacy 206 9 218 10 234 10 Total consumer mortgage 220 10 229 11 242 10 Total consumer 730 45 707 39 633 31 Commercial Commercial and industrial Automotive 113 2 93 4 49 2 Other 121 — 84 — 69 9 Commercial real estate 5 — 5 1 5 — Total commercial 239 2 182 5 123 11 Total consumer and commercial finance receivables and loans $ 969 $ 47 $ 889 $ 44 $ 756 $ 42
Troubled Debt Restructurings on Financing Receivables	The following tables present information related to finance receivables and loans recorded at gross carrying value modified in connection with a TDR during the period. Year ended December 31, ($ in millions) Number of loans Pre-modification gross carrying value Post-modification gross carrying value 2019 Consumer automotive 27,623 $ 476 $ 413 Consumer mortgage Mortgage Finance 8 1 1 Mortgage — Legacy 61 8 8 Total consumer mortgage 69 9 9 Total consumer finance receivables and loans 27,692 $ 485 $ 422 2018 Consumer automotive 26,748 $ 426 $ 378 Consumer mortgage Mortgage Finance 23 9 9 Mortgage — Legacy 204 30 29 Total consumer mortgage 227 39 38 Total consumer finance receivables and loans 26,975 $ 465 $ 416 2017 Consumer automotive 26,156 $ 380 $ 333 Consumer mortgage Mortgage Finance 4 1 1 Mortgage — Legacy 122 21 21 Total consumer mortgage 126 22 22 Total consumer finance receivables and loans 26,282 $ 402 $ 355 Year ended December 31, ($ in millions) Number of loans Pre-modification gross carrying value Post-modification gross carrying value 2019 Commercial and industrial Automotive 7 $ 46 $ 46 Other 3 82 46 Total commercial finance receivables and loans 10 $ 128 $ 92 2018 Commercial and industrial Automotive 3 $ 4 $ 4 Other 3 85 82 Total commercial finance receivables and loans 6 $ 89 $ 86 2017 Commercial and industrial Automotive 4 $ 16 $ 15 Other — 44 44 Commercial real estate 2 3 3 Total commercial finance receivables and loans 6 $ 63 $ 62
Finance receivables and loans redefaulted during the period	The following table presents information about finance receivables and loans recorded at gross carrying value that have redefaulted during the reporting period and were within 12 months or less of being modified as a TDR. Redefault is when finance receivables and loans meet the requirements for evaluation under our charge-off policy (refer to Note 1 for additional information) except for commercial finance receivables and loans, where redefault is defined as 90 days past due. Year ended December 31, ($ in millions) Number of loans Gross carrying value Charge-off amount 2019 Consumer automotive 7,215 $ 81 $ 52 Total consumer finance receivables and loans 7,215 $ 81 $ 52 2018 Consumer automotive 9,711 $ 111 $ 73 Consumer mortgage Mortgage — Legacy 2 — — Total consumer finance receivables and loans 9,713 $ 111 $ 73 2017 Consumer automotive 8,829 $ 102 $ 71 Consumer mortgage Mortgage Finance 1 1 — Mortgage — Legacy 2 — — Total consumer finance receivables and loans 8,832 $ 103 $ 71
Consumer concentration risk	The following table shows the percentage of consumer automotive and consumer mortgage finance receivables and loans by state concentration based on gross carrying value. 2019 (a) 2018 December 31, Consumer automotive Consumer mortgage Consumer automotive Consumer mortgage California 8.5 % 35.1 % 8.4 % 36.9 % Texas 12.4 6.5 12.8 6.2 Florida 8.8 5.1 8.8 4.7 Pennsylvania 4.6 1.9 4.5 1.4 Illinois 4.1 2.6 4.1 3.0 Georgia 3.9 2.8 4.1 2.8 North Carolina 4.0 2.0 3.9 1.7 New York 3.1 3.0 3.1 2.4 Ohio 3.6 0.5 3.5 0.4 New Jersey 2.8 2.3 2.7 2.1 Other United States 44.2 38.2 44.1 38.4 Total consumer loans 100.0 % 100.0 % 100.0 % 100.0 % (a) Presentation is in descending order as a percentage of total consumer finance receivables and loans at December 31, 2019.
Commercial concentration risk	The commercial real estate portfolio consists of finance receivables and loans issued primarily to automotive dealers. The following table presents the percentage of total commercial real estate finance receivables and loans by state concentration based on gross carrying value. December 31, 2019 2018 Texas 15.0 % 15.5 % Florida 11.6 11.6 Michigan 8.2 6.8 California 7.2 8.3 New York 5.9 4.8 North Carolina 4.6 3.6 Georgia 3.5 4.0 New Jersey 2.9 3.1 South Carolina 2.8 3.4 Illinois 2.4 2.0 Other United States 35.9 36.9 Total commercial real estate finance receivables and loans 100.0 % 100.0 %
Commercial criticized risk exposure	The following table presents the percentage of total commercial criticized finance receivables and loans by industry concentration based on gross carrying value. December 31, 2019 2018 Automotive 81.7 % 80.6 % Services 5.4 5.0 Electronics 3.7 2.3 Other 9.2 12.1 Total commercial criticized finance receivables and loans 100.0 % 100.0 %

Leasing (Tables)

Leasing (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Investment in Operating Leases	The following table details our total investment in operating leases. ($ in millions) December 31, 2019 January 1, 2019 (a) Assets Operating lease right-of-use assets (b) $ 168 $ 161 Liabilities Operating lease liabilities (c) $ 196 $ 190 (a) Date of adoption. (b) Included in other assets on our Consolidated Balance Sheet . (c) Included in accrued expenses and other liabilities on our Consolidated Balance Sheet .
Lessee, Operating Lease, Liability, Maturity	The following table presents future minimum rental payments we are required to make under operating leases that have commenced as of December 31, 2019 , and that have noncancelable lease terms expiring after December 31, 2019 . Year ended December 31, ($ in millions) 2020 $ 50 2021 43 2022 29 2023 18 2024 14 2025 and thereafter 62 Total undiscounted cash flows 216 Difference between undiscounted cash flows and discounted cash flows (20 ) Total lease liability $ 196
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum rental payments required under operating leases as of December 31, 2018, prior to the date of adoption and as defined by the previous lease accounting guidance, with noncancelable lease terms expiring after December 31, 2018, were as follows. Year ended December 31, ($ in millions) 2019 $ 48 2020 47 2021 46 2022 37 2023 31 2024 and thereafter 294 Total minimum payments required $ 503
Lease, Cost	The following table details the components of total net operating lease expense. Year ended December 31, ($ in millions) 2019 2018 2017 Operating lease expense $ 45 $ 43 $ 42 Variable lease expense 8 7 7 Total lease expense, net (a) $ 53 $ 50 $ 49 (a) Included in other operating expenses in our Consolidated Statement of Income
Schedule of Property Subject to or Available for Operating Lease	The following table details our investment in operating leases. Year ended December 31, ($ in millions) 2019 2018 Vehicles $ 10,426 $ 9,995 Accumulated depreciation (1,562 ) (1,578 ) Investment in operating leases, net $ 8,864 $ 8,417
Lessor, Operating Lease, Payments to be Received, Maturity	The following table presents future minimum rental payments we have the right to receive under operating leases with noncancelable lease terms expiring after December 31, 2019 . Year ended December 31, ($ in millions) 2020 $ 1,339 2021 851 2022 383 2023 86 2024 6 2025 and thereafter — Total lease payments from operating leases $ 2,665
Depreciation Expense on Operating Lease Assets	We recognized operating lease revenue of $1.5 billion for both the years ended December 31, 2019, and 2018, and $1.9 billion for the year ended December 31, 2017. Depreciation expense on operating lease assets includes remarketing gains and losses recognized on the sale of operating lease assets. The following table summarizes the components of depreciation expense on operating lease assets. Year ended December 31, ($ in millions) 2019 2018 2017 Depreciation expense on operating lease assets (excluding remarketing gains) (a) $ 1,050 $ 1,115 $ 1,368 Remarketing gains, net (69 ) (90 ) (124 ) Net depreciation expense on operating lease assets $ 981 $ 1,025 $ 1,244 (a) Includes variable lease payments related to excess mileage and excessive wear and tear on vehicles of $19 million during the year ended December 31, 2019, $24 million during the year ended December 31, 2018, and $32 million during the year ended December 31, 2017.
Finance Lease, Liability, Maturity	The following table presents future minimum rental payments we have the right to receive under finance leases with noncancelable lease terms expiring after December 31, 2019 . Year ended December 31, ($ in millions) 2020 $ 167 2021 142 2022 94 2023 60 2024 32 2025 and thereafter 19 Total undiscounted cash flows 514 Difference between undiscounted cash flows and discounted cash flows (55 ) Present value of lease payments recorded as lease receivable $ 459

Securitizations and Variable _2

Securitizations and Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2019
Securitizations And Variable Interest Entities [Abstract]
Schedule of Variable Interest Entities	The following table presents our involvement in consolidated and nonconsolidated VIEs in which we hold variable interests. For additional detail related to the assets and liabilities of consolidated variable interest entities refer to the Consolidated Balance Sheet . December 31, ($ in millions) Carrying value of total assets Carrying value of total liabilities Assets sold to nonconsolidated VIEs (a) Maximum exposure to loss in nonconsolidated VIEs 2019 On-balance sheet variable interest entities Consumer automotive $ 20,376 (b) $ 6,070 (c) Commercial automotive 8,009 3,049 Off-balance-sheet variable interest entities Consumer automotive (d) 23 (e) — $ 417 $ 440 (f) Commercial other 1,079 (g) 378 (h) — 1,397 (i) Total $ 29,487 $ 9,497 $ 417 $ 1,837 2018 On-balance sheet variable interest entities Consumer automotive $ 16,255 (b) $ 6,573 (c) Commercial automotive 11,089 3,946 Off-balance-sheet variable interest entities Consumer automotive 45 (e) — $ 1,235 $ 1,280 (f) Commercial other 806 (g) 326 (h) — 1,054 (i) Total $ 28,195 $ 10,845 $ 1,235 $ 2,334 (a) Asset values represent the current unpaid principal balance of outstanding consumer finance receivables and loans within the VIEs. (b) Includes $9.0 billion and $8.4 billion of assets that were not encumbered by VIE beneficial interests held by third parties at December 31, 2019 , and December 31, 2018 , respectively. Ally or consolidated affiliates hold the interests in these assets. (c) Includes $21 million and $25 million of liabilities that were not obligations to third-party beneficial interest holders at December 31, 2019 , and December 31, 2018 , respectively. (d) During the year ended December 31, 2019 , we indicated our intent to exercise clean-up call option related to a nonconsolidated securitization-related VIE. The option enables us to repurchase the remaining transferred financial assets at our discretion once the asset pool declines to a predefined level and redeem the related outstanding debt. As a result of this event, we became the primary beneficiary of the VIE, which included $48 million of consumer automotive loans and $45 million of related debt, and the VIE was consolidated on our Consolidated Balance Sheet. The related amounts were removed from assets sold to nonconsolidated VIEs and maximum exposure to loss in nonconsolidated VIEs. (e) Represents retained notes and certificated residual interests, of which $21 million and $43 million were classified as held-to-maturity securities at December 31, 2019 , and December 31, 2018 , respectively, and $2 million were classified as other assets at both December 31, 2019 , and December 31, 2018 . These assets represent our five percent interest in the credit risk of the assets underlying asset-backed securitizations. (f) Maximum exposure to loss represents the current unpaid principal balance of outstanding loans, retained notes, certificated residual interests, as well as certain noncertificated interests retained from the sale of automotive finance receivables. This measure is based on the very unlikely event that all of our sold loans have defects that would trigger a representation, warranty, and covenant provision and the underlying collateral supporting the loans becomes worthless. This required disclosure is not an indication of our expected loss. (g) Amounts are classified as other assets. (h) Amounts are classified as accrued expenses and other liabilities. (i) For certain nonconsolidated affordable housing entities, maximum exposure to loss represents the yield we guaranteed investors through long-term guarantee contracts. The amount disclosed is based on the unlikely event that the yield delivered to investors in the form of low-income tax housing credits is recaptured. For nonconsolidated equity investments, maximum exposure to loss represents our outstanding investment, additional committed capital, and low-income housing tax credits subject to recapture. The amount disclosed is based on the unlikely event that our committed capital is funded, our investments become worthless, and the tax credits previously delivered to us are recaptured. This required disclosure is not an indication of our expected loss.
On-balance sheet Variable Interest Entities	The assets of consolidated VIEs that can be used only to settle obligations of the consolidated VIEs and the liabilities of those entities for which creditors or beneficial interest holders do not have recourse to our general credit were as follows. December 31, ($ in millions) 2019 2018 Assets Finance receivables and loans, net Consumer $ 10,791 $ 7,282 Commercial 7,919 10,804 Allowance for loan losses (153 ) (114 ) Total finance receivables and loans, net 18,557 17,972 Investment in operating leases, net — 164 Other assets 787 767 Total assets $ 19,344 $ 18,903 Liabilities Long-term debt $ 9,087 $ 10,482 Accrued expenses and other liabilities 11 12 Total liabilities $ 9,098 $ 10,494
Schedule Of Cash Flow Received And Paid To Nonconsolidated Securitization Entities	The following table summarizes cash flows received and paid related to SPEs and asset-backed financings where the transfer is accounted for as a sale and we have a continuing involvement with the transferred consumer automotive assets (for example, servicing) that were outstanding during the years ended December 31, 2019 , 2018 , and 2017 . Additionally, this table contains information regarding cash flows received from and paid to nonconsolidated SPEs that existed during each period. Year ended December 31, ($ in millions) Consumer automotive Consumer mortgage 2019 Cash flows received on retained interests in securitization entities $ 23 $ — Servicing fees 10 — Cash disbursements for repurchases during the period (2 ) — 2018 Cash proceeds from transfers completed during the period $ 24 $ — Cash flows received on retained interests in securitization entities 20 — Servicing fees 18 — Cash disbursements for repurchases during the period (4 ) — Representation and warranty recoveries — 2 2017 Cash proceeds from transfers completed during the period $ 1,187 $ — Cash disbursements for repurchases during the period (a) (491 ) — Servicing fees 31 — Cash flows received on retained interests in securitization entities 21 — Other cash flows 4 — (a) During the second quarter of 2017, we elected to not renew a consumer automotive credit conduit facility and also purchased the related consumer automotive loans and settled associated retained interests.
Schedule of Quantitative Information and Net Credit Losses about Securitized and Other Financial Assets Managed Together	The following tables present quantitative information about delinquencies and net credit losses for off-balance-sheet securitizations and whole-loan sales where we have continuing involvement. Total amount Amount 60 days or more past due December 31, ($ in millions) 2019 2018 2019 2018 Off-balance-sheet securitization entities Consumer automotive $ 417 $ 1,235 $ 6 $ 13 Whole-loan sales (a) Consumer automotive 207 634 2 3 Total $ 624 $ 1,869 $ 8 $ 16 (a) Whole-loan sales are not part of a securitization transaction, but represent consumer automotive pools of loans sold to third-party investors. Net credit losses Year ended December 31, ($ in millions) 2019 2018 Off-balance-sheet securitization entities Consumer automotive $ 6 $ 10 Whole-loan sales (a) Consumer automotive 1 2 Total $ 7 $ 12 (a) Whole-loan sales are not part of a securitization transaction, but represent consumer automotive pools of loans sold to third-party investors.
Activity in Affordable Housing Program Obligation	The following table summarizes information about our affordable housing investments. Year ended December 31, ($ in millions) 2019 2018 2017 Affordable housing tax credits and other tax benefits (a) $ 86 $ 61 $ 43 Tax credit amortization expense recognized as a component of income tax expense 72 51 44 (a) There were no impairment losses recognized during the years ended December 31, 2019 , 2018 , and 2017 , resulting from the forfeiture or ineligibility of tax credits or other circumstances.

Premiums Receivable and Other_2

Premiums Receivable and Other Insurance Assets Premiuns Receivable and Other Insurance Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Premiums and Other Receivables, Net [Abstract]
Premiums Receivable and Other Insurance Assets	Premiums Receivable and Other Insurance Assets Premiums receivable and other insurance assets consisted of the following. December 31, ($ in millions) 2019 2018 Prepaid reinsurance premiums $ 551 $ 527 Reinsurance recoverable on unpaid losses 88 96 Reinsurance recoverable on paid losses 23 22 Premiums receivable 105 88 Deferred policy acquisition costs 1,791 1,593 Total premiums receivable and other insurance assets $ 2,558 $ 2,326

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Other Assets [Abstract]
Schedule of Other Assets	The components of other assets were as follows. December 31, ($ in millions) 2019 2018 Property and equipment at cost $ 1,332 $ 1,250 Accumulated depreciation (686 ) (686 ) Net property and equipment 646 564 Nonmarketable equity investments (a) 1,232 1,410 Investment in qualified affordable housing projects 830 649 Restricted cash held for securitization trusts (b) 738 965 Accrued interest, fees, and rent receivables 589 599 Goodwill (c) 393 240 Equity-method investments (d) 358 262 Other accounts receivable 117 203 Restricted cash and cash equivalents (e) 87 124 Net intangible assets (f) 69 59 Fair value of derivative contracts in receivable position (g) 64 41 Net deferred tax assets 58 317 Other assets 892 720 Total other assets $ 6,073 $ 6,153 (a) Includes investments in FHLB stock of $701 million and $903 million at December 31, 2019 , and 2018 , respectively; FRB stock of $449 million and $448 million at December 31, 2019 , and 2018 , respectively; and equity securities without a readily determinable fair value of $82 million and $59 million at December 31, 2019 , and 2018 , respectively, measured at cost with adjustments for impairment and observable changes in price. During the year ended December 31, 2019 , we recorded $9 million of upward adjustments and $3 million of impairments and downward adjustments related to equity securities without a readily determinable fair value. Through December 31, 2019 , we recorded $10 million of cumulative upward adjustments and $6 million of cumulative impairments and downward adjustments related to equity securities without a readily determinable fair value. (b) Includes restricted cash collected from customer payments on securitized receivables, which are distributed by us to investors as payments on the related secured debt, and cash reserve deposits utilized as a form of credit enhancement for various securitization transactions. (c) Includes goodwill of $27 million within our Insurance operations at both December 31, 2019 , and 2018 ; $20 million within Automotive Finance operations at both December 31, 2019 , and 2018 ; and $346 million and $193 million within Corporate and Other at December 31, 2019 , and 2018 , respectively. The increase in goodwill within Corporate and Other of $153 million was attributable to our acquisition of Health Credit Services, as further described in Note 2. No other changes to the carrying amount of goodwill were recorded during the years ended December 31, 2019 , and 2018 . (d) Primarily relates to investments made in connection with our CRA program. (e) Primarily represents a number of arrangements with third parties where certain restrictions are placed on balances we hold due to collateral agreements associated with operational processes with a third-party bank, or letter of credit arrangements and corresponding collateral requirements. (f) Includes gross intangible assets of $111 million and $88 million at December 31, 2019 , and 2018 , respectively, and accumulated depreciation of $42 million and $29 million at December 31, 2019 , and 2018 . (g) For additional information on derivative instruments and hedging activities, refer to Note 21 .

Deposit Liabilities (Tables)

Deposit Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Deposits [Abstract]
Deposit Liabilities, Type	Deposit liabilities consisted of the following. December 31, ($ in millions) 2019 2018 Noninterest-bearing deposits $ 119 $ 142 Interest-bearing deposits Savings and money-market checking accounts 62,486 56,050 Certificates of deposit 58,146 49,985 Other deposits 1 1 Total deposit liabilities $ 120,752 $ 106,178
Time Deposit Maturities	The following table presents the scheduled maturity of total certificates of deposit at December 31, 2019 . ($ in millions) Due in 2020 $ 41,419 Due in 2021 10,541 Due in 2022 4,061 Due in 2023 996 Due in 2024 1,129 Total certificates of deposit $ 58,146

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Short-term Debt	The following table presents the composition of our short-term borrowings portfolio. 2019 2018 December 31, ($ in millions) Unsecured Secured (a) Total Unsecured Secured (a) Total Demand notes $ 2,581 $ — $ 2,581 $ 2,477 $ — $ 2,477 Federal Home Loan Bank — 2,950 2,950 — 6,825 6,825 Securities sold under agreements to repurchase — — — — 685 685 Total short-term borrowings $ 2,581 $ 2,950 $ 5,531 $ 2,477 $ 7,510 $ 9,987 Weighted average interest rate (b) 1.8 % 2.5 % (a) Refer to the section below titled Long-term Debt for further details on assets restricted as collateral for payment of the related debt. (b) Based on the debt outstanding and the interest rate at December 31 of each year.
Long-term Debt	The following tables present the composition of our long-term debt portfolio. December 31, ($ in millions) Amount Interest rate Weighted average stated interest rate (a) Due date range 2019 Unsecured debt Fixed rate (b) $ 8,566 Variable rate 1 Trust preferred securities (c) 2,575 Hedge basis adjustment (d) 62 Total unsecured debt 11,204 1.71–8.00% 6.34 % 2020–2049 Secured debt Fixed rate 21,477 Variable rate (e) 1,384 Hedge basis adjustment (d) (38 ) Total secured debt (f) (g) (h) 22,823 1.35–4.03% 2.44 % 2020–2027 Total long-term debt $ 34,027 2018 Unsecured debt Fixed rate (b) $ 9,406 Variable rate 1 Trust preferred securities (c) 2,572 Hedge basis adjustment (d) 128 Total unsecured debt 12,107 2.42–8.40% 6.29 % 2019–2049 Secured debt Fixed rate 23,514 Variable rate (e) 8,633 Hedge basis adjustment (d) (61 ) Total secured debt (f) (g) (h) 32,086 1.26–4.50% 2.54 % 2019–2037 Total long-term debt $ 44,193 (a) Based on the debt outstanding and the interest rate at December 31 of each year excluding any impacts of interest rate hedges. (b) Includes subordinated debt of $1.0 billion at both December 31, 2019 , and 2018 . (c) Refer to the section below titled Trust Preferred Securities for further information. (d) Represents the basis adjustment associated with the application of hedge accounting on certain of our long-term debt positions. Refer to Note 21 for additional information. (e) Includes $92 million and $5 million at December 31, 2019 , and 2018 , respectively, of long-term debt that does not have a stated interest rate. (f) Includes $9.1 billion and $10.5 billion of VIE secured debt at December 31, 2019 , and 2018 , respectively. (g) Includes $450 million and $6.7 billion of debt outstanding from our committed secured credit facilities at December 31, 2019 , and 2018 , respectively. (h) Includes advances from the FHLB of Pittsburgh of $13.3 billion and $14.9 billion at December 31, 2019 , and 2018 , respectively. 2019 2018 December 31, ($ in millions) Unsecured Secured Total Unsecured Secured Total Long-term debt (a) Due within one year $ 2,214 $ 7,005 $ 9,219 $ 1,663 $ 7,313 $ 8,976 Due after one year 8,990 15,818 24,808 10,444 24,773 35,217 Total long-term debt (b) (c) $ 11,204 $ 22,823 $ 34,027 $ 12,107 $ 32,086 $ 44,193 (a) Includes basis adjustments related to the application of hedge accounting.
Schedule of Maturities of Long-term Debt	The following table presents the scheduled remaining maturity of long-term debt at December 31, 2019 , assuming no early redemptions will occur. The amounts below include adjustments to the carrying value resulting from the application of hedge accounting. The actual payment of secured debt may vary based on the payment activity of the related pledged assets. ($ in millions) 2020 2021 2022 2023 2024 2025 and thereafter Total Unsecured Long-term debt $ 2,258 $ 697 $ 1,121 $ (9 ) $ 1,470 $ 6,767 $ 12,304 Original issue discount (44 ) (47 ) (52 ) (59 ) (65 ) (833 ) (1,100 ) Total unsecured 2,214 650 1,069 (68 ) 1,405 5,934 11,204 Secured Long-term debt 7,005 9,530 5,552 627 107 2 22,823 Total long-term debt $ 9,219 $ 10,180 $ 6,621 $ 559 $ 1,512 $ 5,936 $ 34,027
Pledged assets for the payment of the related secured borrowings and repurchase agreements	The following summarizes assets restricted as collateral for the payment of the related debt obligation, primarily arising from securitization transactions accounted for as secured borrowings and repurchase agreements. 2019 2018 December 31, ($ in millions) Total (a) Ally Bank Total (a) Ally Bank Investment securities (b) $ 2,698 $ 2,698 $ 10,280 $ 9,564 Mortgage assets held-for-investment and lending receivables 17,135 17,135 16,498 16,498 Consumer automotive finance receivables 13,481 11,534 17,015 9,715 Commercial automotive finance receivables 12,890 12,890 15,563 15,563 Operating leases — — 170 — Total assets restricted as collateral (c) (d) $ 46,204 $ 44,257 $ 59,526 $ 51,340 Secured debt $ 25,773 (e) $ 24,069 $ 39,596 (e) $ 32,072 (a) Ally Bank is a component of the total column. (b) A portion of the restricted investment securities at December 31, 2018 , was restricted under repurchase agreements. Refer to the section above titled Short-term Borrowings for information on the repurchase agreements. (c) Ally Bank has an advance agreement with the FHLB, and had assets pledged to secure borrowings that were restricted as collateral to the FHLB totaling $24.8 billion and $30.8 billion at December 31, 2019 , and December 31, 2018 , respectively. These assets were composed primarily of consumer mortgage finance receivables and loans and investment securities. Ally Bank has access to the FRB Discount Window and had assets pledged and restricted as collateral to the FRB totaling $2.4 billion at both December 31, 2019 , and December 31, 2018 . These assets were composed of consumer automotive finance receivables and loans. Availability under these programs is only for the operations of Ally Bank and cannot be used to fund the operations or liabilities of Ally or its subsidiaries. (d) Excludes restricted cash and cash reserves for securitization trusts recorded within other assets on the Consolidated Balance Sheet . Refer to Note 13 for additional information. (e) Includes $3.0 billion and $7.5 billion of short-term borrowings at December 31, 2019 , and December 31, 2018 , respectively.
Schedule Of Committed Funding Facilities	Committed Secured Credit Facilities Outstanding Unused capacity (a) Total capacity December 31, ($ in millions) 2019 2018 2019 2018 2019 2018 Bank funding Secured $ — $ 3,500 $ — $ 1,300 $ — $ 4,800 Parent funding Secured 450 3,165 2,050 635 2,500 3,800 Total committed secured credit facilities $ 450 $ 6,665 $ 2,050 $ 1,935 $ 2,500 $ 8,600 (a) Funding from committed secured credit facilities is available on request in the event excess collateral resides in certain facilities or the extent incremental collateral is available and contributed to the facilities.

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Accounts Payable and Accrued Liabilities [Abstract]
Schedule of Accrued Liabilities	The components of accrued expenses and other liabilities were as follows. December 31, ($ in millions) 2019 2018 Accounts payable $ 535 $ 516 Unfunded commitments for investment in qualified affordable housing projects 372 319 Employee compensation and benefits 296 255 Reserves for insurance losses and loss adjustment expenses 122 134 Net deferred tax liabilities 67 17 Cash collateral received from counterparties 48 41 Deferred revenue 36 27 Fair value of derivative contracts in payable position (a) 5 37 Other liabilities 491 330 Total accrued expenses and other liabilities $ 1,972 $ 1,676 (a) For additional information on derivative instruments and hedging activities, refer to Note 21 .

Equity Equity (Tables)

Equity Equity (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Schedule of Stockholders Equity	The following table presents changes in the number of shares issued and outstanding. (shares in thousands) (a) 2019 2018 2017 Common stock Total issued at January 1, 492,797 489,884 485,708 New issuances Employee benefits and compensation plans 4,160 2,914 4,176 Total issued at December 31, 496,958 492,797 489,884 Treasury balance at January 1, (87,898 ) (52,830 ) (18,707 ) Repurchase of common stock (b) (34,728 ) (35,068 ) (34,122 ) Total treasury stock at December 31, (122,626 ) (87,898 ) (52,830 ) Total outstanding at December 31, 374,332 404,900 437,054 (a) Figures in the table may not recalculate exactly due to rounding. Number of shares issued, in treasury, and outstanding are calculated based on unrounded numbers. (b) Includes shares of common stock withheld to cover income taxes owed by participants in our share-based incentive plans. Refer to the section titled Capital Planning and Stress Tests in Note 20 for additional information regarding our common-stock-repurchase program.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive (Loss) Income (Tables)	12 Months Ended
	Dec. 31, 2019
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The following table presents changes, net of tax, in each component of accumulated other comprehensive income (loss). ($ in millions) Unrealized (losses) gains on investment securities (a) Translation adjustments and net investment hedges (b) Cash flow hedges (b) Defined benefit pension plans Accumulated other comprehensive income (loss) Balance at January 1, 2017 $ (273 ) $ 14 $ 8 $ (90 ) $ (341 ) Net change 100 2 3 1 106 Balance at December 31, 2017 (173 ) 16 11 (89 ) (235 ) Cumulative effect of changes in accounting principles, net of tax Adoption of Accounting Standards Update 2016-01 27 — — — 27 Adoption of Accounting Standards Update 2018-02 (40 ) 4 — (6 ) (42 ) Balance at January 1, 2018 (186 ) 20 11 (95 ) (250 ) Net change (295 ) (2 ) 8 — (289 ) Balance at December 31, 2018 (481 ) 18 19 (95 ) (539 ) Cumulative effect of changes in accounting principles, net of tax (c) Adoption of Accounting Standards Update 2017-08 8 — — — 8 Balance at January 1, 2019 (473 ) 18 19 (95 ) (531 ) Net change 681 1 (17 ) (11 ) 654 Balance at December 31, 2019 $ 208 $ 19 $ 2 $ (106 ) $ 123 (a) Represents the after-tax difference between the fair value and amortized cost of our available-for-sale securities portfolio. (b) For additional information on derivative instruments and hedging activities, refer to Note 21 . (c) Refer to the section titled Recently Adopted Accounting Standards in Note 1 for additional information.
Reclassification out of Accumulated Other Comprehensive Income	The following tables present the before- and after-tax changes in each component of accumulated other comprehensive income (loss). Year ended December 31, 2019 ($ in millions) Before tax Tax effect After tax Investment securities Net unrealized gains arising during the period $ 968 $ (227 ) $ 741 Less: Net realized gains reclassified to income from continuing operations 78 (a) (18 ) (b) 60 Net change 890 (209 ) 681 Translation adjustments Net unrealized gains arising during the period 7 (2 ) 5 Net investment hedges (c) Net unrealized losses arising during the period (6 ) 2 (4 ) Cash flow hedges (c) Net unrealized losses arising during the period (11 ) 4 (7 ) Less: Net realized gains reclassified to income from continuing operations 12 (d) (2 ) (b) 10 Net change (23 ) 6 (17 ) Defined benefit pension plans Net unrealized losses arising during the period (14 ) 3 (11 ) Other comprehensive income $ 854 $ (200 ) $ 654 (a) Includes gains reclassified to other gain on investments, net in our Consolidated Statement of Income . (b) Includes amounts reclassified to income tax expense from continuing operations in our Consolidated Statement of Income . (c) For additional information on derivative instruments and hedging activities, refer to Note 21 . (d) Includes gains reclassified to interest on deposits and interest on long-term debt in our Consolidated Statement of Income . Year ended December 31, 2018 ($ in millions) Before tax Tax effect After tax Investment securities Net unrealized losses arising during the period $ (375 ) $ 88 $ (287 ) Less: Net realized gains reclassified to income from continuing operations 11 (a) (3 ) (b) 8 Net change (386 ) 91 (295 ) Translation adjustments Net unrealized losses arising during the period (14 ) 3 (11 ) Net investment hedges (c) Net unrealized gains arising during the period 12 (3 ) 9 Cash flow hedges (c) Net unrealized gains arising during the period 12 (2 ) 10 Less: Net realized gains reclassified to income from continuing operations 2 (d) — 2 Net change 10 (2 ) 8 Defined benefit pension plans Net unrealized gains arising during the period 1 (1 ) — Other comprehensive loss $ (377 ) $ 88 $ (289 ) (a) Includes gains reclassified to other gain on investments, net in our Consolidated Statement of Income . (b) Includes amounts reclassified to income tax expense from continuing operations in our Consolidated Statement of Income . (c) For additional information on derivative instruments and hedging activities, refer to Note 21 . (d) Includes gains reclassified to interest on deposits and interest on long-term debt in our Consolidated Statement of Income . Year ended December 31, 2017 ($ in millions) Before tax Tax effect After tax Investment securities Net unrealized gains arising during the period $ 237 $ (45 ) $ 192 Less: Net realized gains reclassified to income from continuing operations 105 (a) (13 ) (b) 92 Net change 132 (32 ) 100 Translation adjustments Net unrealized gains arising during the period 12 (4 ) 8 Net investment hedges (c) Net unrealized losses arising during the period (10 ) 4 (6 ) Cash flow hedges (c) Net unrealized gains arising during the period 5 (2 ) 3 Defined benefit pension plans Net unrealized gains arising during the period 1 — 1 Other comprehensive income $ 140 $ (34 ) $ 106 (a) Includes gains reclassified to other gain on investments, net in our Consolidated Statement of Income . (b) Includes amounts reclassified to income tax expense from continuing operations in our Consolidated Statement of Income . (c) For additional information on derivative instruments and hedging activities, refer to Note 21 .

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the calculation of basic and diluted earnings per common share. Year ended December 31, ($ in millions, except per share data; shares in thousands) (a) 2019 2018 2017 Net income from continuing operations $ 1,721 $ 1,263 $ 926 (Loss) income from discontinued operations, net of tax (6 ) — 3 Net income attributable to common stockholders $ 1,715 $ 1,263 $ 929 Basic weighted-average common shares outstanding (b) 393,234 425,165 453,704 Diluted weighted-average common shares outstanding (b) 395,395 427,680 455,350 Basic earnings per common share Net income from continuing operations $ 4.38 $ 2.97 $ 2.04 (Loss) income from discontinued operations, net of tax (0.02 ) — 0.01 Net income 4.36 2.97 2.05 Diluted earnings per common share Net income from continuing operations 4.35 2.95 2.03 (Loss) income from discontinued operations, net of tax (0.02 ) — 0.01 Net income $ 4.34 $ 2.95 $ 2.04 (a) Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers. (b) Includes shares related to share-based compensation that vested but were not yet issued .

Regulatory Capital and Other _2

Regulatory Capital and Other Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2019
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The following table summarizes our capital ratios under the U.S. Basel III capital framework. December 31, 2019 December 31, 2018 Required minimum (a) Well-capitalized minimum ($ in millions) Amount Ratio Amount Ratio Capital ratios Common Equity Tier 1 (to risk-weighted assets) Ally Financial Inc. $ 13,837 9.54 % $ 13,397 9.14 % 4.50 % (b) Ally Bank 16,627 12.30 16,552 12.61 4.50 6.50 % Tier 1 (to risk-weighted assets) Ally Financial Inc. $ 16,271 11.22 % $ 15,831 10.80 % 6.00 % 6.00 % Ally Bank 16,627 12.30 16,552 12.61 6.00 8.00 Total (to risk-weighted assets) Ally Financial Inc. $ 18,506 12.76 % $ 18,046 12.31 % 8.00 % 10.00 % Ally Bank 17,854 13.21 17,620 13.42 8.00 10.00 Tier 1 leverage (to adjusted quarterly average assets) (c) Ally Financial Inc. $ 16,271 9.08 % $ 15,831 9.00 % 4.00 % (b) Ally Bank 16,627 10.01 16,552 10.69 4.00 5.00 % (a) In addition to the minimum risk-based capital requirements for the Common Equity Tier 1 capital, Tier 1 capital, and total capital ratios, Ally and Ally Bank were required to maintain a minimum capital conservation buffer of 2.5% and 1.875% at December 31, 2019 , and December 31, 2018 , respectively. (b) Currently, there is no ratio component for determining whether a BHC is “well-capitalized.” (c) Federal regulatory reporting guidelines require the calculation of adjusted quarterly average assets using a daily average methodology.
Schedule of Common Share Repurchase Activity	The following table presents information related to our common stock and distributions to our common stockholders over the last eight quarters. Common stock repurchased during period (a) Number of common shares outstanding Cash dividends declared per common share (b) ($ in millions, except per share data; shares in thousands) Approximate dollar value Number of shares Beginning of period End of period 2018 First quarter $ 185 6,473 437,054 432,691 $ 0.13 Second quarter 195 7,280 432,691 425,752 0.13 Third quarter 250 9,194 425,752 416,591 0.15 Fourth quarter 309 12,121 416,591 404,900 0.15 2019 First quarter $ 211 8,113 404,900 399,761 $ 0.17 Second quarter 229 7,775 399,761 392,775 0.17 Third quarter 300 9,287 392,775 383,523 0.17 Fourth quarter 299 9,554 383,523 374,332 0.17 (a) Includes shares of common stock withheld to cover income taxes owed by participants in our share-based incentive plans. (b) On January 13, 2020 , the Ally Board of Directors (our Board) declared a quarterly cash dividend of $0.19 per share on all common stock, payable on February 14, 2020 . Refer to Note 31 for further information regarding this common stock dividend.

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position	The following table summarizes the amounts of derivative instruments reported on our Consolidated Balance Sheet . The amounts are presented on a gross basis, are segregated by derivatives that are designated and qualifying as hedging instruments or those that are not, and are further segregated by type of contract within those two categories. Derivative contracts in a receivable and payable position exclude open trade equity on derivatives cleared through central clearing counterparties. Any associated collateral exchanged with our central clearing counterparties are treated as settlements of the derivative exposure, rather than collateral. Such payments are recognized as settlements of the derivatives contracts in a receivable and payable position on our Consolidated Balance Sheet . Notional amounts are reference amounts from which contractual obligations are derived and are not recorded on the balance sheet. In our view, derivative notional is not an accurate measure of our derivative exposure when viewed in isolation from other factors, such as market rate fluctuations and counterparty credit risk. 2019 2018 Derivative contracts in a Notional amount Derivative contracts in a Notional amount December 31, ($ in millions) receivable position payable position receivable position payable position Derivatives designated as accounting hedges Interest rate contracts Swaps $ — $ — $ 17,101 $ — $ — $ 24,203 Purchased options 62 — 14,100 — — — Foreign exchange contracts Forwards — 3 157 1 — 136 Total derivatives designated as accounting hedges 62 3 31,358 1 — 24,339 Derivatives not designated as accounting hedges Interest rate contracts Futures and forwards — — 81 — — 11 Written options 2 — 522 — 37 6,793 Purchased options — — 416 37 — 6,742 Total interest rate risk 2 — 1,019 37 37 13,546 Foreign exchange contracts Futures and forwards — 2 112 3 — 181 Total foreign exchange risk — 2 112 3 — 181 Total derivatives not designated as accounting hedges 2 2 1,131 40 37 13,727 Total derivatives $ 64 $ 5 $ 32,489 $ 41 $ 37 $ 38,066
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following table presents amounts recorded on our Consolidated Balance Sheet related to cumulative basis adjustments for fair value hedges. December 31, ($ in millions) Carrying amount of the hedged items Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged items Total Discontinued (a) 2019 2018 2019 2018 2019 2018 Assets Available-for-sale securities (b) (c) $ 1,217 $ 1,485 $ 18 $ — $ 18 $ (5 ) Finance receivables and loans, net (d) 33,312 40,850 135 24 44 5 Liabilities Long-term debt $ 11,995 $ 13,001 $ 24 $ 67 $ 127 $ 67 (a) Represents the fair value hedging adjustment on qualifying hedges for which the hedging relationship was discontinued. This represents a subset of the amounts reported in the total hedging adjustment. (b) The carrying amount of hedged available-for-sale securities is presented above using amortized cost. Refer to Note 8 for a reconciliation of the amortized cost and fair value of available-for-sale securities. (c) Includes the amortized cost basis of closed portfolios used to designate hedging relationships in which the hedged item is the last layer expected to be remaining at the end of the hedging relationship. At December 31, 2019 , the amortized cost basis of the closed portfolios used in these hedging relationships was $230 million , the amount identified as the last of layer in the discontinued hedge relationship was $200 million , and the basis adjustment associated with the discontinued last-of-layer relationships was a $2 million asset, which was allocated across the entire remaining pool upon termination of the hedge relationship. There were no open last-of-layer relationships at December 31, 2019. At December 31, 2018 , the amortized cost basis of the closed portfolios used in these hedging relationships was $47 million , the amount identified as the last of layer in the hedge relationship was $28 million , and there was no basis adjustment associated with the last-of-layer relationships. (d) The hedged item represents the carrying value of the hedged portfolio of assets. The amount identified as the last of layer in the open hedge relationship was $10.2 billion as of December 31, 2019 , and $21.4 billion as of December 31, 2018 . The basis adjustment associated with the open last-of-layer relationship was a $91 million asset as of December 31, 2019 , and a $19 million asset as of December 31, 2018 , which would be allocated across the entire remaining closed pool upon termination or maturity of the hedge relationship. The amount that is identified as the last of layer in the discontinued hedge relationship was $12.8 billion at December 31, 2019 . The basis adjustment associated with the discontinued last-of-layer relationship was a $43 million asset as of December 31, 2019 , which was allocated across the entire remaining pool upon termination of the hedge relationship.
Schedule of Derivative Instruments Not Designated as Accounting Hedge	The following table summarizes the location and amounts of gains and losses on derivative instruments not designated as accounting hedges reported in our Consolidated Statement of Income . Year ended December 31, ($ in millions) 2019 2018 2017 Gain (loss) recognized in earnings Interest rate contracts Gain on mortgage and automotive loans, net $ 1 $ — $ 1 Other income, net of losses (11 ) — (3 ) Total interest rate contracts (10 ) — (2 ) Foreign exchange contracts Other income, net of losses — 13 (7 ) Other operating expenses (4 ) — — Total foreign exchange contracts (4 ) 13 (7 ) Total (loss) gain recognized in earnings $ (14 ) $ 13 $ (9 )
Schedule of Location and Amounts of Gains and Losses on Derivative Instruments	The following table summarizes the location and amounts of gains and losses on derivative instruments designated as fair value and cash flow hedges reported in our Consolidated Statement of Income . Interest and fees on finance receivables and loans Interest and dividends on investment securities and other earning assets Interest on deposits Interest on long-term debt Year ended December 31, ($ in millions) 2019 2018 2017 2019 2018 2017 2019 2018 2017 2019 2018 2017 Gain (loss) on fair value hedging relationships Interest rate contracts Hedged fixed-rate unsecured debt $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 41 $ 62 $ 8 Derivatives designated as hedging instruments on fixed-rate unsecured debt — — — — — — — — — (41 ) (61 ) (3 ) Hedged fixed-rate FHLB advances — — — — — — — — — — 47 22 Derivatives designated as hedging instruments on fixed-rate FHLB advances — — — — — — — — — — (47 ) (22 ) Hedged available-for-sale securities — — — 28 (3 ) (1 ) — — — — — — Derivatives designated as hedging instruments on available-for-sale securities — — — (28 ) 3 1 — — — — — — Hedged fixed-rate consumer automotive loans 138 19 (3 ) — — — — — — — — — Derivatives designated as hedging instruments on fixed-rate consumer automotive loans (138 ) (19 ) 1 — — — — — — — — — Total (loss) gain on fair value hedging relationships — — (2 ) — — — — — — — 1 5 (Loss) gain on cash flow hedging relationships Interest rate contracts Hedged deposit liabilities Reclassified from accumulated other comprehensive income into income — — — — — — (4 ) 1 — — — — Hedged variable-rate borrowings Reclassified from accumulated other comprehensive income into income — — — — — — — — — 15 1 — Total (loss) gain on cash flow hedging relationships $ — $ — $ — $ — $ — $ — $ (4 ) $ 1 $ — $ 15 $ 1 $ — Total amounts presented in the Consolidated Statement of Income $ 7,337 $ 6,688 $ 5,819 $ 955 $ 788 $ 599 $ 2,538 $ 1,735 $ 1,077 $ 1,570 $ 1,753 $ 1,653
Schedule of Derivative Instruments	The following table summarizes the location and amounts of gains and losses related to interest and amortization on derivative instruments designated as fair value and cash flow hedges reported in our Consolidated Statement of Income . Interest and fees on finance receivables and loans Interest and dividends on investment securities and other earning assets Interest on deposits Interest on long-term debt Year ended December 31, ($ in millions) 2019 2018 2017 2019 2018 2017 2019 2018 2017 2019 2018 2017 Gain (loss) on fair value hedging relationships Interest rate contracts Amortization of deferred unsecured debt basis adjustments $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 25 $ 51 $ 77 Interest for qualifying accounting hedges of unsecured debt — — — — — — — — — — 8 24 Amortization of deferred secured debt basis adjustments (FHLB advances) — — — — — — — — — (23 ) (17 ) (2 ) Interest for qualifying accounting hedges of secured debt (FHLB advances) — — — — — — — — — — 6 3 Amortization of deferred basis adjustments of available-for-sale securities — — — (3 ) — — — — — — — — Interest for qualifying accounting hedges of available-for-sale securities — — — 2 (1 ) — — — — — — — Amortization of deferred loan basis adjustments (28 ) (14 ) (21 ) — — — — — — — — — Interest for qualifying accounting hedges of consumer automotive loans held-for-investment 22 16 (1 ) — — — — — — — — — Total (loss) gain on fair value hedging relationships (6 ) 2 (22 ) (1 ) (1 ) — — — — 2 48 102 Gain (loss) on cash flow hedging relationships Interest rate contracts Interest for qualifying accounting hedges of variable-rate borrowings — — — — — — — — — — 8 (1 ) Interest for qualifying accounting hedges of deposit liabilities — — — — — — (1 ) 3 — — — — Interest for qualifying accounting hedges of variable-rate commercial loans 1 — — — — — — — — — — — Total gain (loss) on cash flow hedging relationships $ 1 $ — $ — $ — $ — $ — $ (1 ) $ 3 $ — $ — $ 8 $ (1 )
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The following table summarizes the effect of cash flow hedges on accumulated other comprehensive income (loss). Year ended December 31, ($ in millions) 2019 2018 2017 Interest rate contracts (Loss) gain recognized in other comprehensive income (loss) $ (23 ) $ 10 $ 5
Schedule of Net Investment Hedges in Accumulated Other Comprehensive Income (Loss)	The following table summarizes the effect of net investment hedges on accumulated other comprehensive income (loss) and the Consolidated Statement of Income . Year ended December 31, ($ in millions) 2019 2018 2017 Foreign exchange contracts (a) (b) (Loss) gain recognized in other comprehensive income (loss) $ (6 ) $ 12 $ (10 ) (a) There were no amounts excluded from effectiveness testing for the years ended December 31, 2019 , 2018 , or 2017 . (b) Gains and losses reclassified from accumulated other comprehensive income (loss) are reported as other income, net of losses, in the Consolidated Statement of Income . There were no amounts reclassified for the years ended December 31, 2019 , 2018 , or 2017 .

Income Taxes Income Taxes (Tabl

Income Taxes Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The significant components of income tax expense from continuing operations were as follows. Year ended December 31, ($ in millions) 2019 2018 2017 Current income tax (benefit) expense U.S. federal $ (2 ) $ (12 ) $ (17 ) Foreign 4 5 6 State and local 65 35 53 Total current expense 67 28 42 Deferred income tax expense (benefit) U.S. federal 178 328 566 Foreign 2 — — State and local (1 ) 3 (27 ) Total deferred expense 179 331 539 Total income tax expense from continuing operations $ 246 $ 359 $ 581
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of income tax expense from continuing operations with the amounts at the statutory U.S. federal income tax rate is shown in the following table. Year ended December 31, ($ in millions) 2019 2018 2017 Statutory U.S. federal tax expense (a) $ 413 $ 340 $ 527 Change in tax resulting from Valuation allowance change, excluding expirations (219 ) (8 ) (49 ) State and local income taxes, net of federal income tax benefit (b) 50 26 7 Nondeductible expenses 29 28 4 Tax credits, excluding expirations (27 ) (20 ) (12 ) Changes in unrecognized tax benefits 5 22 1 Tax law enactment (1 ) (23 ) 119 Other, net (4 ) (6 ) (16 ) Total income tax expense from continuing operations $ 246 $ 359 $ 581 (a) The statutory U.S. federal tax rate was 21% for both the years ended December 31, 2019 , and 2018 , and 35% for year ended December 31, 2017 . (b) Amount for 2017 includes state deferred tax adjustments primarily offset in the valuation allowance change caption.
Schedule of Deferred Tax Assets and Liabilities	The significant components of deferred tax assets and liabilities are reflected in the following table. December 31, ($ in millions) 2019 2018 Deferred tax assets Tax credit carryforwards $ 1,784 $ 1,796 Adjustments to loan value 448 366 State and local taxes 153 168 Unearned insurance premiums 98 90 Other 214 257 Gross deferred tax assets 2,697 2,677 Valuation allowance (837 ) (1,057 ) Deferred tax assets, net of valuation allowance 1,860 1,620 Deferred tax liabilities Lease transactions 1,325 850 Deferred acquisition costs 366 321 Debt transactions 91 93 Other 87 56 Gross deferred tax liabilities 1,869 1,320 Net deferred tax (liabilities) assets (a) $ (9 ) $ 300 (a) Amounts include $58 million and $317 million of net deferred tax assets included in other assets on our Consolidated Balance Sheet for tax jurisdictions in a total net deferred tax asset position at December 31, 2019 , and 2018 , respectively, and $67 million and $17 million included in accrued expenses and other liabilities on our Consolidated Balance Sheet for tax jurisdictions in a total net deferred tax liability position.
Schedule of Deferred Tax assets and Related Valuation Allowances	The following table summarizes net deferred tax assets including related valuation allowances at December 31, 2019 . ($ in millions) Deferred tax asset (liability) Valuation allowance Net deferred tax asset (liability) Years of expiration Tax credit carryforwards Foreign tax credits $ 1,433 $ (737 ) $ 696 2022–2029 General business credits 351 — 351 2025–2039 Total tax credit carryforwards 1,784 (737 ) 1,047 Tax loss carryforwards Net operating losses — federal 7 (a) — 7 2027–2036 Net operating losses — state 176 (b) (100 ) 76 2020–2039 Total federal and state tax loss carryforwards 183 (100 ) 83 Other net deferred tax liabilities (1,139 ) — (1,139 ) n/a Net deferred tax assets (liabilities) $ 828 $ (837 ) $ (9 ) (a) Federal net operating loss carryforwards are included in the other assets total disclosed in our deferred inventory table above. (b) State net operating loss carryforwards are included in the state and local taxes and other liabilities totals disclosed in our deferred inventory table above.
Schedule of Unrecognized Tax Benefits Roll Forward	The following table provides a reconciliation of the beginning and ending amount of unrecognized tax benefits. ($ in millions) 2019 2018 2017 Balance at January 1, $ 44 $ 15 $ 14 Additions based on tax positions related to the current year — — — Additions for tax positions of prior years 11 29 3 Reductions for tax positions of prior years (5 ) — (1 ) Settlements (2 ) — — Expiration of statute of limitations — — (1 ) Balance at December 31, $ 48 $ 44 $ 15

Share-based Compensation Plan_2

Share-based Compensation Plans Share-based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Share-based Compensation Arrangements by Share-based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block]	The following table presents the changes in outstanding non-vested PSUs and RSUs activity during 2019 . (in thousands, except per share data) Number of units Weighted-average grant date fair value per share RSUs and PSUs Outstanding non-vested at January 1, 2019 4,864 $ 23.71 Granted 3,007 26.29 Vested (3,411 ) 22.37 Forfeited (93 ) 26.28 Outstanding non-vested at December 31, 2019 4,367 26.48
Share-based Compensation Arrangements by Share-based Payment Award, Restricted Stock Units, Vested and Expected to Vest [Table Text Block]	The following table presents the changes in outstanding non-vested PSUs and RSUs activity during 2019 . (in thousands, except per share data) Number of units Weighted-average grant date fair value per share RSUs and PSUs Outstanding non-vested at January 1, 2019 4,864 $ 23.71 Granted 3,007 26.29 Vested (3,411 ) 22.37 Forfeited (93 ) 26.28 Outstanding non-vested at December 31, 2019 4,367 26.48

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on a Recurring Basis	The following tables display the assets and liabilities measured at fair value on a recurring basis including financial instruments elected for the fair value option. We often economically hedge the fair value change of our assets or liabilities with derivatives and other financial instruments. The tables below display the hedges separately from the hedged items; therefore, they do not directly display the impact of our risk-management activities. Recurring fair value measurements December 31, 2019 ($ in millions) Level 1 Level 2 Level 3 Total Assets Investment securities Equity securities (a) $ 608 $ — $ 8 $ 616 Available-for-sale securities Debt securities U.S. Treasury and federal agencies 2,047 1 — 2,048 U.S. States and political subdivisions — 639 2 641 Foreign government 15 171 — 186 Agency mortgage-backed residential — 21,404 — 21,404 Mortgage-backed residential — 2,850 — 2,850 Agency mortgage-backed commercial — 1,382 — 1,382 Mortgage-backed commercial — 42 — 42 Asset-backed — 368 — 368 Corporate debt — 1,363 — 1,363 Total available-for-sale securities 2,062 28,220 2 30,284 Mortgage loans held-for-sale (b) — — 30 30 Finance receivables and loans, net Consumer other (b) — — 11 11 Interests retained in financial asset sales — — 2 2 Derivative contracts in a receivable position Interest rate — 62 2 64 Total derivative contracts in a receivable position — 62 2 64 Total assets $ 2,670 $ 28,282 $ 55 $ 31,007 Liabilities Accrued expenses and other liabilities Derivative contracts in a payable position Foreign currency $ — $ 5 $ — $ 5 Total derivative contracts in a payable position — 5 — 5 Total liabilities $ — $ 5 $ — $ 5 (a) Our investment in any one industry did not exceed 13% . (b) Carried at fair value due to fair value option elections. Recurring fair value measurements December 31, 2018 ($ in millions) Level 1 Level 2 Level 3 Total Assets Investment securities Equity securities (a) $ 766 $ — $ 7 $ 773 Available-for-sale securities Debt securities U.S. Treasury and federal agencies 1,850 1 — 1,851 U.S. States and political subdivisions — 802 — 802 Foreign government 7 138 — 145 Agency mortgage-backed residential — 17,138 — 17,138 Mortgage-backed residential — 2,686 — 2,686 Agency mortgage-backed commercial — 3 — 3 Mortgage-backed commercial — 714 — 714 Asset-backed — 723 — 723 Corporate debt — 1,241 — 1,241 Total available-for-sale securities 1,857 23,446 — 25,303 Mortgage loans held-for-sale (b) — — 8 8 Interests retained in financial asset sales — — 4 4 Derivative contracts in a receivable position Interest rate — 37 — 37 Foreign currency — 4 — 4 Total derivative contracts in a receivable position — 41 — 41 Total assets $ 2,623 $ 23,487 $ 19 $ 26,129 Liabilities Accrued expenses and other liabilities Derivative contracts in a payable position Interest rate $ — $ 37 $ — $ 37 Total derivative contracts in a payable position — 37 — 37 Total liabilities $ — $ 37 $ — $ 37 (a) Our investment in any one industry did not exceed 9% . (b) Carried at fair value due to fair value option elections.
Fair Value, Assets Measured on a Recurring Basis, Unobservable Input Reconciliation	The following tables present the reconciliation for all Level 3 assets and liabilities measured at fair value on a recurring basis. There were no transfers into or out of Level 3 in the periods presented. We often economically hedge the fair value change of our assets or liabilities with derivatives and other financial instruments. The Level 3 items presented below may be hedged by derivatives and other financial instruments that are classified as Level 1 or Level 2. Thus, the following tables do not fully reflect the impact of our risk-management activities. Level 3 recurring fair value measurements Net realized/unrealized gains Fair value at Dec. 31, 2019 Net unrealized gains still held at December 31, 2019 ($ in millions) Fair value at Jan. 1, 2019 included in earnings included in OCI Purchases Sales Issuances Settlements included in earnings included in OCI Assets Investment securities Equity securities $ 7 $ 5 (a) $ — $ — $ — $ — $ (4 ) $ 8 $ 5 $ — Available-for-sale securities — — — 2 — — — 2 — — Mortgage loans held-for-sale (b) 8 12 (c) — 742 (732 ) — — 30 — — Finance receivables and loans, net (b) — 1 (d) — 15 — — (5 ) 11 — — Other assets Interests retained in financial asset sales 4 — — — — — (2 ) 2 — — Derivative assets, net of derivative liabilities — 2 (c) — — — — — 2 2 — Total assets $ 19 $ 20 $ — $ 759 $ (732 ) $ — $ (11 ) $ 55 $ 7 $ — (a) Reported as other gain on investments, net, in the Consolidated Statement of Income . (b) Carried at fair value due to fair value option elections. (c) Reported as gain on mortgage and automotive loans, net, in the Consolidated Statement of Income . (d) Reported as interest and fees on finance receivables and loans in the Consolidated Statement of Income . Level 3 recurring fair value measurements Fair value at Jan. 1, 2018 Net realized/unrealized (losses) gains Purchases Sales Issuances Settlements Fair value at Dec. 31, 2018 Net unrealized losses still held at December 31, 2018 ($ in millions) included in earnings included in OCI included in earnings included in OCI Assets Equity securities $ 19 $ (7 ) (a) $ — $ — $ — $ — $ (5 ) $ 7 $ (10 ) $ — Mortgage loans held-for-sale (b) 13 5 (c) — 303 (313 ) — — 8 — — Other assets Interests retained in financial asset sales 5 — — — — — (1 ) 4 — — Derivative assets 1 (1 ) (c) — — — — — — — — Total assets $ 38 $ (3 ) $ — $ 303 $ (313 ) $ — $ (6 ) $ 19 $ (10 ) $ — (a) Reported as other gain on investments, net, in the Consolidated Statement of Income . (b) Carried at fair value due to fair value option elections. (c) Reported as gain on mortgage and automotive loans, net, in the Consolidated Statement of Income .
Fair Value Measurements - Nonrecurring Basis	The following tables display assets and liabilities measured at fair value on a nonrecurring basis and still held at December 31, 2019 , and December 31, 2018 , respectively. The amounts are as of the end of each period presented, which approximate the fair value measurements that occurred during each period. Nonrecurring fair value measurements Lower-of-cost or fair value reserve, valuation reserve, or cumulative adjustments Total gain (loss) included in earnings December 31, 2019 ($ in millions) Level 1 Level 2 Level 3 Total Assets Loans held-for-sale, net $ — $ — $ 128 $ 128 $ — n/m (a) Commercial finance receivables and loans, net (b) Automotive — — 64 64 (12 ) n/m (a) Other — — 45 45 (21 ) n/m (a) Total commercial finance receivables and loans, net — — 109 109 (33 ) n/m (a) Other assets Nonmarketable equity investments — 5 7 12 — n/m (a) Equity-method investments — — 4 4 (6 ) n/m (a) Repossessed and foreclosed assets (c) — — 12 12 (1 ) n/m (a) Total assets $ — $ 5 $ 260 $ 265 $ (40 ) n/m n/m = not meaningful (a) We consider the applicable valuation allowance, loan loss allowance, or cumulative impairment to be the most relevant indicator of the impact on earnings caused by the fair value measurement. Accordingly, the table above excludes total gains and losses included in earnings for these items. The carrying values are inclusive of the respective valuation allowance, loan loss allowance, or cumulative impairment. (b) Represents the portion of the portfolio specifically impaired during 2019 . The related valuation allowance represents the cumulative adjustment to fair value of those specific receivables. (c) The allowance provided for repossessed and foreclosed assets represents any cumulative valuation adjustment recognized to adjust the assets to fair value. Nonrecurring fair value measurements Lower-of-cost or fair value reserve, valuation reserve, or cumulative adjustments Total gain (loss) included in earnings December 31, 2018 ($ in millions) Level 1 Level 2 Level 3 Total Assets Loans held-for-sale, net Automotive (a) $ — $ — $ 210 $ 210 $ (2 ) n/m (b) Other — — 96 96 — n/m (b) Total loans held-for-sale, net — — 306 306 (2 ) n/m (b) Commercial finance receivables and loans, net (c) Automotive — — 84 84 (10 ) n/m (b) Other — — 55 55 (46 ) n/m (b) Total commercial finance receivables and loans, net — — 139 139 (56 ) n/m (b) Other assets Nonmarketable equity investments — — 1 1 (1 ) n/m (b) Equity-method investments — — 3 3 — n/m (b) Repossessed and foreclosed assets (d) — — 13 13 (1 ) n/m (b) Total assets $ — $ — $ 462 $ 462 $ (60 ) n/m n/m = not meaningful (a) Represents loans within our commercial automotive portfolio. Of this amount, $104 million was valued based upon a sales price for a transaction that closed in January 2019, and $106 million was valued using a discounted cash flow analysis, with a spread over forward interest rates as a significant unobservable input utilizing a range of 0.08 – 1.09% and weighted average of 0.72% . (b) We consider the applicable valuation allowance, loan loss allowance, or cumulative impairment to be the most relevant indicator of the impact on earnings caused by the fair value measurement. Accordingly, the table above excludes total gains and losses included in earnings for these items. The carrying values are inclusive of the respective valuation allowance, loan loss allowance, or cumulative impairment. (c) Represents the portion of the portfolio specifically impaired during 2018 . The related valuation allowance represents the cumulative adjustment to fair value of those specific receivables. (d) The allowance provided for repossessed and foreclosed assets represents any cumulative valuation adjustment recognized to adjust the assets to fair value.
Financial Instruments Disclosure	The following table presents the carrying and estimated fair value of financial instruments, except for those recorded at fair value on a recurring basis presented in the previous section of this note titled Recurring Fair Value. When possible, we use quoted market prices to determine fair value. Where quoted market prices are not available, the fair value is internally derived based on appropriate valuation methodologies with respect to the amount and timing of future cash flows and estimated discount rates. However, considerable judgment is required in interpreting current market data to develop the market assumptions and inputs necessary to estimate fair value. As such, the actual amount received to sell an asset or the amount paid to settle a liability could differ from our estimates. Fair value information presented herein was based on information available at December 31, 2019 , and December 31, 2018 . Estimated fair value ($ in millions) Carrying value Level 1 Level 2 Level 3 Total December 31, 2019 Financial assets Held-to-maturity securities $ 1,568 $ — $ 1,600 $ — $ 1,600 Loans held-for-sale, net 128 — — 128 128 Finance receivables and loans, net 126,957 — — 130,837 130,837 FHLB/FRB stock (a) 1,150 — 1,150 — 1,150 Financial liabilities Deposit liabilities $ 60,146 $ — $ — $ 60,678 $ 60,678 Short-term borrowings 5,531 — — 5,532 5,532 Long-term debt 34,027 — 22,789 14,138 36,927 December 31, 2018 Financial assets Held-to-maturity securities $ 2,362 $ — $ 2,307 $ — $ 2,307 Loans held-for-sale, net 306 — — 306 306 Finance receivables and loans, net 128,684 — — 130,878 130,878 FHLB/FRB stock (a) 1,351 — 1,351 — 1,351 Financial liabilities Deposit liabilities $ 51,985 $ — $ — $ 51,997 $ 51,997 Short-term borrowings 9,987 — — 9,992 9,992 Long-term debt 44,193 — 23,846 21,800 45,646 (a) Included in other assets on our Consolidated Balance Sheet .

Offsetting Assets and Liabili_2

Offsetting Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Offsetting [Abstract]
Offsetting Assets	The composition of offsetting derivative instruments, financial assets, and financial liabilities was as follows. Gross amounts of recognized assets/liabilities Gross amounts offset on the Consolidated Balance Sheet Net amounts of assets/liabilities presented on the Consolidated Balance Sheet Gross amounts not offset on the Consolidated Balance Sheet December 31, ($ in millions) Financial instruments Collateral (a) (b) (c) Net amount 2019 Assets Derivative assets in net asset positions (d) $ 62 $ — $ 62 $ — $ (36 ) $ 26 Derivative assets with no offsetting arrangements 2 — 2 — — 2 Total assets $ 64 $ — $ 64 $ — $ (36 ) $ 28 Liabilities Derivative liabilities in net liability positions (d) $ 5 $ — $ 5 $ — $ (4 ) $ 1 Total liabilities $ 5 $ — $ 5 $ — $ (4 ) $ 1 2018 Assets Derivative assets in net asset positions $ 41 $ — $ 41 $ — $ (4 ) $ 37 Total assets (d) $ 41 $ — $ 41 $ — $ (4 ) $ 37 Liabilities Derivative liabilities in net liability positions (d) $ 37 $ — $ 37 $ — $ — $ 37 Securities sold under agreements to repurchase (e) 685 — 685 — (685 ) — Total liabilities $ 722 $ — $ 722 $ — $ (685 ) $ 37 (a) Financial collateral received/pledged shown as a balance based on the sum of all net asset and liability positions between Ally and each individual derivative counterparty. (b) Amounts disclosed are limited to the financial asset or liability balance and, accordingly, exclude excess collateral received or pledged and noncash collateral received. There was $29 million and $3 million of noncash derivative collateral pledged to us that was excluded at December 31, 2019 , and 2018 , respectively, and $4 million of noncash collateral associated with our repurchase agreements pledged to us that was excluded at December 31, 2018 . We do not record such collateral received on our Consolidated Balance Sheet unless certain conditions are met. (c) Certain agreements grant us the right to sell or pledge the noncash assets we receive as collateral. Noncash collateral pledged to us where the agreement grants us the right to sell or pledge the underlying assets had a fair value of $29 million and $7 million at December 31, 2019 , and 2018 , respectively. We have not sold or pledged any of the noncash collateral received under these agreements as of both December 31, 2019 , and December 31, 2018 . (d) For additional information on derivative instruments and hedging activities, refer to Note 21 . (e) For additional information on securities sold under agreements to repurchase, refer to Note 15 .
Offsetting Liabilities	The composition of offsetting derivative instruments, financial assets, and financial liabilities was as follows. Gross amounts of recognized assets/liabilities Gross amounts offset on the Consolidated Balance Sheet Net amounts of assets/liabilities presented on the Consolidated Balance Sheet Gross amounts not offset on the Consolidated Balance Sheet December 31, ($ in millions) Financial instruments Collateral (a) (b) (c) Net amount 2019 Assets Derivative assets in net asset positions (d) $ 62 $ — $ 62 $ — $ (36 ) $ 26 Derivative assets with no offsetting arrangements 2 — 2 — — 2 Total assets $ 64 $ — $ 64 $ — $ (36 ) $ 28 Liabilities Derivative liabilities in net liability positions (d) $ 5 $ — $ 5 $ — $ (4 ) $ 1 Total liabilities $ 5 $ — $ 5 $ — $ (4 ) $ 1 2018 Assets Derivative assets in net asset positions $ 41 $ — $ 41 $ — $ (4 ) $ 37 Total assets (d) $ 41 $ — $ 41 $ — $ (4 ) $ 37 Liabilities Derivative liabilities in net liability positions (d) $ 37 $ — $ 37 $ — $ — $ 37 Securities sold under agreements to repurchase (e) 685 — 685 — (685 ) — Total liabilities $ 722 $ — $ 722 $ — $ (685 ) $ 37 (a) Financial collateral received/pledged shown as a balance based on the sum of all net asset and liability positions between Ally and each individual derivative counterparty. (b) Amounts disclosed are limited to the financial asset or liability balance and, accordingly, exclude excess collateral received or pledged and noncash collateral received. There was $29 million and $3 million of noncash derivative collateral pledged to us that was excluded at December 31, 2019 , and 2018 , respectively, and $4 million of noncash collateral associated with our repurchase agreements pledged to us that was excluded at December 31, 2018 . We do not record such collateral received on our Consolidated Balance Sheet unless certain conditions are met. (c) Certain agreements grant us the right to sell or pledge the noncash assets we receive as collateral. Noncash collateral pledged to us where the agreement grants us the right to sell or pledge the underlying assets had a fair value of $29 million and $7 million at December 31, 2019 , and 2018 , respectively. We have not sold or pledged any of the noncash collateral received under these agreements as of both December 31, 2019 , and December 31, 2018 . (d) For additional information on derivative instruments and hedging activities, refer to Note 21 . (e) For additional information on securities sold under agreements to repurchase, refer to Note 15 .

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Financial information for our reportable operating segments is summarized as follows. Year ended December 31, ($ in millions) Automotive Finance operations Insurance operations Mortgage Finance operations Corporate Finance operations Corporate and Other Consolidated (a) 2019 Net financing revenue and other interest income $ 4,141 $ 54 $ 171 $ 239 $ 28 $ 4,633 Other revenue 249 1,274 22 45 171 1,761 Total net revenue 4,390 1,328 193 284 199 6,394 Provision for loan losses 962 — 5 36 (5 ) 998 Total noninterest expense 1,810 1,013 148 95 363 3,429 Income (loss) from continuing operations before income tax expense $ 1,618 $ 315 $ 40 $ 153 $ (159 ) $ 1,967 Total assets $ 113,863 $ 8,547 $ 16,279 $ 5,787 $ 36,168 $ 180,644 2018 Net financing revenue and other interest income $ 3,769 $ 54 $ 179 $ 204 $ 184 $ 4,390 Other revenue 269 981 7 38 119 1,414 Total net revenue 4,038 1,035 186 242 303 5,804 Provision for loan losses 920 — 1 12 (15 ) 918 Total noninterest expense 1,750 955 140 86 333 3,264 Income (loss) from continuing operations before income tax expense $ 1,368 $ 80 $ 45 $ 144 $ (15 ) $ 1,622 Total assets $ 117,304 $ 7,734 $ 15,211 $ 4,670 $ 33,950 $ 178,869 2017 Net financing revenue and other interest income $ 3,713 $ 59 $ 132 $ 167 $ 150 $ 4,221 Other revenue 355 1,059 4 45 81 1,544 Total net revenue 4,068 1,118 136 212 231 5,765 Provision for loan losses 1,134 — 8 22 (16 ) 1,148 Total noninterest expense 1,714 950 108 76 262 3,110 Income (loss) from continuing operations before income tax expense $ 1,220 $ 168 $ 20 $ 114 $ (15 ) $ 1,507 Total assets $ 114,089 $ 7,464 $ 11,708 $ 3,979 $ 29,908 $ 167,148 (a) Net financing revenue and other interest income after the provision for loan losses totaled $3.6 billion , $3.5 billion , and $3.1 billion for the years ended December 31, 2019 , 2018 , and 2017 , respectively.

Parent and Guarantor Condense_2

Parent and Guarantor Condensed Consolidating Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Income Statement	Condensed Consolidating Statements of Comprehensive Income Year ended December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Financing revenue and other interest income Interest and fees on finance receivables and loans $ (225 ) $ — $ 7,570 $ (8 ) $ 7,337 Interest and fees on finance receivables and loans — intercompany 11 6 (17 ) — Interest on loans held-for-sale — 17 — 17 Interest and dividends on investment securities and other earning assets — — 955 — 955 Interest on cash and cash equivalents 10 — 68 — 78 Interest on cash and cash equivalents — intercompany 14 — 17 (31 ) — Operating leases 2 — 1,468 — 1,470 Total financing (loss) revenue and other interest income (188 ) — 10,101 (56 ) 9,857 Interest expense Interest on deposits — — 2,538 — 2,538 Interest on short-term borrowings 53 — 82 — 135 Interest on long-term debt 849 — 721 — 1,570 Interest on intercompany debt 23 — 25 (48 ) — Total interest expense 925 — 3,366 (48 ) 4,243 Net depreciation expense on operating lease assets 3 — 978 — 981 Net financing (loss) revenue and other interest income (1,116 ) — 5,757 (8 ) 4,633 Cash dividends from subsidiaries Bank subsidiary 1,950 1,950 — (3,900 ) — Nonbank subsidiaries 436 — — (436 ) — Other revenue Insurance premiums and service revenue earned — — 1,087 — 1,087 Gain on mortgage and automotive loans, net 4 — 24 — 28 Other gain on investments, net 2 — 241 — 243 Other income, net of losses 337 — 611 (545 ) 403 Total other revenue 343 — 1,963 (545 ) 1,761 Total net revenue 1,613 1,950 7,720 (4,889 ) 6,394 Provision for loan losses 35 — 981 (18 ) 998 Noninterest expense Compensation and benefits expense 36 — 1,186 — 1,222 Insurance losses and loss adjustment expenses — — 321 — 321 Other operating expenses 590 — 1,841 (545 ) 1,886 Total noninterest expense 626 — 3,348 (545 ) 3,429 Income from continuing operations before income tax expense and undistributed income of subsidiaries 952 1,950 3,391 (4,326 ) 1,967 Income tax (benefit) expense from continuing operations (566 ) — 812 — 246 Net income from continuing operations 1,518 1,950 2,579 (4,326 ) 1,721 Loss from discontinued operations, net of tax (6 ) — — — (6 ) Undistributed income of subsidiaries Bank subsidiary 210 210 — (420 ) — Nonbank subsidiaries (7 ) — — 7 — Net income 1,715 2,160 2,579 (4,739 ) 1,715 Other comprehensive income, net of tax 654 492 685 (1,177 ) 654 Comprehensive income $ 2,369 $ 2,652 $ 3,264 $ (5,916 ) $ 2,369 Year ended December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Financing revenue and other interest income Interest and fees on finance receivables and loans $ (40 ) $ — $ 6,728 $ — $ 6,688 Interest and fees on finance receivables and loans — intercompany 12 — 5 (17 ) — Interest on loans held-for-sale — — 15 — 15 Interest and dividends on investment securities and other earning assets — — 789 (1 ) 788 Interest on cash and cash equivalents 8 — 64 — 72 Interest on cash and cash equivalents — intercompany 8 — 9 (17 ) — Operating leases 5 — 1,484 — 1,489 Total financing (loss) revenue and other interest income (7 ) — 9,094 (35 ) 9,052 Interest expense Interest on deposits — — 1,735 — 1,735 Interest on short-term borrowings 44 — 105 — 149 Interest on long-term debt 1,009 — 744 — 1,753 Interest on intercompany debt 15 — 20 (35 ) — Total interest expense 1,068 — 2,604 (35 ) 3,637 Net depreciation expense on operating lease assets 8 — 1,017 — 1,025 Net financing (loss) revenue and other interest income (1,083 ) — 5,473 — 4,390 Cash dividends from subsidiaries Bank subsidiary 2,600 2,600 — (5,200 ) — Nonbank subsidiaries 443 — — (443 ) — Other revenue Insurance premiums and service revenue earned — — 1,022 — 1,022 Gain on mortgage and automotive loans, net 70 — 9 (54 ) 25 Other loss on investments, net — — (50 ) — (50 ) Other income, net of losses 411 — 770 (764 ) 417 Total other revenue 481 — 1,751 (818 ) 1,414 Total net revenue 2,441 2,600 7,224 (6,461 ) 5,804 Provision for loan losses 176 — 796 (54 ) 918 Noninterest expense Compensation and benefits expense 83 — 1,072 — 1,155 Insurance losses and loss adjustment expenses — — 295 — 295 Other operating expenses 681 — 1,897 (764 ) 1,814 Total noninterest expense 764 — 3,264 (764 ) 3,264 Income from continuing operations before income tax (benefit) expense and undistributed (loss) income of subsidiaries 1,501 2,600 3,164 (5,643 ) 1,622 Income tax (benefit) expense from continuing operations (300 ) — 659 — 359 Net income from continuing operations 1,801 2,600 2,505 (5,643 ) 1,263 (Loss) income from discontinued operations, net of tax (2 ) — 2 — — Undistributed (loss) income of subsidiaries Bank subsidiary (614 ) (614 ) — 1,228 — Nonbank subsidiaries 78 — — (78 ) — Net income 1,263 1,986 2,507 (4,493 ) 1,263 Other comprehensive loss, net of tax (289 ) (243 ) (308 ) 551 (289 ) Comprehensive income $ 974 $ 1,743 $ 2,199 $ (3,942 ) $ 974 Year ended December 31, 2017 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Financing revenue and other interest income Interest and fees on finance receivables and loans $ (27 ) $ — $ 5,846 $ — $ 5,819 Interest and fees on finance receivables and loans — intercompany 12 — 6 (18 ) — Interest and dividends on investment securities and other earning assets — — 601 (2 ) 599 Interest on cash and cash equivalents 7 — 30 — 37 Interest on cash and cash equivalents — intercompany 4 — 7 (11 ) — Operating leases 11 — 1,856 — 1,867 Total financing revenue and other interest income 7 — 8,346 (31 ) 8,322 Interest expense Interest on deposits 3 — 1,078 (4 ) 1,077 Interest on short-term borrowings 60 — 67 — 127 Interest on long-term debt 1,101 — 552 — 1,653 Interest on intercompany debt 15 — 12 (27 ) — Total interest expense 1,179 — 1,709 (31 ) 2,857 Net depreciation expense on operating lease assets 11 — 1,233 — 1,244 Net financing (loss) revenue and other interest income (1,183 ) — 5,404 — 4,221 Cash dividends from subsidiaries Bank subsidiary 3,300 3,300 — (6,600 ) — Nonbank subsidiaries 752 — — (752 ) — Other revenue Insurance premiums and service revenue earned — — 973 — 973 Gain on mortgage and automotive loans, net 40 — 28 — 68 Other gain on investments, net — — 102 — 102 Other income, net of losses 675 — 834 (1,108 ) 401 Total other revenue 715 — 1,937 (1,108 ) 1,544 Total net revenue 3,584 3,300 7,341 (8,460 ) 5,765 Provision for loan losses 465 — 683 — 1,148 Noninterest expense Compensation and benefits expense 180 — 915 — 1,095 Insurance losses and loss adjustment expenses — — 332 — 332 Other operating expenses 899 — 1,892 (1,108 ) 1,683 Total noninterest expense 1,079 — 3,139 (1,108 ) 3,110 Income from continuing operations before income tax expense and undistributed (loss) income of subsidiaries 2,040 3,300 3,519 (7,352 ) 1,507 Income tax expense from continuing operations 337 — 244 — 581 Net income from continuing operations 1,703 3,300 3,275 (7,352 ) 926 Income (loss) from discontinued operations, net of tax 7 — (4 ) — 3 Undistributed (loss) income of subsidiaries Bank subsidiary (1,168 ) (1,168 ) — 2,336 — Nonbank subsidiaries 387 — — (387 ) — Net income 929 2,132 3,271 (5,403 ) 929 Other comprehensive income, net of tax 106 65 104 (169 ) 106 Comprehensive income $ 1,035 $ 2,197 $ 3,375 $ (5,572 ) $ 1,035
Condensed Balance Sheet	Condensed Consolidating Balance Sheet December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Assets Cash and cash equivalents Noninterest-bearing $ 49 $ — $ 570 $ — $ 619 Interest-bearing 5 — 2,931 — 2,936 Interest-bearing — intercompany 2,051 — 1,087 (3,138 ) — Total cash and cash equivalents 2,105 — 4,588 (3,138 ) 3,555 Equity securities — — 616 — 616 Available-for-sale securities — — 30,284 — 30,284 Held-to-maturity securities — — 1,578 (10 ) 1,568 Loans held-for-sale, net — — 158 — 158 Finance receivables and loans, net Finance receivables and loans, net 2,167 — 126,054 10 128,231 Intercompany loans to Nonbank subsidiaries 161 — 110 (271 ) — Allowance for loan losses (22 ) — (1,241 ) — (1,263 ) Total finance receivables and loans, net 2,306 — 124,923 (261 ) 126,968 Investment in operating leases, net 1 — 8,863 — 8,864 Intercompany receivables from Bank subsidiary 94 — — (94 ) — Nonbank subsidiaries 50 — 77 (127 ) — Investment in subsidiaries Bank subsidiary 16,954 16,954 — (33,908 ) — Nonbank subsidiaries 6,535 — — (6,535 ) — Premiums receivable and other insurance assets — — 2,558 — 2,558 Other assets 2,193 — 5,690 (1,810 ) 6,073 Total assets $ 30,238 $ 16,954 $ 179,335 $ (45,883 ) $ 180,644 Liabilities and equity Deposit liabilities Noninterest-bearing $ — $ — $ 119 $ — $ 119 Interest-bearing 1 — 120,632 — 120,633 Interest-bearing — intercompany — — 2,051 (2,051 ) — Total deposit liabilities 1 — 122,802 (2,051 ) 120,752 Short-term borrowings 2,581 — 2,950 — 5,531 Long-term debt 11,389 — 22,638 — 34,027 Intercompany debt to Bank subsidiary 10 — — (10 ) — Nonbank subsidiaries 1,197 — 161 (1,358 ) — Intercompany payables to Bank subsidiary 18 — — (18 ) — Nonbank subsidiaries 98 — 133 (231 ) — Interest payable 145 — 496 — 641 Unearned insurance premiums and service revenue — — 3,305 — 3,305 Accrued expenses and other liabilities 383 — 3,371 (1,782 ) 1,972 Total liabilities 15,822 — 155,856 (5,450 ) 166,228 Total equity 14,416 16,954 23,479 (40,433 ) 14,416 Total liabilities and equity $ 30,238 $ 16,954 $ 179,335 $ (45,883 ) $ 180,644 December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Assets Cash and cash equivalents Noninterest-bearing $ 55 $ — $ 755 $ — $ 810 Interest-bearing 5 — 3,722 — 3,727 Interest-bearing — intercompany 1,249 — 521 (1,770 ) — Total cash and cash equivalents 1,309 — 4,998 (1,770 ) 4,537 Equity securities — — 773 — 773 Available-for-sale securities — — 25,303 — 25,303 Held-to-maturity securities — — 2,382 (20 ) 2,362 Loans held-for-sale, net — — 314 — 314 Finance receivables and loans, net Finance receivables and loans, net 2,349 — 127,577 — 129,926 Intercompany loans to Nonbank subsidiaries 882 — 397 (1,279 ) — Allowance for loan losses (55 ) — (1,187 ) — (1,242 ) Total finance receivables and loans, net 3,176 — 126,787 (1,279 ) 128,684 Investment in operating leases, net 5 — 8,412 — 8,417 Intercompany receivables from Bank subsidiary 158 — — (158 ) — Nonbank subsidiaries 45 — 129 (174 ) — Investment in subsidiaries Bank subsidiary 16,213 16,213 — (32,426 ) — Nonbank subsidiaries 6,928 — — (6,928 ) — Premiums receivable and other insurance assets — — 2,326 — 2,326 Other assets 2,226 — 5,453 (1,526 ) 6,153 Total assets $ 30,060 $ 16,213 $ 176,877 $ (44,281 ) $ 178,869 Liabilities and equity Deposit liabilities Noninterest-bearing $ — $ — $ 142 $ — $ 142 Interest-bearing 1 — 106,035 — 106,036 Interest-bearing — intercompany — — 1,249 (1,249 ) — Total deposit liabilities 1 — 107,426 (1,249 ) 106,178 Short-term borrowings 2,477 — 7,510 — 9,987 Long-term debt 12,774 — 31,419 — 44,193 Intercompany debt to Bank subsidiary 20 — — (20 ) — Nonbank subsidiaries 918 — 882 (1,800 ) — Intercompany payables to Bank subsidiary 45 — — (45 ) — Nonbank subsidiaries 124 — 129 (253 ) — Interest payable 159 — 364 — 523 Unearned insurance premiums and service revenue — — 3,044 — 3,044 Accrued expenses and other liabilities 274 — 2,962 (1,560 ) 1,676 Total liabilities 16,792 — 153,736 (4,927 ) 165,601 Total equity 13,268 16,213 23,141 (39,354 ) 13,268 Total liabilities and equity $ 30,060 $ 16,213 $ 176,877 $ (44,281 ) $ 178,869
Condensed Cash Flow Statement	Condensed Consolidating Statement of Cash Flows Year ended December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Operating activities Net cash provided by operating activities $ 1,818 $ 1,950 $ 4,628 $ (4,346 ) $ 4,050 Investing activities Purchases of equity securities — — (498 ) — (498 ) Proceeds from sales of equity securities — — 814 — 814 Purchases of available-for-sale securities — — (15,199 ) — (15,199 ) Proceeds from sales of available-for-sale securities — — 7,079 — 7,079 Proceeds from repayments of available-for-sale securities — — 5,154 — 5,154 Purchases of held-to-maturity securities — — (514 ) — (514 ) Proceeds from repayments of held-to-maturity securities — — 302 — 302 Net change in investment securities — intercompany — — 10 (10 ) — Purchases of finance receivables and loans held-for-investment — — (4,974 ) 535 (4,439 ) Proceeds from sales of finance receivables and loans initially held-for-investment 548 — 1,025 (535 ) 1,038 Originations and repayments of finance receivables and loans held-for-investment and other, net (253 ) — 4,497 8 4,252 Net change in loans — intercompany 718 — 284 (1,002 ) — Purchases of operating lease assets — — (4,023 ) — (4,023 ) Disposals of operating lease assets 3 — 2,622 — 2,625 Acquisitions, net of cash acquired — — (171 ) — (171 ) Capital contributions to subsidiaries (2 ) — — 2 — Returns of contributed capital 259 — — (259 ) — Net change in nonmarketable equity investments (13 ) — 203 — 190 Other, net (4 ) — (375 ) — (379 ) Net cash provided by (used in) investing activities 1,256 — (3,764 ) (1,261 ) (3,769 ) Financing activities Net change in short-term borrowings — third party 104 — (4,560 ) — (4,456 ) Net increase in deposits — — 15,349 (802 ) 14,547 Proceeds from issuance of long-term debt — third party 801 — 6,114 — 6,915 Repayments of long-term debt — third party (2,173 ) — (15,051 ) — (17,224 ) Net change in debt — intercompany 271 — (718 ) 447 — Repurchase of common stock (1,039 ) — — — (1,039 ) Dividends paid — third party (273 ) — — — (273 ) Dividends paid and returns of contributed capital — intercompany — (1,950 ) (2,646 ) 4,596 — Capital contributions from parent — — 2 (2 ) — Net cash used in financing activities (2,309 ) (1,950 ) (1,510 ) 4,239 (1,530 ) Effect of exchange-rate changes on cash and cash equivalents and restricted cash — — 3 — 3 Net increase (decrease) in cash and cash equivalents and restricted cash 765 — (643 ) (1,368 ) (1,246 ) Cash and cash equivalents and restricted cash at beginning of year 1,398 — 5,998 (1,770 ) 5,626 Cash and cash equivalents and restricted cash at end of year $ 2,163 $ — $ 5,355 $ (3,138 ) $ 4,380 The following table provides a reconciliation of cash and cash equivalents and restricted cash from the Condensed Consolidating Balance Sheet to the Condensed Consolidating Statement of Cash Flows. December 31, 2019 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Cash and cash equivalents on the Condensed Consolidating Balance Sheet $ 2,105 $ — $ 4,588 $ (3,138 ) $ 3,555 Restricted cash included in other assets on the Condensed Consolidating Balance Sheet (a) 58 — 767 — 825 Total cash and cash equivalents and restricted cash in the Condensed Consolidating Statement of Cash Flows $ 2,163 $ — $ 5,355 $ (3,138 ) $ 4,380 (a) Restricted cash balances relate primarily to Ally securitization arrangements. Refer to Note 13 for additional details describing the nature of restricted cash balances. Year ended December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Operating activities Net cash provided by operating activities $ 1,659 $ 2,600 $ 5,536 $ (5,645 ) $ 4,150 Investing activities Purchases of equity securities — — (1,076 ) — (1,076 ) Proceeds from sales of equity securities — — 787 — 787 Purchases of available-for-sale securities — — (7,868 ) — (7,868 ) Proceeds from sales of available-for-sale securities — — 852 — 852 Proceeds from repayments of available-for-sale securities — — 3,215 — 3,215 Purchases of held-to-maturity securities — — (578 ) — (578 ) Proceeds from repayments of held-to-maturity securities — — 147 — 147 Net change in investment securities — intercompany — — 54 (54 ) — Purchases of finance receivables and loans held-for-investment (131 ) — (7,101 ) 1,539 (5,693 ) Proceeds from sales of finance receivables and loans initially held-for-investment 1,596 — 34 (1,539 ) 91 Originations and repayments of finance receivables and loans held-for-investment and other, net 3,489 — (6,734 ) — (3,245 ) Net change in loans — intercompany (20 ) — (2 ) 22 — Purchases of operating lease assets — — (3,709 ) — (3,709 ) Disposals of operating lease assets 10 — 3,079 — 3,089 Capital contributions to subsidiaries (61 ) (6 ) — 67 — Returns of contributed capital 266 — — (266 ) — Net change in nonmarketable equity investments (16 ) — (165 ) — (181 ) Other, net — — (340 ) — (340 ) Net cash provided by (used in) investing activities 5,133 (6 ) (19,405 ) (231 ) (14,509 ) Financing activities Net change in short-term borrowings — third party (694 ) — (732 ) — (1,426 ) Net (decrease) increase in deposits (11 ) — 12,989 (111 ) 12,867 Proceeds from issuance of long-term debt — third party 69 — 18,332 — 18,401 Repayments of long-term debt — third party (4,774 ) — (13,166 ) — (17,940 ) Net change in debt — intercompany (198 ) — (10 ) 208 — Repurchase of common stock (939 ) — — — (939 ) Dividends paid — third party (242 ) — — — (242 ) Dividends paid and returns of contributed capital — intercompany — (2,600 ) (3,309 ) 5,909 — Capital contributions from parent — 6 61 (67 ) — Net cash (used in) provided by financing activities (6,789 ) (2,594 ) 14,165 5,939 10,721 Effect of exchange-rate changes on cash and cash equivalents and restricted cash — — (5 ) — (5 ) Net increase in cash and cash equivalents and restricted cash 3 — 291 63 357 Cash and cash equivalents and restricted cash at beginning of year 1,395 — 5,707 (1,833 ) 5,269 Cash and cash equivalents and restricted cash at end of year $ 1,398 $ — $ 5,998 $ (1,770 ) $ 5,626 The following table provides a reconciliation of cash and cash equivalents and restricted cash from the Condensed Consolidating Balance Sheet to the Condensed Consolidating Statement of Cash Flows. December 31, 2018 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Cash and cash equivalents on the Condensed Consolidating Balance Sheet $ 1,309 $ — $ 4,998 $ (1,770 ) $ 4,537 Restricted cash included in other assets on the Condensed Consolidating Balance Sheet (a) 89 — 1,000 — 1,089 Total cash and cash equivalents and restricted cash in the Condensed Consolidating Statement of Cash Flows $ 1,398 $ — $ 5,998 $ (1,770 ) $ 5,626 (a) Restricted cash balances relate primarily to Ally securitization arrangements. Refer to Note 13 for additional details describing the nature of restricted cash balances. Year ended December 31, 2017 ($ in millions) Parent Guarantors Nonguarantors Consolidating adjustments Ally consolidated Operating activities Net cash provided by operating activities $ 4,591 $ 3,300 $ 3,466 $ (7,278 ) $ 4,079 Investing activities Purchases of equity securities — — (899 ) — (899 ) Proceeds from sales of equity securities — — 1,049 — 1,049 Purchases of available-for-sale securities — — (10,335 ) — (10,335 ) Proceeds from sales of available-for-sale securities — — 3,584 — 3,584 Proceeds from repayments of available-for-sale securities — — 2,899 — 2,899 Purchases of held-to-maturity securities — — (1,026 ) — (1,026 ) Proceeds from repayments of held-to-maturity securities — — 68 — 68 Net change in investment securities — intercompany 7 — 291 (298 ) — Purchases of finance receivables and loans held-for-investment (35 ) — (5,417 ) — (5,452 ) Proceeds from sales of finance receivables and loans initially held-for-investment 106 — 1,233 — 1,339 Originations and repayments of finance receivables and loans held-for-investment and other, net 860 — 33 (1,956 ) (1,063 ) Net change in loans — intercompany 2,068 — 217 (2,285 ) — Purchases of operating lease assets — — (4,052 ) — (4,052 ) Disposals of operating lease assets 13 — 5,554 — 5,567 Capital contributions to subsidiaries (1,212 ) (5 ) — 1,217 — Returns of contributed capital 1,567 — — (1,567 ) — Net change in nonmarketable equity investments — — (187 ) — (187 ) Other, net (31 ) — (99 ) (89 ) (219 ) Net cash provided by (used in) investing activities 3,343 (5 ) (7,087 ) (4,978 ) (8,727 ) Financing activities Net change in short-term borrowings — third party (453 ) — (810 ) — (1,263 ) Net (decrease) increase in deposits (156 ) — 15,466 (1,138 ) 14,172 Proceeds from issuance of long-term debt — third party 354 — 15,654 1,961 17,969 Repayments of long-term debt — third party (6,111 ) — (21,797 ) — (27,908 ) Net change in debt — intercompany (225 ) — (2,074 ) 2,299 — Repurchase of common stock (753 ) — — — (753 ) Dividends paid — third party (184 ) — — — (184 ) Dividends paid and returns of contributed capital — intercompany — (3,300 ) (5,619 ) 8,919 — Capital contributions from parent — 5 1,212 (1,217 ) — Net cash (used in) provided by financing activities (7,528 ) (3,295 ) 2,032 10,824 2,033 Effect of exchange-rate changes on cash and cash equivalents and restricted cash — — 3 — 3 Net increase (decrease) in cash and cash equivalents and restricted cash 406 — (1,586 ) (1,432 ) (2,612 ) Cash and cash equivalents and restricted cash at beginning of year 989 — 7,293 (401 ) 7,881 Cash and cash equivalents and restricted cash at end of year $ 1,395 $ — $ 5,707 $ (1,833 ) $ 5,269

Guarantees and Commitments Gu_2

Guarantees and Commitments Guarantees and Commitments (Tables)	12 Months Ended
	Dec. 31, 2019
Guarantees and Commitments [Abstract]
Schedule of Guarantor Obligations [Table Text Block]	Guarantees are defined as contracts or indemnification agreements that contingently require us to make payments to third parties based on changes in the underlying agreements with the guaranteed parties. The following summarizes our outstanding guarantees, including those of our discontinued operations, made to third parties on our Consolidated Balance Sheet , for the periods shown. 2019 2018 December 31, ($ in millions) Maximum liability Carrying value of liability Maximum liability Carrying value of liability Standby letters of credit and other guarantees $ 249 $ 6 $ 218 $ 7
Financing Commitments [Table Text Block]	The contractual commitments were as follows. December 31, ($ in millions) 2019 2018 Unused revolving credit line commitments and other (a) $ 4,384 $ 3,435 Commitments to provide capital to investees (b) 504 394 Mortgage loan origination commitments (c) 314 171 Home equity lines of credit (d) 226 253 Construction-lending commitments (e) 127 85 (a) The unused portion of revolving lines of credit reset at prevailing market rates and, as such, approximate market value. (b) We are committed to contribute capital to certain investees. (c) Commitments with mortgage loan applicants in which the loan terms, including interest rate and price, are guaranteed for a designated period of time subject to the completion of underwriting procedures. (d) We are committed to fund the remaining unused balances on home equity lines of credit. (e) We are committed to fund the remaining unused balance while loans are in the construction period.
Long-term Purchase Commitment [Table Text Block]	We have entered into multiple agreements for sponsorship, information technology, voice and communication technology, and related maintenance. Many of the agreements are subject to variable price provisions, fixed or minimum price provisions, and termination or renewal provisions. Year ended December 31, ($ in millions) 2020 $ 68 2021 38 2022 40 2023 37 2024 14 2025 and thereafter 27 Total future payment obligations $ 224

Quarterly Financial Statement_2

Quarterly Financial Statements (unaudited) Quarterly Financial Statements (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Statements (unaudited) [Table Text Block]	($ in millions) First quarter Second quarter Third quarter Fourth quarter 2019 Net financing revenue and other interest income $ 1,132 $ 1,157 $ 1,188 $ 1,156 Other revenue 466 395 413 487 Total net revenue 1,598 1,552 1,601 1,643 Provision for loan losses 282 177 263 276 Total noninterest expense 830 881 838 880 Income from continuing operations before income tax expense 486 494 500 487 Income tax expense (benefit) from continuing operations 111 (90 ) 119 106 Net income from continuing operations 375 584 381 381 Loss from discontinued operations, net of tax (1 ) (2 ) — (3 ) Net income $ 374 $ 582 $ 381 $ 378 Basic earnings per common share (a) Net income from continuing operations $ 0.93 $ 1.47 $ 0.98 $ 1.00 Net income 0.93 1.46 0.97 0.99 Diluted earnings per common share (a) Net income from continuing operations 0.92 1.46 0.97 0.99 Net income 0.92 1.46 0.97 0.99 Cash dividends declared per common share $ 0.17 $ 0.17 $ 0.17 $ 0.17 2018 Net financing revenue and other interest income $ 1,049 $ 1,094 $ 1,107 $ 1,140 Other revenue 354 364 398 298 Total net revenue 1,403 1,458 1,505 1,438 Provision for loan losses 261 158 233 266 Total noninterest expense 814 839 807 804 Income from continuing operations before income tax expense 328 461 465 368 Income tax expense from continuing operations 76 113 91 79 Net income from continuing operations 252 348 374 289 (Loss) income from discontinued operations, net of tax (2 ) 1 — 1 Net income $ 250 $ 349 $ 374 $ 290 Basic earnings per common share (a) Net income from continuing operations $ 0.58 $ 0.81 $ 0.89 $ 0.70 Net income 0.57 0.81 0.89 0.70 Diluted earnings per common share (a) Net income from continuing operations 0.57 0.80 0.88 0.70 Net income 0.57 0.81 0.88 0.70 Cash dividends declared per common share $ 0.13 $ 0.13 $ 0.15 $ 0.15 (a) Earnings per share is calculated quarterly on an independent basis, therefore the total of the amounts presented for each year above may not reconcile to the annual amounts presented in Note 19 .

Description of Business, Basi_3

Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies Description of Business, Basis of Presentation, and Changes in Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of loan portfolio segments	4
Operating lease, right-of-use assets	$ 168
Operating lease, liabilities	$ 196
Phase-in of capital impact of Accounting Standards Update 2016-13	25.00%
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use assets		$ 161
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 29
Operating lease, liabilities		$ 190
Accounting Standards Update 2017-08 | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	10
Accounting Standards Update 2017-08 | Accumulated other comprehensive (loss) income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ (8)
Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Phase-in of capital impact of Accounting Standards Update 2016-13	25.00%
Accounting Standards Update 2016-13 | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ (1,000)
Accounting Standards Update 2016-13 | Allowance for loan losses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ (1,300)

Acquisitions Acquistions (Detai

Acquisitions Acquistions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Oct. 01, 2019
Business Acquisition [Line Items]
Cash consideration	$ 177
Finance receivables and loans		$ 75
Intangible assets		23
Cash and short-term investments		6
Other assets		6
Debt		(62)
Employee compensation and benefits		(5)
Other liabilities		$ (19)
Weighted average amortization period on acquired intangible assets	3 years
Goodwill amortization period for income taxes	15 years
Corporate and Other
Business Acquisition [Line Items]
Goodwill	$ 153

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 727	$ 689
Other revenue	$ 487	$ 413	$ 395	$ 466	$ 298	$ 398	$ 364	$ 354	1,761	1,414	$ 1,544
Corporate and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									77	75
Other revenue									171	119	81
Noninsurance contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									542	506
Unearned revenue, remaining performance obligation, amount	2,900				2,600				2,900	2,600		$ 2,600	$ 2,500
Unearned revenue, revenue recognized									816	786
Capitalized contract cost, net	1,700				$ 1,500				1,700	1,500		$ 1,500	$ 1,400
Capitalized contract cost, amortization									463	427
Noninsurance contracts | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Remarketing fee income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									74	79
Remarketing fee income | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Brokerage commissions and other revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									61	62
Brokerage commissions and other revenue | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									61	62
Deposit account and other banking fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									16	13
Deposit account and other banking fees | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									16	13
Brokered/agent commissions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14	15
Brokered/agent commissions | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									20	14
Other | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Out of scope of Topic 606
Disaggregation of Revenue [Line Items]
Other revenue									1,034	725
Out of scope of Topic 606 | Corporate and Other
Disaggregation of Revenue [Line Items]
Other revenue									94	44
Automotive Finance operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									93	92
Other revenue									249	269	355
Automotive Finance operations | Noninsurance contracts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Automotive Finance operations | Remarketing fee income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									74	79
Automotive Finance operations | Brokerage commissions and other revenue | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Automotive Finance operations | Deposit account and other banking fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Automotive Finance operations | Brokered/agent commissions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Automotive Finance operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									19	13
Automotive Finance operations | Out of scope of Topic 606 | Operating Segments
Disaggregation of Revenue [Line Items]
Other revenue									156	177
Automotive Finance operations | Sale of off-lease vehicles
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									69	90
Insurance operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									557	522
Other revenue									1,274	981	1,059
Insurance operations | Noninsurance contracts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									542	506
Insurance operations | Remarketing fee income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Insurance operations | Brokerage commissions and other revenue | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Insurance operations | Deposit account and other banking fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Insurance operations | Brokered/agent commissions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									14	15
Insurance operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									1	1
Insurance operations | Out of scope of Topic 606 | Operating Segments
Disaggregation of Revenue [Line Items]
Other revenue									717	459
Mortgage Finance operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Other revenue									22	7	4
Mortgage Finance operations | Noninsurance contracts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Mortgage Finance operations | Remarketing fee income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Mortgage Finance operations | Brokerage commissions and other revenue | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Mortgage Finance operations | Deposit account and other banking fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Mortgage Finance operations | Brokered/agent commissions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Mortgage Finance operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Mortgage Finance operations | Out of scope of Topic 606 | Operating Segments
Disaggregation of Revenue [Line Items]
Other revenue									22	7
Corporate Finance operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Other revenue									45	38	$ 45
Corporate Finance operations | Noninsurance contracts | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Corporate Finance operations | Remarketing fee income | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Corporate Finance operations | Brokerage commissions and other revenue | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Corporate Finance operations | Deposit account and other banking fees | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Corporate Finance operations | Brokered/agent commissions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Corporate Finance operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Corporate Finance operations | Out of scope of Topic 606 | Operating Segments
Disaggregation of Revenue [Line Items]
Other revenue									45	$ 38
2020 | Noninsurance contracts
Disaggregation of Revenue [Line Items]
Unearned revenue, remaining performance obligation, amount	768								768
2021 | Noninsurance contracts
Disaggregation of Revenue [Line Items]
Unearned revenue, remaining performance obligation, amount	682								682
2022 | Noninsurance contracts
Disaggregation of Revenue [Line Items]
Unearned revenue, remaining performance obligation, amount	569								569
2023 | Noninsurance contracts
Disaggregation of Revenue [Line Items]
Unearned revenue, remaining performance obligation, amount	433								433
2024 and thereafter | Noninsurance contracts
Disaggregation of Revenue [Line Items]
Unearned revenue, remaining performance obligation, amount	$ 417								$ 417

Insurance Premiums and Servic_3

Insurance Premiums and Service Revenue Insurance Premiums and Service Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Insurance Premiums and Service Revenue [Abstract]
Direct premiums written	$ 491	$ 420	$ 384
Direct premiums earned	464	414	364
Assumed premiums written	0	0	2
Assumed premiums earned	2	4	5
Premiums written, gross	491	420	386
Premiums earned, gross	466	418	369
Ceded premiums written	(232)	(219)	(254)
Ceded premiums earned	(209)	(197)	(188)
Premiums written, net	259	201	132
Premiums earned, net	257	221	181
Service revenue written	1,051	973	864
Service revenue earned	830	801	792
Insurance premiums and service revenue written	1,310	1,174	996
Insurance premiums and service revenue earned	$ 1,087	$ 1,022	$ 973

Other Income, Net of Losses (Sc

Other Income, Net of Losses (Schedule of Other Income, Net of Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Nonoperating Income (Expense) [Abstract]
Late charges and other administrative fees	$ 114	$ 110	$ 102
Remarketing fees	74	79	104
Income from equity-method investments	62	46	14
Servicing fees	17	27	51
Other income, net	136	155	130
Total other income, net of losses	$ 403	$ 417	$ 401

Reserves for Insurance Losses_3

Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses (Short-duration Insurance Contracts, Claims Development) (Details) $ in Millions	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	$ 2,667
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	2,643
Short-duration insurance contracts, liability for unpaid claims and allocated claim adjustment expense, net, not separately presented	8
Short-duration insurance contracts, liability for unpaid claims and allocated claim adjustment expense, net	32	$ 35	$ 30
Short-duration insurance contracts, accident Year 2012
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	421	422	422	$ 423	$ 423	$ 423	$ 430	$ 435
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 0
Short-duration insurance contract, cumulative number of reported claims	772,549
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 421	421	421	419	418	416	412	$ 391
Short-duration insurance contracts, accident Year 2013
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	368	368	369	370	370	365	376
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 0
Short-duration insurance contract, cumulative number of reported claims	672,278
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 368	368	368	368	366	364	$ 347
Short-duration insurance contracts, accident Year 2014
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	388	388	388	388	389	390
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 0
Short-duration insurance contract, cumulative number of reported claims	525,298
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 388	388	388	388	388	$ 369
Short-duration insurance contracts, accident Year 2015
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	272	272	272	271	274
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 0
Short-duration insurance contract, cumulative number of reported claims	342,267
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 272	272	272	272	$ 252
Short-duration insurance contracts, accident Year 2016
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	328	328	327	326
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 0
Short-duration insurance contract, cumulative number of reported claims	476,034
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 328	328	327	$ 302
Short-duration insurance contracts, accident Year 2017
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	315	314	310
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 0
Short-duration insurance contract, cumulative number of reported claims	481,646
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 315	315	$ 289
Short-duration insurance contracts, accident Year 2018
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	272	271
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 0
Short-duration insurance contract, cumulative number of reported claims	505,982
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 273	$ 245
Short-duration insurance contract, accident Year 2019
Claims Development [Line Items]
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net	303
Liability for unpaid claims and claims adjustment expense, incurred but not reported (IBNR) claims, amount	$ 23
Short-duration insurance contract, cumulative number of reported claims	515,689
Short-duration insurance contracts, cumulative paid claims and allocated claim adjustment expense, net	$ 278

Reserves for Insurance Losses_4

Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses (Short-duration Contracts, Schedule of Historical Claims Duration) (Details)	Dec. 31, 2019
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Percentage payout of incurred claims, Year One	92.60%
Percentage payout of incurred claims, Year Two	6.60%
Percentage payout of incurred claims, Year Three	0.40%
Percentage payout of incurred claims, Year Four	0.20%
Percentage payout of incurred claims, Year Five	0.10%
Percentage payout of incurred claims, Year Six	0.10%
Percentage payout of incurred claims, Year Seven	0.10%
Percentage payout of incurred claims, Year Eight	0.00%

Reserves for Insurance Losses_5

Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses (Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Short-duration insurance contracts, liability for unpaid claims and allocated claim adjustment expense, net	$ 32	$ 35	$ 30
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments	88	96	108	$ 108
Short-duration Insurance Contracts, Liability for Unpaid Claims and Claims Adjustment Expense, Accumulated Unallocated Claim Adjustment Expense	2	3	2
Reserves for insurance losses and loss adjustment expenses	$ 122	$ 134	$ 140	$ 149

Reserves for Insurance Losses_6

Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses (Rollforward of Reserves for Insurance Losses and Loss Adjustment Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves for insurance losses and loss adjustment expenses	$ 134	$ 140	$ 149
Reinsurance recoverable	96	108	108
Net reserves for insurance losses and loss adjustment expenses	38	32	41
Net insurance losses and loss adjustment expenses, current year	321	291	332
Net insurance losses and loss adjustment expenses, prior years	0	4	0
Net insurance losses and loss adjustment expenses incurred	321	295	332
Net insurance losses and loss adjustment expenses paid or payable, current year	(295)	(263)	(309)
Net insurance losses and loss adjustment expenses paid or payable, prior years	(30)	(26)	(32)
Total net insurance losses and loss adjustment expenses paid or payable	(325)	(289)	(341)
Net reserves for insurance losses and loss adjustment expenses	34	38	32
Reinsurance recoverable	88	96	108
Gross reserves for insurance losses and loss adjustment expenses	$ 122	$ 134	$ 140

Other Operating Expenses (Sched

Other Operating Expenses (Schedule Of Other Operating Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Expenses [Abstract]
Insurance commissions	$ 475	$ 440	$ 415
Technology and communications	311	299	284
Advertising and marketing	180	172	133
Lease and loan administration	172	164	159
Professional services	126	133	113
Regulatory and licensing fees	115	121	113
Vehicle remarketing and repossession	105	111	110
Premises and equipment depreciation	96	87	89
Occupancy	57	45	46
Non-income taxes	34	29	21
Amortization of intangible assets	13	11	11
Other operating expenses	202	202	189
Total other operating expenses	$ 1,886	$ 1,814	$ 1,683

Investment Securities (Investme

Investment Securities (Investment Table) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Debt securities, available-for-sale, fair value	$ 30,284	$ 25,303
Debt securities, held-to-maturity, amortized cost	1,568	2,362
Held-to-maturity securities, fair value	1,600	2,307
Debt Securities, held-to-maturity, transfer, amount	943	0	$ 0
Debt Securities, held-to-maturity, transfer, unrealized gain	2
Available-for-sale securities
Schedule of Investments [Line Items]
Debt Securities, held-to-maturity, transfer, amount	945
Securities pledged for Federal Home Loan Bank, at fair value	1,900	9,200
Securities, amount eligible to be repledged or sold by counterparty	118	821
Held-to-maturity securities
Schedule of Investments [Line Items]
Debt Securities, held-to-maturity, transfer, amount	943
Operating Segments | Insurance operations | Available-for-sale securities
Schedule of Investments [Line Items]
Deposit securities	12	12
US Treasury | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	2,059	1,911
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	6	0
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(17)	(60)
Debt securities, available-for-sale, fair value	2,048	1,851
US States and political subdivisions | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	623	816
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	19	3
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(1)	(17)
Debt securities, available-for-sale, fair value	641	802
Foreign government | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	184	145
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3	1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(1)	(1)
Debt securities, available-for-sale, fair value	186	145
Agency mortgage-backed residential | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	21,183	17,486
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	257	47
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(36)	(395)
Debt securities, available-for-sale, fair value	21,404	17,138
Agency mortgage-backed residential | Held-to-maturity securities
Schedule of Investments [Line Items]
Debt securities, held-to-maturity, amortized cost	1,547	2,319
Debt securities, held-to-maturity, unrecognized gain	38	6
Debt securities, held-to-maturity, unrecognized loss	6	61
Held-to-maturity securities, fair value	1,579	2,264
Mortgage-backed residential | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	2,841	2,796
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	20	1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(11)	(111)
Debt securities, available-for-sale, fair value	2,850	2,686
Agency mortgage-backed commercial | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	1,344	3
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	44	0
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(6)	0
Debt securities, available-for-sale, fair value	1,382	3
Mortgage-backed commercial | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	41	715
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	1	1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	0	(2)
Debt securities, available-for-sale, fair value	42	714
Asset-backed | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	365	723
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3	2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	0	(2)
Debt securities, available-for-sale, fair value	368	723
Asset-backed | Held-to-maturity securities
Schedule of Investments [Line Items]
Debt securities, held-to-maturity, amortized cost	21	43
Debt securities, held-to-maturity, unrecognized gain	0	0
Debt securities, held-to-maturity, unrecognized loss	0	0
Held-to-maturity securities, fair value	21	43
Corporate debt | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	1,327	1,286
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	37	1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(1)	(46)
Debt securities, available-for-sale, fair value	1,363	1,241
Available-for-sale debt securities | Available-for-sale securities
Schedule of Investments [Line Items]
Debt securities, available-for-sale, amortized cost	29,967	25,881
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	390	56
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(73)	(634)
Debt securities, available-for-sale, fair value	30,284	25,303
Held-to-maturity securities
Schedule of Investments [Line Items]
Debt securities, held-to-maturity, amortized cost	1,568	2,362
Debt securities, held-to-maturity, unrecognized gain	38	6
Debt securities, held-to-maturity, unrecognized loss	6	61
Held-to-maturity securities, fair value	1,600	2,307
Federal Home Loan Bank certificates and obligations | Held-to-maturity securities
Schedule of Investments [Line Items]
Securities pledged for Federal Home Loan Bank, at fair value	$ 915	$ 1,200

Investment Securities (Invest_2

Investment Securities (Investments Classified by Contractual Maturity Date) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 30,284	$ 25,303
Cash equivalents	73	35
Held-to-maturity securities
Schedule of Investments [Line Items]
Debt securities, held-to-maturity, amortized cost, before other-than-temporary impairment	$ 1,568	$ 2,362
Debt securities, held-to-maturity, yield	3.20%	3.20%
Debt securities, held-to-maturity, maturity, within one year, amortized Cost	$ 0	$ 0
Debt securities, held-to-maturity, due in one year or less, yield	0.00%	0.00%
Debt securities, held-to-maturity, maturity, one through five years, amortized Cost	$ 21	$ 42
Debt securities, held-to-maturity, due after one year through five years, yield	2.20%	2.00%
Debt securities, held-to-maturity, maturity, after five through ten years, amortized cost	$ 0	$ 1
Debt securities, held-to-maturity, due after five years through ten years, yield	0.00%	3.30%
Debt securities, held-to-maturity, maturity, after 10 Years, amortized cost	$ 1,547	$ 2,319
Debt securities, held-to-maturity, due after ten years, yield	3.20%	3.20%
Available-for-sale securities | US Treasury
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 2,048	$ 1,851
Debt securities, available-for-sale, yield	1.50%	1.90%
Debt securities, available-for-sale, due in one year or less	$ 65	$ 12
Debt securities, available-for-sale, due in one year or less, yield	2.10%	1.00%
Debt securities, available-for-sale, due after one year through five years	$ 1,590	$ 1,277
Debt securities, available-for-sale, due after one year through five years, yield	1.40%	1.80%
Debt securities, available-for-sale, due after five years through ten years	$ 393	$ 562
Debt securities, available-for-sale, due after five years through ten years, yield	1.70%	2.00%
Debt securities, available-for-sale, due after ten years	$ 0	$ 0
Debt securities, available-for-sale, due after ten years, yield	0.00%	0.00%
Debt securities, available-for-sale, amortized cost	$ 2,059	$ 1,911
Available-for-sale securities | US States and political subdivisions
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 641	$ 802
Debt securities, available-for-sale, yield	3.10%	3.00%
Debt securities, available-for-sale, due in one year or less	$ 22	$ 49
Debt securities, available-for-sale, due in one year or less, yield	2.70%	1.90%
Debt securities, available-for-sale, due after one year through five years	$ 75	$ 43
Debt securities, available-for-sale, due after one year through five years, yield	2.30%	2.30%
Debt securities, available-for-sale, due after five years through ten years	$ 159	$ 252
Debt securities, available-for-sale, due after five years through ten years, yield	2.80%	2.60%
Debt securities, available-for-sale, due after ten years	$ 385	$ 458
Debt securities, available-for-sale, due after ten years, yield	3.40%	3.40%
Debt securities, available-for-sale, amortized cost	$ 623	$ 816
Available-for-sale securities | Foreign government
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 186	$ 145
Debt securities, available-for-sale, yield	1.90%	2.40%
Debt securities, available-for-sale, due in one year or less	$ 35	$ 18
Debt securities, available-for-sale, due in one year or less, yield	0.40%	3.10%
Debt securities, available-for-sale, due after one year through five years	$ 65	$ 60
Debt securities, available-for-sale, due after one year through five years, yield	2.30%	2.30%
Debt securities, available-for-sale, due after five years through ten years	$ 86	$ 67
Debt securities, available-for-sale, due after five years through ten years, yield	2.30%	2.40%
Debt securities, available-for-sale, due after ten years	$ 0	$ 0
Debt securities, available-for-sale, due after ten years, yield	0.00%	0.00%
Debt securities, available-for-sale, amortized cost	$ 184	$ 145
Available-for-sale securities | Agency mortgage-backed residential
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 21,404	$ 17,138
Debt securities, available-for-sale, yield	3.20%	3.30%
Debt securities, available-for-sale, due in one year or less	$ 0	$ 0
Debt securities, available-for-sale, due in one year or less, yield	0.00%	0.00%
Debt securities, available-for-sale, due after one year through five years	$ 0	$ 0
Debt securities, available-for-sale, due after one year through five years, yield	0.00%	0.00%
Debt securities, available-for-sale, due after five years through ten years	$ 47	$ 54
Debt securities, available-for-sale, due after five years through ten years, yield	2.00%	1.90%
Debt securities, available-for-sale, due after ten years	$ 21,357	$ 17,084
Debt securities, available-for-sale, due after ten years, yield	3.20%	3.30%
Debt securities, available-for-sale, amortized cost	$ 21,183	$ 17,486
Available-for-sale securities | Mortgage-backed residential
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 2,850	$ 2,686
Debt securities, available-for-sale, yield	3.20%	3.30%
Debt securities, available-for-sale, due in one year or less	$ 0	$ 0
Debt securities, available-for-sale, due in one year or less, yield	0.00%	0.00%
Debt securities, available-for-sale, due after one year through five years	$ 0	$ 0
Debt securities, available-for-sale, due after one year through five years, yield	0.00%	0.00%
Debt securities, available-for-sale, due after five years through ten years	$ 0	$ 0
Debt securities, available-for-sale, due after five years through ten years, yield	0.00%	0.00%
Debt securities, available-for-sale, due after ten years	$ 2,850	$ 2,686
Debt securities, available-for-sale, due after ten years, yield	3.20%	3.30%
Debt securities, available-for-sale, amortized cost	$ 2,841	$ 2,796
Available-for-sale securities | Agency mortgage-backed commercial
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 1,382	$ 3
Debt securities, available-for-sale, yield	2.90%	3.10%
Debt securities, available-for-sale, due in one year or less	$ 0	$ 0
Debt securities, available-for-sale, due in one year or less, yield	0.00%	0.00%
Debt securities, available-for-sale, due after one year through five years	$ 3	$ 3
Debt securities, available-for-sale, due after one year through five years, yield	3.20%	3.10%
Debt securities, available-for-sale, due after five years through ten years	$ 1,109	$ 0
Debt securities, available-for-sale, due after five years through ten years, yield	3.00%	0.00%
Debt securities, available-for-sale, due after ten years	$ 270	$ 0
Debt securities, available-for-sale, due after ten years, yield	2.40%	0.00%
Debt securities, available-for-sale, amortized cost	$ 1,344	$ 3
Available-for-sale securities | Mortgage-backed commercial
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 42	$ 714
Debt securities, available-for-sale, yield	3.50%	3.80%
Debt securities, available-for-sale, due in one year or less	$ 0	$ 0
Debt securities, available-for-sale, due in one year or less, yield	0.00%	0.00%
Debt securities, available-for-sale, due after one year through five years	$ 0	$ 0
Debt securities, available-for-sale, due after one year through five years, yield	0.00%	0.00%
Debt securities, available-for-sale, due after five years through ten years	$ 0	$ 46
Debt securities, available-for-sale, due after five years through ten years, yield	0.00%	3.90%
Debt securities, available-for-sale, due after ten years	$ 42	$ 668
Debt securities, available-for-sale, due after ten years, yield	3.50%	3.80%
Debt securities, available-for-sale, amortized cost	$ 41	$ 715
Available-for-sale securities | Asset-backed
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 368	$ 723
Debt securities, available-for-sale, yield	3.50%	3.50%
Debt securities, available-for-sale, due in one year or less	$ 0	$ 0
Debt securities, available-for-sale, due in one year or less, yield	0.00%	0.00%
Debt securities, available-for-sale, due after one year through five years	$ 317	$ 478
Debt securities, available-for-sale, due after one year through five years, yield	3.60%	3.40%
Debt securities, available-for-sale, due after five years through ten years	$ 5	$ 121
Debt securities, available-for-sale, due after five years through ten years, yield	2.70%	4.00%
Debt securities, available-for-sale, due after ten years	$ 46	$ 124
Debt securities, available-for-sale, due after ten years, yield	3.00%	3.30%
Debt securities, available-for-sale, amortized cost	$ 365	$ 723
Available-for-sale securities | Corporate debt
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 1,363	$ 1,241
Debt securities, available-for-sale, yield	3.20%	3.10%
Debt securities, available-for-sale, due in one year or less	$ 125	$ 144
Debt securities, available-for-sale, due in one year or less, yield	2.90%	2.80%
Debt securities, available-for-sale, due after one year through five years	$ 580	$ 496
Debt securities, available-for-sale, due after one year through five years, yield	3.00%	2.90%
Debt securities, available-for-sale, due after five years through ten years	$ 649	$ 581
Debt securities, available-for-sale, due after five years through ten years, yield	3.40%	3.30%
Debt securities, available-for-sale, due after ten years	$ 9	$ 20
Debt securities, available-for-sale, due after ten years, yield	3.30%	5.50%
Debt securities, available-for-sale, amortized cost	$ 1,327	$ 1,286
Available-for-sale securities | Available-for-sale debt securities
Schedule of Investments [Line Items]
Total available-for-sale debt securities	$ 30,284	$ 25,303
Debt securities, available-for-sale, yield	3.10%	3.20%
Debt securities, available-for-sale, due in one year or less	$ 247	$ 223
Debt securities, available-for-sale, due in one year or less, yield	2.30%	2.60%
Debt securities, available-for-sale, due after one year through five years	$ 2,630	$ 2,357
Debt securities, available-for-sale, due after one year through five years, yield	2.10%	2.40%
Debt securities, available-for-sale, due after five years through ten years	$ 2,448	$ 1,683
Debt securities, available-for-sale, due after five years through ten years, yield	2.80%	2.80%
Debt securities, available-for-sale, due after ten years	$ 24,959	$ 21,040
Debt securities, available-for-sale, due after ten years, yield	3.20%	3.30%
Debt securities, available-for-sale, amortized cost	$ 29,967	$ 25,881
Debt securities, available-for-sale, maturity, within one year, amortized cost	246	224
Debt securities, available-for-sale, maturity, after one through five years, amortized cost	2,624	2,405
Debt securities, available-for-sale, maturity, after five through ten years, amortized cost	2,378	1,743
Debt securities, available-for-sale, maturity, after ten years, amortized cost	24,719	21,509
Held-to-maturity securities | Agency mortgage-backed residential
Schedule of Investments [Line Items]
Debt securities, held-to-maturity, amortized cost, before other-than-temporary impairment	$ 1,547	$ 2,319
Debt securities, held-to-maturity, yield	3.20%	3.20%
Debt securities, held-to-maturity, maturity, within one year, amortized Cost	$ 0	$ 0
Debt securities, held-to-maturity, due in one year or less, yield	0.00%	0.00%
Debt securities, held-to-maturity, maturity, one through five years, amortized Cost	$ 0	$ 0
Debt securities, held-to-maturity, due after one year through five years, yield	0.00%	0.00%
Debt securities, held-to-maturity, maturity, after five through ten years, amortized cost	$ 0	$ 0
Debt securities, held-to-maturity, due after five years through ten years, yield	0.00%	0.00%
Debt securities, held-to-maturity, maturity, after 10 Years, amortized cost	$ 1,547	$ 2,319
Debt securities, held-to-maturity, due after ten years, yield	3.20%	3.20%
Held-to-maturity securities | Asset-backed
Schedule of Investments [Line Items]
Debt securities, held-to-maturity, amortized cost, before other-than-temporary impairment	$ 21	$ 43
Debt securities, held-to-maturity, yield	2.20%	2.00%
Debt securities, held-to-maturity, maturity, within one year, amortized Cost	$ 0	$ 0
Debt securities, held-to-maturity, due in one year or less, yield	0.00%	0.00%
Debt securities, held-to-maturity, maturity, one through five years, amortized Cost	$ 21	$ 42
Debt securities, held-to-maturity, due after one year through five years, yield	2.20%	2.00%
Debt securities, held-to-maturity, maturity, after five through ten years, amortized cost	$ 0	$ 1
Debt securities, held-to-maturity, due after five years through ten years, yield	0.00%	3.30%
Debt securities, held-to-maturity, maturity, after 10 Years, amortized cost	$ 0	$ 0
Debt securities, held-to-maturity, due after ten years, yield	0.00%	0.00%

Investment Securities (Invest_3

Investment Securities (Investment Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Taxable interest	$ 858	$ 690	$ 534
Taxable dividends	14	14	12
Interest and dividends exempt from U.S. federal income tax	15	25	22
Interest and dividends on investment securities and other earning assets	955	788	599
Excludes other earning assets
Interest and dividends on investment securities and other earning assets	$ 887	$ 729	$ 568

Investment Securities (Schedule

Investment Securities (Schedule Of Realized Gain (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Abstract]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	$ 0	$ 0	$ 0
Available-for-sale securities, gross realized gains	82	12	106
Available-for-sale securities, gross realized losses	(4)	(1)	(4)
Net realized gains on available-for-sale securities	78	11	102
Net realized gain on equity securities	73	60
Net unrealized gain (loss) on equity securities	92	(121)
Other gain (loss) on investments, net	$ 243	$ (50)	$ 102

Investment Securities (Schedu_2

Investment Securities (Schedule of Unrealized Loss on Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	$ 7,012	$ 8,074
Debt securities, available-for-sale, unrealized loss, less than 12 months	(46)	(138)
Debt securities, available-for-sale, fair value, 12 months or longer	1,450	12,046
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(27)	(496)
Debt Securities, held-to-maturity, less than 12 Months, fair value	283	473
Debt securities, held-to-maturity, unrealized loss, less than 12 Months	(6)	(6)
Debt Securities, held-to-maturity, 12 Months or Longer, fair value	3	1,395
Debt securities, held-to-maturity, unrealized loss, 12 months or longer	0	(55)
US Treasury
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	1,267	31
Debt securities, available-for-sale, unrealized loss, less than 12 months	(11)	0
Debt securities, available-for-sale, fair value, 12 months or longer	279	1,758
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(6)	(60)
US States and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	72	259
Debt securities, available-for-sale, unrealized loss, less than 12 months	(1)	(3)
Debt securities, available-for-sale, fair value, 12 months or longer	5	317
Debt securities, available-for-sale, unrealized loss, 12 months or longer	0	(14)
Foreign government
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	40	6
Debt securities, available-for-sale, unrealized loss, less than 12 months	(1)	0
Debt securities, available-for-sale, fair value, 12 months or longer	3	74
Debt securities, available-for-sale, unrealized loss, 12 months or longer	0	(1)
Agency mortgage-backed residential
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	4,606	5,537
Debt securities, available-for-sale, unrealized loss, less than 12 months	(23)	(94)
Debt securities, available-for-sale, fair value, 12 months or longer	908	7,808
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(13)	(301)
Debt Securities, held-to-maturity, less than 12 Months, fair value	283	457
Debt securities, held-to-maturity, unrealized loss, less than 12 Months	(6)	(6)
Debt Securities, held-to-maturity, 12 Months or Longer, fair value	0	1,376
Debt securities, held-to-maturity, unrealized loss, 12 months or longer	0	(55)
Mortgage-backed residential
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	613	1,024
Debt securities, available-for-sale, unrealized loss, less than 12 months	(4)	(20)
Debt securities, available-for-sale, fair value, 12 months or longer	203	1,360
Debt securities, available-for-sale, unrealized loss, 12 months or longer	(7)	(91)
Agency mortgage-backed commercial
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	335	0
Debt securities, available-for-sale, unrealized loss, less than 12 months	(6)	0
Debt securities, available-for-sale, fair value, 12 months or longer	0	0
Debt securities, available-for-sale, unrealized loss, 12 months or longer	0	0
Mortgage-backed commercial
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	0	347
Debt securities, available-for-sale, unrealized loss, less than 12 months	0	(1)
Debt securities, available-for-sale, fair value, 12 months or longer	0	36
Debt securities, available-for-sale, unrealized loss, 12 months or longer	0	(1)
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	8	294
Debt securities, available-for-sale, unrealized loss, less than 12 months	0	(1)
Debt securities, available-for-sale, fair value, 12 months or longer	11	124
Debt securities, available-for-sale, unrealized loss, 12 months or longer	0	(1)
Debt Securities, held-to-maturity, less than 12 Months, fair value	0	16
Debt securities, held-to-maturity, unrealized loss, less than 12 Months	0	0
Debt Securities, held-to-maturity, 12 Months or Longer, fair value	3	19
Debt securities, held-to-maturity, unrealized loss, 12 months or longer	0	0
Corporate debt
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, fair value, less than 12 months	71	576
Debt securities, available-for-sale, unrealized loss, less than 12 months	0	(19)
Debt securities, available-for-sale, fair value, 12 months or longer	41	569
Debt securities, available-for-sale, unrealized loss, 12 months or longer	$ (1)	$ (27)

Finance Receivables and Loans_3

Finance Receivables and Loans, Net (Schedule of Accounts, Notes, Loans and Financing Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 128,231	$ 129,926
Unamortized premiums and discounts and deferred fees and costs	503	587
Consumer portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	89,924	87,240
Consumer portfolio segment | Fair value | Finance receivables and Loans, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Fair Value Disclosure	11
Consumer portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	72,390	70,539
Consumer portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	17,322	16,701
Consumer portfolio segment | Mortgage Finance operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	16,181	15,155
Interest-only mortgage loans	$ 11	18
Interest Only Mortgage Percentage Beginning Principal Amortization Next Year	47.00%
Consumer portfolio segment | Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 1,141	1,546
Interest-only mortgage loans	$ 212	341
Interest-only mortgage loans having exited the interest-only period	99.00%
Consumer portfolio segment | Other loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 212	0
Commercial portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	38,307	42,686
Commercial portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	28,332	33,672
Commercial portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	4,961	4,809
Commercial portfolio segment | Other loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 5,014	$ 4,205

Finance Receivables and Loans_4

Finance Receivables and Loans, Net (Allowance for Credit Losses on Financing Receivables) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses	$ 1,242	$ 1,276
Allowance for loan and lease losses, charge-offs	(1,490)	(1,433)
Allowance for loan and lease losses, recoveries	514	488
Allowance for loan and lease losses, net charge-offs	(976)	(945)
Provision for loan losses	998	918	$ 1,148
Allowance for Loan and Lease Losses, Adjustments, Other	(1)	(7)
Allowance for loan losses	1,263	1,242	1,276
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, individually evaluated for impairment	89	123
Allowance for loan losses, collectively evaluated for impairment	1,174	1,119
Finance receivables and loans, net	128,231	129,926
Finance receivables and loans, individually evaluated for impairment	961	1,075
Finance receivables and loans, collectively evaluated for impairment		128,851
Excludes fair value option elected other loans
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Finance receivables and loans, net	128,220
Finance receivables and loans, collectively evaluated for impairment	127,259
Consumer portfolio segment
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Finance receivables and loans, net	89,924	87,240
Consumer portfolio segment | Excludes fair value option elected other loans
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Finance receivables and loans, net	89,913
Consumer portfolio segment | Fair value | Finance receivables and Loans, net
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans Receivable, Fair Value Disclosure	11
Consumer portfolio segment | Automotive loan
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses	1,048	1,066
Allowance for loan and lease losses, charge-offs	(1,423)	(1,383)
Allowance for loan and lease losses, recoveries	493	456
Allowance for loan and lease losses, net charge-offs	(930)	(927)
Provision for loan losses	957	911
Allowance for Loan and Lease Losses, Adjustments, Other	0	(2)
Allowance for loan losses	1,075	1,048	1,066
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, individually evaluated for impairment	38	44
Allowance for loan losses, collectively evaluated for impairment	1,037	1,004
Finance receivables and loans, net	72,390	70,539
Finance receivables and loans, individually evaluated for impairment	538	495
Finance receivables and loans, collectively evaluated for impairment	71,852	70,044
Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses	53	79
Allowance for loan and lease losses, charge-offs	(13)	(35)
Allowance for loan and lease losses, recoveries	21	25
Allowance for loan and lease losses, net charge-offs	8	(10)
Provision for loan losses	(13)	(15)
Allowance for Loan and Lease Losses, Adjustments, Other	(2)	(1)
Allowance for loan losses	46	53	79
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, individually evaluated for impairment	18	23
Allowance for loan losses, collectively evaluated for impairment	28	30
Finance receivables and loans, net	17,322	16,701
Finance receivables and loans, individually evaluated for impairment	208	231
Finance receivables and loans, collectively evaluated for impairment	17,114	16,470
Consumer portfolio segment | Other
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses	0
Allowance for loan and lease losses, charge-offs	(5)
Allowance for loan and lease losses, recoveries	0
Allowance for loan and lease losses, net charge-offs	(5)
Provision for loan losses	14
Allowance for Loan and Lease Losses, Adjustments, Other	0
Allowance for loan losses	9	0
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, individually evaluated for impairment	0
Allowance for loan losses, collectively evaluated for impairment	9
Finance receivables and loans, individually evaluated for impairment	0
Consumer portfolio segment | Other | Excludes fair value option elected other loans
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Finance receivables and loans, net	201
Finance receivables and loans, collectively evaluated for impairment	201
Commercial portfolio segment
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses	141	131
Allowance for loan and lease losses, charge-offs	(49)	(15)
Allowance for loan and lease losses, recoveries	0	7
Allowance for loan and lease losses, net charge-offs	(49)	(8)
Provision for loan losses	40	22
Allowance for Loan and Lease Losses, Adjustments, Other	1	(4)
Allowance for loan losses	133	141	$ 131
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses, individually evaluated for impairment	33	56
Allowance for loan losses, collectively evaluated for impairment	100	85
Finance receivables and loans, net	38,307	42,686
Finance receivables and loans, individually evaluated for impairment	215	349
Finance receivables and loans, collectively evaluated for impairment	38,092	42,337
Commercial portfolio segment | Automotive loan
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Finance receivables and loans, net	28,332	33,672
Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Finance receivables and loans, net	$ 4,961	$ 4,809

Finance Receivables and Loans_5

Finance Receivables and Loans, Net (Schedule of Sales of Financing Receivables and Loans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Sale	$ 960	$ 826
Financing receivable, sales and transfers	131
Loans held-for-sale transferred to finance receivables and loans held-for-investment	79
Consumer portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Sale	20	578
Consumer portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Sale	940	10
Commercial portfolio segment | Commercial Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Sale	$ 0	$ 238

Finance Receivables and Loans_6

Finance Receivables and Loans, Net (Schedule of Purchases of Financing Receivables and Loans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Oct. 01, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	$ 4,145	$ 5,357
Business Combination, Acquired Receivables			$ 75
Consumer portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	531	896
Consumer portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	3,451	4,446
Consumer portfolio segment | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	117	0
Commercial portfolio segment | Commercial Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	$ 46	$ 15

Finance Receivables and Loans_7

Finance Receivables and Loans, Net (Past Due Financing Receivables and Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		$ 3,151
Financing receivable, recorded investment, current		126,775
Total finance receivables and loans	$ 128,231	129,926
Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	3,369
Financing receivable, recorded investment, current	124,851
Total finance receivables and loans	128,220
Consumer portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		3,098
Financing receivable, recorded investment, current		84,142
Total finance receivables and loans	89,924	87,240
Consumer portfolio segment | Fair value | Finance receivables and Loans, net
Financing Receivable, Past Due [Line Items]
Loans Receivable, Fair Value Disclosure	11
Consumer portfolio segment | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	3,286
Financing receivable, recorded investment, current	86,627
Total finance receivables and loans	89,913
Consumer portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	3,142	2,940
Financing receivable, recorded investment, current	69,248	67,599
Total finance receivables and loans	72,390	70,539
Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	137	158
Financing receivable, recorded investment, current	17,185	16,543
Total finance receivables and loans	17,322	16,701
Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	76	76
Financing receivable, recorded investment, current	16,105	15,079
Total finance receivables and loans	16,181	15,155
Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	61	82
Financing receivable, recorded investment, current	1,080	1,464
Total finance receivables and loans	1,141	1,546
Consumer portfolio segment | Other loan
Financing Receivable, Past Due [Line Items]
Total finance receivables and loans	212	0
Consumer portfolio segment | Other loan | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	7
Financing receivable, recorded investment, current	194
Total finance receivables and loans	201
Commercial portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	83	53
Financing receivable, recorded investment, current	38,224	42,633
Total finance receivables and loans	38,307	42,686
Commercial portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	62	32
Financing receivable, recorded investment, current	28,270	33,640
Total finance receivables and loans	28,332	33,672
Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	4	1
Financing receivable, recorded investment, current	4,957	4,808
Total finance receivables and loans	4,961	4,809
Commercial portfolio segment | Other loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	17	20
Financing receivable, recorded investment, current	4,997	4,185
Total finance receivables and loans	5,014	4,205
Financing receivables, 30 to 59 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		2,204
Financing receivables, 30 to 59 days past due | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,303
Financing receivables, 30 to 59 days past due | Consumer portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		2,204
Financing receivables, 30 to 59 days past due | Consumer portfolio segment | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,269
Financing receivables, 30 to 59 days past due | Consumer portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	2,185	2,107
Financing receivables, 30 to 59 days past due | Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	81	97
Financing receivables, 30 to 59 days past due | Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	56	67
Financing receivables, 30 to 59 days past due | Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	25	30
Financing receivables, 30 to 59 days past due | Consumer portfolio segment | Other loan | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	3
Financing receivables, 30 to 59 days past due | Commercial portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	34	0
Financing receivables, 30 to 59 days past due | Commercial portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	34	0
Financing receivables, 30 to 59 days past due | Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Financing receivables, 30 to 59 days past due | Commercial portfolio segment | Other loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Financing receivables, 60 to 89 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		557
Financing receivables, 60 to 89 days past due | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	611
Financing receivables, 60 to 89 days past due | Consumer portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		552
Financing receivables, 60 to 89 days past due | Consumer portfolio segment | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	611
Financing receivables, 60 to 89 days past due | Consumer portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	590	537
Financing receivables, 60 to 89 days past due | Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	19	15
Financing receivables, 60 to 89 days past due | Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	11	5
Financing receivables, 60 to 89 days past due | Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	8	10
Financing receivables, 60 to 89 days past due | Consumer portfolio segment | Other loan | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	2
Financing receivables, 60 to 89 days past due | Commercial portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	5
Financing receivables, 60 to 89 days past due | Commercial portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	1
Financing receivables, 60 to 89 days past due | Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	0
Financing receivables, 60 to 89 days past due | Commercial portfolio segment | Other loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	0	4
Financing receivables, equal to greater than 90 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		390
Financing receivables, equal to greater than 90 days past due | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	455
Financing receivables, equal to greater than 90 days past due | Consumer portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due		342
Financing receivables, equal to greater than 90 days past due | Consumer portfolio segment | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	406
Financing receivables, equal to greater than 90 days past due | Consumer portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	367	296
Financing receivables, equal to greater than 90 days past due | Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	37	46
Financing receivables, equal to greater than 90 days past due | Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	9	4
Financing receivables, equal to greater than 90 days past due | Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	28	42
Financing receivables, equal to greater than 90 days past due | Consumer portfolio segment | Other loan | Excludes fair value option elected other loans
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	2
Financing receivables, equal to greater than 90 days past due | Commercial portfolio segment
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	49	48
Financing receivables, equal to greater than 90 days past due | Commercial portfolio segment | Automotive loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	28	31
Financing receivables, equal to greater than 90 days past due | Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	4	1
Financing receivables, equal to greater than 90 days past due | Commercial portfolio segment | Other loan
Financing Receivable, Past Due [Line Items]
Financing receivable, recorded investment, past due	$ 17	$ 16

Finance Receivables and Loans_8

Finance Receivables and Loans, Net (Schedule of Financing Receivables, Non Accrual Status) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	$ 1,036	$ 1,092
Consumer portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	821	743
Consumer portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	762	664
Consumer portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	57	79
Consumer portfolio segment | Mortgage Finance operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	17	9
Consumer portfolio segment | Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	40	70
Consumer portfolio segment | Other loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	2	0
Commercial portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	215	349
Commercial portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	73	203
Commercial portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	4	4
Commercial portfolio segment | Other loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded investment, nonaccrual status	$ 138	$ 142

Finance Receivables and Loans_9

Finance Receivables and Loans, Net (Financing Receivable Credit Quality Indicators) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 128,231	$ 129,926
Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	128,220
Consumer portfolio segment
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	89,924	87,240
Consumer portfolio segment | Fair value | Finance receivables and Loans, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Fair Value Disclosure	11
Consumer portfolio segment | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	89,913
Consumer portfolio segment | Performing Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net		86,497
Consumer portfolio segment | Performing Financial Instruments | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	89,092
Consumer portfolio segment | Nonperforming Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net		743
Consumer portfolio segment | Nonperforming Financial Instruments | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	821
Consumer portfolio segment | Automotive loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	72,390	70,539
Consumer portfolio segment | Automotive loan | Performing Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	71,628	69,875
Consumer portfolio segment | Automotive loan | Nonperforming Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	762	664
Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	17,322	16,701
Consumer portfolio segment | Real estate-backed loan | Performing Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	17,265	16,622
Consumer portfolio segment | Real estate-backed loan | Nonperforming Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	57	79
Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	16,181	15,155
Consumer portfolio segment | Mortgage Finance operations | Performing Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	16,164	15,146
Consumer portfolio segment | Mortgage Finance operations | Nonperforming Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	17	9
Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	1,141	1,546
Consumer portfolio segment | Mortgage - Legacy | Performing Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	1,101	1,476
Consumer portfolio segment | Mortgage - Legacy | Nonperforming Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	40	70
Consumer portfolio segment | Other loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	212	0
Consumer portfolio segment | Other loan | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	201
Consumer portfolio segment | Other loan | Performing Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net		0
Consumer portfolio segment | Other loan | Performing Financial Instruments | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	199
Consumer portfolio segment | Other loan | Nonperforming Financial Instruments
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net		$ 0
Consumer portfolio segment | Other loan | Nonperforming Financial Instruments | Excludes fair value option elected other loans
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 2

Finance Receivables and Loan_10

Finance Receivables and Loans, Net (Schedule of Pass And Criticized Credit Quality Indicators of Finance Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 128,231	$ 129,926
Commercial portfolio segment
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	38,307	42,686
Commercial portfolio segment | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	34,080	38,710
Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,227	3,976
Commercial portfolio segment | Automotive loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	28,332	33,672
Commercial portfolio segment | Automotive loan | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	25,235	30,799
Commercial portfolio segment | Automotive loan | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	3,097	2,873
Commercial portfolio segment | Other loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	5,014	4,205
Commercial portfolio segment | Other loan | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,225	3,373
Commercial portfolio segment | Other loan | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	789	832
Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,961	4,809
Commercial portfolio segment | Real estate-backed loan | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,620	4,538
Commercial portfolio segment | Real estate-backed loan | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 341	$ 271

Finance Receivables and Loan_11

Finance Receivables and Loans, Net (Impaired Financing Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	$ 1,013	$ 1,105
Financing receivable, impaired, gross carrying value	961	1,075
Financing receivable, impaired, with no allowance	261	332
Financing receivable, impaired, with related allowance	700	743
Financing receivable, impaired, allowance for impaired loans	89	123
Consumer portfolio segment
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	766	739
Financing receivable, impaired, gross carrying value	746	726
Financing receivable, impaired, with no allowance	183	176
Financing receivable, impaired, with related allowance	563	550
Financing receivable, impaired, allowance for impaired loans	56	67
Consumer portfolio segment | Automotive loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	553	503
Financing receivable, impaired, gross carrying value	538	495
Financing receivable, impaired, with no allowance	113	105
Financing receivable, impaired, with related allowance	425	390
Financing receivable, impaired, allowance for impaired loans	38	44
Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	213	236
Financing receivable, impaired, gross carrying value	208	231
Financing receivable, impaired, with no allowance	70	71
Financing receivable, impaired, with related allowance	138	160
Financing receivable, impaired, allowance for impaired loans	18	23
Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	14	15
Financing receivable, impaired, gross carrying value	14	15
Financing receivable, impaired, with no allowance	6	6
Financing receivable, impaired, with related allowance	8	9
Financing receivable, impaired, allowance for impaired loans	0	1
Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	199	221
Financing receivable, impaired, gross carrying value	194	216
Financing receivable, impaired, with no allowance	64	65
Financing receivable, impaired, with related allowance	130	151
Financing receivable, impaired, allowance for impaired loans	18	22
Commercial portfolio segment
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	247	366
Financing receivable, impaired, gross carrying value	215	349
Financing receivable, impaired, with no allowance	78	156
Financing receivable, impaired, with related allowance	137	193
Financing receivable, impaired, allowance for impaired loans	33	56
Commercial portfolio segment | Automotive loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	73	203
Financing receivable, impaired, gross carrying value	73	203
Financing receivable, impaired, with no allowance	1	112
Financing receivable, impaired, with related allowance	72	91
Financing receivable, impaired, allowance for impaired loans	12	10
Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	4	4
Financing receivable, impaired, gross carrying value	4	4
Financing receivable, impaired, with no allowance	4	4
Financing receivable, impaired, with related allowance	0	0
Financing receivable, impaired, allowance for impaired loans	0	0
Commercial portfolio segment | Other loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, unpaid principal balance	170	159
Financing receivable, impaired, gross carrying value	138	142
Financing receivable, impaired, with no allowance	73	40
Financing receivable, impaired, with related allowance	65	102
Financing receivable, impaired, allowance for impaired loans	$ 21	$ 46

Finance Receivables and Loan_12

Finance Receivables and Loans, Net (Schedule of Average Balance and Interest Income of Impaired Finance Receivables) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	$ 969	$ 889	$ 756
Financing receivable, impaired, interest income	47	44	42
Consumer portfolio segment
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	730	707	633
Financing receivable, impaired, interest income	45	39	31
Consumer portfolio segment | Automotive loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	510	478	391
Financing receivable, impaired, interest income	35	28	21
Consumer portfolio segment | Real estate-backed loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	220	229	242
Financing receivable, impaired, interest income	10	11	10
Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	14	11	8
Financing receivable, impaired, interest income	1	1	0
Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	206	218	234
Financing receivable, impaired, interest income	9	10	10
Commercial portfolio segment
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	239	182	123
Financing receivable, impaired, interest income	2	5	11
Commercial portfolio segment | Automotive loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	113	93	49
Financing receivable, impaired, interest income	2	4	2
Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	5	5	5
Financing receivable, impaired, interest income	0	1	0
Commercial portfolio segment | Other loan
Financing Receivable, Impaired [Line Items]
Financing receivable, impaired, average balance	121	84	69
Financing receivable, impaired, interest income	$ 0	$ 0	$ 9

Finance Receivables and Loan_13

Finance Receivables and Loans, Net (Troubled Debt Restructurings) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, gross carrying value	$ 867	$ 812	$ 712
Loans and leases receivable, impaired, commitment to lend	$ 17	$ 4	$ 6
Consumer portfolio segment | Automotive loan
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	27,623	26,748,000,000	26,156,000,000
Financing receivable, modifications, pre-modification gross carrying value	$ 476	$ 426	$ 380
Financing receivable, modifications, post-modification gross carrying value	$ 413	$ 378	$ 333
Consumer portfolio segment | Mortgage Finance operations
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	8	23,000,000	4,000,000
Financing receivable, modifications, pre-modification gross carrying value	$ 1	$ 9	$ 1
Financing receivable, modifications, post-modification gross carrying value	$ 1	$ 9	$ 1
Consumer portfolio segment | Mortgage - Legacy
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	61	204,000,000	122,000,000
Financing receivable, modifications, pre-modification gross carrying value	$ 8	$ 30	$ 21
Financing receivable, modifications, post-modification gross carrying value	$ 8	$ 29	$ 21
Consumer portfolio segment | Residential Mortgage
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	69	227,000,000	126,000,000
Financing receivable, modifications, pre-modification gross carrying value	$ 9	$ 39	$ 22
Financing receivable, modifications, post-modification gross carrying value	$ 9	$ 38	$ 22
Consumer portfolio segment | Consumer Loan
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	27,692	26,975,000,000	26,282,000,000
Financing receivable, modifications, pre-modification gross carrying value	$ 485	$ 465	$ 402
Financing receivable, modifications, post-modification gross carrying value	$ 422	$ 416	$ 355
Commercial portfolio segment
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	10	6,000,000	6,000,000
Financing receivable, modifications, pre-modification gross carrying value	$ 128	$ 89	$ 63
Financing receivable, modifications, post-modification gross carrying value	$ 92	$ 86	$ 62
Commercial portfolio segment | Automotive loan
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	7	3,000,000	4,000,000
Financing receivable, modifications, pre-modification gross carrying value	$ 46	$ 4	$ 16
Financing receivable, modifications, post-modification gross carrying value	$ 46	$ 4	$ 15
Commercial portfolio segment | Real estate-backed loan
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans			2,000,000
Financing receivable, modifications, pre-modification gross carrying value			$ 3
Financing receivable, modifications, post-modification gross carrying value			$ 3
Commercial portfolio segment | Other loan
Financing Receivable, Troubled Debt Restructuring
Financing receivable, modifications, number of loans	3	3,000,000	0
Financing receivable, modifications, pre-modification gross carrying value	$ 82	$ 85	$ 44
Financing receivable, modifications, post-modification gross carrying value	$ 46	$ 82	$ 44

Finance Receivables and Loan_14

Finance Receivables and Loans, Net (Finance receivables and loans redefaulted during the period) (Details) - Consumer portfolio segment $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Accounts, Notes, Loans and Financing Receivable
Financing receivable, modifications, subsequent default, number of loans	7,215	9,713	8,832,000,000
Financing receivable, modifications, subsequent default, gross carrying value	$ 81	$ 111	$ 103
Financing receivables, impaired, troubled debt restructuring, charge-off amount	$ 52	$ 73	$ 71
Automotive loan
Accounts, Notes, Loans and Financing Receivable
Financing receivable, modifications, subsequent default, number of loans	7,215	9,711	8,829,000,000
Financing receivable, modifications, subsequent default, gross carrying value	$ 81	$ 111	$ 102
Financing receivables, impaired, troubled debt restructuring, charge-off amount	$ 52	$ 73	$ 71
Mortgage Finance operations
Accounts, Notes, Loans and Financing Receivable
Financing receivable, modifications, subsequent default, number of loans			1,000,000
Financing receivable, modifications, subsequent default, gross carrying value			$ 1
Financing receivables, impaired, troubled debt restructuring, charge-off amount			$ 0
Mortgage - Legacy
Accounts, Notes, Loans and Financing Receivable
Financing receivable, modifications, subsequent default, number of loans		2	2,000,000
Financing receivable, modifications, subsequent default, gross carrying value		$ 0	$ 0
Financing receivables, impaired, troubled debt restructuring, charge-off amount		$ 0	$ 0

Finance Receivables and Loan_15

Finance Receivables and Loans, Net Finance Receivables and Loans, Net (Consumer Concentration Risk) (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 128,231,000,000	$ 129,926,000,000
Consumer portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	89,924,000,000	87,240,000,000
Consumer portfolio segment | California and Texas
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.249	0.254
Consumer automotive | Consumer portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	72,390,000,000	70,539,000,000
Consumer automotive | Consumer portfolio segment | California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.085	0.084
Consumer automotive | Consumer portfolio segment | Texas
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.124	0.128
Consumer automotive | Consumer portfolio segment | Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.088	0.088
Consumer automotive | Consumer portfolio segment | Pennsylvania
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.046	0.045
Consumer automotive | Consumer portfolio segment | Illinois
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.041	0.041
Consumer automotive | Consumer portfolio segment | Georgia
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.039	0.041
Consumer automotive | Consumer portfolio segment | North Carolina
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.040	0.039
Consumer automotive | Consumer portfolio segment | New York
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.031	0.031
Consumer automotive | Consumer portfolio segment | Ohio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.036	0.035
Consumer automotive | Consumer portfolio segment | New Jersey
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.028	0.027
Consumer automotive | Consumer portfolio segment | Other United States
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.442	0.441
Consumer automotive | Consumer portfolio segment | United States
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	1	1
Real estate-backed loan | Consumer portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	17,322,000,000	16,701,000,000
Real estate-backed loan | Consumer portfolio segment | California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.351	0.369
Real estate-backed loan | Consumer portfolio segment | Texas
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.065	0.062
Real estate-backed loan | Consumer portfolio segment | Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.051	0.047
Real estate-backed loan | Consumer portfolio segment | Pennsylvania
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.019	0.014
Real estate-backed loan | Consumer portfolio segment | Illinois
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.026	0.030
Real estate-backed loan | Consumer portfolio segment | Georgia
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.028	0.028
Real estate-backed loan | Consumer portfolio segment | North Carolina
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.020	0.017
Real estate-backed loan | Consumer portfolio segment | New York
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.030	0.024
Real estate-backed loan | Consumer portfolio segment | Ohio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.005	0.004
Real estate-backed loan | Consumer portfolio segment | New Jersey
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.023	0.021
Real estate-backed loan | Consumer portfolio segment | Other United States
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.382	0.384
Real estate-backed loan | Consumer portfolio segment | United States
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 1	$ 1

Finance Receivables and Loan_16

Finance Receivables and Loans, Net Finance Receivables and Loans, Net (Commercial Concentration Risk) (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 128,231,000,000	$ 129,926,000,000
Commercial portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	38,307,000,000	42,686,000,000
Commercial portfolio segment | Texas
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.150	0.155
Commercial portfolio segment | Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.116	0.116
Commercial portfolio segment | Michigan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.082	0.068
Commercial portfolio segment | California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.072	0.083
Commercial portfolio segment | New York
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.059	0.048
Commercial portfolio segment | North Carolina
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.046	0.036
Commercial portfolio segment | Georgia
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.035	0.040
Commercial portfolio segment | New Jersey
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.029	0.031
Commercial portfolio segment | South Carolina
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.028	0.034
Commercial portfolio segment | Illinois
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.024	0.020
Commercial portfolio segment | Other United States
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0.359	0.369
Commercial portfolio segment | United States
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	$ 1	$ 1

Finance Receivables and Loan_17

Finance Receivables and Loans, Net Finance Receivables and Loans, Net (Commercial Criticized Exposures by Industry) (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 128,231,000,000	$ 129,926,000,000
Commercial portfolio segment
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	38,307,000,000	42,686,000,000
Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	4,227,000,000	3,976,000,000
Weighted average | Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	1	1
Automotive | Weighted average | Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	0.817	0.806
Services | Weighted average | Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	0.054	0.050
Electronics | Weighted average | Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	0.037	0.023
Other | Weighted average | Commercial portfolio segment | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Finance receivables and loans, net	$ 0.092	$ 0.121

Leasing (Investments In Operati

Leasing (Investments In Operating Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	7 years
Lessee, operating lease, noncancellable lease term	367 days
Lessee, operating lease, lease extension, maximum	48 months
Operating lease, right-of-use assets	$ 168
Operating lease, liabilities	196
Cash paid for amounts included in the measurement of lease liabilities	49
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 52
Operating lease, weighted average discount rate	2.85%
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, option to terminate	P2Y
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, option to terminate	P6Y
Land and Building | Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Option to Extend	P3Y
Land and Building | Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Option to Extend	P15Y
Corporate Facilities | Minimum
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	8 months
Corporate Facilities | Maximum
Lessee, Lease, Description [Line Items]
Operating lease, weighted-average remaining lease term	12 years
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease, right-of-use assets		$ 161
Operating lease, liabilities		$ 190

Leasing Leasing (Lessee, Operat

Leasing Leasing (Lessee, Operating Lease, Liability, Maturity) (Details) $ in Millions	Dec. 31, 2019USD ($)
Leases [Abstract]
2020	$ 50
2021	43
2022	29
2023	18
2024	14
2025 and thereafter	62
Total undiscounted cash flows	216
Difference between undiscounted cash flows and discounted cash flows	(20)
Operating lease, liabilities	196
Lessee, Operating Lease, Lease Not yet Commenced, Undiscounted Future Lease Payments	$ 290
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract	15 years

Leasing Leasing (Schedule of Fu

Leasing Leasing (Schedule of Future Minimum Rental Payments for Operating Leases) (Details) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 48
2020	47
2021	46
2022	37
2023	31
2024 and thereafter	294
Total minimum payments required	$ 503

Leasing Leasing (Lease, Cost) (

Leasing Leasing (Lease, Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Operating lease expense	$ 45	$ 43	$ 42
Variable lease expense	8	7	7
Total lease expense, net	$ 53	$ 50	$ 49

Leasing Leasing (Schedule of Pr

Leasing Leasing (Schedule of Property Subject to or Available for Operating Lease) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Residual value guarantee	15.00%
Vehicles available for operating lease, gross	$ 10,426	$ 9,995
Lessor Operating Lease Accumulated Depreciation	1,562	1,578
Investment in operating leases, net	$ 8,864	$ 8,417
Minimum
Lessor, Lease, Description [Line Items]
Lessor, operating lease, lessee option to purchase underlying asset	P24M
Maximum
Lessor, Lease, Description [Line Items]
Lessor, operating lease, lessee option to purchase underlying asset	P60M
Vehicles
Lessor, Lease, Description [Line Items]
Operating Lease, Residual Value of Leased Asset	$ 352

Leasing Leasing (Lessor, Operat

Leasing Leasing (Lessor, Operating Lease, Payments to be Received, Maturity) (Details) $ in Millions	Dec. 31, 2019USD ($)
Leases [Abstract]
2019	$ 1,339
2020	851
2021	383
2022	86
2023	6
2025 and thereafter	0
Total lease payments from operating leases	$ 2,665

Leasing Leasing (Depreciation E

Leasing Leasing (Depreciation Expense on Operating Lease Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases, Operating [Abstract]
Operating Lease, Lease Income	$ 1,470	$ 1,489	$ 1,867
Depreciation expense on operating lease assets	1,050	1,115	1,368
Remarketing (gains) and losses, net	(69)	(90)	(124)
Net depreciation expense on operating lease assets	981	1,025	1,244
Variable lease payments, excessive wear and tear	$ 19	$ 24	$ 32

Leasing Leasing (Sales-type and

Leasing Leasing (Sales-type and Direct Financing Leases, Lease Receivable, Maturity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Direct financing lease, net investment in lease	$ 472	$ 439
Direct financing lease, present value of lease payments recorded as lease receivable	459	425
Direct financing lease, unguaranteed residual asset	13	14
Direct financing lease, interest income	25	$ 22	$ 22
2020	167
2021	142
2022	94
2023	60
2024	32
2025 and thereafter	19
Total undiscounted cash flows	514
Direct financing leases, lease receivable, difference between undiscounted cash flows and discounted cash flows	$ (55)

Securitizations and Variable _3

Securitizations and Variable Interest Entities (Schedule of Variable Interest Entities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale, Gain (Loss) on Sale	$ 0	$ 1	$ 2
Variable Interest Entitiy, Assets Deconsolidated	417	1,235
Variable interest entity, maximum loss exposure	1,837	2,334
Variable interest entity, carrying value of assets for which we have continuing involvement	29,487	28,195
Variable interest entity, carrying value of liabilities for which we have continuing involvement	9,497	10,845
On-balance sheet variable interest entities | Consumer Automotive Industry Sector
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	20,376	16,255
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	6,070	6,573
Variable Interest Entity, Consolidated, Assets, Not Pledged	9,000	8,400
Variable Interest Entity, Consolidated, Liabilities, No Recourse	21	25
On-balance sheet variable interest entities | Commercial Automotive Industry Sector
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	8,009	11,089
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	3,049	3,946
Off-balance sheet variable interest entities | Consumer Automotive Industry Sector
Variable Interest Entity [Line Items]
Variable interest entity, nonconsolidated, carrying amount, assets	23	45
Variable interest entity, nonconsolidated, carrying amount, liabilities	0	0
Variable Interest Entitiy, Assets Deconsolidated	417	1,235
Variable interest entity, maximum loss exposure	440	1,280
Off-balance sheet variable interest entities | Consumer Automotive Industry Sector | Held-to-maturity Securities
Variable Interest Entity [Line Items]
Variable interest entity, nonconsolidated, carrying amount, assets	21	43
Off-balance sheet variable interest entities | Consumer Automotive Industry Sector | Other Assets
Variable Interest Entity [Line Items]
Variable interest entity, nonconsolidated, carrying amount, assets	2	2
Off-balance sheet variable interest entities | Commercial Other Industry Sector
Variable Interest Entity [Line Items]
Variable interest entity, nonconsolidated, carrying amount, assets	1,079	806
Variable interest entity, nonconsolidated, carrying amount, liabilities	378	326
Variable Interest Entitiy, Assets Deconsolidated	0	0
Variable interest entity, maximum loss exposure	1,397	$ 1,054
Amount reconsolidated during the period | Consumer Automotive Industry Sector
Variable Interest Entity [Line Items]
Assets of nonconsolidated variable interest entity	48
Amount reconsolidated during the period | Consumer Automotive Industry Sector | Debt
Variable Interest Entity [Line Items]
Assets of nonconsolidated variable interest entity	$ 45

Securitizations and Variable _4

Securitizations and Variable Interest Entities Securitizations and Variable Interest Entities (On-balance Sheet Variable Interest Entities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	$ 128,231	$ 129,926
Loans and Leases Receivable, Allowance	(1,263)	(1,242)	$ (1,276)
Finance receivables and loans, net	126,968	128,684
Investment in operating leases, net	8,864	8,417
Other assets	6,073	6,153
Assets	180,644	178,869	167,148
Long-term debt	34,027	44,193
Accrued expenses and other liabilities	1,972	1,676
Liabilities	166,228	165,601
On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	18,710	18,086
Loans and Leases Receivable, Allowance	(153)	(114)
Finance receivables and loans, net	18,557	17,972
Investment in operating leases, net	0	164
Other assets	787	767
Assets	19,344	18,903
Long-term debt	9,087	10,482
Accrued expenses and other liabilities	11	12
Liabilities	9,098	10,494
Consumer portfolio segment
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	89,924	87,240
Consumer portfolio segment | On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	10,791	7,282
Commercial portfolio segment
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	38,307	42,686
Loans and Leases Receivable, Allowance	(133)	(141)	$ (131)
Commercial portfolio segment | On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	$ 7,919	$ 10,804

Securitizations and Variable _5

Securitizations and Variable Interest Entities (Schedule of Cash Flow Received from and Paid to Nonconsolidated Securitization Entities) (Details) - Off-balance sheet variable interest entities - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consumer Automotive Industry Sector
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash flows received on retained interests in securitization entities	$ (23)	$ (20)	$ (21)
Cash flows between transferor and transferee, servicing fees	10	18	31
Cash flows between transferor and transferee, disbursement for repurchases during the period	2	4	491
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers		24	1,187
Cash Flow Between Transferee and Transferor Representations And Warranties Obligations		0
Other cash flows			4
Consumer Mortgage Industry Sector
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash flows received on retained interests in securitization entities	0	0	0
Cash flows between transferor and transferee, servicing fees	0	0	0
Cash flows between transferor and transferee, disbursement for repurchases during the period	$ 0	0	0
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers		0	0
Cash Flow Between Transferee and Transferor Representations And Warranties Obligations		$ 2
Other cash flows			$ 0

Securitizations and Variable _6

Securitizations and Variable Interest Entities (Schedule of Quantitative Information and Net Credit Losses about Securitized and Other Financial Assets Managed Together) (Details) - Consumer Automotive Industry Sector - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items]
Loans managed and securitized, principal amount outstanding	$ 624	$ 1,869
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Delinquent Amount at End of Period	8	16
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Net Credit Losses During Period	7	12
Whole Loan Sales
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items]
Loans managed and securitized, principal amount outstanding	207	634
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Delinquent Amount at End of Period	2	3
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Net Credit Losses During Period	1	2
Variable Interest Entity, Not Primary Beneficiary [Member]
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items]
Loans managed and securitized, principal amount outstanding	417	1,235
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Delinquent Amount at End of Period	6	13
Derecognized Assets, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together, Net Credit Losses During Period	$ 6	$ 10

Securitizations and Variable _7

Securitizations and Variable Interest Entities Securitizations and Variable Interest Entities (Affordable Housing Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Securitizations And Variable Interest Entities [Abstract]
Affordable Housing Tax Credits and Other Tax Benefits, Amount	$ 86	$ 61	$ 43
Amortization Method Qualified Affordable Housing Project Investments, Amortization	72	51	44
Affordable Housing Project Investment, Write-down, Amount	0	0	$ 0
Amortization Method Qualified Affordable Housing Project Investments	830	649
Qualified Affordable Housing Project Investments, Commitment	$ 372	$ 319

Premiums Receivable and Other_3

Premiums Receivable and Other Insurance Assets Premiums Receivable and Other Insurance Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Premiums and Other Receivables, Net [Abstract]
Prepaid reinsurance premiums	$ 551	$ 527
Reinsurance recoverables on unpaid losses	88	96
Reinsurance recoverables on paid losses	23	22
Premiums receivable	105	88
Deferred policy acquisition cost	1,791	1,593
Premiums receivable and other insurance assets	$ 2,558	$ 2,326

Other Assets (Schedule of Other

Other Assets (Schedule of Other Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Other Assets [Abstract]
Property and equipment at cost	$ 1,332	$ 1,250
Accumulated depreciation, property and equipment	(686)	(686)
Property and equipment, net	646	564
Nonmarketable equity securities	1,232	1,410
Investments in qualified affordable housing projects	830	649
Restricted cash collections for securitization trusts	738	965
Accrued interest, late fees, and rent receivables	589	599
Goodwill	393	240
Equity method investments	358	262
Other accounts receivable	117	203
Restricted cash and cash equivalents	87	124
Net intangible assets	69	59
Fair value of derivative contracts in receivable position	64	41
Deferred tax assets, net	58	317
Other assets, other	892	720
Total other assets	6,073	6,153
Federal Home Loan Bank stock	701	903
Federal Reserve Bank stock	449	448
Equity securities without a readily determinable fair value	82	59
Equity securities without readily determinable fair value, upward price adjustment, annual amount	9
Equity securities without readily determinable fair value, impairment loss, annual amount	3
Equity securities without readily determinable fair value, upward price adjustment, cumulative amount	10
Impairment related to equity securities without a readily determinable fair value	6
Intangible Assets, Gross (Excluding Goodwill)	111	88
Goodwill [Line Items]
Goodwill	393	240
Accumulated depreciation of intangible assets	42	29
Corporate and Other
Other Assets [Abstract]
Goodwill	346	193
Goodwill [Line Items]
Goodwill	346	193
Goodwill, acquired during period	153
Insurance operations | Operating Segments
Other Assets [Abstract]
Goodwill	27	27
Goodwill [Line Items]
Goodwill	27	27
Automotive Finance operations | Operating Segments
Other Assets [Abstract]
Goodwill	20	20
Goodwill [Line Items]
Goodwill	$ 20	$ 20

Deposit Liabilities (Schedule o

Deposit Liabilities (Schedule of Deposit Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Noninterest-bearing deposits	$ 119	$ 142
Interest-bearing Deposit Liabilities, by Component [Abstract]
Interest-bearing deposits, savings and money-market checking accounts	62,486	56,050
Interest-bearing deposits, certificates of deposits	58,146	49,985
Interest-bearing deposits, other	1	1
Total deposit liabilities	120,752	106,178
Certificates of deposit, $100,000 or more	25,600	21,000
Certificates of deposit, in excess of $250,000 federal insurance limit	$ 8,200	$ 6,100

Deposit Liabilities Deposit Lia

Deposit Liabilities Deposit Liabilities (Time Deposit Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Due in 2020	$ 41,419
Due in 2021	10,541
Due in 2022	4,061
Due in 2023	996
Due in 2024	1,129
Total certificates of deposit	$ 58,146	$ 49,985

Debt (Schedule of Short-term De

Debt (Schedule of Short-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Demand notes	$ 2,581	$ 2,477
Federal Home Loan Bank, advances	2,950	6,825
Securities sold under agreements to repurchase	0	685
Total short-term borrowings	$ 5,531	$ 9,987
Weighted Average Interest Rate	1.80%	2.50%
Non-derivative Cash Collateral Placed with Counterparties Associated with the Repurchase Agreements	$ 0	$ 0
Non-derivative cash collateral received from counterparties associated with repurchase agreements	0	8
Non-derivative noncash collateral received from counterparties associated with repurchase agreements	0	4
Unsecured debt
Short-term Debt [Line Items]
Demand notes	2,581	2,477
Federal Home Loan Bank, advances	0	0
Securities sold under agreements to repurchase	0	0
Total short-term borrowings	2,581	2,477
Secured debt
Short-term Debt [Line Items]
Demand notes	0	0
Federal Home Loan Bank, advances	2,950	6,825
Securities sold under agreements to repurchase	0	685
Total short-term borrowings	2,950	$ 7,510
Financial instruments sold under agreements to repurchase	$ 0

Debt (Long-term Debt) (Details)

Debt (Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total long-term debt	$ 34,027	$ 44,193
Debt Instrument, Interest Rate, Stated Percentage	8.125%
Subordinated Debt	$ 1,000	1,000
Secured Debt	25,773	39,596
Long-term debt, due within one year	9,219	8,976
Long-term debt, due after one year	24,808	35,217
Debt converted from fixed-rate into variable-rate	7,000	0
Unsecured debt
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Amount	8,566	9,406
Long-term Debt, Percentage Bearing Variable Interest, Amount	1	1
Trust preferred securities	2,575	2,572
Long-term Debt, Fair Value Hedge Basis Adjustment	62	128
Total long-term debt	$ 11,204	$ 12,107
Debt, Weighted Average Interest Rate	6.34%	6.29%
Long-term debt, due within one year	$ 2,214	$ 1,663
Long-term debt, due after one year	$ 8,990	$ 10,444
Unsecured debt | Minimum
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.71%	2.42%
Unsecured debt | Maximum
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.00%	8.40%
Secured debt
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Amount	$ 21,477	$ 23,514
Long-term Debt, Percentage Bearing Variable Interest, Amount	1,384	8,633
Long-term Debt, Fair Value Hedge Basis Adjustment	(38)	(61)
Total long-term debt	$ 22,823	$ 32,086
Debt, Weighted Average Interest Rate	2.44%	2.54%
Long-term Debt, No stated interest rate	$ 92	$ 5
Variable Interest Entity Debt	9,100	10,500
Long-term debt, due within one year	7,005	7,313
Long-term debt, due after one year	15,818	24,773
Secured debt | Committed funding facilities
Debt Instrument [Line Items]
Long-term line of credit	$ 450	$ 6,665
Secured debt | Minimum
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.35%	1.26%
Secured debt | Maximum
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.03%	4.50%
Federal Home Loan Bank advances
Debt Instrument [Line Items]
Secured Debt	$ 13,300	$ 14,900

Debt (Scheduled Remaining Matur

Debt (Scheduled Remaining Maturity of Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of principal in next 12 months	$ 9,219
Long-term debt, maturities, repayments of principal in year two	10,180
Long-term debt, maturities, repayments of principal in year three	6,621
Long-term debt, maturities, repayments of principal in year four	559
Long-term debt, maturities, repayments of principal in year five	1,512
Long-term debt, maturities, repayments of principal after year five	5,936
Total long-term debt	34,027	$ 44,193
Unsecured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of principal in next 12 months	2,214
Long-term debt, maturities, repayments of principal in year two	650
Long-term debt, maturities, repayments of principal in year three	1,069
Long-term debt, maturities, repayments of principal in year four	(68)
Long-term debt, maturities, repayments of principal in year five	1,405
Long-term debt, maturities, repayments of principal after year five	5,934
Total long-term debt	11,204	12,107
Secured debt
Debt Instrument [Line Items]
Total long-term debt	22,823	$ 32,086
Long-term debt | Unsecured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of principal in next 12 months	2,258
Long-term debt, maturities, repayments of principal in year two	697
Long-term debt, maturities, repayments of principal in year three	1,121
Long-term debt, maturities, repayments of principal in year four	(9)
Long-term debt, maturities, repayments of principal in year five	1,470
Long-term debt, maturities, repayments of principal after year five	6,767
Total long-term debt	12,304
Long-term debt | Secured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of principal in next 12 months	7,005
Long-term debt, maturities, repayments of principal in year two	9,530
Long-term debt, maturities, repayments of principal in year three	5,552
Long-term debt, maturities, repayments of principal in year four	627
Long-term debt, maturities, repayments of principal in year five	107
Long-term debt, maturities, repayments of principal after year five	2
Total long-term debt	22,823
Original issue discount | Unsecured debt
Debt Instrument [Line Items]
Debt instrument, unamortized discount, current	(44)
Debt instrument, unamortized discount	(1,100)
Original issue discount | Unsecured debt | Debt instrument, redemption, period two
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(47)
Original issue discount | Unsecured debt | Debt instrument, redemption, period three
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(52)
Original issue discount | Unsecured debt | Debt Instrument, redemption, period four
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(59)
Original issue discount | Unsecured debt | Debt Instrument, redemption, period five
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(65)
Original issue discount | Unsecured debt | Debt instrument, redemption, period six
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	$ (833)

Debt (Pledged Assets Related to

Debt (Pledged Assets Related to Secured Borrowings and Repurchase Agreement) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Pledged Assets related to secured borrowings [Line Items]
Pledged financial instruments, investment securities	$ 2,698	$ 10,280
Pledged assets, mortgage assets held-for-investment and lending receivables	17,135	16,498
Pledged assets,operating leases	0	170
Pledged assets, restricted as collateral	46,204	59,526
Short-term borrowings	5,531	9,987
Secured Debt	25,773	39,596
Ally Bank
Pledged Assets related to secured borrowings [Line Items]
Pledged financial instruments, investment securities	2,698	9,564
Pledged assets, mortgage assets held-for-investment and lending receivables	17,135	16,498
Pledged assets,operating leases	0	0
Pledged assets, restricted as collateral	44,257	51,340
Secured Debt	24,069	32,072
Pledged assets for Federal Home Loan Bank | Ally Bank
Pledged Assets related to secured borrowings [Line Items]
Pledged assets, restricted as collateral	24,800	30,800
Pledged assets for Federal Reserve Bank | Ally Bank
Pledged Assets related to secured borrowings [Line Items]
Pledged assets, restricted as collateral	2,400	2,400
Consumer portfolio segment | Automotive loan
Pledged Assets related to secured borrowings [Line Items]
Pledged assets, finance receivables	13,481	17,015
Consumer portfolio segment | Automotive loan | Ally Bank
Pledged Assets related to secured borrowings [Line Items]
Pledged assets, finance receivables	11,534	9,715
Commercial portfolio segment | Automotive loan
Pledged Assets related to secured borrowings [Line Items]
Pledged assets, finance receivables	12,890	15,563
Commercial portfolio segment | Automotive loan | Ally Bank
Pledged Assets related to secured borrowings [Line Items]
Pledged assets, finance receivables	12,890	15,563
Secured debt
Pledged Assets related to secured borrowings [Line Items]
Short-term borrowings	$ 2,950	$ 7,510

Debt (Narrative - Trust Preferr

Debt (Narrative - Trust Preferred Securities) (Details) $ / shares in Units, $ in Billions	Dec. 31, 2019USD ($)$ / shares
Narrative - Trust Preferred Securities [Line Items]
Trust preferred securities, fixed rate, floating rate, percentage	8.125%
Preferred stock, liquidation amount per share | $ / shares	$ 25
Distribution payable in addition to annual rate equal to three-month London interbank offer rate, percentage	5.785%
Period of consecutive quarters for which Ally has right to defer interest payments, maximum	20
Redemption price, percentage of principal debt, plus accrued and unpaid interest	100.00%
Fixed income interest rate
Narrative - Trust Preferred Securities [Line Items]
Trust preferred securities	$ 2.6
Trust Preferred Securities Subject to Mandatory Redemption
Narrative - Trust Preferred Securities [Line Items]
Series 2 TRUPS included in Tier 1 capital	$ 2.5

Debt (Committed Funding Facilit

Debt (Committed Funding Facilities) (Details) - Committed funding facilities - Secured debt - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 2,500	$ 8,600
Long-term line of credit	450	6,665
Line of credit facility, remaining borrowing capacity	2,050	1,935
Revolving credit facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	2,500
Secured funding facilities, revolving, one year or greater
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	1,100
Ally Bank
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	0	4,800
Long-term line of credit	0	3,500
Line of credit facility, remaining borrowing capacity	0	1,300
Ally Financial Inc
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	2,500	3,800
Long-term line of credit	450	3,165
Line of credit facility, remaining borrowing capacity	$ 2,050	$ 635

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Schedule of Accrued Expenses and Other Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Payable and Accrued Liabilities [Abstract]
Accounts payable	$ 535	$ 516
Unfunded commitments for investment in qualified affordable housing projects	372	319
Employee compensation and benefits	296	255
Reserves for insurance losses and loss adjustment expenses	122	134	$ 140	$ 149
Net deferred tax liabilities	67	17
Cash collateral received from counterparties	48	41
Deferred revenue	36	27
Fair value of derivative contracts in payable position	5	37
Other liabilities	491	330
Total accrued expenses and other liabilities	$ 1,972	$ 1,676

Equity Equity (Details)

Equity Equity (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Equity [Abstract]
Common stock, shares outstanding	374,331,998	404,899,599	437,054,000	383,523,000	392,775,000	399,761,000	416,591,000	425,752,000	432,691,000
Change in Common Stock Outstanding
Total issued at January 1,	492,797,409	489,884,000	485,708,000
Employee benefits and compensation plans	4,160,000	2,914,000	4,176,000
Total issued at December 31,	496,957,805	492,797,409	489,884,000
Treasury balance at January 1,	87,897,810	52,830,000	18,707,000
Repurchase of common stock	34,728,000	35,068,000	34,122,000
Treasury balance at December 31,	122,625,807	87,897,810	52,830,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive (Loss) Income (Rollforward) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018	Jan. 01, 2017
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract]
Accumulated other comprehensive income (loss), investment securities, adjustment, after tax	$ 208	$ (481)	$ (173)	$ (473)	$ (186)	$ (273)
Other comprehensive income (loss), investment securities, net change, after tax	681	(295)	100
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), translation adjustment, net of tax	19	18	16	18	20	14
Other comprehensive income (loss), foreign currency translation adjustment, net of tax	1	(2)	2
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from cash flow hedges, net of tax	2	19	11	19	11	8
Other comprehensive income (loss), cash flow hedges, net change, after tax	(17)	8	3
Other Comprehensive Income (Loss), Defined Benefit Plan, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), defined benefit pension plans, after tax	(106)	(95)	(89)	(95)	(95)	(90)
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, after tax	(11)	0	1
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total accumulated other comprehensive loss, net of tax	(123)	539	235	531	250	$ 341
Other comprehensive income (loss), net of tax	$ 654	$ (289)	$ 106
Accounting Standards Update 2016-01
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract]
Accumulated other comprehensive income (loss), investment securities, adjustment, after tax					27
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), translation adjustment, net of tax					0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from cash flow hedges, net of tax					0
Other Comprehensive Income (Loss), Defined Benefit Plan, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), defined benefit pension plans, after tax					0
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total accumulated other comprehensive loss, net of tax					(27)
Accounting Standards Update 2018-02
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract]
Accumulated other comprehensive income (loss), investment securities, adjustment, after tax					(40)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), translation adjustment, net of tax					4
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from cash flow hedges, net of tax					0
Other Comprehensive Income (Loss), Defined Benefit Plan, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), defined benefit pension plans, after tax					(6)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total accumulated other comprehensive loss, net of tax					$ 42
Accounting Standards Update 2017-08
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract]
Accumulated other comprehensive income (loss), investment securities, adjustment, after tax				8
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), translation adjustment, net of tax				0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from cash flow hedges, net of tax				0
Other Comprehensive Income (Loss), Defined Benefit Plan, Net of Tax [Abstract]
Accumulated other comprehensive income (loss), defined benefit pension plans, after tax				0
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Total accumulated other comprehensive loss, net of tax				$ (8)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive (Loss) Income (Before and After Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax [Abstract]
Other compehrensive income (loss), investment securities, net unrealized gains (losses) arising during the period, before tax	$ 968	$ (375)	$ 237
Other compehrensive income (loss), investement securities, net realized gains reclassified to income from continuing operations, before tax	78	11	105
Other comprehensive income, investment securities, net change, before tax	890	(386)	132
Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax [Abstract]
Other comprehensive income (loss), investment securities, unrealized holding gains (losses) arising during the period, tax	(227)	88	(45)
Other comprehensive income (loss), investment securities, net realized gains reclassified to income from continuing operations, tax effect	(18)	(3)	(13)
Other comprehensive income (loss), investment securities, net change, tax effect	(209)	91	(32)
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract]
Other comprehensive income (loss), investment securities, net unrealized gains (losses) arising during the period, after tax	741	(287)	192
Other comprehensive income (loss), investment securities, net realized gains reclassified to income from continuing operations, after tax	60	8	92
Other comprehensive income (loss), investment securities, net change, after tax	681	(295)	100
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]
Other comprehensive income (loss), translation adjustments, net change, before tax	7	(14)	12
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Other comprehensive income (loss), translation adjustments, net unrealized gains (losses) arising during the period, tax effect	(2)	3	(4)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Other comprehensive income (loss), translation adjustments, net unrealized gains (losses) arising during the period, after tax	5	(11)	8
Other Comprehensive Income (Loss), Net investment hedges, before Tax [Abstract]
Other comprehensive income (loss), net investment hedges, unrealized gains (losses) arising during the period, before tax	(6)	12	(10)
Other Comprehensive Income (Loss), Net investment hedges, Tax [Abstract]
Other comprehensive income (loss), net investment hedges, net unrealized gains arising during the period, tax effect	2	(3)	4
Other Comprehensive Income (Loss), Net investment hedges, Net of Tax [Abstract]
Net investment hedges, unrealized gains (losses) arising during the period, after tax	(4)	9	(6)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax [Abstract]
Other comprehensive income (loss), cash flow hedges, net unrealized gains (losses) arising during the period before tax	(11)	12	5
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification, before tax	12	2
Other comprehensive income (loss), cash flow hedge, gain (loss), after reclassification, before tax	(23)	10
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax [Abstract]
Other comprehensive income (loss), cash flow hedges, net unrealized gains arising during the period, tax	4	(2)	(2)
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification, tax	(2)	0
Other comprehensive income (loss), cash flow hedge, gain (loss), after reclassification, tax	6	(2)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Other comprehensive income (loss), cash flow hedges, net unrealized gains (losses) arising during the period	(7)	10	3
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification, after tax	10	2	0
Other comprehensive income (loss), cash flow hedge, gain (loss), after reclassification and tax	(17)	8	3
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Tax [Abstract]
Other comprehensive income (loss), defined benefit pension plans, net unrealized gains (losses) arising during period, before tax	(14)	1	1
Other Comprehensive (Income) Loss, Defined Benefit Plan, Tax [Abstract]
Other comprehensive income (loss), defined benefit pension plans, net unrealized gains (losses) arising during period, tax	3	(1)	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Net of Tax [Abstract]
Other comprehensive (income), defined benefit pension plans, net unrealized gains (losses) arising during period, after tax	(11)	0	1
Other Comprehensive Income (Loss), before Tax [Abstract]
Other comprehensive income (loss), before tax	854	(377)	140
Other Comprehensive Income (Loss), Tax [Abstract]
Other comprehensive income (loss), tax effect	(200)	88	(34)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other comprehensive income (loss), net of tax	$ 654	$ (289)	$ 106

Earnings per Common Share (Sche

Earnings per Common Share (Schedule of Basic and Diluted Earnings per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income from continuing operations	$ 381	$ 381	$ 584	$ 375	$ 289	$ 374	$ 348	$ 252	$ 1,721	$ 1,263	$ 926
(Loss) income from discontinued operations, net of tax	(3)	0	(2)	(1)	1	0	1	(2)	(6)	0	3
Net income attributable to common shareholders	$ 378	$ 381	$ 582	$ 374	$ 290	$ 374	$ 349	$ 250	$ 1,715	$ 1,263	$ 929
Basic weighted-average common shares outstanding									393,234	425,165	453,704
Diluted weighted-average common shares outstanding									395,395	427,680	455,350
Earnings Per Share, Basic [Abstract]
Net income from continuing operations, basic earnings per common share	$ 1	$ 0.98	$ 1.47	$ 0.93	$ 0.70	$ 0.89	$ 0.81	$ 0.58	$ 4.38	$ 2.97	$ 2.04
Loss from discontinued operations, net of tax, basic earnings per common share									(0.02)	0	0.01
Net income, basic earnings per common share	0.99	0.97	1.46	0.93	0.70	0.89	0.81	0.57	4.36	2.97	2.05
Earnings Per Share, Diluted [Abstract]
Net income from continuing operations, diluted earnings per common share	0.99	0.97	1.46	0.92	0.70	0.88	0.80	0.57	4.35	2.95	2.03
Loss from discontinued operations, net of tax, diluted earnings per common share									(0.02)	0	0.01
Net income, diluted earnings per common share	$ 0.99	$ 0.97	$ 1.46	$ 0.92	$ 0.70	$ 0.88	$ 0.81	$ 0.57	$ 4.34	$ 2.95	$ 2.04

Regulatory Capital and Other _3

Regulatory Capital and Other Regulatory Matters (Schedule of Regulatory Capital Amount and Ratios) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
BHC enhanced prudential standards, minimum	$ 100,000
Liquidity coverage ratio weighted wholesale funding threshold	$ 50,000
Common Equity Tier One Capital – threshold for deduction of certain items, individually	10.00%
Common Equity Tier One Capital - threshold for deduction of certain items, collectively	15.00%
Risk weighting for certain items not deducted	100.00%
Common Equity Tier One Capital - threshold for deduction of certain items, transitional	25.00%
Risk weighting for certain items not deducted, transitional	250.00%
Phase-in of capital impact of Accounting Standards Update 2016-13	25.00%
BHC stress test threshold	$ 50,000
BHC capital requirement, dividend payout ratio	30.00%
Ally Financial Inc
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier one capital ratio	9.54%	9.14%
Common equity tier one capital	$ 13,837	$ 13,397
Tier one capital to risk-weighted assets, amount	$ 16,271	$ 15,831
Tier one capital to risk-weighted assets, ratio	11.22%	10.80%
Capital to risk-weighted assets, amount	$ 18,506	$ 18,046
Capital to risk-weighted assets, ratio	12.76%	12.31%
Tier one leverage to adjusted quarterly average assets, amount	$ 16,271	$ 15,831
Tier one leverage to adjusted quarterly average assets, ratio	9.08%	9.00%
Ally Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier one capital ratio	12.30%	12.61%
Common equity tier one capital	$ 16,627	$ 16,552
Tier one capital to risk-weighted assets, amount	$ 16,627	$ 16,552
Tier one capital to risk-weighted assets, ratio	12.30%	12.61%
Capital to risk-weighted assets, amount	$ 17,854	$ 17,620
Capital to risk-weighted assets, ratio	13.21%	13.42%
Tier one leverage to adjusted quarterly average assets, amount	$ 16,627	$ 16,552
Tier one leverage to adjusted quarterly average assets, ratio	10.01%	10.69%
Minimum
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier one capital ratio	4.50%
Tier one capital to risk-weighted assets, required minimum	6.00%
Capital to risk-weighted assets, required minimum	8.00%
Minimum capital conservation buffer	2.50%	1.875%
Tier one leverage ratio, minimum	4.00%
Minimum | Ally Financial Inc
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier one capital ratio	4.50%
Tier one capital to risk-weighted assets, required minimum	6.00%
Capital to risk-weighted assets, required minimum	8.00%
Tier one leverage ratio, minimum	4.00%
Tier one capital to risk-weighted assets, well-capitalized minimum	6.00%
Capital to risk weighted assets, well-capitalzed minimum	10.00%
Minimum | Ally Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier one capital ratio	4.50%
Tier one capital to risk-weighted assets, required minimum	6.00%
Capital to risk-weighted assets, required minimum	8.00%
Tier one leverage ratio, minimum	4.00%
Common Equity Tier One Capital Ratio Required To Be Well Capitalized	6.50%
Tier one capital to risk-weighted assets, well-capitalized minimum	8.00%
Capital to risk weighted assets, well-capitalzed minimum	10.00%
Tier one leverage to adjusted quarterly average assets, well-capitalized minimum	5.00%

Regulatory Capital and Other _4

Regulatory Capital and Other Regulatory Matters (Common Share Repurchases) (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 13, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Accelerated Share Repurchases [Line Items]
Treasury stock, common, amount		$ 299	$ 309		$ 300	$ 229	$ 211	$ 250	$ 195	$ 185
Treasury stock, common, shares		9,554,000	12,121,000		9,287,000	7,775,000	8,113,000	9,194,000	7,280,000	6,473,000
Common stock, shares outstanding		374,331,998	404,899,599	437,054,000	383,523,000	392,775,000	399,761,000	416,591,000	425,752,000	432,691,000
Dividends declared, amount per common share		$ 0.17	$ 0.15		$ 0.17	$ 0.17	$ 0.17	$ 0.15	$ 0.13	$ 0.13
Assets		$ 180,644	$ 178,869	$ 167,148
Cash dividends from bank subsidiaries		0	0	0
FRB required reserve balance		416	279
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments		129
Ally Bank
Accelerated Share Repurchases [Line Items]
Assets		167,500	159,000
Current period
Accelerated Share Repurchases [Line Items]
Stock repurchase program, authorized amount		$ 1,250
Increase (decrease) in share repurchase program		25.00%
Common stock | Subsequent event
Accelerated Share Repurchases [Line Items]
Dividends Payable, Date Declared	Jan. 13, 2020
Dividends Payable, Date to be Paid	Feb. 14, 2020
Guarantors
Accelerated Share Repurchases [Line Items]
Assets		$ 16,954	16,213
Cash dividends from bank subsidiaries		$ 1,950	$ 2,600	$ 3,300

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Noncash collateral placed with counterparties	$ 118	$ 105
Cash collateral placed with counterparties		26
Cash collateral received from counterparties	40	30
Noncash collateral received from counterparties	$ 29	$ 3

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities (Fair Value Amounts of Derivative Instruments Reported on our Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	$ 64	$ 41
Fair value of derivative contracts in payable position	5	37
Derivative, notional amount	32,489	38,066
Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	62	1
Fair value of derivative contracts in payable position	3	0
Derivative, notional amount	31,358	24,339
Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	2	40
Fair value of derivative contracts in payable position	2	37
Derivative, notional amount	1,131	13,727
Interest rate contracts | Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	2	37
Fair value of derivative contracts in payable position	0	37
Derivative, notional amount	1,019	13,546
Interest rate swaps | Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	0
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	17,101	24,203
Interest rate purchased options | Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	62	0
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	14,100	0
Interest rate purchased options | Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	37
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	416	6,742
Interest rate futures and forwards | Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	0
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	81	11
Interest rate written options | Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	2	0
Fair value of derivative contracts in payable position	0	37
Derivative, notional amount	522	6,793
Foreign exchange contracts | Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	3
Fair value of derivative contracts in payable position	2	0
Derivative, notional amount	112	181
Foreign exchange forwards | Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	1
Fair value of derivative contracts in payable position	3	0
Derivative, notional amount	157	136
Foreign exchange futures and forwards | Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	3
Fair value of derivative contracts in payable position	2	0
Derivative, notional amount	$ 112	$ 181

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities (Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Fair Value Hedge	$ 1,217	$ 1,485
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	18	0
Closed Portfolio and Beneficial Interest, Last-of-Layer, Amortized Cost	230	47
Hedged Asset, Discontinued Fair Value Hedge, Last-of-Layer, Amount		28
Hedge basis adjustment, last-of-layer		0
Hedged asset, last-of-layer, amount	0
Finance receivables and Loans, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Fair Value Hedge	33,312	40,850
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	135	24
Hedge basis adjustment, last-of-layer	91	19
Hedged asset, last-of-layer, amount	10,200	21,400
Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Fair Value Hedge	11,995	13,001
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	24	67
Discontinued hedge | Available-for-sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	18	(5)
Hedged Asset, Discontinued Fair Value Hedge, Last-of-Layer, Amount	200
Hedge basis adjustment, last-of-layer	2
Discontinued hedge | Finance receivables and Loans, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	44	5
Hedged Asset, Discontinued Fair Value Hedge, Last-of-Layer, Amount	12,800
Hedge basis adjustment, last-of-layer	43
Discontinued hedge | Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	$ 127	$ 67

Derivative Instruments and He_6

Derivative Instruments and Hedging Activities (Statement of Gains and Losses on Derivative Instruments Reported in Statement of Comprehensive Income) (Details) - Not designated as hedging instrument - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	$ (14)	$ 13	$ (9)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	(10)	0	(2)
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	(4)	13	(7)
Gains on mortgage and automotive loans | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	1	0	1
Other income, net of losses | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	(11)	0	(3)
Other income, net of losses | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	0	13	(7)
Other operating expenses | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments, net, pretax	$ (4)	$ 0	$ 0

Derivative Instruments and He_7

Derivative Instruments and Hedging Activities (Derivative Instruments Designated as Fair Value Hedges, Gain (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Interest and fees on finance receivables and loans	$ 7,337	$ 6,688	$ 5,819
Interest and dividends on investment securities and other earning assets	955	788	599
Interest on deposits	2,538	1,735	1,077
Interest on long-term debt	1,570	1,753	1,653
Earnings on cash flow hedges to be recognized within twelve months	19
Designated as hedging instrument | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on fair value hedges	0	0	(2)
Derivative, Gain (Loss) on Derivative, Net	0	0	0
Designated as hedging instrument | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on fair value hedges	0	0	0
Derivative, Gain (Loss) on Derivative, Net	0	0	0
Designated as hedging instrument | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on fair value hedges	0	0	0
Derivative, Gain (Loss) on Derivative, Net	(4)	1	0
Designated as hedging instrument | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on fair value hedges	0	1	5
Derivative, Gain (Loss) on Derivative, Net	15	1	0
Designated as hedging instrument | Unsecured debt | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Unsecured debt | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Unsecured debt | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Unsecured debt | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	41	62	8
Change in unrealized gain (loss) on fair value hedging instruments	(41)	(61)	(3)
Designated as hedging instrument | Federal Home Loan Bank certificates and obligations | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Federal Home Loan Bank certificates and obligations | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Federal Home Loan Bank certificates and obligations | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Federal Home Loan Bank certificates and obligations | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	47	22
Change in unrealized gain (loss) on fair value hedging instruments	0	(47)	(22)
Designated as hedging instrument | Available-for-sale securities | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Available-for-sale securities | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	28	(3)	(1)
Change in unrealized gain (loss) on fair value hedging instruments	(28)	3	1
Designated as hedging instrument | Available-for-sale securities | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Available-for-sale securities | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Fixed-rate automotive loans | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	138	19	(3)
Change in unrealized gain (loss) on fair value hedging instruments	(138)	(19)	1
Designated as hedging instrument | Fixed-rate automotive loans | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Fixed-rate automotive loans | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Fixed-rate automotive loans | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	0	0	0
Change in unrealized gain (loss) on fair value hedging instruments	0	0	0
Designated as hedging instrument | Deposit liabilities | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	0	0	0
Designated as hedging instrument | Deposit liabilities | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	0	0	0
Designated as hedging instrument | Deposit liabilities | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	(4)	1	0
Designated as hedging instrument | Deposit liabilities | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	0	0	0
Designated as hedging instrument | Variable-rate borrowings | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	0	0	0
Designated as hedging instrument | Variable-rate borrowings | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	0	0	0
Designated as hedging instrument | Variable-rate borrowings | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	0	0	0
Designated as hedging instrument | Variable-rate borrowings | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cash flow hedge gain (loss) reclassified to earnings	$ 15	$ 1	$ 0

Derivative Instruments and He_8

Derivative Instruments and Hedging Activities (Interest and Amortization on Derivative Instruments) (Details) - Designated as hedging instrument - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Total Interest And Amortization Income (Expense) Hedging Relationship	$ (6)	$ 2	$ (22)
Gain (loss) on cash flow hedging relationships	1	0	0
Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Total Interest And Amortization Income (Expense) Hedging Relationship	(1)	(1)	0
Gain (loss) on cash flow hedging relationships	0	0	0
Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Total Interest And Amortization Income (Expense) Hedging Relationship	0	0	0
Gain (loss) on cash flow hedging relationships	(1)	3	0
Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Total Interest And Amortization Income (Expense) Hedging Relationship	2	48	102
Gain (loss) on cash flow hedging relationships	0	8	(1)
Unsecured debt | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Unsecured debt | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Unsecured debt | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Unsecured debt | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	25	51	77
Gain (loss) on interest for qualifying hedge	0	8	24
Federal Home Loan Bank certificates and obligations | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Federal Home Loan Bank certificates and obligations | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Federal Home Loan Bank certificates and obligations | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Federal Home Loan Bank certificates and obligations | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	(23)	(17)	(2)
Gain (loss) on interest for qualifying hedge	0	6	3
Available-for-sale securities | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Available-for-sale securities | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	(3)	0	0
Gain (loss) on interest for qualifying hedge	2	(1)	0
Available-for-sale securities | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Available-for-sale securities | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Fixed-rate automotive loans | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	(28)	(14)	(21)
Gain (loss) on interest for qualifying hedge	22	16	(1)
Fixed-rate automotive loans | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Fixed-rate automotive loans | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Fixed-rate automotive loans | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on amortization of deferred basis adjustments	0	0	0
Gain (loss) on interest for qualifying hedge	0	0	0
Variable-rate borrowings | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Variable-rate borrowings | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Variable-rate borrowings | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Variable-rate borrowings | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	8	(1)
Deposit liabilities | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Deposit liabilities | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Deposit liabilities | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	(1)	3	0
Deposit liabilities | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Variable-rate commercial borrowings | Interest and fees on finance receivables and loans
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	1	0	0
Variable-rate commercial borrowings | Interest and dividends on investment securities and other earning assets
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Variable-rate commercial borrowings | Interest on deposits
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	0	0	0
Variable-rate commercial borrowings | Interest on long-term debt
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on interest for qualifying hedge	$ 0	$ 0	$ 0

Derivative Instruments and He_9

Derivative Instruments and Hedging Activities (Derivative Instruments Used in Net Investment Hedge Accounting Relationships) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other comprehensive income (loss), net investment hedge, foreign exchange contracts	$ (6)	$ 12	$ (10)
Interest rate contracts | Cash flow hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other comprehensive income (loss), cash flow hedge, interest rate contracts	(23)	10	5
Foreign exchange contracts | Net investment hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other comprehensive income (loss), net investment hedge, foreign exchange contracts	(6)	12	(10)
Derivative, Excluded Component, Gain (Loss), Recognized in Earnings	0	0	0
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax	$ 0	$ 0	$ 0

Income Taxes Income Taxes (Sche

Income Taxes Income Taxes (Schedule of Significant Components of Income Tax Expense) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)									$ (2)	$ (12)	$ (17)
Current Foreign Tax Expense (Benefit)									4	5	6
Current State and Local Tax Expense (Benefit)									65	35	53
Total current tax expense (benefit)									67	28	42
Deferred Federal Income Tax Expense (Benefit)									178	328	566
Deferred Foreign Income Tax Expense (Benefit)									2	0	0
Deferred State and Local Income Tax Expense (Benefit)									(1)	3	(27)
Deferred Income Tax Expense (Benefit)									179	331	539
Income tax expense from continuing operations	$ 106	$ 119	$ (90)	$ 111	$ 79	$ 91	$ 113	$ 76	$ 246	$ 359	$ 581

Income Taxes Income Taxes (Sc_2

Income Taxes Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory U.S. federal tax expense									$ 413	$ 340	$ 527
Valuation allowance change, excluding expirations									(219)	(8)	(49)
State and local income taxes, net of federal income tax benefit									50	26	7
Nondeductible expenses									29	28	4
Tax credits, excluding expirations									(27)	(20)	(12)
Changes in unrecognized tax expenses (benefits)									5	22	1
Change in enacted tax rate, amount									(1)	(23)	119
Other tax adjustments, net									(4)	(6)	(16)
Income tax expense from continuing operations	$ 106	$ 119	$ (90)	$ 111	$ 79	$ 91	$ 113	$ 76	$ 246	$ 359	$ 581
Federal statutory income tax rate									21.00%	0.00%	35.00%

Income Taxes Income Taxes (Sc_3

Income Taxes Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Deferred tax assets, tax credit carryforwards	$ 1,784	$ 1,796
Deferred tax assets, adjustment to loan value	448	366
Deferred tax assets, state and local taxes	153	168
Deferred tax assets, unearned insurance premiums	98	90
Deferred tax assets, other	214	257
Deferred tax assets, gross	2,697	2,677
Deferred tax assets, valuation allowance	(837)	(1,057)
Deferred tax assets, net of valuation allowance	1,860	1,620
Deferred tax liabilities, lease transactions	1,325	850
Deferred tax liabilities, deferred acquisiton cost	366	321
Deferred tax liabilities, debt transactions	91	93
Deferred tax liabilities, other	87	56
Deferred tax liabilities, gross	1,869	1,320
Net deferred tax (liabilities) assets	(9)	300
Deferred tax assets, net	58	317
Deferred tax liabilities, net	$ 67	$ 17

Income Taxes Income Taxes (Sc_4

Income Taxes Income Taxes (Schedule of Deferred Tax Assets and Related Valuation Allowance Recognized for Net Operating and Other Loss Carryforwards and Tax Carryforwards) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Deferred tax assets, tax credit carryforwards	$ 1,784	$ 1,796
Valuation allowance, tax credit carryforwards	(737)
Net deferred tax assets, tax credit carryforwards	1,047
Deferred tax assets, federal and state tax carryforwards	183
Federal and state tax carryforwards valuation allowance	(100)
Net deferred tax assets federal and state tax carryforwards	83
Deferred tax liabilities, tax credit carryforwards	(1,139)
Valuation allowance, other net deferred tax liabilities	0
Deferred tax assets, gross, net of deferred tax liabilities	828
Deferred tax assets, valuation allowance	(837)	(1,057)
Deferred Tax Liabilities, Net	9	$ (300)
Foreign tax credits
Operating Loss Carryforwards [Line Items]
Deferred tax assets, tax credit carryforwards	1,433
Valuation allowance, tax credit carryforwards	(737)
Net deferred tax assets, tax credit carryforwards	696
General business tax credit carryforward
Operating Loss Carryforwards [Line Items]
Deferred tax assets, tax credit carryforwards	351
Valuation allowance, tax credit carryforwards	0
Net deferred tax assets, tax credit carryforwards	351
Federal jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards	7
Operating loss carryforwards, valuation allowance	0
Net deferred tax assets operating loss carryforwards	7
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards	176
Operating loss carryforwards, valuation allowance	(100)
Net deferred tax assets operating loss carryforwards	$ 76

Income Taxes Income Taxes (Sc_5

Income Taxes Income Taxes (Schedule of Unrecognized Tax Benefits Roll Forward) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits	$ 44	$ 15	$ 14
Unrecognized tax benefits, additions based on current period tax positions	0	0	0
Unrecognized tax benefits, additions for prior period tax positions	11	29	3
Unrecognized tax benefits, reductions for prior period tax positions	(5)	0	(1)
Unrecognized tax benefits, reductions resulting from settlements	(2)	0	0
Unrecognized tax benefits, reduction resulting from expiration of statue of limitations	0	0	(1)
Unrecognized tax benefits	$ 48	$ 44	$ 15

Income Taxes Income Taxes (Narr

Income Taxes Income Taxes (Narrative - Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 38	$ 34	$ 12
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	1	1	1
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	1	$ 1	$ 1
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 36

Share-based Compensation Plan_3

Share-based Compensation Plans Shared-based Compensation Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Incentive compensation plan, shares available for future grants of equity-based awards	30,703,972
Share-based compensation, RSUs and PSUs, outstanding, non-vested	4,864,000
Share-based compensation, RSUs and PSUs, outstanding, non-vested, weighted-average grant date fair value per share	$ 23.71
Share-based compensation, RSUs and PSUs, granted	3,007,000
Share-based compensation, RSUs and PSUs, granted, weighted-average grant date fair value per share	$ 26.29
Share-based compensation, RSUs and PSUs, vested	(3,411,000)
Share-based compensation, RSUs and PSUs, vested, weighted-average grant date fair value per share	$ 22.37
Share-based compensation, RSUs and PSUs, forfeited	(93,000)
Share-based compensation, RSUs and PSUs, forfeited, weighted-average grant date fair value per share	$ 26.28
Share-based compensation, RSUs and PSUs, outstanding, non-vested	4,367,000	4,864,000
Share-based compensation, RSUs and PSUs, outstanding, non-vested, weighted-average grant date fair value per share	$ 26.48	$ 23.71
Share-based compensation, expense	$ 67,000,000	$ 72,000,000	$ 60,000,000
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSU awards payable upon vest	0
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSU awards payable upon vest	$ 1.50

Fair Value (Fair Value Measurem

Fair Value (Fair Value Measurements - Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 616	$ 773
Derivative assets	28	37
Derivative liabilities	$ (1)	$ (37)
Investment in any one industry did not exceed percentage	13.00%	9.00%
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 30,284	$ 25,303
Derivative assets	64	41
Assets, fair value	31,007	26,129
Derivative liabilities	(5)	(37)
Liabilities, fair value	5	37
Fair value, measurements, recurring | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		(37)
Fair value, measurements, recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(5)
Fair value, measurements, recurring | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	616	773
Fair value, measurements, recurring | US Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2,048	1,851
Fair value, measurements, recurring | US States and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	641	802
Fair value, measurements, recurring | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	186	145
Fair value, measurements, recurring | Agency mortgage-backed | Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	21,404	17,138
Fair value, measurements, recurring | Agency mortgage-backed | Commercial Loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,382	3
Fair value, measurements, recurring | Mortgage-backed residential
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2,850	2,686
Fair value, measurements, recurring | Mortgage-backed commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	42	714
Fair value, measurements, recurring | Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	368	723
Fair value, measurements, recurring | Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,363	1,241
Fair value, measurements, recurring | Loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held-for-sale, fair value	30	8
Fair value, measurements, recurring | Finance receivables and Loans, net | Consumer portfolio segment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	11
Fair value, measurements, recurring | Interests retained in financial asset sales
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained interest, fair value	2	4
Fair value, measurements, recurring | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	64	37
Fair value, measurements, recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		4
Fair value, measurements, recurring | Fair value, inputs, level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2,062	1,857
Derivative assets	0	0
Assets, fair value	2,670	2,623
Derivative liabilities	0	0
Liabilities, fair value	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	608	766
Fair value, measurements, recurring | Fair value, inputs, level 1 | US Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2,047	1,850
Fair value, measurements, recurring | Fair value, inputs, level 1 | US States and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	15	7
Fair value, measurements, recurring | Fair value, inputs, level 1 | Agency mortgage-backed | Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Agency mortgage-backed | Commercial Loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Mortgage-backed residential
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Mortgage-backed commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held-for-sale, fair value	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Finance receivables and Loans, net | Consumer portfolio segment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Interests retained in financial asset sales
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained interest, fair value	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Fair value, measurements, recurring | Fair value, inputs, level 1 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0
Fair value, measurements, recurring | Fair value, inputs, level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	28,220	23,446
Derivative assets	62	41
Assets, fair value	28,282	23,487
Derivative liabilities	(5)	(37)
Liabilities, fair value	5	37
Fair value, measurements, recurring | Fair value, inputs, level 2 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		(37)
Fair value, measurements, recurring | Fair value, inputs, level 2 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	(5)
Fair value, measurements, recurring | Fair value, inputs, level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 2 | US Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1	1
Fair value, measurements, recurring | Fair value, inputs, level 2 | US States and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	639	802
Fair value, measurements, recurring | Fair value, inputs, level 2 | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	171	138
Fair value, measurements, recurring | Fair value, inputs, level 2 | Agency mortgage-backed | Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	21,404	17,138
Fair value, measurements, recurring | Fair value, inputs, level 2 | Agency mortgage-backed | Commercial Loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,382	3
Fair value, measurements, recurring | Fair value, inputs, level 2 | Mortgage-backed residential
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2,850	2,686
Fair value, measurements, recurring | Fair value, inputs, level 2 | Mortgage-backed commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	42	714
Fair value, measurements, recurring | Fair value, inputs, level 2 | Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	368	723
Fair value, measurements, recurring | Fair value, inputs, level 2 | Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,363	1,241
Fair value, measurements, recurring | Fair value, inputs, level 2 | Loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held-for-sale, fair value	0	0
Fair value, measurements, recurring | Fair value, inputs, level 2 | Finance receivables and Loans, net | Consumer portfolio segment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	0
Fair value, measurements, recurring | Fair value, inputs, level 2 | Interests retained in financial asset sales
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained interest, fair value	0	0
Fair value, measurements, recurring | Fair value, inputs, level 2 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	62	37
Fair value, measurements, recurring | Fair value, inputs, level 2 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		4
Fair value, measurements, recurring | Fair value, inputs, level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2	0
Derivative assets	2	0
Assets, fair value	55	19
Derivative liabilities	0	0
Liabilities, fair value	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	8	7
Fair value, measurements, recurring | Fair value, inputs, level 3 | US Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | US States and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Agency mortgage-backed | Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Agency mortgage-backed | Commercial Loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Mortgage-backed residential
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Mortgage-backed commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Loans held-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held-for-sale, fair value	30	8
Fair value, measurements, recurring | Fair value, inputs, level 3 | Finance receivables and Loans, net | Consumer portfolio segment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivables and loans, net	11
Fair value, measurements, recurring | Fair value, inputs, level 3 | Interests retained in financial asset sales
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained interest, fair value	2	4
Fair value, measurements, recurring | Fair value, inputs, level 3 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 2	0
Fair value, measurements, recurring | Fair value, inputs, level 3 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		$ 0

Fair Value (Fair Value Measur_2

Fair Value (Fair Value Measurements - Reconciliation of Level 3 Assets And Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	$ 0	$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset, gain (loss) included in earnings	20	(3)
Fair value, measurement, recurring, asset, gain (loss) included in other comprehensive income (loss)	0	0
Fair value, measurement, recurring, asset, purchases	759	303
Fair value, measurement, recurring, asset, sales	(732)	(313)
Fair value, measurement , recurring, asset, issuances	0	0
Fair value, measurement, recurring, asset, settlements	(11)	(6)
Fair value, assets, recurring, net unrealized gains (losses)	7	(10)
Fair value, assets measured on recurring basis, change in unrealized gain (loss) included in other comprehensive income	0	0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset, gain (loss) included in earnings	5	(7)
Fair value, measurement, recurring, asset, gain (loss) included in other comprehensive income (loss)	0	0
Fair value, measurement, recurring, asset, purchases	0	0
Fair value, measurement, recurring, asset, sales	0	0
Fair value, measurement , recurring, asset, issuances	0	0
Fair value, measurement, recurring, asset, settlements	(4)	(5)
Fair value, assets, recurring, net unrealized gains (losses)	5	(10)
Fair value, assets measured on recurring basis, change in unrealized gain (loss) included in other comprehensive income	0	0
Available-for-sale securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset, gain (loss) included in earnings	0
Fair value, measurement, recurring, asset, gain (loss) included in other comprehensive income (loss)	0
Fair value, measurement, recurring, asset, purchases	2
Fair value, measurement, recurring, asset, sales	0
Fair value, measurement , recurring, asset, issuances	0
Fair value, measurement, recurring, asset, settlements	0
Fair value, assets, recurring, net unrealized gains (losses)	0
Fair value, assets measured on recurring basis, change in unrealized gain (loss) included in other comprehensive income	0
Loans held-for-sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset, gain (loss) included in earnings	12	5
Fair value, measurement, recurring, asset, gain (loss) included in other comprehensive income (loss)	0	0
Fair value, measurement, recurring, asset, purchases	742	303
Fair value, measurement, recurring, asset, sales	(732)	(313)
Fair value, measurement , recurring, asset, issuances	0	0
Fair value, measurement, recurring, asset, settlements	0	0
Fair value, assets, recurring, net unrealized gains (losses)	0	0
Fair value, assets measured on recurring basis, change in unrealized gain (loss) included in other comprehensive income	0	0
Finance receivables and Loans, net
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, assets, recurring, net unrealized gains (losses)	0
Fair value, assets measured on recurring basis, change in unrealized gain (loss) included in other comprehensive income	0
Finance receivables and Loans, net | Consumer Loan
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset, gain (loss) included in earnings	1
Fair value, measurement, recurring, asset, gain (loss) included in other comprehensive income (loss)	0
Fair value, measurement, recurring, asset, purchases	15
Fair value, measurement, recurring, asset, sales	0
Fair value, measurement , recurring, asset, issuances	0
Fair value, measurement, recurring, asset, settlements	(5)
Interests retained in financial asset sales
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset, gain (loss) included in earnings	0	0
Fair value, measurement, recurring, asset, gain (loss) included in other comprehensive income (loss)	0	0
Fair value, measurement, recurring, asset, purchases	0	0
Fair value, measurement, recurring, asset, sales	0	0
Fair value, measurement , recurring, asset, issuances	0	0
Fair value, measurement, recurring, asset, settlements	(2)	(1)
Fair value, assets, recurring, net unrealized gains (losses)	0	0
Fair value, assets measured on recurring basis, change in unrealized gain (loss) included in other comprehensive income	0	0
Derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset, gain (loss) included in earnings	2	(1)
Fair value, measurement, recurring, asset, gain (loss) included in other comprehensive income (loss)	0	0
Fair value, measurement, recurring, asset, purchases	0	0
Fair value, measurement, recurring, asset, sales	0	0
Fair value, measurement , recurring, asset, issuances	0	0
Fair value, measurement, recurring, asset, settlements	0	0
Fair value, assets, recurring, net unrealized gains (losses)	2	0
Fair value, assets measured on recurring basis, change in unrealized gain (loss) included in other comprehensive income	0	0
Fair value, measurements, recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset value, beginning balance	19	38
Fair value, measurement, recurring, asset value, ending balance	55	19
Fair value, measurements, recurring | Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset value, beginning balance	7	19
Fair value, measurement, recurring, asset value, ending balance	8	7
Fair value, measurements, recurring | Available-for-sale securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset value, beginning balance	0
Fair value, measurement, recurring, asset value, ending balance	2	0
Fair value, measurements, recurring | Loans held-for-sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset value, beginning balance	8	13
Fair value, measurement, recurring, asset value, ending balance	30	8
Fair value, measurements, recurring | Finance receivables and Loans, net | Consumer Loan
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset value, beginning balance	0
Fair value, measurement, recurring, asset value, ending balance	11	0
Fair value, measurements, recurring | Interests retained in financial asset sales
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset value, beginning balance	4	5
Fair value, measurement, recurring, asset value, ending balance	2	4
Fair value, measurements, recurring | Derivative assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, measurement, recurring, asset value, beginning balance	0	1
Fair value, measurement, recurring, asset value, ending balance	$ 2	$ 0

Fair Value (Fair Value Measur_3

Fair Value (Fair Value Measurements - Nonrecurring Basis) (Details) $ in Millions	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	$ 158	$ 314
Automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		210
Lower of cost or fair value, valuation reserve, or cumulative adjustments		(2)
Automotive | Valuation technique, market approach | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		104
Automotive | Valuation technique, discounted cash flow | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		$ 106
Automotive | Valuation technique, discounted cash flow | Minimum | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.0008
Automotive | Valuation technique, discounted cash flow | Maximum | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.0109
Automotive | Valuation technique, discounted cash flow | Weighted average | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.0072
Loans held-for-sale, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		$ 96
Lower of cost or fair value, valuation reserve, or cumulative adjustments		0
Loans held-for-sale | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	128	306
Lower of cost or fair value, valuation reserve, or cumulative adjustments	0	(2)
Commercial finance receivables and loans, automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	64	84
Lower of cost or fair value, valuation reserve, or cumulative adjustments	(12)	(10)
Commercial finance receivables and loans, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	45	55
Lower of cost or fair value, valuation reserve, or cumulative adjustments	(21)	(46)
Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	109	139
Lower of cost or fair value, valuation reserve, or cumulative adjustments	(33)	(56)
Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	12	1
Lower of cost or fair value, valuation reserve, or cumulative adjustments	0	(1)
Equity method investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	4	3
Lower of cost or fair value, valuation reserve, or cumulative adjustments	(6)	0
Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	12	13
Lower of cost or fair value, valuation reserve, or cumulative adjustments	(1)	(1)
Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	265	462
Lower of cost or fair value, valuation reserve, or cumulative adjustments	(40)	(60)
Fair value, inputs, level 1 | Automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		0
Fair value, inputs, level 1 | Loans held-for-sale, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		0
Fair value, inputs, level 1 | Loans held-for-sale | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	0	0
Fair value, inputs, level 1 | Commercial finance receivables and loans, automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	0	0
Fair value, inputs, level 1 | Commercial finance receivables and loans, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	0	0
Fair value, inputs, level 1 | Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	0	0
Fair value, inputs, level 1 | Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	0	0
Fair value, inputs, level 1 | Equity method investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	0	0
Fair value, inputs, level 1 | Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	0	0
Fair value, inputs, level 1 | Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	0	0
Fair value, inputs, level 2 | Automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		0
Fair value, inputs, level 2 | Loans held-for-sale, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		0
Fair value, inputs, level 2 | Loans held-for-sale | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	0	0
Fair value, inputs, level 2 | Commercial finance receivables and loans, automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	0	0
Fair value, inputs, level 2 | Commercial finance receivables and loans, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	0	0
Fair value, inputs, level 2 | Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	0	0
Fair value, inputs, level 2 | Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	5	0
Fair value, inputs, level 2 | Equity method investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	0	0
Fair value, inputs, level 2 | Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	0	0
Fair value, inputs, level 2 | Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	5	0
Fair value, inputs, level 3 | Automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		210
Fair value, inputs, level 3 | Loans held-for-sale, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net		96
Fair value, inputs, level 3 | Loans held-for-sale | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, net	128	306
Fair value, inputs, level 3 | Commercial finance receivables and loans, automotive | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	64	84
Fair value, inputs, level 3 | Commercial finance receivables and loans, other | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	45	55
Fair value, inputs, level 3 | Commercial | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial finance receivables and loans, net, fair value	109	139
Fair value, inputs, level 3 | Nonmarketable equity investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	7	1
Fair value, inputs, level 3 | Equity method investments | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	4	3
Fair value, inputs, level 3 | Repossessed and foreclosed assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value	12	13
Fair value, inputs, level 3 | Assets | Fair Value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	$ 260	$ 462

Fair Value (Fair Value of Finan

Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 1,568	$ 2,362
Loans held-for-sale, net	158	314
Finance receivables and loans, net	126,968	128,684
Deposit liabilities	120,752	106,178
Short-term borrowings	5,531	9,987
Long-term debt	34,027	44,193
Reported value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,568	2,362
Loans held-for-sale, net	128	306
Finance receivables and loans, net	126,957	128,684
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,150	1,351
Deposit liabilities	60,146	51,985
Short-term borrowings	5,531	9,987
Long-term debt	34,027	44,193
Estimate of fair value measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,600	2,307
Loans held-for-sale, net	128	306
Finance receivables and loans, net	130,837	130,878
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,150	1,351
Deposit liabilities	60,678	51,997
Short-term borrowings	5,532	9,992
Long-term debt	36,927	45,646
Estimate of fair value measurement | Fair value, inputs, level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0	0
Loans held-for-sale, net	0	0
Finance receivables and loans, net	0	0
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	0	0
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Estimate of fair value measurement | Fair value, inputs, level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	1,600	2,307
Loans held-for-sale, net	0	0
Finance receivables and loans, net	0	0
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	1,150	1,351
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	22,789	23,846
Estimate of fair value measurement | Fair value, inputs, level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0	0
Loans held-for-sale, net	128	306
Finance receivables and loans, net	130,837	130,878
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	0	0
Deposit liabilities	60,678	51,997
Short-term borrowings	5,532	9,992
Long-term debt	$ 14,138	$ 21,800

Offsetting Assets and Liabili_3

Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Offsetting [Abstract]
Derivative Asset, Fair Value, Gross Asset	$ 62	$ 41
Net amounts of assets presented on the Condensed Consolidated Balance Sheet	62	41
Derivative Asset, Financial Instruments Not Offset	0	0
Derivative, Collateral, Obligation to Return Cash	(36)	(4)
Derivative Assets in Net Asset Position	26	37
Derivative Assets With No Offsetting Arrangements	2
Derivative Assets, Gross Amounts Offset on the Condensed Consolidated Balance Sheet	0	0
Derivative, Collateral, Obligation to Return Securities - No Offsetting Arrangements	0
Derivative, Collateral, Obligation to Return Cash - No Offsetting Arrangements	0
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	64	41
Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement Not Offset Against Collateral	64	41
Derivative Asset	28	37
Derivative Liability, Fair Value, Gross Liability	5	37
Derivative Liabilities - Gross Amounts Offset on the Condensed Consolidated Balance Sheet	0	0
Net Amounts of Liabilities Presented on the Condensed Consolidated Balance Sheet	5	37
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	0	0
Derivative Liabilities, Collateral Amounts Not Offset	(4)	0
Derivative, Net Liability Position, Aggregate Fair Value	1	37
Total liabilities, gross amounts recognized	5	722
Total liabilities, net amounts presented on the balance sheet	5	722
Derivative Liabilities, Financial Instruments Not Offset	0	0
Derivative Liability	1	37
Securities Sold under Agreements to Repurchase, Gross Amounts Recognized	0	685
Securities Sold under Agreements to Repurchase, Net Amounts Presented		685
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities		0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash		(685)
Securities Sold Under Agreements to Repurchase, Net Amount		0
Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Collateral, Right to Reclaim Cash	(4)	(685)
Derivative Asset, Fair Value of Collateral	29	3
Securities Purchased under Agreements to Resell, Fair Value of Collateral		4
Customer Securities for which Entity has Right to Sell or Repledge, Fair Value	$ 29	$ 7

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Number of operating segments									4
Net financing revenue and other interest income	$ 1,156	$ 1,188	$ 1,157	$ 1,132	$ 1,140	$ 1,107	$ 1,094	$ 1,049	$ 4,633	$ 4,390	$ 4,221
Other revenue	487	413	395	466	298	398	364	354	1,761	1,414	1,544
Total net revenue	1,643	1,601	1,552	1,598	1,438	1,505	1,458	1,403	6,394	5,804	5,765
Provision for loan losses	276	263	177	282	266	233	158	261	998	918	1,148
Noninterest expense	880	838	881	830	804	807	839	814	3,429	3,264	3,110
Income (loss) from continuing operations before income tax expense	487	$ 500	$ 494	$ 486	368	$ 465	$ 461	$ 328	1,967	1,622	1,507
Assets	180,644				178,869				180,644	178,869	167,148
Net financing revenue and other interest income after provision for loan losses									3,600	3,500	3,100
Operating Segments | Automotive Finance operations
Segment Reporting Information [Line Items]
Net financing revenue and other interest income									4,141	3,769	3,713
Other revenue									249	269	355
Total net revenue									4,390	4,038	4,068
Provision for loan losses									962	920	1,134
Noninterest expense									1,810	1,750	1,714
Income (loss) from continuing operations before income tax expense									1,618	1,368	1,220
Assets	113,863				117,304				113,863	117,304	114,089
Operating Segments | Insurance operations
Segment Reporting Information [Line Items]
Net financing revenue and other interest income									54	54	59
Other revenue									1,274	981	1,059
Total net revenue									1,328	1,035	1,118
Provision for loan losses									0	0	0
Noninterest expense									1,013	955	950
Income (loss) from continuing operations before income tax expense									315	80	168
Assets	8,547				7,734				8,547	7,734	7,464
Operating Segments | Mortgage Finance operations
Segment Reporting Information [Line Items]
Net financing revenue and other interest income									171	179	132
Other revenue									22	7	4
Total net revenue									193	186	136
Provision for loan losses									5	1	8
Noninterest expense									148	140	108
Income (loss) from continuing operations before income tax expense									40	45	20
Assets	16,279				15,211				16,279	15,211	11,708
Operating Segments | Corporate Finance operations
Segment Reporting Information [Line Items]
Net financing revenue and other interest income									239	204	167
Other revenue									45	38	45
Total net revenue									284	242	212
Provision for loan losses									36	12	22
Noninterest expense									95	86	76
Income (loss) from continuing operations before income tax expense									153	144	114
Assets	5,787				4,670				5,787	4,670	3,979
Corporate and Other
Segment Reporting Information [Line Items]
Net financing revenue and other interest income									28	184	150
Other revenue									171	119	81
Total net revenue									199	303	231
Provision for loan losses									(5)	(15)	(16)
Noninterest expense									363	333	262
Income (loss) from continuing operations before income tax expense									(159)	(15)	(15)
Assets	$ 36,168				$ 33,950				$ 36,168	$ 33,950	$ 29,908

Parent and Guarantor Condense_3

Parent and Guarantor Condensed Consolidating Financial Statements (Schedule of Condensed Consolidating Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									$ 7,337	$ 6,688	$ 5,819
Interest on loans held-for-sale									17	15	0
Interest and dividends on investment securities and other earning assets									955	788	599
Interest on cash and cash equivalents									78	72	37
Operating leases									1,470	1,489	1,867
Financing revenue (loss) and other interest income									9,857	9,052	8,322
Interest on deposits									2,538	1,735	1,077
Interest on short-term borrowings									135	149	127
Interest on long-term debt									1,570	1,753	1,653
Interest on intercompany debt									0	0	0
Interest expense									4,243	3,637	2,857
Net depreciation expense on operating lease assets									981	1,025	1,244
Net financing (loss) revenue	$ 1,156	$ 1,188	$ 1,157	$ 1,132	$ 1,140	$ 1,107	$ 1,094	$ 1,049	4,633	4,390	4,221
Cash dividends from bank subsidiaries									0	0	0
Cash dividends from nonbank subsidiaries									0	0	0
Insurance premiums and service revenue earned									1,087	1,022	973
Gain on mortgage and automotive loans, net									28	25	68
Other gain on investments, net									243	(50)	102
Other income, net of losses									403	417	401
Total other revenue	487	413	395	466	298	398	364	354	1,761	1,414	1,544
Total net revenue	1,643	1,601	1,552	1,598	1,438	1,505	1,458	1,403	6,394	5,804	5,765
Provision for loan losses									998	918	1,148
Compensation and benefits expense									1,222	1,155	1,095
Insurance losses and loss adjustment expenses									321	295	332
Other operating expenses									1,886	1,814	1,683
Total noninterest expense	880	838	881	830	804	807	839	814	3,429	3,264	3,110
Income from continuing operations before income tax expense and undistributed (loss) income of subsidiaries	487	500	494	486	368	465	461	328	1,967	1,622	1,507
Income tax (benefit) expense from continuing operations	106	119	(90)	111	79	91	113	76	246	359	581
Net income from continuing operations	381	381	584	375	289	374	348	252	1,721	1,263	926
Income (loss) from discontinued operations, net of tax									(6)	0	3
Undistributed income (loss) of bank subsidiary									0	0	0
Undistributed income (loss) of nonbank subsidiaries									0	0	0
Net income	$ 378	$ 381	$ 582	$ 374	$ 290	$ 374	$ 349	$ 250	1,715	1,263	929
Other comprehensive income (loss), net of tax									654	(289)	106
Comprehensive income									2,369	974	1,035
Affiliated entity
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									0	0	0
Interest on cash and cash equivalents									0	0	0
Gain on mortgage and automotive loans, net									0	0	0
Consolidating adjustments
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									(8)	0	0
Interest on loans held-for-sale									0	0
Interest and dividends on investment securities and other earning assets									0	(1)	(2)
Interest on cash and cash equivalents									0	0	0
Operating leases									0	0	0
Financing revenue (loss) and other interest income									(56)	(35)	(31)
Interest on deposits									0	0	(4)
Interest on short-term borrowings									0	0	0
Interest on long-term debt									0	0	0
Interest on intercompany debt									(48)	(35)	(27)
Interest expense									(48)	(35)	(31)
Net depreciation expense on operating lease assets									0	0	0
Net financing (loss) revenue									(8)	0	0
Cash dividends from bank subsidiaries									(3,900)	(5,200)	(6,600)
Cash dividends from nonbank subsidiaries									(436)	(443)	(752)
Insurance premiums and service revenue earned									0	0	0
Gain on mortgage and automotive loans, net									0	(54)	0
Other gain on investments, net									0	0	0
Other income, net of losses									(545)	(764)	(1,108)
Total other revenue									(545)	(818)	(1,108)
Total net revenue									(4,889)	(6,461)	(8,460)
Provision for loan losses									(18)	(54)	0
Compensation and benefits expense									0	0	0
Insurance losses and loss adjustment expenses									0	0	0
Other operating expenses									(545)	(764)	(1,108)
Total noninterest expense									(545)	(764)	(1,108)
Income from continuing operations before income tax expense and undistributed (loss) income of subsidiaries									(4,326)	(5,643)	(7,352)
Income tax (benefit) expense from continuing operations									0	0	0
Net income from continuing operations									(4,326)	(5,643)	(7,352)
Income (loss) from discontinued operations, net of tax									0	0	0
Undistributed income (loss) of bank subsidiary									(420)	1,228	2,336
Undistributed income (loss) of nonbank subsidiaries									7	(78)	(387)
Net income									(4,739)	(4,493)	(5,403)
Other comprehensive income (loss), net of tax									(1,177)	551	(169)
Comprehensive income									(5,916)	(3,942)	(5,572)
Consolidating adjustments | Affiliated entity
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									(17)	(17)	(18)
Interest on cash and cash equivalents									(31)	(17)	(11)
Gain on mortgage and automotive loans, net									(1,002)	22	(2,285)
Parent
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									(225)	(40)	(27)
Interest on loans held-for-sale									0	0
Interest and dividends on investment securities and other earning assets									0	0	0
Interest on cash and cash equivalents									10	8	7
Operating leases									2	5	11
Financing revenue (loss) and other interest income									(188)	(7)	7
Interest on deposits									0	0	3
Interest on short-term borrowings									53	44	60
Interest on long-term debt									849	1,009	1,101
Interest on intercompany debt									23	15	15
Interest expense									925	1,068	1,179
Net depreciation expense on operating lease assets									3	8	11
Net financing (loss) revenue									(1,116)	(1,083)	(1,183)
Cash dividends from bank subsidiaries									1,950	2,600	3,300
Cash dividends from nonbank subsidiaries									436	443	752
Insurance premiums and service revenue earned									0	0	0
Gain on mortgage and automotive loans, net									4	70	40
Other gain on investments, net									2	0	0
Other income, net of losses									337	411	675
Total other revenue									343	481	715
Total net revenue									1,613	2,441	3,584
Provision for loan losses									35	176	465
Compensation and benefits expense									36	83	180
Insurance losses and loss adjustment expenses									0	0	0
Other operating expenses									590	681	899
Total noninterest expense									626	764	1,079
Income from continuing operations before income tax expense and undistributed (loss) income of subsidiaries									952	1,501	2,040
Income tax (benefit) expense from continuing operations									(566)	(300)	337
Net income from continuing operations									1,518	1,801	1,703
Income (loss) from discontinued operations, net of tax									(6)	(2)	7
Undistributed income (loss) of bank subsidiary									210	(614)	(1,168)
Undistributed income (loss) of nonbank subsidiaries									(7)	78	387
Net income									1,715	1,263	929
Other comprehensive income (loss), net of tax									654	(289)	106
Comprehensive income									2,369	974	1,035
Parent | Affiliated entity
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									11	12	12
Interest on cash and cash equivalents									14	8	4
Gain on mortgage and automotive loans, net									718	(20)	2,068
Guarantors
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									0	0	0
Interest on loans held-for-sale										0
Interest and dividends on investment securities and other earning assets									0	0	0
Interest on cash and cash equivalents									0	0	0
Operating leases									0	0	0
Financing revenue (loss) and other interest income									0	0	0
Interest on deposits									0	0	0
Interest on short-term borrowings									0	0	0
Interest on long-term debt									0	0	0
Interest on intercompany debt									0	0	0
Interest expense									0	0	0
Net depreciation expense on operating lease assets									0	0	0
Net financing (loss) revenue									0	0	0
Cash dividends from bank subsidiaries									1,950	2,600	3,300
Cash dividends from nonbank subsidiaries									0	0	0
Insurance premiums and service revenue earned									0	0	0
Gain on mortgage and automotive loans, net									0	0	0
Other gain on investments, net									0	0	0
Other income, net of losses									0	0	0
Total other revenue									0	0	0
Total net revenue									1,950	2,600	3,300
Provision for loan losses									0	0	0
Compensation and benefits expense									0	0	0
Insurance losses and loss adjustment expenses									0	0	0
Other operating expenses									0	0	0
Total noninterest expense									0	0	0
Income from continuing operations before income tax expense and undistributed (loss) income of subsidiaries									1,950	2,600	3,300
Income tax (benefit) expense from continuing operations									0	0	0
Net income from continuing operations									1,950	2,600	3,300
Income (loss) from discontinued operations, net of tax									0	0	0
Undistributed income (loss) of bank subsidiary									210	(614)	(1,168)
Undistributed income (loss) of nonbank subsidiaries									0	0	0
Net income									2,160	1,986	2,132
Other comprehensive income (loss), net of tax									492	(243)	65
Comprehensive income									2,652	1,743	2,197
Guarantors | Affiliated entity
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans										0	0
Interest on cash and cash equivalents									0	0	0
Gain on mortgage and automotive loans, net									0	0	0
Nonguarantors
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									7,570	6,728	5,846
Interest on loans held-for-sale									17	15
Interest and dividends on investment securities and other earning assets									955	789	601
Interest on cash and cash equivalents									68	64	30
Operating leases									1,468	1,484	1,856
Financing revenue (loss) and other interest income									10,101	9,094	8,346
Interest on deposits									2,538	1,735	1,078
Interest on short-term borrowings									82	105	67
Interest on long-term debt									721	744	552
Interest on intercompany debt									25	20	12
Interest expense									3,366	2,604	1,709
Net depreciation expense on operating lease assets									978	1,017	1,233
Net financing (loss) revenue									5,757	5,473	5,404
Cash dividends from bank subsidiaries									0	0	0
Cash dividends from nonbank subsidiaries									0	0	0
Insurance premiums and service revenue earned									1,087	1,022	973
Gain on mortgage and automotive loans, net									24	9	28
Other gain on investments, net									241	(50)	102
Other income, net of losses									611	770	834
Total other revenue									1,963	1,751	1,937
Total net revenue									7,720	7,224	7,341
Provision for loan losses									981	796	683
Compensation and benefits expense									1,186	1,072	915
Insurance losses and loss adjustment expenses									321	295	332
Other operating expenses									1,841	1,897	1,892
Total noninterest expense									3,348	3,264	3,139
Income from continuing operations before income tax expense and undistributed (loss) income of subsidiaries									3,391	3,164	3,519
Income tax (benefit) expense from continuing operations									812	659	244
Net income from continuing operations									2,579	2,505	3,275
Income (loss) from discontinued operations, net of tax									0	2	(4)
Undistributed income (loss) of bank subsidiary									0	0	0
Undistributed income (loss) of nonbank subsidiaries									0	0	0
Net income									2,579	2,507	3,271
Other comprehensive income (loss), net of tax									685	(308)	104
Comprehensive income									3,264	2,199	3,375
Nonguarantors | Affiliated entity
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									6	5	6
Interest on cash and cash equivalents									17	9	7
Gain on mortgage and automotive loans, net									$ 284	$ (2)	$ 217

Parent and Guarantor Condense_4

Parent and Guarantor Condensed Consolidating Financial Statements (Schedule of Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Jan. 01, 2017
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, noninterest-bearing	$ 619		$ 810
Cash and cash equivalents, interest-bearing	2,936		3,727
Cash and cash equivalents	3,555		4,537
Equity securities	616		773
Available-for-sale securities	30,284		25,303
Held-to-maturity securities	1,568		2,362
Loans held-for-sale, net	158		314
Finance receivables and loans, net	128,231		129,926
Intercompany loans to nonbank subsidiary	0		0
Allowance for loan losses	(1,263)		(1,242)
Total finance receivables and loans, net	126,968		128,684
Net Investment in Lease	8,864		8,417
Intercompany receivables from bank subsidiary	0		0
Intercompany receivables from nonbank subsidiary	0		0
Investment in bank subsidiaries	0		0
Investment in nonbank subsidiaries	0		0
Premiums receivable and other insurance assets	2,558		2,326
Other assets	6,073		6,153
Assets	180,644		178,869		$ 167,148
Deposit liabilities, noninterest-bearing	119		142
Deposit liabilities, interest-bearing	120,633		106,036
Deposit liabilities	120,752		106,178
Short-term borrowings	5,531		9,987
Long-term debt	34,027		44,193
Interest payable	641		523
Unearned insurance premiums and service revenue	3,305		3,044
Accrued expenses and other liabilities	1,972		1,676
Total liabilities	166,228		165,601
Equity	14,416	$ 13,266	13,268	$ 13,375	$ 13,494	$ 13,317
Total liabilities and equity	180,644		178,869
Affiliated entity
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, interest-bearing	0		0
Deposit liabilities, interest-bearing	0		0
Intercompany debt payable to bank subsidiaries	0		0
Intercompany debt payable to nonbank subsidiaries	0		0
Intercompany payables to bank subsidiary	0		0
Intercompany payables to nonbank subsidiaries	0		0
Consolidating adjustments
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, noninterest-bearing	0		0
Cash and cash equivalents, interest-bearing	0		0
Cash and cash equivalents	(3,138)		(1,770)
Equity securities	0		0
Available-for-sale securities	0		0
Held-to-maturity securities	(10)		(20)
Loans held-for-sale, net	0		0
Finance receivables and loans, net	10		0
Intercompany loans to nonbank subsidiary	(271)		(1,279)
Allowance for loan losses	0		0
Total finance receivables and loans, net	(261)		(1,279)
Net Investment in Lease	0		0
Intercompany receivables from bank subsidiary	(94)		(158)
Intercompany receivables from nonbank subsidiary	(127)		(174)
Investment in bank subsidiaries	(33,908)		(32,426)
Investment in nonbank subsidiaries	(6,535)		(6,928)
Premiums receivable and other insurance assets	0		0
Other assets	(1,810)		(1,526)
Assets	(45,883)		(44,281)
Deposit liabilities, noninterest-bearing	0		0
Deposit liabilities, interest-bearing	0		0
Deposit liabilities	(2,051)		(1,249)
Short-term borrowings	0		0
Long-term debt	0		0
Interest payable	0		0
Unearned insurance premiums and service revenue	0		0
Accrued expenses and other liabilities	(1,782)		(1,560)
Total liabilities	(5,450)		(4,927)
Equity	(40,433)		(39,354)
Total liabilities and equity	(45,883)		(44,281)
Consolidating adjustments | Affiliated entity
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, interest-bearing	(3,138)		(1,770)
Deposit liabilities, interest-bearing	(2,051)		(1,249)
Intercompany debt payable to bank subsidiaries	(10)		(20)
Intercompany debt payable to nonbank subsidiaries	(1,358)		(1,800)
Intercompany payables to bank subsidiary	(18)		(45)
Intercompany payables to nonbank subsidiaries	(231)		(253)
Parent
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, noninterest-bearing	49		55
Cash and cash equivalents, interest-bearing	5		5
Cash and cash equivalents	2,105		1,309
Equity securities	0		0
Available-for-sale securities	0		0
Held-to-maturity securities	0		0
Loans held-for-sale, net	0		0
Finance receivables and loans, net	2,167		2,349
Intercompany loans to nonbank subsidiary	161		882
Allowance for loan losses	(22)		(55)
Total finance receivables and loans, net	2,306		3,176
Net Investment in Lease	1		5
Intercompany receivables from bank subsidiary	94		158
Intercompany receivables from nonbank subsidiary	50		45
Investment in bank subsidiaries	16,954		16,213
Investment in nonbank subsidiaries	6,535		6,928
Premiums receivable and other insurance assets	0		0
Other assets	2,193		2,226
Assets	30,238		30,060
Deposit liabilities, noninterest-bearing	0		0
Deposit liabilities, interest-bearing	1		1
Deposit liabilities	1		1
Short-term borrowings	2,581		2,477
Long-term debt	11,389		12,774
Interest payable	145		159
Unearned insurance premiums and service revenue	0		0
Accrued expenses and other liabilities	383		274
Total liabilities	15,822		16,792
Equity	14,416		13,268
Total liabilities and equity	30,238		30,060
Parent | Affiliated entity
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, interest-bearing	2,051		1,249
Deposit liabilities, interest-bearing	0		0
Intercompany debt payable to bank subsidiaries	10		20
Intercompany debt payable to nonbank subsidiaries	1,197		918
Intercompany payables to bank subsidiary	18		45
Intercompany payables to nonbank subsidiaries	98		124
Guarantors
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, noninterest-bearing	0		0
Cash and cash equivalents, interest-bearing	0		0
Cash and cash equivalents	0		0
Equity securities	0		0
Available-for-sale securities	0		0
Held-to-maturity securities	0		0
Loans held-for-sale, net	0		0
Finance receivables and loans, net	0		0
Intercompany loans to nonbank subsidiary	0		0
Allowance for loan losses	0		0
Total finance receivables and loans, net	0		0
Net Investment in Lease	0		0
Intercompany receivables from bank subsidiary	0		0
Intercompany receivables from nonbank subsidiary	0		0
Investment in bank subsidiaries	16,954		16,213
Investment in nonbank subsidiaries	0		0
Premiums receivable and other insurance assets	0		0
Other assets	0		0
Assets	16,954		16,213
Deposit liabilities, noninterest-bearing	0		0
Deposit liabilities, interest-bearing	0		0
Deposit liabilities	0		0
Short-term borrowings	0		0
Long-term debt	0		0
Interest payable	0		0
Unearned insurance premiums and service revenue	0		0
Accrued expenses and other liabilities	0		0
Total liabilities	0		0
Equity	16,954		16,213
Total liabilities and equity	16,954		16,213
Guarantors | Affiliated entity
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, interest-bearing	0		0
Deposit liabilities, interest-bearing	0		0
Intercompany debt payable to bank subsidiaries	0		0
Intercompany debt payable to nonbank subsidiaries	0		0
Intercompany payables to bank subsidiary	0		0
Intercompany payables to nonbank subsidiaries	0		0
Nonguarantors
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, noninterest-bearing	570		755
Cash and cash equivalents, interest-bearing	2,931		3,722
Cash and cash equivalents	4,588		4,998
Equity securities	616		773
Available-for-sale securities	30,284		25,303
Held-to-maturity securities	1,578		2,382
Loans held-for-sale, net	158		314
Finance receivables and loans, net	126,054		127,577
Intercompany loans to nonbank subsidiary	110		397
Allowance for loan losses	(1,241)		(1,187)
Total finance receivables and loans, net	124,923		126,787
Net Investment in Lease	8,863		8,412
Intercompany receivables from bank subsidiary	0		0
Intercompany receivables from nonbank subsidiary	77		129
Investment in bank subsidiaries	0		0
Investment in nonbank subsidiaries	0		0
Premiums receivable and other insurance assets	2,558		2,326
Other assets	5,690		5,453
Assets	179,335		176,877
Deposit liabilities, noninterest-bearing	119		142
Deposit liabilities, interest-bearing	120,632		106,035
Deposit liabilities	122,802		107,426
Short-term borrowings	2,950		7,510
Long-term debt	22,638		31,419
Interest payable	496		364
Unearned insurance premiums and service revenue	3,305		3,044
Accrued expenses and other liabilities	3,371		2,962
Total liabilities	155,856		153,736
Equity	23,479		23,141
Total liabilities and equity	179,335		176,877
Nonguarantors | Affiliated entity
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents, interest-bearing	1,087		521
Deposit liabilities, interest-bearing	2,051		1,249
Intercompany debt payable to bank subsidiaries	0		0
Intercompany debt payable to nonbank subsidiaries	161		882
Intercompany payables to bank subsidiary	0		0
Intercompany payables to nonbank subsidiaries	$ 133		$ 129

Parent and Guarantor Condense_5

Parent and Guarantor Condensed Consolidating Financial Statements (Statement of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net cash provided by operating activities	$ 4,050	$ 4,150	$ 4,079
Purchases of equity securities	(498)	(1,076)	(899)
Proceeds from sales of equity securities	814	787	1,049
Purchases of available-for-sale securities	(15,199)	(7,868)	(10,335)
Proceeds from sales of available-for-sale securities	7,079	852	3,584
Proceeds from repayments of available-for-sale securities	5,154	3,215	2,899
Purchases of held-to-maturity securities	(514)	(578)	(1,026)
Proceeds from repayments of held-to-maturity securities	302	147	68
Purchases of finance receivables and loans held-for-investment	(4,439)	(5,693)	(5,452)
Proceeds from sales of finance receivables and loans initially held-for-investment	1,038	91	1,339
Originations and repayments of finance receivables and loans held-for-investment and other, net	4,252	(3,245)	(1,063)
Net change in intercompany loans	28	25	68
Purchases of operating lease assets	(4,023)	(3,709)	(4,052)
Disposals of operating lease assets	2,625	3,089	5,567
Acquisitions, net of acquired cash	(171)	0	0
Capital contributions to subsidiaries	0	0	0
Returns of contributed capital	0	0	0
Net change in nonmarketable equity investments	190	(181)	(187)
Payments for (proceeds from) other, net	(379)	(340)	(219)
Net cash provided by (used in) investing activities	(3,769)	(14,509)	(8,727)
Net change in short-term borrowings	(4,456)	(1,426)	(1,263)
Net (decrease) increase in deposits	14,547	12,867	14,172
Proceeds from issuance of long-term debt	6,915	18,401	17,969
Repayments of long-term debt	(17,224)	(17,940)	(27,908)
Repurchase of common stock	(1,039)	(939)	(753)
Dividends paid	(273)	(242)	(184)
Capital contributions from parent	0	0	0
Net cash provided by (used in) financing activities	(1,530)	10,721	2,033
Effect of exchange-rate changes on cash and cash equivalents and restricted cash	3	(5)	3
Cash and cash equivalents	3,555	4,537
Restricted Cash	825	1,089
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net decrease in cash and cash equivalents and restricted cash	(1,246)	357	(2,612)
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash	4,380	5,626	5,269
Cash and cash equivalents and restricted cash	5,626	5,269	7,881
Affiliated entity
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net change in intercompany investment securities	0	0	0
Net change in intercompany loans	0	0	0
Net Change in Debt, Intercompany	0	0	0
Dividends paid and returns of contributed capital, intercompany	0	0	0
Consolidating adjustments
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net cash provided by operating activities	(4,346)	(5,645)	(7,278)
Purchases of equity securities	0	0	0
Proceeds from sales of equity securities	0	0	0
Purchases of available-for-sale securities	0	0	0
Proceeds from sales of available-for-sale securities	0	0	0
Proceeds from repayments of available-for-sale securities	0	0	0
Purchases of held-to-maturity securities	0	0	0
Proceeds from repayments of held-to-maturity securities	0	0	0
Purchases of finance receivables and loans held-for-investment	535	1,539	0
Proceeds from sales of finance receivables and loans initially held-for-investment	(535)	(1,539)	0
Originations and repayments of finance receivables and loans held-for-investment and other, net	8	0	(1,956)
Net change in intercompany loans	0	(54)	0
Purchases of operating lease assets	0	0	0
Disposals of operating lease assets	0	0	0
Acquisitions, net of acquired cash	0
Capital contributions to subsidiaries	2	67	1,217
Returns of contributed capital	(259)	(266)	(1,567)
Net change in nonmarketable equity investments	0	0	0
Payments for (proceeds from) other, net	0	0	(89)
Net cash provided by (used in) investing activities	(1,261)	(231)	(4,978)
Net change in short-term borrowings	0	0	0
Net (decrease) increase in deposits	(802)	(111)	(1,138)
Proceeds from issuance of long-term debt	0	0	1,961
Repayments of long-term debt	0	0	0
Repurchase of common stock	0	0	0
Dividends paid	0	0	0
Capital contributions from parent	(2)	(67)	(1,217)
Net cash provided by (used in) financing activities	4,239	5,939	10,824
Effect of exchange-rate changes on cash and cash equivalents and restricted cash	0	0	0
Cash and cash equivalents	(3,138)	(1,770)
Restricted Cash	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net decrease in cash and cash equivalents and restricted cash	(1,368)	63	(1,432)
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash	(3,138)	(1,770)	(1,833)
Cash and cash equivalents and restricted cash	(1,770)	(1,833)	(401)
Consolidating adjustments | Affiliated entity
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net change in intercompany investment securities	(10)	(54)	(298)
Net change in intercompany loans	(1,002)	22	(2,285)
Net Change in Debt, Intercompany	447	208	2,299
Dividends paid and returns of contributed capital, intercompany	4,596	5,909	8,919
Parent
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net cash provided by operating activities	1,818	1,659	4,591
Purchases of equity securities	0	0	0
Proceeds from sales of equity securities	0	0	0
Purchases of available-for-sale securities	0	0	0
Proceeds from sales of available-for-sale securities	0	0	0
Proceeds from repayments of available-for-sale securities	0	0	0
Purchases of held-to-maturity securities	0	0	0
Proceeds from repayments of held-to-maturity securities	0	0	0
Purchases of finance receivables and loans held-for-investment	0	(131)	(35)
Proceeds from sales of finance receivables and loans initially held-for-investment	548	1,596	106
Originations and repayments of finance receivables and loans held-for-investment and other, net	(253)	3,489	860
Net change in intercompany loans	4	70	40
Purchases of operating lease assets	0	0	0
Disposals of operating lease assets	3	10	13
Acquisitions, net of acquired cash	0
Capital contributions to subsidiaries	(2)	(61)	(1,212)
Returns of contributed capital	259	266	1,567
Net change in nonmarketable equity investments	(13)	(16)	0
Payments for (proceeds from) other, net	(4)	0	(31)
Net cash provided by (used in) investing activities	1,256	5,133	3,343
Net change in short-term borrowings	104	(694)	(453)
Net (decrease) increase in deposits	0	(11)	(156)
Proceeds from issuance of long-term debt	801	69	354
Repayments of long-term debt	(2,173)	(4,774)	(6,111)
Repurchase of common stock	(1,039)	(939)	(753)
Dividends paid	(273)	(242)	(184)
Capital contributions from parent	0	0	0
Net cash provided by (used in) financing activities	(2,309)	(6,789)	(7,528)
Effect of exchange-rate changes on cash and cash equivalents and restricted cash	0	0	0
Cash and cash equivalents	2,105	1,309
Restricted Cash	58	89
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net decrease in cash and cash equivalents and restricted cash	765	3	406
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash	2,163	1,398	1,395
Cash and cash equivalents and restricted cash	1,398	1,395	989
Parent | Affiliated entity
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net change in intercompany investment securities	0	0	7
Net change in intercompany loans	718	(20)	2,068
Net Change in Debt, Intercompany	271	(198)	(225)
Dividends paid and returns of contributed capital, intercompany	0	0	0
Guarantors
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net cash provided by operating activities	1,950	2,600	3,300
Purchases of equity securities	0	0	0
Proceeds from sales of equity securities	0	0	0
Purchases of available-for-sale securities	0	0	0
Proceeds from sales of available-for-sale securities	0	0	0
Proceeds from repayments of available-for-sale securities	0	0	0
Purchases of held-to-maturity securities	0	0	0
Proceeds from repayments of held-to-maturity securities	0	0	0
Purchases of finance receivables and loans held-for-investment	0	0	0
Proceeds from sales of finance receivables and loans initially held-for-investment	0	0	0
Originations and repayments of finance receivables and loans held-for-investment and other, net	0	0	0
Net change in intercompany loans	0	0	0
Purchases of operating lease assets	0	0	0
Disposals of operating lease assets	0	0	0
Acquisitions, net of acquired cash	0
Capital contributions to subsidiaries	0	(6)	(5)
Returns of contributed capital	0	0	0
Net change in nonmarketable equity investments	0	0	0
Payments for (proceeds from) other, net	0	0	0
Net cash provided by (used in) investing activities	0	(6)	(5)
Net change in short-term borrowings	0	0	0
Net (decrease) increase in deposits	0	0	0
Proceeds from issuance of long-term debt	0	0	0
Repayments of long-term debt	0	0	0
Repurchase of common stock	0	0	0
Dividends paid	0	0	0
Capital contributions from parent	0	6	5
Net cash provided by (used in) financing activities	(1,950)	(2,594)	(3,295)
Effect of exchange-rate changes on cash and cash equivalents and restricted cash	0	0	0
Cash and cash equivalents	0	0
Restricted Cash	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net decrease in cash and cash equivalents and restricted cash	0	0	0
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash	0	0	0
Cash and cash equivalents and restricted cash	0	0	0
Guarantors | Affiliated entity
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net change in intercompany investment securities	0	0	0
Net change in intercompany loans	0	0	0
Net Change in Debt, Intercompany	0	0	0
Dividends paid and returns of contributed capital, intercompany	(1,950)	(2,600)	(3,300)
Nonguarantors
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net cash provided by operating activities	4,628	5,536	3,466
Purchases of equity securities	(498)	(1,076)	(899)
Proceeds from sales of equity securities	814	787	1,049
Purchases of available-for-sale securities	(15,199)	(7,868)	(10,335)
Proceeds from sales of available-for-sale securities	7,079	852	3,584
Proceeds from repayments of available-for-sale securities	5,154	3,215	2,899
Purchases of held-to-maturity securities	(514)	(578)	(1,026)
Proceeds from repayments of held-to-maturity securities	302	147	68
Purchases of finance receivables and loans held-for-investment	(4,974)	(7,101)	(5,417)
Proceeds from sales of finance receivables and loans initially held-for-investment	1,025	34	1,233
Originations and repayments of finance receivables and loans held-for-investment and other, net	4,497	(6,734)	33
Net change in intercompany loans	24	9	28
Purchases of operating lease assets	(4,023)	(3,709)	(4,052)
Disposals of operating lease assets	2,622	3,079	5,554
Acquisitions, net of acquired cash	(171)
Capital contributions to subsidiaries	0	0	0
Returns of contributed capital	0	0	0
Net change in nonmarketable equity investments	203	(165)	(187)
Payments for (proceeds from) other, net	(375)	(340)	(99)
Net cash provided by (used in) investing activities	(3,764)	(19,405)	(7,087)
Net change in short-term borrowings	(4,560)	(732)	(810)
Net (decrease) increase in deposits	15,349	12,989	15,466
Proceeds from issuance of long-term debt	6,114	18,332	15,654
Repayments of long-term debt	(15,051)	(13,166)	(21,797)
Repurchase of common stock	0	0	0
Dividends paid	0	0	0
Capital contributions from parent	2	61	1,212
Net cash provided by (used in) financing activities	(1,510)	14,165	2,032
Effect of exchange-rate changes on cash and cash equivalents and restricted cash	3	(5)	3
Cash and cash equivalents	4,588	4,998
Restricted Cash	767	1,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Net decrease in cash and cash equivalents and restricted cash	(643)	291	(1,586)
Cash and cash equivalents and restricted cash [Roll Forward]
Cash and cash equivalents and restricted cash	5,355	5,998	5,707
Cash and cash equivalents and restricted cash	5,998	5,707	7,293
Nonguarantors | Affiliated entity
Parent and Guarantor Consolidating Statement of Cash Flows [Line Items]
Net change in intercompany investment securities	10	54	291
Net change in intercompany loans	284	(2)	217
Net Change in Debt, Intercompany	(718)	(10)	(2,074)
Dividends paid and returns of contributed capital, intercompany	$ (2,646)	$ (3,309)	$ (5,619)

Guarantees and Commitments Gu_3

Guarantees and Commitments Guarantees and Commitments (Standby letters of credit and other guarantees) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Guarantor Obligations [Line Items]
Standby letters of credit and other guarantees	$ 6	$ 7
Standby letters of credit, cash collateral received	0
Maximum
Guarantor Obligations [Line Items]
Standby letters of credit and other guarantees	$ 249	$ 218

Guarantees and Commitments Gu_4

Guarantees and Commitments Guarantees and Commitments (Financing Commitments) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Guarantees and Commitments [Abstract]
Unused revolving credit line commitments and other	$ 4,384	$ 3,435
Commitments to provide capital to investees	504	394
Mortgage loan origination commitments	314	171
Home equity lines of credit commitments	226	253
Construction-lending commitments	$ 127	$ 85

Guarantees and Commitments Gu_5

Guarantees and Commitments Guarantees and Commitments (Contractual Commitments) (Details) $ in Millions	Dec. 31, 2019USD ($)
Guarantees and Commitments [Abstract]
Other Commitment, Due in Next Twelve Months	$ 68
Other Commitment, Due in Second Year	38
Other Commitment, Due in Third Year	40
Other Commitment, Due in Fourth Year	37
Other Commitment, Due in Fifth Year	14
Other Commitment, Due after Fifth Year	27
Total future payment obligations	$ 224

Quarterly Financial Statement_3

Quarterly Financial Statements (unaudited) Quarterly Financial Statements (unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net financing revenue and other interest income	$ 1,156	$ 1,188	$ 1,157	$ 1,132	$ 1,140	$ 1,107	$ 1,094	$ 1,049	$ 4,633	$ 4,390	$ 4,221
Other revenue	487	413	395	466	298	398	364	354	1,761	1,414	1,544
Total net revenue	1,643	1,601	1,552	1,598	1,438	1,505	1,458	1,403	6,394	5,804	5,765
Provision for loan losses	276	263	177	282	266	233	158	261	998	918	1,148
Total noninterest expense	880	838	881	830	804	807	839	814	3,429	3,264	3,110
Income from continuing operations before income tax expense	487	500	494	486	368	465	461	328	1,967	1,622	1,507
Income tax expense from continuing operations	106	119	(90)	111	79	91	113	76	246	359	581
Net income from continuing operations	381	381	584	375	289	374	348	252	1,721	1,263	926
Loss from discontinued operations, net of tax	(3)	0	(2)	(1)	1	0	1	(2)	(6)	0	3
Net income	$ 378	$ 381	$ 582	$ 374	$ 290	$ 374	$ 349	$ 250	$ 1,715	$ 1,263	$ 929
Net income from continuing operations, basic earnings per common share	$ 1	$ 0.98	$ 1.47	$ 0.93	$ 0.70	$ 0.89	$ 0.81	$ 0.58	$ 4.38	$ 2.97	$ 2.04
Earnings Per Share, Basic	0.99	0.97	1.46	0.93	0.70	0.89	0.81	0.57	4.36	2.97	2.05
Net income from continuing operations, diluted earnings per common share	0.99	0.97	1.46	0.92	0.70	0.88	0.80	0.57	4.35	2.95	2.03
Earnings Per Share, Diluted	0.99	0.97	1.46	0.92	0.70	0.88	0.81	0.57	4.34	2.95	2.04
Cash dividends declared per common share	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.15	$ 0.15	$ 0.13	$ 0.13	$ 0.68	$ 0.56	$ 0.40

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions

Feb. 18, 2020

Jan. 13, 2020

Dec. 31, 2019

Sep. 30, 2019

Jun. 30, 2019

Mar. 31, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Subsequent Event [Line Items]

Cash dividends declared per common share

$ 0.17

$ 0.17

$ 0.17

$ 0.17

$ 0.15

$ 0.15

$ 0.13

$ 0.13

$ 0.68

$ 0.56

$ 0.40

Payments to Acquire Businesses, Gross

$ 177

Subsequent event

Subsequent Event [Line Items]

Business Acquisition, Date of Acquisition Agreement

Feb. 18, 2020

Payments to Acquire Businesses, Gross

$ 2,650

Business combination, cash consideration to be paid

1,350

Equity Issued in Business Combination, Fair Value Disclosure

$ 1,300

Subsequent event | Common stock

Subsequent Event [Line Items]

Dividends Payable, Date Declared

Jan. 13, 2020

Cash dividends declared per common share

$ 0.19

Dividend, increase per common share

$ 0.02

Dividends Payable, Date to be Paid

Feb. 14, 2020

Dividends Payable, Date of Record

Jan. 31, 2020

Uncategorized Items - ally20191

Label	Element	Value
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation	$ 79,000,000
Treasury Stock, Value, Acquired, Cost Method	us-gaap_TreasuryStockValueAcquiredCostMethod	753,000,000
Dividends, Common Stock, Cash	us-gaap_DividendsCommonStockCash	184,000,000
Retained Earnings [Member]
Net Income (Loss) Attributable to Parent	us-gaap_NetIncomeLoss	929,000,000
Dividends, Common Stock, Cash	us-gaap_DividendsCommonStockCash	184,000,000
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(6,510,000,000)
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(7,151,000,000)
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(5,499,000,000)
Treasury Stock [Member]
Treasury Stock, Value, Acquired, Cost Method	us-gaap_TreasuryStockValueAcquiredCostMethod	753,000,000
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(1,110,000,000)
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(2,049,000,000)
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(357,000,000)
Common Stock Including Additional Paid in Capital [Member]
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation	79,000,000
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	21,166,000,000
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	21,345,000,000
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	21,245,000,000
AOCI Attributable to Parent [Member]
Other Comprehensive Income (Loss), Net of Tax	us-gaap_OtherComprehensiveIncomeLossNetOfTax	106,000,000
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(250,000,000)
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(341,000,000)
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	(531,000,000)
Accounting Standards Update 2014-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(126,000,000)
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(126,000,000)
Accounting Standards Update 2017-08 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(2,000,000)
Accounting Standards Update 2017-08 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(10,000,000)
Accounting Standards Update 2017-08 [Member] | AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	8,000,000
Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	7,000,000
Accounting Standards Update 2016-01 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(20,000,000)
Accounting Standards Update 2016-01 [Member] | AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	27,000,000
Accounting Standards Update 2018-02 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Accounting Standards Update 2018-02 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	42,000,000
Accounting Standards Update 2018-02 [Member] | AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (42,000,000)