Ally Financial (ALLY) 10-Q 31 Oct 14 2014 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	9 Months Ended
	Sep. 30, 2014	Oct. 30, 2014	Jun. 30, 2013
Document And Entity Information [Abstract]	'	'	'
Entity Registrant Name	'Ally Financial Inc.	'	'
Entity Central Index Key	'0000040729	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Document Type	'10-Q	'	'
Document Period End Date	30-Sep-14	'	'
Document Fiscal Year Focus	'2014	'	'
Document Fiscal Period Focus	'Q3	'	'
Amendment Flag	'false	'	'
Entity Common Stock, Shares Outstanding	479,818,096	479,818,096	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Public Float	'	'	$0

Consolidated_Statement_of_Inco

Consolidated Statement of Income (USD $)	3 Months Ended			9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Financing Revenue and Other Interest Income [Abstract]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	$1,114	$1,119	$3,345	$3,393
Interest on loans held-for-sale	'	0	0	1	19
Interest and dividends on available-for-sale investment securities	'	94	85	282	229
Interest-bearing cash	'	2	3	6	8
Operating leases	'	899	832	2,653	2,354
Total financing revenue and other interest income	'	2,109	2,039	6,287	6,003
Interest Expense [Abstract]	'	'	'	'	'
Interest on deposits	'	166	163	495	489
Interest on short-term borrowings	'	12	15	40	47
Interest on long-term debt	'	493	609	1,576	2,013
Total interest expense	'	671	787	2,111	2,549
Depreciation expense on operating lease assets	'	549	515	1,600	1,449
Net financing revenue (loss)	'	889	737	2,576	2,005
Other revenue [Abstract]	'	'	'	'	'
Servicing fees	'	6	13	22	114
Servicing asset valuation and hedge activities, net	'	0	0	0	-213
Total servicing income, net	'	6	13	22	-99
Insurance premiums and service revenue earned	'	246	251	736	768
Gain (loss) on mortgage and automotive loans, net	'	0	15	6	52
Gains (Losses) on Extinguishment of Debt	-160	0	-42	-46	-42
Other gain (loss) on investments, net	'	45	41	129	156
Other income, net of losses	'	78	93	214	324
Total other revenue	'	375	371	1,061	1,159
Total net revenue (loss)	'	1,264	1,108	3,637	3,164
Provision for loan losses	'	102	141	302	361
Noninterest Expense [Abstract]	'	'	'	'	'
Compensation and benefits expense	'	241	245	710	782
Insurance losses and loss adjustment expenses	'	97	85	353	346
Other operating expenses	'	404	432	1,213	1,393
Total noninterest expense	'	742	762	2,276	2,521
Income (loss) from continuing operations before income tax expense	'	420	205	1,059	282
Income tax expense (benefit) from continuing operations	'	127	28	285	-55
Net income (loss) from continuing operations	'	293	177	774	337
Income (loss) from discontinued operations, net of tax	'	130	-86	199	-80
Net income (loss)	'	423	91	973	257
Other comprehensive income (loss), net of tax	'	-55	4	126	-494
Comprehensive income (loss)	'	$368	$95	$1,099	($237)
Earnings Per Share, Basic [Abstract]	'	'	'	'	'
Net income (loss) from continuing operations, Per Basic Share	'	$0.47	($0.06)	$1.19	($0.64)
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	'	$0.27	($0.21)	$0.41	($0.19)
Net (loss) income, Basic	'	$0.74	($0.27)	$1.60	($0.83)
Earnings Per Share, Diluted [Abstract]	'	'	'	'	'
Net income (loss) from continuing operations, Per Diluted Share	'	$0.47	($0.06)	$1.19	($0.64)
Income (loss) from discontinued operations, net of tax	'	$0.27	($0.21)	$0.41	($0.19)
Net (loss) income, Diluted	'	$0.74	($0.27)	$1.60	($0.83)

Consolidated_Balance_Sheet

Consolidated Balance Sheet (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets [Abstract]	'	'
Cash and Due from Banks	$1,318	$1,315
Interest-bearing Deposits in Banks and Other Financial Institutions	4,381	4,216
Total cash and cash equivalents	5,699	5,531
Investment securities	16,714	17,083
Loans held-for-sale, net	3	35
Finance receivables and loans, net [Abstract]	'	'
Finance receivables and loans, net	99,518	100,328
Allowance for loan losses	-1,113	-1,208
Total finance receivables and loans, net	98,405	99,120
Investment in operating leases, net	19,341	17,680
Premiums receivable and other insurance assets	1,678	1,613
Other Assets	6,752	9,589
Assets of operations held-for-sale	603	516
Total assets	149,195	151,167
Liabilities and Equity [Abstract]	'	'
Noninterest-bearing deposit liabilities	73	60
Interest-bearing deposit liabilities	56,778	53,290
Total deposit liabilities	56,851	53,350
Short-term borrowings	5,255	8,545
Long-term debt	67,299	69,465
Interest payable	542	888
Unearned insurance premiums and service revenue	2,369	2,314
Accrued expenses and other liabilities	1,689	2,397
Total liabilities	134,005	136,959
Equity [Abstract]	'	'
Common stock and paid-in-capital	21,022	20,939
Preferred stock	1,255	1,255
Retained Earnings (Accumulated Deficit)	-6,937	-7,710
Accumulated Other Comprehensive Income (Loss), Net of Tax	-150	-276
Stockholders' Equity Attributable to Parent	15,190	14,208
Total liabilities and equity	149,195	151,167
Variable Interest Entity, Primary Beneficiary [Member]	'	'
Finance receivables and loans, net [Abstract]	'	'
Finance receivables and loans, net	30,515	32,265
Allowance for loan losses	-193	-174
Total finance receivables and loans, net	30,322	32,091
Investment in operating leases, net	3,581	4,620
Other Assets	1,675	3,436
Total assets	35,578	40,147
Liabilities and Equity [Abstract]	'	'
Short-term borrowings	0	250
Long-term debt	24,621	24,147
Accrued expenses and other liabilities	175	43
Total liabilities	$24,796	$24,440

Consolidated_Balance_Sheet_Par

Consolidated Balance Sheet (Paranthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Loans Held-for-sale, Fair Value Disclosure	$3	$16
Loans Receivable, Fair Value Disclosure	$1	$1
Common Stock, Par or Stated Value Per Share	$0.01	'
Common Stock, Shares Authorized	1,100,000,000	'
Common Stock, Shares, Issued	479,845,945	'
Entity Common Stock, Shares Outstanding	479,818,096	'

Consolidated_Statement_Of_Chan

Consolidated Statement Of Changes In Equity (USD $)	Total	Common stock and paid-in capital [Member]	Mandatorily convertible preferred stock held by U.S. Department Of Treasury [Member]	Preferred stock [Member]	Retained earnings (accumulated deficit) [Member]	Accumulated Other Comprehensive Income [Member]
In Millions
Beginning Balance at Dec. 31, 2012	$19,898	$19,668	$5,685	$1,255	($7,021)	$311
Net income (loss)	257	'	'	'	'	'
Preferred stock dividends - U.S. Department of Treasury	-401	'	'	'	-401	'
Preferred stock dividends	-200	'	'	'	-200	'
Other comprehensive income (loss)	-494	'	'	'	'	-494
Adjustments to Additional Paid in Capital, Other	1	1	'	'	'	'
Ending Balance at Sep. 30, 2013	19,061	19,669	5,685	1,255	-7,365	-183
Beginning Balance at Dec. 31, 2013	14,208	20,939	0	1,255	-7,710	-276
Net income (loss)	973	'	'	'	'	'
Preferred stock dividends - U.S. Department of Treasury	0	'	'	'	'	'
Preferred stock dividends	-200	'	'	'	-200	'
Employee Benefits and Share-based Compensation	83	83	'	'	'	'
Other comprehensive income (loss)	126	'	'	'	'	126
Ending Balance at Sep. 30, 2014	$15,190	$21,022	$0	$1,255	($6,937)	($150)

Consolidated_Statement_Of_Cash

Consolidated Statement Of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Net Cash Provided by (Used in) Operating Activities [Abstract]	'		'
Net income (loss)	$973		$257
Depreciation, Amortization and Accretion, Net	2,133		2,106
Changes In Fair Value Of Mortgage Servicing Rights	0		102
Provision for Loan Losses Expensed Including Discontinued Operations	302		431
Gain Loss on Sales of Loans Net Including Discontinued Operations	-6		-52
Available-for-sale Securities Gross Realized Gain Loss Excluding Otti Including Disc Ops	-129		-156
Gains (Losses) on Extinguishment of Debt	46		42
Payments for Origination and Purchases of Loans Held-for-sale	0		-6,234
Proceeds from Sale of Loans Held-for-sale	59		8,647
Total Charge Recorded Related to ResCap Bankruptcy	-150		1,350
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	7		-932
Deferred income taxes	174		-604
Interest payable	-346		51
Other assets	42		2,943
Other liabilities	-529		-3,456
Other, net	-118		-130
Net cash provided by (used in) operating activities	2,458		4,365
Net Cash Provided by (Used in) Investing Activities [Abstract]	'		'
Purchases of available-for-sale securities	-4,117		-12,747
Proceeds from sales of available-for-sale securities	2,974		4,721
Proceeds from maturities of available-for-sale securities	1,877		3,893
Net (increase) decrease in finance receivables and loans	-1,267		2,744
Proceeds from Sale of Loans Held-for-investment	1,557		0
Purchases of operating lease assets	-7,770		-7,251
Disposals of operating lease assets	4,505		2,080
Proceeds from Sale of Mortgage Servicing Rights (MSR)	0		911
Proceeds from sale of business units, net	47	[1]	6,937	[1]
Increase (Decrease) in Restricted Cash	2,128		2,297
Other, net	71		-55
Net cash (used in) provided by investing activities	5		3,530
Net Cash Provided by (Used in) Financing Activities [Abstract]	'		'
Net change in short-term borrowings	-3,298		-936
Net increase in bank deposits	3,501		4,057
Proceeds from issuance of long-term debt	18,942		13,347
Repayments of long-term debt	-21,239		-26,725
Dividends paid	-200		-601
Net cash provided by (used in) financing activities	-2,294		-10,858
Effect of exchange-rate changes on cash and cash equivalents	-1		47
Cash and Cash Equivalents, Period Increase (Decrease)	168		-2,916
Net Cash Provided by (Used in) Discontinued Operations	0	[1],[2]	1,952	[1],[2]
Cash and cash equivalents at beginning of period	5,531		7,513
Cash and cash equivalents at end of period	5,699		6,549
Supplemental Cash Flow Information [Abstract]	'		'
Interest	2,380		2,890
Income taxes	$13		$67
[1]	The amount at SeptemberB 30, 2013, is net of cash and cash equivalents of $1,418 million of business units at the time of disposition.
[2]	Cash flows of discontinued operations are reflected within operating, investing, and financing activities in the Condensed Consolidated Statement of Cash Flows. The cash balance of these operations is reported as assets of operations held-for-sale on the Condensed Consolidated Balance Sheet.

Description_Of_Business_Basis_

Description Of Business, Basis Of Presentation, And Changes In Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
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 Changes in Significant Accounting Policies
	Ally Financial Inc. (formerly GMAC Inc. and referred to herein as Ally, we, our, or us) is a leading, independent, diversified, financial services firm. Founded in 1919, we are a leading automotive financial services company with approximately 95 years of experience, providing a broad array of financial products and services to automotive dealers and their customers. We operate as a financial holding company and a bank holding company. Our banking subsidiary, Ally Bank, is an indirect wholly owned subsidiary of Ally Financial Inc. and a leading franchise in the growing direct (internet, telephone, mobile, and mail) banking market.
	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. 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 at the date of the financial statements and that affect income and expenses during the reporting period. In developing the estimates and assumptions, management uses all available evidence; however, actual results could differ.
	The Condensed Consolidated Financial Statements at September 30, 2014, and for the three months and nine months ended September 30, 2014, and 2013, are unaudited but reflect all adjustments that are, in management’s opinion, necessary for the fair presentation of the results for the interim periods presented. All such adjustments are of a normal recurring nature. These unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements (and the related notes) included in our Annual Report on Form 10-K for the year ended December 31, 2013, as filed on March 3, 2014, with the U.S. Securities and Exchange Commission (SEC).
	Initial Public Offering of Common Stock, Stock Split, and Changes in Number of Shares Authorized
	In April 2014, we completed an initial public offering (IPO) of our common stock. All proceeds from the offering were obtained by the U.S. Department of the Treasury (Treasury) as the single selling stockholder. In connection with the IPO, we effected a 310-for-one stock split on shares of our common stock, $0.01 par value per share. Accordingly, all references in the Condensed Consolidated Financial Statements to share and per share amounts relating to common stock have been adjusted, on a retroactive basis, to recognize the 310-for-one stock split. In addition, on April 9, 2014, we increased the number of shares authorized for issuance of common stock to 1.1 billion and decreased the number of shares authorized for issuance of Series A Preferred Stock to approximately 41 million.
	Significant Accounting Policies
	Income Taxes
	In calculating the provision for interim income taxes, in accordance with Accounting Standards Codification (ASC) 740, Income Taxes, we apply an estimated annual effective tax rate to year-to-date ordinary income. At the end of each interim period, we estimate the effective tax rate expected to be applicable for the full fiscal year. This method differs from that described in Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K, which describes our annual significant income tax accounting policy and related methodology.
	Refer to Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K regarding additional significant accounting policies.
	Recently Adopted Accounting Standards
	Liabilities — Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation Is Fixed at the Reporting Date (ASU 2013-04)
	As of January 1, 2014, we adopted Accounting Standards Update (ASU) 2013-04. The guidance within the ASU requires an entity to measure obligations resulting from joint and several liability arrangements for which the total amount of the obligation within the scope of this guidance is fixed at the reporting date, as the sum of the following: (a) The amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and (b) any additional amount the reporting entity expects to pay on behalf of its co-obligors. The amendments were effective retrospectively for all arrangements within its scope. It further requires an entity to disclose the nature and amount of the obligation as well as other information about those obligations. The adoption of this guidance did not have a material effect on our consolidated financial condition or results of operations.
	Foreign Currency Matters — Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (ASU 2013-05)
	As of January 1, 2014, we adopted ASU 2013-05. The guidance within the ASU closes diversity in practice in this area and requires a reporting entity that ceases to have a controlling financial interest, in a subsidiary or group of assets or a business, within a foreign entity to release any related Cumulative Translation Adjustment (CTA) into net income. The CTA should be released into net income only if the sale or transfer results in the complete or substantially complete liquidation of the foreign entity. For an equity method investment that is a foreign entity, a pro rata portion of the CTA should be released into net income upon a partial sale of such an investment. This ASU further clarifies that the sale of an investment in a foreign entity includes both events that result in the loss of a controlling financial interest in a foreign entity, irrespective of any retained investment, and events that result in step acquisition under which an acquirer obtains control of an acquiree in which it held an equity interest immediately before the acquisition date. Under these circumstances, the CTA should be released into net income upon their occurrence. The amendments are to be applied prospectively for all transactions within its scope. Since the guidance is prospective and we have previously sold or exited substantially all of our international businesses and released the related CTA upon those dispositions, the adoption of this guidance did not have a material effect on our consolidated financial condition or results of operations.
	Income Taxes — Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (ASU 2013-11)
	As of January 1, 2014, we adopted ASU 2013-11. The guidance within the ASU closes diversity in practice and requires an unrecognized tax benefit, or a portion of an unrecognized tax benefit, to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The guidance further includes an exception that if a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available to settle any additional income taxes that would result from the disallowance of a tax position at the reporting date or the tax law of the applicable jurisdiction does not require the entity to use them and the entity does not intend to use them, the unrecognized tax benefit for such purpose should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The assessment of whether a deferred tax asset is available is based on the unrecognized tax benefit and deferred tax asset that exist at the reporting date and should be made presuming disallowance of the tax position at the reporting date. The amendments are to be applied prospectively to all unrecognized tax benefits that exist at the effective date. The adoption of this guidance did not have a material effect to our consolidated financial condition or results of operations.
	Investments — Accounting for Investments in Qualified Affordable Housing Projects (ASU 2014-01)
	As of January 1, 2014, we adopted ASU 2014-01. The amendments in this ASU allow an entity to make an accounting policy election to account for investments in qualified affordable housing projects using a proportional amortization method, if certain conditions are met. Under the election, the entity would amortize the initial cost of the investment in proportion to the tax credits and other benefits received while recognizing the net investment performance in the statement of comprehensive income as a component of income tax expense. The amendments are to be applied retrospectively to all periods presented. We have elected to utilize the proportional amortization method for qualifying affordable housing investments and therefore will be presenting the amortization and tax impacts of such investments as a component of income tax expense under the proportional amortization method. The adoption of this guidance did not have a material effect to our consolidated financial condition or results of operations.
	Recently Issued Accounting Standards
	Receivables — Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure (ASU 2014-04)
	In January 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-04. The amendments in this ASU clarify the timing for which an entity should reclassify a loan that has been foreclosed or where an in substance repossession has occurred to real estate owned. The guidance requires such reclassification to occur when the entity obtains legal title upon completion of foreclosure or the borrower conveys all interest in the residential real estate property to the entity to satisfy the loan through completion of a deed in lieu of foreclosure or similar legal agreement. In addition, the ASU clarifies that redemption rights of the borrower should be ignored for purposes of determining whether legal title has transferred. The amendments are effective for us beginning on January 1, 2015. The amendments can be applied using either a modified retrospective or prospective basis. Under the modified retrospective approach, the entity should record a cumulative-effect adjustment to residential consumer mortgage loans and residential real estate owned as of the beginning of the annual period for which the amendments are effective. Early adoption is permitted. Management is assessing the impact of the adoption of this guidance.
	Presentation of Financial Statements and Property, Plant, and Equipment — Reporting Discontinued Operations and Disclosure of Disposals of Components of an Entity (ASU 2014-08)
	In April 2014, the FASB issued ASU 2014-08. The amendments in this ASU modify the requirements for the reporting of discontinued operations. In order to qualify as a discontinued operation, the disposal of a component of an entity, a group of components, or a business of an entity must represent a strategic shift that has (or will have) a major effect on an entity’s operations and financial results. The ASU further indicates that the timing for recording a discontinued operation is when one of the following occurs: the component, group of components, or business meets the criteria to be classified as held for sale; the component, group of components, or business is disposed of by sale; or the component, group of components, or business is disposed of other than by sale (for example abandonment or spinoff). In addition, the ASU also requires additional disclosure items about an entity’s discontinued operations. The amendments are effective for us beginning on January 1, 2015. The amendments are to be applied prospectively solely to newly identified disposals that qualify as discontinued operations after the effective date. Items previously reported as discontinued operations will maintain their classification based on the prior guidance. Early adoption is permitted, but only for disposals that have not been previously reported as discontinued operations in previously issued financial statements. Because the guidance is prospective only for newly identified disposals that qualify as a discontinued operation, this guidance is not expected to have a material impact to our consolidated financial condition or results of operations upon adoption.
	Revenue from Contracts with Customers (ASU 2014-09)
	In May 2014, the FASB issued ASU 2014-09. The purpose of this guidance is to streamline and consolidate existing revenue recognition principles in GAAP and to converge revenue recognition principles with International Financial Reporting Standards (IFRS). The core principle of the amendments is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to receive in exchange for those goods or services. The amendments include a five step process for consideration of the main principle, guidance on accounting treatment for costs associated with a contract, and disclosure requirements related to the revenue process. The amendments are effective for us beginning on January 1, 2017. The amendments can be applied either through a full retrospective application or retrospectively with a cumulative effect adjustment on the date of initial adoption. Early adoption is prohibited. Management is assessing the impact of the adoption of this guidance.
	Transfers and Servicing — Repurchase-to-Maturity Transactions, Repurchase Financings and Disclosures (ASU 2014-11)
	In June 2014, the FASB issued ASU 2014-11. The amendments in this ASU change the accounting for repurchase to maturity transactions and repurchase financing transactions such that both will be reported as secured borrowings when the guidance becomes effective. In addition to the changes to how these transactions are reported, the ASU also includes new disclosure requirements. The amendments are effective for us beginning on January 1, 2015. The amendments are to be applied to all transactions that fall under the guidance as of the date of adoption with a cumulative effect adjustment recorded on the date of initial adoption. Early adoption is prohibited. The guidance is not expected to have a material impact to our consolidated financial condition or results of operations.

Discontinued_and_Heldforsale_O

Discontinued and Held-for-sale Operations	9 Months Ended
	Sep. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	'
	Discontinued and Held-for-sale Operations
	Discontinued Operations
	We classify operations as discontinued when operations and cash flows will be eliminated from our ongoing operations and we do not expect to retain any significant continuing involvement in their operations after the respective disposal transactions. For all periods presented, the operating results for these discontinued operations have been removed from continuing operations and presented separately as discontinued operations, net of tax, in the Condensed Consolidated Statement of Comprehensive Income. The Notes to the Condensed Consolidated Financial Statements have been adjusted to exclude discontinued operations unless otherwise noted.
	Select Mortgage Operations
	During the first quarter of 2013, the operations of ResCap were classified as discontinued.
	Select Insurance Operations
	During the first quarter of 2013, we completed the sale of our U.K.-based operations. During the second quarter of 2013, we sold our Mexican insurance business, ABA Seguros.
	Select Automotive Finance Operations
	During the fourth quarter of 2012, we committed to sell our automotive finance operations in Europe and Latin America to General Motors Financial Company, Inc. (GM Financial). On the same date, we entered into an agreement with GM Financial to acquire our 40% interest in a motor vehicle finance joint venture in China. During the second quarter of 2013, we completed the sale of our operations in Europe and the majority of Latin America. The transaction included European operations in Germany, the United Kingdom, Italy, Sweden, Switzerland, Austria, Belgium, France and the Netherlands, and Latin American operations in Mexico, Chile, and Colombia. On October 1, 2013, we completed the sale of the remaining Latin American operations in Brazil. The agreement for the sale of our interest in a motor vehicle finance joint venture in China is subject to certain regulatory and other approvals. We currently expect the sale to be completed in late 2014, or as soon as practicable thereafter.
	During the first quarter of 2013, we sold our Canadian automotive finance operations, Ally Credit Canada Limited and ResMor Trust.
	Select Financial Information
	Select financial information of discontinued operations is summarized below. The pretax income or loss, including direct costs to transact a sale, includes any impairment recognized to present the operations at the lower-of-cost or fair value. Fair value was based on the estimated sales price, which could differ from the ultimate sales price due to price volatility, changing interest rates, changing foreign-currency rates, and future economic conditions.
		Three months ended September 30,						Nine months ended September 30,
	($ in millions)	2014			2013			2014			2013
	Select Mortgage operations
	Total net revenue	$	—		$	—		$	—		$	—
	Pretax loss including direct costs to transact a sale (a) (b)	(1		)	(158		)	(4		)	(1,762		)
	Tax benefit (c)	(86		)	(40		)	(87		)	(573		)
	Select Insurance operations
	Total net revenue	$	—		$	—		$	—		$	190
	Pretax income including direct costs to transact a sale (a)	6			5			6			319
	Tax expense (benefit) (c)	7			3			7			(12		)
	Select Automotive Finance operations
	Total net revenue	$	29		$	119		$	95		$	544
	Pretax income including direct costs to transact a sale (a)	46			58			101			752
	Tax expense (benefit) (c)	—			28			4			(25		)
	Select Corporate and Other operations
	Total net revenue	$	—		$	—		$	—		$	—
	Pretax income	—			—			23			1
	Tax expense	—			—			3			—
	(a)	Includes certain treasury and other corporate activity recognized by Corporate and Other.
	(b)	2013 periods include amounts related to our former Residential Capital, LLC (ResCap) subsidiary.
	(c)	Includes certain income tax activity recognized by Corporate and Other.
	Held-for-sale Operations
	The assets of operations held-for-sale are summarized below.
	($ in millions)	Select
		Automotive Finance
		operations (a)
	September 30, 2014
	Assets
	Other assets	$	603
	Total assets	$	603
	December 31, 2013
	Assets
	Other assets	$	516
	Total assets	$	516
	(a)	Represents our joint venture in China that is being sold to GM Financial.

Other_Income_Net_Of_Losses

Other Income, Net Of Losses	9 Months Ended
	Sep. 30, 2014
Other Nonoperating Income (Expense) [Abstract]	'
Other Income, Net of Losses [Text Block]	'
	Other Income, Net of Losses
	Details of other income, net of losses, were as follows.
		Three months ended September 30,					Nine months ended September 30,
	($ in millions)	2014			2013		2014			2013
	Remarketing fees	$	28		$	20	$	85		$	59
	Late charges and other administrative fees	23			25		66			71
	Fair value adjustment on derivatives (a)	(4		)	21		(19		)	31
	Mortgage processing fees and other mortgage income	—			—		—			81
	Other, net	31			27		82			82
	Total other income, net of losses	$	78		$	93	$	214		$	324
	(a)	Refer to Note 19 for a description of derivative instruments and hedging activities.

Other_Operating_Expenses

Other Operating Expenses	9 Months Ended
	Sep. 30, 2014
Operating Expenses [Abstract]	'
Other Operating Expenses [Text Block]	'
	Other Operating Expenses
	Details of other operating expenses were as follows.
		Three months ended September 30,				Nine months ended September 30,
	($ in millions)	2014		2013		2014		2013
	Insurance commissions	$	95	$	93	$	279	$	278
	Technology and communications	77		87		255		250
	Lease and loan administration	32		29		92		141
	Advertising and marketing	27		33		81		96
	Professional services	20		38		73		140
	Regulatory and licensing fees	23		25		69		87
	Premises and equipment depreciation	23		20		61		61
	Vehicle remarketing and repossession	22		15		61		42
	Occupancy	12		12		34		34
	State and local non-income taxes	12		1		32		17
	Mortgage representation and warranty obligation, net	—		22		1		103
	Other	61		57		175		144
	Total other operating expenses	$	404	$	432	$	1,213	$	1,393

Investment_Securities

Investment Securities	9 Months Ended
	Sep. 30, 2014
Available-for-sale Securities [Abstract]	'
Investment Securities [Text Block]	'
	Investment Securities
	Our portfolio of securities includes bonds, equity securities, asset- and mortgage-backed securities, interests in securitization trusts, and other investments. The cost, fair value, and gross unrealized gains and losses on available-for-sale securities were as follows.
			September 30, 2014															December 31, 2013
			Amortized cost			Gross unrealized								Fair				Amortized cost				Gross unrealized						Fair
	($ in millions)					gains				losses				value								gains			losses			value
	Available-for-sale securities
	Debt securities
	U.S. Treasury and federal agencies		$	1,313		$	1			$	(28	)		$	1,286			$	1,495			$	1		$	(69	)	$	1,427
	U.S. States and political subdivisions		386			16				—				402				316				—			(1		)	315
	Foreign government		226			6				—				232				287				4			(3		)	288
	Mortgage-backed residential (a)		11,018			78				(212		)		10,884				11,131				49			(398		)	10,782
	Mortgage-backed commercial		213			—				(1		)		212				39				—			—			39
	Asset-backed		1,982			8				(3		)		1,987				2,207				15			(3		)	2,219
	Corporate debt		970			18				(5		)		983				1,052				23			(6		)	1,069
	Total debt securities		16,108			127				(249		)		15,986				16,527				92			(480		)	16,139
	Equity securities		721			30				(23		)		728				898				74			(28		)	944
	Total available-for-sale securities (b)		$	16,829		$	157			$	(272	)		$	16,714			$	17,425			$	166		$	(508	)	$	17,083
	(a)	Residential mortgage-backed securities include agency-backed bonds totaling $8,175 million and $8,266 million at September 30, 2014, and December 31, 2013, respectively.
	(b)	Certain entities related to our Insurance operations are required to deposit securities with state regulatory authorities. Amounts deposited totaled $15 million and $15 million at September 30, 2014, and December 31, 2013, respectively.
	The maturity distribution of available-for-sale debt securities outstanding is summarized in the following tables. Prepayments may cause actual maturities to differ from scheduled maturities.
			Total						Due in							Due after							Due after					Due after
									one year							one year							five years					ten years (a)
									or less							through							through
																five years							ten years
	($ in millions)		Amount			Yield			Amount				Yield			Amount				Yield			Amount			Yield		Amount			Yield
	September 30, 2014
	Fair value of available-for-sale debt securities (b)
	U.S. Treasury and federal agencies		$	1,286		1.3	%		$	7			3.1	%		$	791			1.2	%		$	488		1.5	%	$	—		—	%
	U.S. States and political subdivisions		402			3.5			36				1.2			15				2			108			2.8		243			4.3
	Foreign government		232			2.7			—				—			124				2.6			108			2.9		—			—
	Mortgage-backed residential		10,884			2.8			—				—			65				2.1			—			—		10,819			2.8
	Mortgage-backed commercial		212			2.1			—				—			—				—			—			—		212			2.1
	Asset-backed		1,987			2			26				2.3			1,300				2			479			1.9		182			2.5
	Corporate debt		983			3.9			34				3.1			480				3			413			4.9		56			5.8
	Total available-for-sale debt securities		$	15,986		2.6			$	103			2.2			$	2,775			1.9			$	1,596		2.6		$	11,512		2.8
	Amortized cost of available-for-sale debt securities		$	16,108					$	102						$	2,773						$	1,596				$	11,637
	December 31, 2013
	Fair value of available-for-sale debt securities (b)
	U.S. Treasury and federal agencies		$	1,427		1.3	%		$	9			3	%		$	766			1.2	%		$	652		1.3	%	$	—		—	%
	U.S. States and political subdivisions		315			3.3			39				1.3			10				0.6			102			2.6		164			4.3
	Foreign government		288			2.7			18				2.7			105				2.4			164			2.9		1			2.7
	Mortgage-backed residential		10,782			2.7			—				—			90				2.1			3			4.2		10,689			2.7
	Mortgage-backed commercial		39			1.3			—				—			—				—			—			—		39			1.3
	Asset-backed		2,219			2			76				2.4			1,483				1.9			491			1.9		169			2.7
	Corporate debt		1,069			4.1			24				3.4			547				3			430			5.3		68			5.7
	Total available-for-sale debt securities		$	16,139		2.5			$	166			2.3			$	3,001			1.9			$	1,842		2.5		$	11,130		2.7
	Amortized cost of available-for-sale debt securities		$	16,527					$	165						$	3,000						$	1,882				$	11,480
	(a)	Investments with no stated maturities are included as contractual maturities of greater than 10 years. Actual maturities may differ due to call or prepayment options.
	(b)	Yields on tax-exempt obligations are computed on a tax-equivalent basis.
	The balances of cash equivalents were $2.1 billion and $2.4 billion at September 30, 2014, and December 31, 2013, respectively, and were composed primarily of money market accounts and short-term securities, including U.S. Treasury bills.
	The following table presents gross gains and losses realized upon the sales of available-for-sale securities and other-than-temporary impairment.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014				2013
	Gross realized gains	$	48		$	59			$	150			$	196
	Gross realized losses	(3		)	(7		)		(11		)		(21		)
	Other-than-temporary impairment	—			(11		)		(10		)		(19		)
	Other gain on investments, net	$	45		$	41			$	129			$	156
	The following table presents interest and dividends on available-for-sale securities.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014				2013
	Taxable interest	$	87		$	79			$	256			$	210
	Taxable dividends	6			6				18				19
	Interest and dividends exempt from U.S. federal income tax	1			—				8				—
Interest and dividends on available-for-sale securities	$	94		$	85			$	282			$	229
Certain available-for-sale securities were sold at a loss in 2014 and 2013 as a result of market conditions within these respective periods (e.g., change in market interest rates or a downgrade in the rating of a debt security). The table below summarizes available-for-sale securities in an unrealized loss position in accumulated other comprehensive income. Based on the methodology described below that was applied to these securities, we believe that the unrealized losses relate to factors other than credit losses in the current market environment. As of September 30, 2014, we did not have the intent to sell the debt securities with an unrealized loss position in accumulated other comprehensive income, and it is not more likely than not that we will be required to sell these securities before recovery of their amortized cost basis. As of September 30, 2014, we had the ability and intent to hold equity securities with an unrealized loss position in accumulated other comprehensive income, and it is not more likely than not that we will be required to sell these securities before recovery of their amortized cost basis. As a result, we believe that the securities with an unrealized loss position in accumulated other comprehensive income are not considered to be other-than-temporarily impaired at September 30, 2014. Refer to Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information related to investment securities and our methodology for evaluating potential other-than-temporary impairments.
		September 30, 2014															December 31, 2013
		Less than							12 months								Less than							12 months
		12 months							or longer								12 months							or longer
($ in millions)		Fair			Unrealized				Fair				Unrealized				Fair				Unrealized			Fair			Unrealized
		value			loss				value				loss				value				loss			value			loss
Available-for-sale securities
Debt securities
U.S. Treasury and federal agencies		$	—		$	—			$	1,245			$	(28	)		$	1,405			$	(69	)	$	—		$	—
U.S. States and political subdivisions		21			—				—				—				212				(1		)	—			—
Foreign government		43			—				—				—				114				(3		)	—			—
Mortgage-backed		1,428			(12		)		4,229				(201		)		7,503				(388		)	100			(10		)
Asset-backed		699			(3		)		16				—				407				(3		)	1			—
Corporate debt		238			(4		)		20				(1		)		310				(6		)	3			—
Total temporarily impaired debt securities		2,429			(19		)		5,510				(230		)		9,951				(470		)	104			(10		)
Temporarily impaired equity securities		255			(21		)		14				(2		)		167				(12		)	100			(16		)
Total temporarily impaired available-for-sale securities		$	2,684		$	(40	)		$	5,524			$	(232	)		$	10,118			$	(482	)	$	204		$	(26	)

Finance_Receivables_And_Loans_

Finance Receivables And Loans, Net	9 Months Ended
	Sep. 30, 2014
Loans and Leases Receivable, Net Reported Amount, by Category Alternative [Abstract]	'
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	'
	Finance Receivables and Loans, Net
	The composition of finance receivables and loans, net, reported at carrying value before allowance for loan losses was as follows.
	($ in millions)		September 30, 2014				December 31, 2013
	Consumer automobile (a)		$	58,675			$	56,417
	Consumer mortgage (b)(c)		7,595				8,444
	Commercial
	Commercial and industrial
	Automobile		28,453				30,948
	Other		1,756				1,664
	Commercial Real Estate — Automobile		3,039				2,855
	Total commercial		33,248				35,467
	Total finance receivables and loans (d)		$	99,518			$	100,328
	(a)	Includes $16 million and $1 million of fair value adjustment for loans in hedge accounting relationships at September 30, 2014, and December 31, 2013, respectively. Refer to Note 19 for additional information.
	(b)	Includes interest-only mortgage loans of $1.3 billion and $1.5 billion at September 30, 2014, and December 31, 2013, respectively, the majority of which are expected to start principal amortization in 2015 or beyond.
	(c)	Includes consumer mortgages at a fair value of $1 million at both September 30, 2014, and December 31, 2013, as a result of fair value option election.
	(d)	Totals are net of unearned income, unamortized premiums and discounts, and deferred fees and costs of $392 million and $595 million at September 30, 2014, and December 31, 2013, respectively.
	The following tables present an analysis of the activity in the allowance for loan losses on finance receivables and loans.
	Three months ended September 30, 2014 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at July 1, 2014		$	729			$	302			$	140			$	1,171
	Charge-offs		(188		)		(13		)		—				(201		)
	Recoveries		51				1				—				52
	Net charge-offs		(137		)		(12		)		—				(149		)
	Provision for loan losses		112				(7		)		(3		)		102
	Other		(11		)		—				—				(11		)
	Allowance at September 30, 2014		$	693			$	283			$	137			$	1,113
	Three months ended September 30, 2013 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at July 1, 2013		$	610			$	431			$	142			$	1,183
	Charge-offs		(168		)		(16		)		—				(184		)
	Recoveries		53				5				—				58
	Net charge-offs		(115		)		(11		)		—				(126		)
	Provision for loan losses		156				(12		)		(3		)		141
	Other		—				(1		)		1				—
	Allowance at September 30, 2013		$	651			$	407			$	140			$	1,198
	Nine months ended September 30, 2014 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at January 1, 2014		$	673			$	389			$	146			$	1,208
	Charge-offs		(511		)		(38		)		(5		)		(554		)
	Recoveries		170				6				11				187
	Net charge-offs		(341		)		(32		)		6				(367		)
	Provision for loan losses		372				(55		)		(15		)		302
	Other		(11		)		(19		)		—				(30		)
	Allowance at September 30, 2014		$	693			$	283			$	137			$	1,113
	Allowance for loan losses
	Individually evaluated for impairment		$	25			$	180			$	15			$	220
	Collectively evaluated for impairment		668				103				122				893
	Loans acquired with deteriorated credit quality		—				—				—				—
	Finance receivables and loans at historical cost
	Ending balance		58,675				7,594				33,248				99,517
	Individually evaluated for impairment		289				904				73				1,266
	Collectively evaluated for impairment		58,384				6,690				33,175				98,249
	Loans acquired with deteriorated credit quality		2				—				—				2
	Nine months ended September 30, 2013 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at January 1, 2013		$	575			$	452			$	143			$	1,170
	Charge-offs		(443		)		(71		)		(3		)		(517		)
	Recoveries		155				13				6				174
	Net charge-offs		(288		)		(58		)		3				(343		)
	Provision for loan losses		355				14				(8		)		361
	Other		9				(1		)		2				10
	Allowance at September 30, 2013		$	651			$	407			$	140			$	1,198
	Allowance for loan losses
Individually evaluated for impairment		$	22			$	199			$	28			$	249
Collectively evaluated for impairment		629				208				112				949
Loans acquired with deteriorated credit quality		—				—				—				—
Finance receivables and loans at historical cost
Ending balance		56,450				8,772				30,059				95,281
Individually evaluated for impairment		269				916				251				1,436
Collectively evaluated for impairment		56,170				7,856				29,808				93,834
Loans acquired with deteriorated credit quality		11				—				—				11
The following table presents information about significant sales of finance receivables and loans recorded at historical cost and transfers of finance receivables and loans from held-for-investment to held-for-sale.
		Three months ended September 30,								Nine months ended September 30,
($ in millions)		2014				2013				2014				2013
Consumer automobile		$	1,562			$	—			$	1,562			$	—
Consumer mortgage		—				—				40				—
Commercial		—				2				—				47
Total sales and transfers		$	1,562			$	2			$	1,602			$	47
The following table presents information about significant purchases of finance receivables and loans.
		Three months ended September 30,								Nine months ended September 30,
($ in millions)		2014				2013				2014				2013
Consumer mortgage		$	83			$	—			$	98			$	—
Total purchases		$	83			$	—			$	98			$	—
The following table presents an analysis of our past due finance receivables and loans, net, recorded at historical cost reported at carrying value before allowance for loan losses.
($ in millions)		30-59 days				60-89 days				90 days				Total				Current				Total finance
		past due				past due				or more				past due								receivables and loans
										past due
September 30, 2014
Consumer automobile		$	1,179			$	243			$	145			$	1,567			$	57,108			$	58,675
Consumer mortgage (a)		110				41				138				289				7,305				7,594
Commercial
Commercial and industrial
Automobile		—				—				—				—				28,453				28,453
Other		—				—				—				—				1,756				1,756
Commercial real estate — Automobile		—				—				—				—				3,039				3,039
Total commercial		—				—				—				—				33,248				33,248
Total consumer and commercial		$	1,289			$	284			$	283			$	1,856			$	97,661			$	99,517
December 31, 2013
Consumer automobile		$	1,145			$	255			$	157			$	1,557			$	54,860			$	56,417
Consumer mortgage		82				31				124				237				8,206				8,443
Commercial
Commercial and industrial
Automobile		—				—				36				36				30,912				30,948
Other		—				—				—				—				1,664				1,664
Commercial real estate — Automobile		—				—				6				6				2,849				2,855
Total commercial		—				—				42				42				35,425				35,467
Total consumer and commercial		$	1,227			$	286			$	323			$	1,836			$	98,491			$	100,327
(a)	During the three months ended September 30, 2014, we completed a sub-servicing transfer of our mortgage held-for-investment loan portfolio. This caused what is expected to be a temporary increase in the delinquency levels at September 30, 2014, and is not believed to be indicative of a degradation in underlying credit quality.
The following table presents the carrying value before allowance for loan losses of our finance receivables and loans recorded at historical cost on nonaccrual status.
($ in millions)		September 30, 2014				December 31, 2013
Consumer automobile		$	355			$	329
Consumer mortgage		193				192
Commercial
Commercial and industrial
Automobile		21				116
Other		51				74
Commercial real estate — Automobile		1				14
Total commercial		73				204
Total consumer and commercial finance receivables and loans		$	621			$	725
Management performs a quarterly analysis of the consumer automobile, consumer mortgage, 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 tables below present the population of loans by quality indicators for our consumer automobile, 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 historical cost reported at carrying value before allowance for loan losses. Nonperforming loans include finance receivables and loans on nonaccrual status when the principal or interest has been delinquent for 90 days or when full collection is determined not to be probable. Refer to Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information.
		September 30, 2014												December 31, 2013
($ in millions)		Performing				Nonperforming				Total				Performing				Nonperforming				Total
Consumer automobile		$	58,320			$	355			$	58,675			$	56,088			$	329			$	56,417
Consumer mortgage		7,401				193				7,594				8,251				192				8,443
The following table presents pass and criticized credit quality indicators based on regulatory definitions for our commercial finance receivables and loans recorded at historical cost reported at carrying value before allowance for loan losses.
		September 30, 2014												December 31, 2013
($ in millions)		Pass				Criticized (a)				Total				Pass				Criticized (a)				Total
Commercial
Commercial and industrial
Automobile		$	26,879			$	1,574			$	28,453			$	29,194			$	1,754			$	30,948
Other		1,501				255				1,756				1,388				276				1,664
Commercial real estate — Automobile		2,938				101				3,039				2,770				85				2,855
Total commercial		$	31,318			$	1,930			$	33,248			$	33,352			$	2,115			$	35,467
(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 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K.
The following table presents information about our impaired finance receivables and loans recorded at historical cost.
($ in millions)		Unpaid principal balance				Carrying value before allowance				Impaired with no allowance				Impaired with an allowance				Allowance for impaired loans
September 30, 2014
Consumer automobile		$	289			$	289			$	—			$	289			$	25
Consumer mortgage		909				904				128				776				180
Commercial
Commercial and industrial
Automobile		21				21				4				17				1
Other		51				51				—				51				14
Commercial real estate — Automobile		1				1				1				—				—
Total commercial		73				73				5				68				15
Total consumer and commercial finance receivables and loans		$	1,271			$	1,266			$	133			$	1,133			$	220
December 31, 2013
Consumer automobile		$	281			$	281			$	—			$	281			$	23
Consumer mortgage		924				919				128				791				199
Commercial
Commercial and industrial
Automobile		116				116				57				59				7
Other		74				74				—				74				16
Commercial real estate — Automobile		14				14				9				5				3
Total commercial		204				204				66				138				26
Total consumer and commercial finance receivables and loans		$	1,409			$	1,404			$	194			$	1,210			$	248
The following tables present average balance and interest income for our impaired finance receivables and loans.
		2014								2013
Three months ended September 30, ($ in millions)		Average				Interest				Average				Interest
		balance				income				balance				income
Consumer automobile		$	297			$	5			$	275			$	5
Consumer mortgage		914				7				924				7
Commercial
Commercial and industrial
Automobile		32				—				163				2
Other		51				—				84				—
Commercial real estate — Automobile		3				—				29				—
Total commercial		86				—				276				2
Total consumer and commercial finance receivables and loans		$	1,297			$	12			$	1,475			$	14
		2014								2013
Nine months ended September 30, ($ in millions)		Average				Interest				Average				Interest
		balance				income				balance				income
Consumer automobile		$	298			$	14			$	274			$	14
Consumer mortgage		923				22				905				22
Commercial
Commercial and industrial
Automobile		68				1				160				5
Other		62				4				69				1
Commercial real estate — Automobile		7				—				33				1
Total commercial		137				5				262				7
Total consumer and commercial finance receivables and loans		$	1,358			$	41			$	1,441			$	43
Troubled Debt Restructurings
Troubled Debt Restructurings (TDRs) are loan modifications where concessions were granted to borrowers experiencing financial difficulties. Numerous initiatives 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. Additionally for automobile loans, we may offer several types of assistance to aid our customers, including extension of the loan maturity date and rewriting the loan terms. Total TDRs recorded at historical cost and reported at carrying value before allowance for loan losses were $1.3 billion at both September 30, 2014, and December 31, 2013. Refer to Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information.
The following tables present information related to finance receivables and loans recorded at historical cost modified in connection with a TDR during the period.
		2014											2013
Three months ended September 30,		Number of			Pre-modification				Post-modification				Number of			Pre-modification				Post-modification
($ in millions)		loans			carrying value before				carrying value before				loans			carrying value before				carrying value before
					allowance				allowance							allowance				allowance
Consumer automobile		4,361			$	72			$	63			4,610			$	69			$	57
Consumer mortgage		37			7				6				121			33				32
Commercial
Commercial and industrial
Automobile		—			—				—				2			5				5
Other		—			—				—				1			27				27
Commercial real estate — Automobile		—			—				—				1			7				7
Total commercial		—			—				—				4			39				39
Total consumer and commercial finance receivables and loans		4,398			$	79			$	69			4,735			$	141			$	128
		2014											2013
Nine months ended September 30,		Number of			Pre-modification				Post-modification				Number of			Pre-modification				Post-modification
($ in millions)		loans			carrying value before				carrying value before				loans			carrying value before				carrying value before
					allowance				allowance							allowance				allowance
Consumer automobile		13,681			$	223			$	193			14,309			$	216			$	182
Consumer mortgage		350			71				66				853			246				203
Commercial
Commercial and industrial
Automobile		3			23				23				8			37				37
Other		3			48				48				4			80				78
Commercial real estate — Automobile		—			—				—				5			20				20
Total commercial		6			71				71				17			137				135
Total consumer and commercial finance receivables and loans		14,037			$	365			$	330			15,179			$	599			$	520
The following tables present information about finance receivables and loans recorded at historical cost 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 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information) except for commercial finance receivables and loans, where redefault is defined as 90 days past due.
		2014											2013
Three months ended September 30, ($ in millions)		Number of			Carrying value				Charge-off amount				Number of			Carrying value				Charge-off amount
		loans			before allowance								loans			before allowance
Consumer automobile		1,790			$	22			$	12			1,562			$	19			$	9
Consumer mortgage		5			1				—				4			2				—
Commercial
Commercial and industrial — Automobile		—			—				—				—			—				—
Commercial real estate — Automobile		—			—				—				—			—				—
Total commercial		—			—				—				—			—				—
Total consumer and commercial finance receivables and loans		1,795			$	23			$	12			1,566			$	21			$	9
		2014											2013
Nine months ended September 30, ($ in millions)		Number of			Carrying value				Charge-off amount				Number of			Carrying value				Charge-off amount
		loans			before allowance								loans			before allowance
Consumer automobile		5,020			$	62			$	33			4,309			$	53			$	26
Consumer mortgage		10			2				—				16			4				—
Commercial
Commercial and industrial — Automobile		—			—				—				—			—				—
Commercial real estate — Automobile		—			—				—				—			—				—
Total commercial		—			—				—				—			—				—
Total consumer and commercial finance receivables and loans		5,030			$	64			$	33			4,325			$	57			$	26
At September 30, 2014, and December 31, 2013, commercial commitments to lend additional funds to borrowers owing receivables whose terms had been modified in a TDR were $4 million and $26 million, respectively.

Investment_In_Operating_Leases

Investment In Operating Leases, Net	9 Months Ended
	Sep. 30, 2014
Leases, Operating [Abstract]	'
Operating Leases of Lessor Disclosure [Text Block]	'
	Investment in Operating Leases, Net
	Investments in operating leases were as follows.
	($ in millions)		September 30, 2014				December 31, 2013
	Vehicles and other equipment		$	22,845			$	21,125
	Accumulated depreciation		(3,504		)		(3,445		)
	Investment in operating leases, net		$	19,341			$	17,680
	Depreciation expense on operating lease assets includes remarketing gains and losses recognized on the sale of operating lease assets. The following summarizes the components of depreciation expense on operating lease assets.
		Three months ended September 30,								Nine months ended September 30,
	($ in millions)	2014				2013				2014			2013
	Depreciation expense on operating lease assets (excluding remarketing gains)	$	654			$	610			$	1,982		$	1,699
	Remarketing gains	(105		)		(95		)		(382		)	(250		)
	Depreciation expense on operating lease assets	$	549			$	515			$	1,600		$	1,449

Securitizations_And_Variable_I

Securitizations And Variable Interest Entities	9 Months Ended
	Sep. 30, 2014
Securitizations And Variable Interest Entities [Abstract]	'
Securitizations And Variable Interest Entities Disclosure [Text Block]	'
	Securitizations and Variable Interest Entities
	Overview
	We are involved in several types of securitization and financing transactions that utilize special-purpose entities (SPEs). An SPE is an entity that is designed to fulfill a specified limited need of the sponsor. Our principal use of SPEs is to obtain liquidity by securitizing certain of our financial assets and operating lease assets.
	The SPEs involved in our securitization and other financing transactions are generally considered variable interest entities (VIEs). VIEs are entities that have either a total equity investment at risk that is insufficient to permit the entity to finance its activities without additional subordinated financial support or whose equity investors at risk lack the ability to control the entity's activities.
	Due to the deconsolidation of ResCap, our mortgage securitization activity and involvement with certain mortgage-related VIEs has substantially decreased. We no longer securitize consumer mortgage loans through transactions involving the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac), and the Government National Mortgage Association (Ginnie Mae) (collectively, the Government-sponsored Enterprises, or GSEs), or through private-label mortgage securitizations. Accordingly, the discussion below represents our current involvement with variable interest entities as of September 30, 2014, except where otherwise stated or where comparative information is presented.
	Securitizations
	We provide a wide range of consumer and commercial automobile loans, operating leases, and commercial loans to a diverse customer base. We often securitize these loans (also referred to as financial assets) and leases through the use of securitization entities, which may or may not be consolidated on our Condensed Consolidated Balance Sheet. We securitize consumer and commercial automobile loans, operating leases, and other commercial loans through private-label securitizations.
	In executing a securitization transaction, 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 securitization entity for cash, servicing rights, and typically, other retained interests. The securitization entity is funded through the issuance of beneficial interests in the securitized financial assets. The beneficial interests take the form of either notes or trust certificates, which are sold to investors and/or retained by us. These beneficial interests are collateralized by the transferred leases and loans and entitle the investors to specified cash flows generated from the underlying securitized assets. In addition to providing a source of liquidity and cost-efficient funding, securitizing these leases and financial assets also reduces our credit exposure to the borrowers beyond any economic interest we may retain.
	Each securitization is governed by various legal documents that limit and specify the activities of the securitization entity. The securitization entity is generally allowed to acquire the loans, to issue beneficial interests to investors to fund the acquisition of the loans, and to enter into derivatives or other yield maintenance contracts to hedge or 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 securitization entity holds and the beneficial interests it issues. Servicing functions include, but are not limited to, general collection activity on current and noncurrent accounts, loss mitigation efforts including repossession and sale of collateral, as well as advancing principal and interest payments before collecting them from individual borrowers. Our servicing responsibilities, which constitute continued involvement in the transferred financial assets, consist of primary servicing (i.e., servicing the underlying transferred financial assets) and master servicing (i.e., servicing the beneficial interests that result from the securitization transactions).
	Cash flows from the assets initially transferred into the securitization entity represent the sole source for payment of distributions on the beneficial interests issued by the securitization entity and for payments to the parties that perform services for the securitization entity, such as the servicer or the trustee. In certain securitization transactions, a liquidity facility may exist to provide temporary liquidity to the entity. The liquidity provider generally is reimbursed prior to other parties in subsequent distribution periods.
	We typically hold retained beneficial interests in our securitizations, which may represent a form of significant continuing economic interest. These retained interests include, but are not limited to, senior or subordinate asset-backed securities and residuals; and other residual interests. Certain of these retained interests provide credit enhancement to the trust as they may absorb credit losses or other cash shortfalls. Additionally, the securitization agreements may require cash flows to be directed away from certain of our retained interests due to specific over-collateralization requirements, which may or may not be performance-driven.
	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 burdensome (a clean-up call option). The repurchase price is typically the par amount of the loans plus accrued interest. Additionally, we may hold other conditional repurchase options that allow us to repurchase a transferred financial asset if certain events outside our control occur. The typical conditional repurchase option is a delinquent loan repurchase option that gives us the option to purchase the loan or contract if it exceeds a certain prespecified delinquency level. 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 and warranty provisions, these securitizations are nonrecourse to us, thereby transferring the risk of future credit losses to the extent the beneficial interests in the securitization entities are held by third parties. Representation and warranty provisions generally require us to repurchase loans or indemnify the investor or other party for incurred losses to the extent it is determined that the loans were ineligible or were otherwise defective at the time of sale. Refer to Note 26 for detail on representation and warranty provisions. We did not provide any noncontractual financial support to any of these entities during the nine months ended September 30, 2014 or 2013.
	Consolidation of Variable Interest Entities
	The determination of whether the assets and liabilities of the VIEs are consolidated on our balance sheet (also referred to as on-balance sheet) or not consolidated on our balance sheet (also referred to as off-balance sheet) depends on the terms of the related transaction and our continuing involvement (if any) with the VIE. We are deemed the primary beneficiary and therefore consolidate VIEs for which we have both (a) the power, through voting rights or similar rights, to direct the activities that most significantly impact the VIE's economic performance, and (b) a variable interest (or variable interests) that (i) obligates us to absorb losses that could potentially be significant to the VIE and/or (ii) provides us the right to receive residual returns of the VIE that could potentially be significant to the VIE. We determine whether we hold a significant variable interest in a VIE based on a consideration of both qualitative and quantitative factors regarding the nature, size, and form of our involvement with the VIE. We assess whether we are the primary beneficiary of a VIE on an ongoing basis.
	We are generally determined to be the primary beneficiary in VIEs established for our securitization activities when we have a controlling financial interest in the VIE, primarily due to our servicing activities, and we hold a significant beneficial interest in the VIE. The consolidated VIEs included in the Condensed Consolidated Balance Sheet represent separate entities with which we are involved. 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 and warranty provisions or when we are the counterparty to certain derivative transactions involving the VIE. 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, presented below based upon the legal transfer of the underlying assets in order to reflect legal ownership, are restricted for the benefit of the beneficial interest holders. Refer to Note 22 for discussion of the assets and liabilities for which the fair value option has been elected.
	The nature, purpose, and activities of nonconsolidated securitization entities are similar to those of our consolidated securitization entities with the primary difference being the nature and extent of our continuing involvement. We are generally not determined to be the primary beneficiary in VIEs established for our securitization activities when we either do not hold potentially significant variable interests or do not provide servicing or asset management functions for the financial assets held by the securitization entity. Additionally, to qualify for off-balance sheet treatment, transfers of financial assets must meet appropriate sale accounting conditions. For nonconsolidated securitization entities, 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, servicing rights, or retained interests (if applicable). Typically, we conclude that the fee we are paid for servicing consumer automobile finance receivables represents adequate compensation, and consequently, we do not recognize a servicing asset or liability. Liabilities incurred as part of these securitization transactions, such as representation and warranty provisions, are recorded at fair value at the time of sale and are reported as accrued expenses and other liabilities on our Condensed 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.
	We have involvement with various other on-balance sheet, immaterial VIEs. Most of these VIEs are used for additional liquidity whereby we sell certain financial assets into the VIE and issue beneficial interests to third parties for cash. We also provide long-term guarantee contracts to investors in certain nonconsolidated affordable housing entities and have extended a line of credit to provide liquidity and minimize our exposure under these contracts. 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 have involvement with various other nonconsolidated affordable housing entities and venture capital funds. We do not consolidate these entities and our involvement is limited to the capital contributed and committed to these funds.
	Our involvement with consolidated and nonconsolidated VIEs in which we hold variable interests is presented below.
	($ in millions)		Consolidated				Assets of				Maximum exposure to
			involvement				nonconsolidated				loss in nonconsolidated
			with VIEs				VIEs (a)				VIEs
	September 30, 2014
	On-balance sheet variable interest entities
	Consumer automobile		$	33,331		(b)
	Commercial automobile		16,499
	Commercial other		—
	Off-balance sheet variable interest entities
	Consumer automobile		—				$	2,032			$	2,032		(c)
	Commercial other		121			(d)	—			(e)	291
	Total		$	49,951			$	2,032			$	2,323
	December 31, 2013
	On-balance sheet variable interest entities
	Consumer automobile		$	19,072
	Commercial automobile		20,511
	Commercial other		564
	Off-balance sheet variable interest entities
	Consumer automobile		—				$	899			$	899		(c)
	Commercial other		(24		)	(d)	—			(e)	40
	Total		$	40,123			$	899			$	939
	(a)	Asset values represent the current unpaid principal balance of outstanding consumer finance receivables and loans within the VIEs.
	(b)	Includes $14.3 billion of unsecuritized involvement with VIEs and thus not restricted for use as collateral to beneficial interest holders at September 30, 2014.
	(c)	Maximum exposure to loss represents the current unpaid principal balance of outstanding loans based on our customary representation and warranty provisions. This measure is based on the unlikely event that all of the loans have underwriting defects or other defects that trigger a representation and warranty provision and the collateral supporting the loans is worthless. This required disclosure is not an indication of our expected loss.
	(d)	Includes $143 million and $0 million classified as other assets, offset by $22 million and $24 million classified as accrued expenses and other liabilities at September 30, 2014, and December 31, 2013, respectively.
	(e)	Includes VIEs for which we have no management oversight and therefore we are not able to provide the total assets of the VIE.
	Cash Flows with Off-balance Sheet Variable Interest Entities
	The following table summarizes cash flows received and paid related to securitization entities, asset-backed financings, or other similar transfers of financial assets where the transfer is accounted for as a sale and we have a continuing involvement with the transferred assets (e.g., servicing) that were outstanding during the nine months ended September 30, 2014 and 2013. Additionally, this table contains information regarding cash flows received from and paid to nonconsolidated securitization entities that existed during each period.
	Nine months ended September 30, ($ in millions)		Consumer automobile				Consumer
							mortgage GSEs
	2014
	Cash proceeds from transfers completed during the period		$	1,557			$	—
	Servicing fees		6				—
	Representations and warranties obligations		—				(9		)
	2013
	Cash proceeds from transfers completed during the period		$	—			$	8,676
	Servicing fees		10				68
	Representations and warranties obligations		—				(65		)
	Other cash flows		—				70
	Delinquencies and Net Credit Losses
	The following tables represent on-balance sheet loans held-for-sale and finance receivables and loans, off-balance sheet securitizations, and whole-loan sales where we have continuing involvement. The tables present quantitative information about delinquencies and net credit losses. Refer to Note 9 for further detail on total serviced assets.
			Total Amount								Amount 60 days or more past due (a)
	($ in millions)		September 30, 2014				December 31, 2013				September 30, 2014				December 31, 2013
On-balance sheet loans (b)
Consumer automobile		$	58,675			$	56,417			$	388			$	412
Consumer mortgage		7,598				8,460				181				164
Commercial automobile		31,492				33,803				—				42
Commercial other		1,756				1,683				—				—
Total on-balance sheet loans		99,521				100,363				569				618
Off-balance sheet securitization entities (c)
Consumer automobile		2,032				899				3				3
Total off-balance sheet securitization entities		2,032				899				3				3
Whole-loan transactions (d)		1,238				2,848				37				69
Total		$	102,791			$	104,110			$	609			$	690
(a)	Includes both accruing and non-accruing loans 60 days or more past due.
(b)	Includes current unpaid principal balance and any related unamortized deferred fees and costs.
(c)	Asset values represent the current unpaid principal balance of outstanding consumer finance receivables and loans within the VIEs.
(d)	Whole-loan transactions are not part of a securitization transaction, but represent consumer automobile pools of loans sold to third-party investors.
		Net credit losses
		Three months ended September 30,								Nine months ended September 30,
($ in millions)		2014				2013				2014				2013
On-balance sheet loans
Consumer automobile		$	137			$	115			$	341			$	288
Consumer mortgage		12				11				32				58
Commercial automobile		—				—				1				—
Commercial other		—				—				(7		)		(3		)
Total on-balance sheet loans		149				126				367				343
Off-balance sheet securitization entities
Consumer automobile		—				1				1				3
Total off-balance sheet securitization entities		—				1				1				3
Whole-loan transactions		1				3				5				8
Total		$	150			$	130			$	373			$	354

Servicing_Activities

Servicing Activities	9 Months Ended
	Sep. 30, 2014
Servicing Activities [Abstract]	'
Servicing Activities [Text Block]	'
	Servicing Activities
	Mortgage Servicing Rights
	The following table summarizes past activity related to mortgage servicing rights (MSRs), which were carried at fair value. Management estimated fair value using our transaction data and other market data or, in periods when there were limited MSRs market transactions that were directly observable, internally developed discounted cash flow models (an income approach) were used to estimate the fair value. These internal valuation models estimated net cash flows based on internal operating assumptions that we believed would be used by market participants in orderly transactions combined with market-based assumptions for loan prepayment rates, interest rates, and discount rates that we believed approximate yields required by investors in this asset.
	Nine months ended September 30, ($ in millions)		2014			2013
	Estimated fair value at January 1,		$	—		$	952
	Additions		—			60
	Sales (a)		—			(911		)
	Changes in fair value
	Due to changes in valuation inputs or assumptions used in the valuation model		—			(32		)
	Other changes in fair value		—			(69		)
	Estimated fair value at September 30,		$	—		$	—
	(a)	Includes the sales of agency MSRs during the second quarter of 2013.
	Changes in fair value due to changes in valuation inputs or assumptions used in the valuation model included all changes due to a revaluation by a model or by a benchmarking exercise. Other changes in fair value primarily included the accretion of the present value of the discount related to forecasted cash flows and the economic runoff of the portfolio.
	Risk Mitigation Activities
	The primary risk of servicing rights is interest rate risk and the resulting impact on prepayments. A significant decline in interest rates could lead to higher-than-expected prepayments that could reduce the value of the MSRs. We previously economically hedged the impact of these risks with both derivative and nonderivative financial instruments. Refer to Note 19 for additional information regarding the derivative financial instruments used to economically hedge MSRs.
	The components of servicing valuation and hedge activities, net, were as follows.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014		2013
	Change in estimated fair value of mortgage servicing rights	$	—		$	—			$	—	$	(101	)
	Change in fair value of derivative financial instruments	—			—				—		(112		)
	Servicing asset valuation and hedge activities, net	$	—		$	—			$	—	$	(213	)
	Mortgage Servicing Fees
	The components of mortgage servicing fees were as follows.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014		2013
	Contractual servicing fees, net of guarantee fees and including subservicing	$	—		$	—			$	—	$	61
	Late fees	—			—				—		1
	Ancillary fees	—			—				—		4
	Total mortgage servicing fees	$	—		$	—			$	—	$	66
	Automobile Finance Servicing Activities
	We service consumer automobile contracts. Historically, we have sold a portion of our consumer automobile contracts. With respect to contracts we sell, we retain the right to service and earn a servicing fee for our servicing function. Typically, we conclude that the fee we are paid for servicing consumer automobile finance receivables represents adequate compensation, and consequently, we do not recognize a servicing asset or liability. We recognized automobile servicing fees of $6 million and $22 million during the three months and nine months ended September 30, 2014, respectively, compared to $13 million and $48 million for the three months and nine months ended September 30, 2013, respectively.
	Automobile Finance Serviced Assets
	The current unpaid principal balance and any related unamortized deferred fees and costs of total serviced automobile finance loans outstanding were as follows.
	($ in millions)	September 30, 2014			December 31, 2013
	On-balance sheet automobile finance loans and leases
	Consumer automobile	$	58,675		$	56,417
	Commercial automobile	31,492			33,803
	Operating leases	19,341			17,680
	Other	52			54
	Off-balance sheet automobile finance loans
	Loans sold to third-party investors
	Securitizations	2,052			887
	Whole-loan	1,189			2,748
	Total serviced automobile finance loans and leases	$	112,801		$	111,589

Other_Assets

Other Assets	9 Months Ended
	Sep. 30, 2014
Other Assets [Abstract]	'
Other Assets Disclosure [Text Block]	'
	Other Assets
	The components of other assets were as follows.
	($ in millions)	September 30, 2014			December 31, 2013
	Property and equipment at cost	$	754		$	709
	Accumulated depreciation	(529		)	(474		)
	Net property and equipment	225			235
	Deferred tax assets	1,788			2,040
	Restricted cash collections for securitization trusts (a)	1,724			3,664
	Other accounts receivable	369			290
	Cash reserve deposits held-for-securitization trusts (b)	296			402
	Nonmarketable equity securities	275			337
	Unamortized debt issuance cost	254			312
	Collateral placed with counterparties	243			328
	Fair value of derivative contracts in receivable position (c)	235			362
	Restricted cash and cash equivalents	123			205
	Other assets	1,220			1,414
	Total other assets	$	6,752		$	9,589
	(a)	Represents cash collections from customer payments on securitized receivables. These funds are distributed to investors as payments on the related secured debt.
	(b)	Represents credit enhancement in the form of cash reserves for various securitization transactions.
	(c)	For additional information on derivative instruments and hedging activities, refer to Note 19.

Deposit_Liabilities

Deposit Liabilities	9 Months Ended
	Sep. 30, 2014
Deposits [Abstract]	'
Deposit Liabilities Disclosures [Text Block]	'
	Deposit Liabilities
	Deposit liabilities consisted of the following.
	($ in millions)	September 30, 2014		December 31, 2013
	Noninterest-bearing deposits	$	73	$	60
	Interest-bearing deposits
	Savings and money market checking accounts	25,383		21,210
	Certificates of deposit	31,027		31,640
	Dealer deposits	368		440
	Total deposit liabilities	$	56,851	$	53,350
	At both September 30, 2014, and December 31, 2013, certificates of deposit included $13.1 billion of certificates of deposit in denominations of $100 thousand or more.

ShortTerm_Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2014
Short-term Debt [Abstract]	'
Short-term Debt [Text Block]	'
	Short-term Borrowings
	The following table presents the composition of our short-term borrowings portfolio.
			September 30, 2014						December 31, 2013
	($ in millions)		Unsecured		Secured (a)		Total		Unsecured		Secured (a)		Total
	Demand notes		$	3,376	$	—	$	3,376	$	3,225	$	—	$	3,225
	Federal Home Loan Bank		—		1,300		1,300		—		3,570		3,570
	Securities sold under agreements to repurchase (b)		—		579		579		—		1,500		1,500
	Other (c)		—		—		—		—		250		250
	Total short-term borrowings		$	3,376	$	1,879	$	5,255	$	3,225	$	5,320	$	8,545
	(a)	Refer to Note 13 for further details on assets restricted as collateral for payment of the related debt.
	(b)	We periodically enter into term repurchase agreements, short-term borrowing arrangements in which we sell financial instruments to one or more investors while simultaneously committing to repurchase them at a specified future date, at the stated price plus accrued interest. The financial instruments sold under agreement to repurchase typically consist of U.S. government and agency securities.
	(c)	Other relates to secured borrowings at Corporate Finance at December 31, 2013.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2014
Long-term Debt, Unclassified [Abstract]	'
Long-term Debt [Text Block]	'
	Long-term Debt
	The following table presents the composition of our long-term debt portfolio.
			September 30, 2014									December 31, 2013
	($ in millions)		Unsecured			Secured			Total			Unsecured			Secured			Total
	Long-term debt
	Due within one year		$	6,572		$	11,798		$	18,370		$	5,321		$	11,851		$	17,172
	Due after one year (a)		17,065			31,450			48,515			21,425			30,423			51,848
	Fair value adjustment (b)		414			—			414			445			—			445
	Total long-term debt		$	24,051		$	43,248		$	67,299		$	27,191		$	42,274		$	69,465
	(a)	Includes $2.6 billion of trust preferred securities at both September 30, 2014 and December 31, 2013, respectively.
	(b)	Represents the fair value adjustment associated with the application of hedge accounting on certain of our long-term unsecured debt positions. Refer to Note 19 for additional information.
	The following table presents the scheduled remaining maturity of long-term debt, assuming no early redemptions will occur. The actual payment of secured debt may vary based on the payment activity of the related pledged assets.
	Year ended December 31, ($ in millions)		2014			2015			2016			2017			2018			2019 and			Fair value		Total
																		thereafter			adjustment
	Unsecured
	Long-term debt		$	1,746		$	4,920		$	1,934		$	4,377		$	1,278		$	10,837		$	414	$	25,506
	Original issue discount		(40		)	(58		)	(68		)	(80		)	(93		)	(1,116		)	—		(1,455		)
	Total unsecured		1,706			4,862			1,866			4,297			1,185			9,721			414		24,051
	Secured
	Long-term debt		2,848			12,832			10,408			9,699			3,778			3,683			—		43,248
	Total long-term debt		$	4,554		$	17,694		$	12,274		$	13,996		$	4,963		$	13,404		$	414	$	67,299
	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.
			September 30, 2014						December 31, 2013
	($ in millions)		Total			Ally Bank (a)			Total			Ally Bank (a)
	Investment securities		$	584		$	584		$	2,864		$	2,864
	Mortgage finance receivables and loans		7,708			7,708			8,524			8,524
	Consumer automobile finance receivables		33,749			12,047			32,947			12,332
	Commercial automobile finance receivables		19,286			18,770			21,249			21,249
	Investment in operating leases, net		4,925			3,967			5,810			3,190
	Other assets		—			—			563			—
	Total assets restricted as collateral (b)(c)		$	66,252		$	43,076		$	71,957		$	48,159
	Secured debt (d)		$	45,127		$	24,420		$	47,594		$	27,818
	(a)	Ally Bank is a component of the total column.
	(b)	Ally Bank has an advance agreement with the Federal Home Loan Bank of Pittsburgh (FHLB) and had assets pledged to secure borrowings that were restricted as collateral to the FHLB totaling $10.7 billion and $12.7 billion at September 30, 2014, and December 31, 2013, respectively. These assets were composed primarily of consumer mortgage finance receivables and loans, net. Ally Bank has access to the Federal Reserve Bank Discount Window. Ally Bank had assets pledged and restricted as collateral to the Federal Reserve Bank totaling $3.3 billion and $3.2 billion at September 30, 2014, and December 31, 2013, respectively. These assets were composed of consumer automobile finance receivables and loans, net and investment in operating leases, net. 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.
	(c)	Excludes restricted cash and cash reserves for securitization trusts recorded within other assets on the Condensed Consolidated Balance Sheet. Refer to Note 10 for additional information.
	(d)	Includes $1.9 billion and $5.3 billion of short-term borrowings at September 30, 2014, and December 31, 2013, respectively.
	Funding Facilities
	We utilize both committed and other credit facilities. The amounts outstanding under our various funding facilities are included on our Condensed Consolidated Balance Sheet.
	As of September 30, 2014, Ally Bank had exclusive access to $3.5 billion of funding capacity from committed credit facilities. Funding programs supported by the Federal Reserve and the FHLB, together with repurchase agreements, complement Ally Bank’s private committed facilities.
	The total capacity in our committed funding facilities is provided by banks and other financial institutions through private transactions. The committed secured funding facilities can be revolving in nature and allow for additional funding during the commitment period, or they can be amortizing and not allow for any further funding after the closing date. At September 30, 2014, $20.9 billion of our $22.6 billion of committed capacity was revolving. Our revolving facilities generally have an original tenor ranging from 364 days to two years. As of September 30, 2014, we had $15.1 billion of committed funding capacity from revolving facilities with a remaining tenor greater than 364 days.
	Committed Funding Facilities
			Outstanding						Unused Capacity (a)						Total Capacity
	($ in millions)		September 30, 2014			December 31, 2013			September 30, 2014			December 31, 2013			September 30, 2014			December 31, 2013
	Bank funding
	Secured		$	3,000		$	2,750		$	500		$	250		$	3,500		$	3,000
	Parent funding
	Secured (b)		14,613			15,159			4,517			6,497			19,130			21,656
	Total committed facilities		$	17,613		$	17,909		$	5,017		$	6,747		$	22,630		$	24,656
	(a)	Funding from committed secured facilities is available on request in the event excess collateral resides in certain facilities or is available to the extent incremental collateral is available and contributed to the facilities.
	(b)	Includes the secured facility of Corporate Finance at December 31, 2013.

Accrued_Expenses_and_Other_Lia

Accrued Expenses and Other Liabilities	9 Months Ended
	Sep. 30, 2014
Accounts Payable and Accrued Liabilities [Abstract]	'
Accounts Payable and Accrued Liabilities Disclosure [Text Block]	'
	Accrued Expenses and Other Liabilities
	The components of accrued expenses and other liabilities were as follows.
	($ in millions)	September 30, 2014		December 31, 2013
	Accounts payable	$	333	$	414
	Fair value of derivative contracts in payable position (a)	299		317
	Employee compensation and benefits	255		437
	Reserves for insurance losses and loss adjustment expenses	229		275
	Deferred revenue	147		122
	Collateral received from counterparties	17		159
	Other liabilities (b)	409		673
	Total accrued expenses and other liabilities	$	1,689	$	2,397
	(a)	For additional information on derivative instruments and hedging activities, refer to Note 19.
	(b)	Included $150 million accrual for insurance proceeds to be contributed to the ResCap estate at December 31, 2013. The outstanding accrual was paid in April 2014.

Preferred_Stock

Preferred Stock	9 Months Ended
	Sep. 30, 2014
Preferred Stock, Including Additional Paid in Capital [Abstract]	'
Preferred Stock [Text Block]	'
	Preferred Stock
	Refer to Note 1 for additional information related to our initial public offering of common stock, stock split, and change in number of shares authorized. The following table summarizes information about our Series A and Series G preferred stock.
			September 30, 2014			December 31, 2013
	Preferred stock
	Series A preferred stock (a)
	Carrying value ($ in millions)		$	1,021		$	1,021
	Par value (per share)		0.01			0.01
	Liquidation preference (per share)		25			25
	Number of shares authorized (b)		40,870,560			160,870,560
	Number of shares issued and outstanding		40,870,560			40,870,560
	Dividend/coupon
	Prior to May 15, 2016		8.5		%	8.5		%
	On and after May 15, 2016		Three month			Three month
			LIBOR + 6.243%			LIBOR + 6.243%
	Series G preferred stock (c)
	Carrying value ($ in millions)		$	234		$	234
	Par value (per share)		0.01			0.01
	Liquidation preference (per share)		1,000			1,000
	Number of shares authorized		2,576,601			2,576,601
	Number of shares issued and outstanding		2,576,601			2,576,601
	Dividend/coupon		7		%	7		%
	(a)	Nonredeemable prior to May 15, 2016.
	(b)	Refer to Note 1 for additional information related to a change in number of shares authorized, which occurred on April 9, 2014.
	(c)	Redeemable beginning at December 31, 2011.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Abstract]	'
Comprehensive Income (Loss) Note [Text Block]	'
	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 gains				Translation adjustments and net investment hedges				Cash flow hedges			Defined benefit pension plans			Accumulated other comprehensive income (loss)
		(losses) on investment securities
	Balance at December 31, 2012	$	76			$	368			$	2		$	(135	)	$	311
	2013 net change	(323		)		(216		)		3			42			(494		)
	Balance at September 30, 2013	$	(247	)		$	152			$	5		$	(93	)	$	(183	)
	Balance at December 31, 2013	$	(269	)		$	65			$	5		$	(77	)	$	(276	)
	2014 net change	148				(27		)		1			4			126
	Balance at September 30, 2014	$	(121	)		$	38			$	6		$	(73	)	$	(150	)
	The following tables present the before- and after-tax changes in each component of accumulated other comprehensive income (loss).
	Three months ended September 30, 2014 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized losses arising during the period	$	(15	)		$	5			$	(10	)
	Less: Net realized gains reclassified to income from continuing operations	45			(a)	(1		)	(b)	44
	Net change	(60		)		6				(54		)
	Translation adjustments
	Net unrealized losses arising during the period	(11		)		4				(7		)
	Net investment hedges
	Net unrealized gains arising during the period	8				(3		)		5
	Cash flow hedges
	Net unrealized gains arising during the period	1				—				1
	Other comprehensive loss	$	(62	)		$	7			$	(55	)
	(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
	(b)	Includes amounts reclassified to income tax expense (benefit) from continuing operations in our Condensed Consolidated Statement of Comprehensive Income.
	Three months ended September 30, 2013 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized gains arising during the period	$	46			$	7			$	53
	Less: Net realized gains reclassified to income from continuing operations	41			(a)	—				41
	Net change	5				7				12
	Translation adjustments
	Net unrealized gains arising during the period	5				(2		)		3
	Net investment hedges
	Net unrealized losses arising during the period	(14		)		6				(8		)
	Cash flow hedges
	Net unrealized losses arising during the period	(4		)		1				(3		)
	Other comprehensive (loss) income	$	(8	)		$	12			$	4
	(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
	Nine months ended September 30, 2014 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized gains arising during the period	$	358			$	(89	)		$	269
	Less: Net realized gains reclassified to income from continuing operations	129			(a)	(8		)	(b)	121
	Net change	229				(81		)		148
	Translation adjustments
	Net unrealized losses arising during the period	(21		)		8				(13		)
	Less: Net realized gains reclassified to income from discontinued operations, net of tax	23				(3		)		20
	Net change	(44		)		11				(33		)
	Net investment hedges
	Net unrealized gains arising during the period	10				(4		)		6
	Cash flow hedges
	Net unrealized gains arising during the period	1				—				1
	Defined benefit pension plans
	Less: Net losses reclassified to income from continuing operations	(7		)	(c)	3				(4		)
	Other comprehensive income	$	203			$	(77	)		$	126
	(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
	(b)	Includes amounts reclassified to income tax expense (benefit) from continuing operations in our Condensed Consolidated Statement of Comprehensive Income.
	(c)	Includes losses reclassified to compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income.
	Nine months ended September 30, 2013 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized losses arising during the period	$	(289	)		$	128			$	(161	)
	Less: Net realized gains reclassified to income from continuing operations	156			(a)	(2		)	(b)	154
	Less: Net realized gains reclassified to income from discontinued operations, net of tax	10				(2		)		8
	Net change	(455		)		132				(323		)
Translation adjustments
Net unrealized losses arising during the period	(98		)		21				(77		)
Less: Net realized gains reclassified to income from discontinued operations, net of tax	345				2				347
Net change	(443		)		19				(424		)
Net investment hedges
Net unrealized gains arising during the period	52				(19		)		33
Less: Net realized losses reclassified to income from discontinued operations, net of tax	(261		)		86				(175		)
Net change	313				(105		)		208
Cash flow hedges
Net unrealized gains arising during the period	(1		)		—				(1		)
Less: Net realized losses reclassified to income from continuing operations	(7		)	(c)	3			(b)	(4		)
Net change	6				(3		)		3
Defined benefit pension plans
Net unrealized gains, prior service costs, and transition obligation arising during the period	2				—				2
Less: Net losses reclassified to income from continuing operations	(2		)	(d)	—				(2		)
Less: Net losses reclassified to income from discontinued operations, net of tax	(49		)		11				(38		)
Net change	53				(11		)		42
Other comprehensive loss	$	(526	)		$	32			$	(494	)
(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
(b)	Includes amounts reclassified to income tax expense (benefit) from continuing operations in our Condensed Consolidated Statement of Comprehensive Income.
(c)	Includes losses reclassified to interest on long-term debt in our Condensed Consolidated Statement of Comprehensive Income.
(d)	Includes losses reclassified to compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income.

Earnings_Per_Common_Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share [Text Block]	'
	Earnings per Common Share
	The following table presents the calculation of basic and diluted earnings per common share.
			Three months ended						Nine months ended
			September 30,						September 30,
	($ in millions, except share data)		2014			2013			2014			2013
	Net income from continuing operations		$	293		$	177		$	774		$	337
	Preferred stock dividends — U.S. Department of the Treasury		—			(134		)	—			(401		)
	Preferred stock dividends		(67		)	(67		)	(200		)	(200		)
	Net income (loss) from continuing operations attributable to common shareholders		226			(24		)	574			(264		)
	Income (loss) from discontinued operations, net of tax		130			(86		)	199			(80		)
	Net income (loss) attributable to common shareholders		$	356		$	(110	)	$	773		$	(344	)
	Basic weighted-average common shares outstanding (a)		481,611,138			412,600,700			480,916,395			412,600,700
	Diluted weighted-average common shares outstanding (a) (b)		482,506,091			412,600,700			481,545,506			412,600,700
	Basic earnings per common share
	Net income (loss) from continuing operations		$	0.47		$	(0.06	)	$	1.19		$	(0.64	)
	Income (loss) from discontinued operations, net of tax		0.27			(0.21		)	0.41			(0.19		)
	Net income (loss)		$	0.74		$	(0.27	)	$	1.6		$	(0.83	)
	Diluted earnings per common share
	Net income (loss) from continuing operations		$	0.47		$	(0.06	)	$	1.19		$	(0.64	)
	Income (loss) from discontinued operations, net of tax		0.27			(0.21		)	0.41			(0.19		)
	Net income (loss)		$	0.74		$	(0.27	)	$	1.6		$	(0.83	)
	(a)	Includes shares related to share-based compensation that have vested but have not been issued for the three months and nine months ended September 30, 2014.
	(b)	Due to the antidilutive effect of converting the Fixed Rate Cumulative Mandatorily Convertible Preferred Stock into common shares for the three months and nine months ended September 30, 2013 and the net loss from continuing operations attributable to common shareholders for the three months and nine months ended September 30, 2013, net income (loss) from continuing operations attributable to common shareholders and basic weighted-average common shares outstanding were used to calculate basic and diluted earnings per share.
	The effects of converting the outstanding Fixed Rate Cumulative Mandatorily Convertible Preferred Stock into common shares are not included in the diluted earnings per share calculation for the three months and nine months ended September 30, 2013, as the effects would be antidilutive for these periods. Accordingly, 178 million of the potential common shares were excluded from the diluted earnings per share calculation for the three months and nine months ended September 30, 2013.

Regulatory_Capital

Regulatory Capital	9 Months Ended
	Sep. 30, 2014
Regulatory Capital Requirements [Abstract]	'
Regulatory Capital Requirements under Banking Regulations [Text Block]	'
	Regulatory Capital and Other Regulatory Matters
	As a bank holding company, we and our wholly owned state-chartered banking subsidiary, Ally Bank, are subject to risk-based and leverage capital requirements issued by U.S. banking regulators that require us to maintain regulatory capital ratios above minimum levels. 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, we must meet specific capital guidelines that involve quantitative measures of our assets and certain off-balance sheet items. Our capital amounts and classifications are also subject to qualitative judgments by the regulators about components, risk-weightings, and other factors.
	A risk-based capital ratio is the ratio of a banking organization’s regulatory capital (numerator) to its risk-weighted assets (denominator). Under the existing Basel I capital rules, regulatory capital is divided into two tiers: Tier 1 capital and Tier 2 capital. Tier 1 capital generally consists of common equity, minority interests, qualifying noncumulative preferred stock, and the fixed rate cumulative preferred stock sold to Treasury under the Troubled Asset Relief Program (TARP), less goodwill and other adjustments. Tier 2 capital generally consists of perpetual preferred stock not qualifying as Tier 1 capital, limited amounts of subordinated debt and the allowance for loan losses, and other adjustments. The amount of Tier 2 capital may not exceed the amount of Tier 1 capital. Total regulatory capital is the sum of Tier 1 and Tier 2 capital. Under the existing Basel I capital rules, risk-weighted assets are determined by allocating assets and specified off-balance sheet financial instruments into several broad risk-weight categories with higher risk weights (expressed in percentage) assigned to asset classes that present greater perceived risk. Under the existing Basel I capital rules, banking organizations are required to maintain a minimum Total risk-based capital ratio (Total capital to risk-weighted assets) of 8% and a Tier 1 risk-based capital ratio (Tier 1 capital to risk-weighted assets) of 4%.
	The U.S. banking regulators also have established minimum leverage capital ratio requirements. The Tier 1 leverage ratio is defined as Tier 1 capital divided by adjusted quarterly average total assets (which reflect adjustments for disallowed goodwill and certain intangible assets). Under the existing Basel I capital rules, the minimum U.S. Tier 1 leverage ratio is 3% or 4% depending on factors specified in the regulations.
	Under the U.S. banking regulators’ existing regulations, a banking organization meets the regulatory definition of “well-capitalized” when its Total risk-based capital ratio equals or exceeds 10% and its Tier 1 risk-based capital ratio equals or exceeds 6%; and for insured depository institutions, when its leverage ratio equals or exceeds 5%, unless subject to a regulatory directive to maintain higher capital levels. To maintain its status as a financial holding company, Ally and its bank subsidiary, Ally Bank, must remain “well-capitalized” and “well-managed,” as defined under applicable law.
	In the context of capital planning and stress testing, the U.S. banking regulators have also developed a measure of capital called “Tier 1 common,” which is defined as Tier 1 capital less noncommon elements, including qualifying perpetual preferred stock, minority interest in subsidiaries, trust preferred securities, and mandatory convertible preferred securities. Tier 1 common is used by banking regulators, investors and analysts to assess and compare the quality and composition of Ally's capital with the capital of other financial services companies. Also, bank holding companies with total consolidated assets of $50 billion or more, such as Ally, must develop and maintain a capital plan annually, and among other elements, the capital plan must include a discussion of how we will maintain a pro forma Tier 1 common risk-based capital ratio (Tier 1 common to risk-weighted assets) above 5% under expected conditions and certain stressed scenarios.
	During 2010, Ally, IB Finance Holding Company, LLC, Ally Bank, and the Federal Deposit Insurance Corporation (FDIC) entered into a Capital and Liquidity Maintenance Agreement (CLMA). The effective date of the CLMA was August 24, 2010. The CLMA requires capital at Ally Bank to be maintained at a level such that Ally Bank's leverage ratio is at least 15%. For this purpose, the leverage ratio is determined in accordance with the FDIC's regulations related to capital maintenance.
	The U.S. banking regulators have issued the U.S. Basel III final rules to replace the existing Basel I capital rules. Refer to Note 20 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information about the U.S. Basel III final rules and their applicability to Ally and Ally Bank. Compliance with evolving capital requirements is a strategic priority for Ally. We expect to be in compliance with all applicable requirements within the established timeframes.
	The following table summarizes our capital ratios.
		September 30, 2014				December 31, 2013				Required			Well-capitalized
	($ in millions)	Amount		Ratio		Amount		Ratio		minimum			minimum
	Risk-based capital
	Tier 1 (to risk-weighted assets)
	Ally Financial Inc.	$	16,227	12.65	%	$	15,165	11.79	%	4	%		6	%
	Ally Bank	15,898		17.32		15,159		16.73		4			6
	Total (to risk-weighted assets)
	Ally Financial Inc.	$	17,275	13.47	%	$	16,405	12.76	%	8	%		10	%
	Ally Bank	16,493		17.97		15,809		17.45		8			10
	Tier 1 leverage (to adjusted quarterly average assets) (a)
	Ally Financial Inc.	$	16,227	10.91	%	$	15,165	10.23	%	3.00–4.00%			(b)
	Ally Bank	15,898		15.71		15,159		15.77		15		(c)	5	%
	Tier 1 common (to risk-weighted assets)
	Ally Financial Inc.	$	12,427	9.69	%	$	11,366	8.84	%	n/a			n/a
	Ally Bank	15,898		17.32		15,159		16.73		n/a			n/a
	n/a =160;not applicable
	(a)	Federal regulatory reporting guidelines require the calculation of adjusted quarterly average assets using a daily average methodology.
	(b)	There is no Tier 1 leverage component in the definition of "well-capitalized" for a bank holding company.
	(c)	Ally Bank, in accordance with the CLMA, is required to maintain a Tier 1 leverage ratio of at least 15%.
	At September 30, 2014, Ally and Ally Bank were “well-capitalized” and met all capital requirements to which each was subject.
	Capital Planning and Stress Tests
	As a bank holding company with $50 billion or more of consolidated assets, Ally is required to conduct periodic stress tests and submit a proposed capital plan to the Board of Governors of the Federal Reserve System (FRB) every January, which the FRB must take action on by the following March. The proposed capital plan must include a description of all planned capital actions over a nine-quarter planning horizon. The proposed capital plan must also include a discussion of how Ally will maintain capital above the minimum regulatory capital ratios and above a Tier 1 common equity-to-total risk-weighted assets ratio of 5%, and serve as a source of strength to Ally Bank. The FRB must approve Ally's proposed capital plan before Ally may take any proposed capital action.
	In November 2013, the FRB issued instructions for the 2014 Comprehensive Capital Analysis and Review (CCAR) and the 2014 supervisory stress test scenarios. On January 6, 2014, Ally and Ally Bank submitted the 2014 capital plan and stress tests as required by the rules and the 2014 CCAR instructions, and in March 2014, the FRB indicated that it did not object to our 2014 capital plan. On July 7, 2014, in accordance with the requirements of the Dodd-Frank Act, Ally submitted to the FRB its results of a mid-year stress test conducted under multiple macroeconomic scenarios. Ally disclosed the results of the most severe scenario in September in accordance with regulatory requirements. On October 17, 2014 the FRB issued a final rule that modifies the capital plan rule and stress testing requirements. The final rule adjusts when bank holding companies must submit their capital plans to the FRB. For CCAR 2015, the bank holding companies are required to submit capital plans on or before January 5, 2015, unchanged from prior years. Beginning in 2016, bank holding companies will be required to submit their capital plans to the Federal Reserve on or before April 5.
	In addition, each January, Ally Bank must conduct a stress test and submit the results to the FDIC.

Derivative_Instruments_And_Hed

Derivative Instruments And Hedging Activities	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments and Hedging Activities Disclosure [Text Block]	'
	Derivative Instruments and Hedging Activities
	We enter into interest rate, foreign-currency, and equity swaps, futures, forwards, options, and swaptions in connection with our market risk management activities. Derivative instruments are used to manage interest rate risk relating to specific groups of assets and liabilities, including automotive loan assets and debt. We use foreign exchange contracts to mitigate foreign-currency risk associated with foreign-currency-denominated debt, foreign exchange transactions, and our net investment in foreign subsidiaries. In addition, we also enter into equity option contracts to manage our exposure to the equity markets, as well as prepaid equity forward contracts to hedge the price risk related to certain of our executive share-based compensation plans. 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 market risks related to our investment portfolio and certain of our executive share-based compensation plans.
	Interest Rate Risk
	We monitor our mix of fixed- and variable-rate assets and liabilities. When it is cost-effective to do so, we 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 interest rate swaps, forwards, futures, options, and swaptions 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.
	Derivatives qualifying for hedge accounting consist of receive-fixed swaps designated as fair value hedges of specific fixed-rate debt obligations, pay-fixed swaps designated as fair value hedges of specific portfolios of fixed-rate held-for-investment retail automotive loan assets, and pay-fixed swaps designated as cash flow hedges of the expected future cash flows in the form of interest payments on certain outstanding variable-rate borrowings associated with our secured debt.
	We also execute economic hedges, which consist of interest rate swaps and interest rate caps held to mitigate interest rate risk associated with our debt portfolio. Other economic hedges include interest rate swaps, futures, forwards, options, and swaptions to hedge our net fixed versus variable interest rate exposure.
	In the past, we used a multitude of derivative instruments to manage interest rate risk related to MSRs, mortgage loan commitments, and mortgage loans held-for-sale. They included, but were not limited to, interest rate swaps, forward sales of mortgage backed securities, interest rate futures contracts, options on U.S. Treasuries, swaptions, interest rate floors, and interest rate caps. Since we no longer have exposures to these activities, we no longer utilize these hedge strategies.
	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 investments in foreign subsidiaries. However, we have reduced our foreign exchange exposure to net investments in foreign operations through the sales of discontinued international businesses. Refer to Note 2 for further details on these sales.
	Our remaining foreign subsidiaries maintain both assets and liabilities in local currencies. These local currencies are generally the subsidiaries' functional currencies for accounting purposes. Foreign-currency-exchange-rate gains and losses arise when the assets or liabilities of our subsidiaries are denominated in currencies that differ from its functional currency. In addition, 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 utilize a cross-currency swap to economically hedge foreign exchange exposure on foreign-currency-denominated debt by converting the funding currency to our functional currency. This swap was entered into concurrent with the debt issuance with the terms of the derivative matching the terms of the underlying debt.
	We also enter into foreign currency forwards to economically hedge our foreign-denominated debt, our centralized lending program, and foreign-denominated third party loans. The hedge of foreign-denominated debt was entered into concurrent with the debt issuance with the terms of the derivative matching the terms of the underlying debt. The centralized lending program manages liquidity for our subsidiary businesses, but as of September 30, 2014, this activity is immaterial. Foreign-currency-denominated loan agreements are executed with our foreign subsidiaries in their local currencies. We evaluate our foreign-currency exposure resulting from intercompany lending and manage our currency risk exposure by entering into foreign-currency derivatives with external counterparties. Our remaining foreign-currency derivatives, such as hedges of foreign-denominated third party loans, are recorded at fair value with changes recorded as income offsetting the gains and losses on the associated foreign-currency transactions.
	Market Risk
	We enter into equity options to economically hedge our exposure to the equity markets. We purchase options to assume a long position on certain equities and write options to assume a short position.
	During the quarter ended September 30, 2014, we also entered into prepaid equity forward contracts to economically hedge the price risk associated with certain of our executive share-based compensation plans described in Note 21. The prepaid equity forward contracts are hybrid instruments containing an embedded forward contract, which is considered a derivative instrument. The embedded derivative instrument is bifurcated from the host contract and is recorded at fair value with changes in fair value recorded in compensation and benefits expense. The balance of the prepaid component of these equity forward contracts is $89 million as of September 30, 2014, and was recorded within other assets on the Condensed Consolidated Balance Sheet.
	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.
	To mitigate the risk of counterparty default, we generally maintain collateral agreements with our 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 value of our total obligation to each other. Contractual terms provide for standard and customary exchange of collateral based on changes in the market value of the outstanding derivatives. The securing party posts additional collateral when their obligation rises or removes collateral when it falls. We also have unilateral collateral agreements whereby we are the only entity required to post 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. If a credit risk-related event had been triggered, the amount of additional collateral required to be posted by us would have been insignificant.
	We placed cash and securities collateral totaling $243 million and $328 million at September 30, 2014 and December 31, 2013, respectively, in accounts maintained by counterparties, $18 million of which relates to non-derivative collateral at September 30, 2014 and December 31, 2013. We received cash collateral from counterparties totaling $17 million and $159 million at September 30, 2014 and December 31, 2013, respectively. The receivables for collateral placed and the payables for collateral received are included on our Condensed Consolidated Balance Sheet in other assets and accrued expenses and other liabilities, respectively. In certain circumstances, we receive or post securities as collateral with counterparties. We do not record such collateral received on our Condensed Consolidated Balance Sheet unless certain conditions are met. At September 30, 2014 and December 31, 2013, we received noncash collateral of $7 million and $18 million, respectively.
	Balance Sheet Presentation
	The following table summarizes the fair value amounts of derivative instruments reported on our Condensed Consolidated Balance Sheet. The fair value 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. At September 30, 2014 and December 31, 2013, $235 million and $362 million, respectively, of the derivative contracts in a receivable position were classified as other assets on the Condensed Consolidated Balance Sheet. At September 30, 2014 and December 31, 2013, $299 million and $317 million of derivative contracts in a liability position were classified as accrued expenses and other liabilities on the Condensed Consolidated Balance Sheet.
			September 30, 2014									December 31, 2013
			Derivative contracts in a						Notional			Derivative contracts in a					Notional
	($ in millions)		receivable			payable			amount			receivable position (a)			payable		amount
			position (a)			position (b)									position (b)
	Derivatives qualifying for hedge accounting
	Interest rate contracts
	Swaps (c)		$	71		$	51		$	19,959		$	204		$	169	$	21,606
	Foreign exchange contracts
	Forwards		3			—			304			3			—		326
	Total derivatives qualifying for hedge accounting		74			51			20,263			207			169		21,932
	Economic hedges
	Interest rate contracts
	Swaps		33			49			12,649			36			44		13,613
	Futures and forwards		6			—			12,253			11			3		29,836
	Written options		—			94			28,651			—			94		11,132
	Purchased options		95			—			30,097			95			—		22,962
	Total interest rate risk		134			143			83,650			142			141		77,543
	Foreign exchange contracts
	Swaps		15			92			1,263			12			1		1,379
	Futures and forwards		7			4			286			1			1		330
	Written options		—			—			—			—			—		17
	Purchased options		—			—			—			—			—		17
	Total foreign exchange risk		22			96			1,549			13			2		1,743
	Equity contracts
	Forwards		—			6			89			—			—		—
	Written options		—			3			1			—			5		3
	Purchased options		5			—			—			—			—		—
	Total equity risk		5			9			90			—			5		3
	Total economic hedges		161			248			85,289			155			148		79,289
	Total derivatives		$	235		$	299		$	105,552		$	362		$	317	$	101,221
	(a)	Includes accrued interest of $51 million and $120 million at September 30, 2014 and December 31, 2013, respectively.
	(b)	Includes accrued interest of $9 million and $12 million at September 30, 2014 and December 31, 2013, respectively.
	(c)	Includes fair value hedges consisting of receive-fixed swaps on fixed-rate debt obligations with $43 million and $196 million in a receivable position, $46 million and $163 million in a payable position, and of a $5.9 billion and $8.5 billion notional amount at September 30, 2014 and December 31, 2013, respectively. Other fair value hedges include pay-fixed swaps on portfolios of held-for-investment automotive loan assets with $28 million and $9 million in a receivable position, $5 million and $5 million in a payable position, and of a $14.1 billion and $12.6 billion notional amount at September 30, 2014 and December 31, 2013, respectively. Also includes cash flow hedges consisting of pay-fixed swaps on floating rate debt obligations with $1 million in a payable position, and of a $495 million notional amount at December 31, 2013.
	Statement of Comprehensive Income Presentation
	The following table summarizes the location and amounts of gains and losses on derivative instruments reported in our Condensed Consolidated Statement of Comprehensive Income.
			Three months ended September 30,						Nine months ended September 30,
	($ in millions)		2014			2013			2014			2013
	Derivatives qualifying for hedge accounting
	Gain (loss) recognized in earnings on derivatives
	Interest rate contracts
Interest and fees on finance receivables and loans (a)		$	28		$	3		$	22		$	3
Interest on long-term debt (b)		(39		)	11			102			(302		)
(Loss) gain recognized in earnings on hedged items (c)
Interest rate contracts
Interest and fees on finance receivables and loans		(15		)	(3		)	14			(3		)
Interest on long-term debt		49			(15		)	(90		)	311
Total derivatives qualifying for hedge accounting		23			(4		)	48			9
Economic derivatives
(Loss) gain recognized in earnings on derivatives
Interest rate contracts
Servicing asset valuation and hedge activities, net		—			—			—			(112		)
Loss on mortgage and automotive loans, net		—			—			—			(37		)
Other income, net of losses		(5		)	20			(24		)	26
Total interest rate contracts		(5		)	20			(24		)	(123		)
Foreign exchange contracts (d)
Interest on long-term debt		(108		)	52			(117		)	71
Other income, net of losses		8			(4		)	8			25
Total foreign exchange contracts		(100		)	48			(109		)	96
Equity contracts
Compensation and benefits expense		(6		)	—			(6		)	—
Total equity contracts		(6		)	—			(6		)	—
(Loss) gain recognized in earnings on derivatives		$	(88	)	$	64		$	(91	)	$	(18	)
(a)	Amounts exclude losses related to interest for qualifying accounting hedges of portfolios of retail automotive loans held-for-investment of $16 million and $1 million for the three months ended September 30, 2014 and 2013, respectively, and $43 million and $1 million for the nine months ended September 30, 2014 and 2013, respectively. These losses are primarily offset by the fixed coupon receipts on the retail automotive loans held-for-investment.
(b)	Amounts exclude gains related to interest for qualifying accounting hedges of debt, which are primarily offset by the fixed coupon payment on the long-term debt. The gains were $27 million and $33 million for the three months ended September 30, 2014 and 2013, respectively, and $89 million and $94 million for the nine months ended September 30, 2014 and 2013, respectively.
(c)	Amounts exclude gains related to amortization of deferred basis adjustments on the de-designated hedged item of $38 million and $112 million for the three months ended September 30, 2014 and 2013, respectively, and $120 million and $188 million for the nine months ended September 30, 2014 and 2013, respectively.
(d)	Amounts exclude gains and losses related to the revaluation of the related foreign-denominated debt or receivable. Gains of $102 million and losses of $47 million were recognized for the three months ended September 30, 2014 and 2013, respectively. Gains of $112 million and losses of $94 million were recognized for the nine months ended September 30, 2014 and 2013, respectively.
The following table summarizes derivative instruments used in cash flow and net investment hedge accounting relationships.
		Three months ended September 30,						Nine months ended September 30,
($ in millions)		2014			2013			2014			2013
Cash flow hedges
Interest rate contracts
Loss reclassified from accumulated other comprehensive income to interest on long-term debt (a)		$	(1	)	$	—		$	(1	)	$	(7	)
Gain recorded directly to interest on long-term debt		—			—			—			1
Total interest on long-term debt		$	(1	)	$	—		$	(1	)	$	(6	)
Gain (loss) recognized in other comprehensive income		$	1		$	(4	)	$	1		$	6
Net investment hedges
Foreign exchange contracts
Loss reclassified from accumulated other comprehensive income (loss) to income from discontinued operations, net		$	—		$	—		$	—		$	(261	)
Total loss from discontinued operations, net		$	—		$	—		$	—		$	(261	)
Gain (loss) recognized in other comprehensive income (b)		$	8		$	(14	)	$	10		$	313
(a)	The amount represents losses reclassified from other comprehensive income (OCI) into earnings as a result of the discontinuance of hedge accounting because it is probable that the forecasted transaction will not occur.
(b)	The amounts represent the effective portion of net investment hedges. There are offsetting amounts recognized in accumulated other comprehensive income related to the revaluation of the related net investment in foreign operations. There were losses of $10 million and gains of $9 million for the three months ended September 30, 2014 and 2013, respectively. There were losses of $37 million and $530 million for the nine months ended September 30, 2014 and 2013, respectively.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Tax Disclosure [Text Block]	'
	Income Taxes
	We recognized total income tax expense from continuing operations of $127 million and $285 million during the three months and nine months ended September 30, 2014, compared to income tax expense of $28 million and an income tax benefit of $55 million for the same periods in 2013. The increase in income tax expense for the three months ended September 30, 2014, compared to the same period in 2013, was driven primarily by tax expense attributable to higher pretax earnings. The increase in income tax expense for the nine months ended September 30, 2014, compared to the same period in 2013, was driven by tax expense attributable to higher pretax earnings and certain tax benefits recorded in the nine months ended September 30, 2013, which did not occur in the nine months ended September 30, 2014, related to the 2013 retroactive reinstatement of the active financing exception by the American Taxpayer Relief Act of 2012 and from a 2013 release of valuation allowance related to the measurement of foreign tax credit carryforwards anticipated to be utilized in the future.
	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 capital loss, foreign tax credit, 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.
	The successful completion of the sale of our joint venture in China, which is currently classified as held-for-sale as of September 30, 2014, may result in additional capital gains that would allow us to realize additional capital loss carryforwards. Any resulting reversal of valuation allowance on these deferred tax assets would be recognized as an income tax benefit upon such reversal.

Sharebased_Compensation_Plans_

Share-based Compensation Plans (Notes)	9 Months Ended
	Sep. 30, 2014
Share-based Compensation Plans [Abstract]	'
Compensation and Employee Benefit Plans [Text Block]	'
	Share-based Compensation Plans
	Based on our transactions with Treasury during 2009, we are required to comply with certain limitations on executive pay as determined by the Special Master of TARP Compensation (Special Master). We have established stock salary, or Deferred Stock Units (DSUs), and TARP Stock, or Incentive Restricted Stock Units (IRSUs), as forms of compensation to our senior executives, which have been approved by the Special Master. We also granted Restricted Stock Units (RSUs) to executives under the Long-Term Equity Compensation Incentive Plan (LTIP), and have adopted the Ally Financial 2014 Incentive Compensation Plan, which allows us to grant an array of equity-based and cash incentive awards to our named executive officers and other employees and service providers (other than our non-employee directors). Each of our approved compensation plans and awards were designed to provide our executives with an opportunity to share in the future growth in value of Ally, which is necessary to attract and retain key executives.
	Prior to our initial public offering (IPO) in April 2014, all share-based awards were settled in cash and required liability treatment under the accounting guidance. Accounting treatment for liability-classified awards requires compensation expense to be adjusted each period until the awards are settled based on the value of the underlying share price. Pursuant to the terms of the LTIP, the Ally Board of Directors is required to determine a share price valuation (Share Price Valuation) for share-based compensation awards not less than annually. The Share Price Valuation determined by the Board prior to the IPO, assisted by an independent advisor, considered, among other things, the stock price performance, on an indexed basis, of publicly traded common stock issued by certain comparative companies and considered Ally’s common stock as if it were freely tradable in the public markets. After the IPO, the share price valuation is based on the trading price for our stock. Also, after the IPO, certain awards, both existing and future grants, will be settled in stock and, as a result, will be accounted for as equity awards under the accounting guidance. For equity-classified awards, the compensation expense to be recognized over the vesting and service period is determined on the grant date. Certain awards will continue to require liability treatment and receive the same treatment as previously noted. For valuation purposes, we utilize Ally’s share price as of the grant date and the end of each reporting period for determining the necessary share-based compensation expense, depending on the classification of the awards. The per-share fair value based on market price for purposes of share-based compensation was $23.14 as of September 30, 2014.
	During the three months ended September 30, 2014, we entered into prepaid equity forward contracts to economically hedge a portion of the price risk driven by fluctuations in the fair value of our DSU and IRSU awards. The prepaid equity forward contracts are hybrid instruments containing an embedded forward contract, which is considered a derivative instrument. The embedded derivative instrument is bifurcated from the host contract and is recorded at fair value with changes in fair value recorded as compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income. For further information on our derivative instruments, refer to Note 19.
	RSU Awards
	RSU awards are incentive awards that have been granted to employees as phantom shares of Ally. Prior to our IPO, these awards were paid in cash. As a result, RSU awards required liability treatment and were remeasured quarterly at the Share Price Valuation until they were paid. The compensation costs related to these awards were ratably charged to expense over the applicable service period. Changes in the value related to the portion of the awards that had vested and had not been paid were recognized in earnings in the period in which the changes occurred. After the IPO, the majority of existing RSU awards will settle in the form of Ally common stock, which changed the award classification from a liability award to an equity award. As a result of this classification change, a modification to the accounting for the existing awards was required. As part of the modification, the stock closing price on the date of the IPO (April 10, 2014) of $23.98 was used as the modification date value, which resulted in the recording of an increase to additional paid-in capital of $62 million, with a corresponding decrease in the liability. The remaining RSU cost for these awards, based on the modification date value, will be ratably charged to expense over the applicable service periods with an offset to additional paid-in capital. RSU awards granted in 2011 and 2012 can vest in one of two different methods. The first method allows vesting ratably over a three-year period starting on the date the award was issued, with awards fully vesting in February 2014 and February 2015. The second method allows vesting ratably over a two-year period, starting on the date the award was issued, with awards fully vesting in February 2013 and February 2014. RSU awards granted in 2013 and 2014 vest using a single method where vesting is ratable over a two-year period starting on the date the award was issued, with the majority of the awards fully vesting in January 2015 and January 2016. At September 30, 2014, there were a total of approximately 4 million award shares outstanding. We recognized expense related to RSU awards of $9 million and $35 million for the three months and nine months ended September 30, 2014, respectively. These costs were recorded as compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income.
	DSU Awards
	DSU awards are granted to senior executives as phantom shares of Ally and are included as part of their base salary. DSU awards are generally granted ratably each pay period throughout the year, vest immediately upon grant, and are paid in cash. DSUs awarded in 2012, 2013 and 2014 will generally be redeemable in three equal installments: the first on the final payroll date of the respective year of grant, the second ratably over the first year following the grant date, and the third ratably over the second year following the grant date. The DSU awards require liability treatment and are remeasured monthly at fair value based on market price until they are paid, with each change in value fully charged to compensation expense in the period in which the change occurs. At September 30, 2014, there were a total of approximately 3 million DSU award shares outstanding. We recognized expense related to DSU awards of $11 million and $27 million for the three months and nine months ended September 30, 2014, respectively, for the outstanding awards, recorded as compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income.
	IRSU Awards
	IRSU awards are incentive awards that have been granted to senior executives as phantom shares of Ally and vest based on continued service with Ally. IRSU awards from 2009 and 2010 have fully vested. The majority of IRSU awards from 2011 are also fully vested, with any remaining awards scheduled to vest by the end of 2014. There were no IRSU awards granted to senior executives in 2012. IRSU awards from 2013 vest two-thirds after two years from grant date and in full three years from grant date. After the vesting requirement is met, IRSU awards are paid in cash, and payouts are made only as we repay our TARP obligations. Payouts are allowed in 25% increments based on the percentage of TARP obligations that have been repaid, as determined in accordance with the established guidelines for determining "repayment." As of September 30, 2014, Ally had repaid 75% of its TARP obligations. Payouts are based on fair value of Ally shares at the time of the payout. The awards require liability treatment and are remeasured monthly at fair value based on market price until they are paid. The compensation costs related to these awards are ratably charged to expense over the requisite service period. Changes in value relating to the portion of the awards that have vested and have not been paid are recognized in earnings in the period in which the changes occur. At September 30, 2014, there were a total of approximately 1 million IRSU award shares outstanding. We recognized an immaterial amount of expense related to IRSU awards for the three months ended September 30, 2014, and a reduction of expense related to IRSU awards of $3 million for the nine months ended September 30, 2014, for the outstanding awards, recorded as compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income.

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Disclosures [Text Block]	'
	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. Fair value is based on the assumptions 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.
	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.
	Transfers	Transfers into or out of any hierarchy level are recognized at the end of the reporting period in which the transfer occurred. During the nine months ended September 30, 2014, transfers from Level 3 into Level 2 included $78 million of derivative contracts in a receivable position and $81 million of derivative contracts in a payable position based on increased observability of significant inputs related to the valuation of our interest rate caps. There were no additional transfers between any levels during the nine months ended September 30, 2014.
	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.
	•	Available-for-sale securities — Available-for-sale securities are carried at fair value based on observable market prices, when available. If observable market prices are not available, our valuations are based on internally developed discounted cash flow models (an income approach) that use a market-based discount rate and consider recent market transactions, experience with similar securities, current business conditions, and analysis of the underlying collateral, as available. To estimate cash flows, we are required to utilize various significant assumptions including market observable inputs (e.g., forward interest rates) and internally developed inputs (including prepayment speeds, delinquency levels, and credit losses).
	•	Mortgage loans held-for-sale, net — Our mortgage loans held-for-sale are accounted for at fair value because of fair value option elections. Mortgage loans held-for-sale are typically pooled together and sold into certain exit markets depending on underlying attributes of the loan, such as GSE eligibility, product type, interest rate, and credit quality. Mortgage loans classified as Level 2 were mainly GSE-eligible mortgage loans carried at fair value due to fair value option election, which are valued predominantly using published forward agency prices. It also includes any domestic loans where recently negotiated market prices for the loan pool exist with a counterparty (which approximates fair value) or quoted market prices for similar loans are available.
	Refer to the section within this note titled Fair Value Option for Financial Assets and Financial Liabilities for further information about the fair value elections.
	•	MSRs — MSRs were classified as Level 3. Management estimated fair value using our transaction data and other market data or, in periods when there were limited MSR market transactions that were directly observable, internally developed discounted cash flow models (an income approach) were used to estimate the fair value. These internal valuation models estimated net cash flows based on internal operating assumptions that we believed would be used by market participants in orderly transactions combined with market-based assumptions for loan prepayment rates, interest rates, and discount rates that we believed approximate yields required by investors in this asset. Cash flows primarily included servicing fees, float income, and late fees in each case less operating costs to service the loans. The estimated cash flows were discounted using an option-adjusted spread-derived discount rate. As of June 30, 2013, we no longer held such positions as a result of our exit from the mortgage servicing business.
	•	Interests retained in financial asset sales — The interests retained are in securitization trusts and deferred purchase prices on the sale of whole-loans. 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 (e.g., forward interest rates) and internally developed inputs (e.g., 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 Eurodollar futures, options of Eurodollar futures, equity options, and centrally-cleared interest rate swaps. To determine the fair value of these instruments, we utilize the quoted market prices for the particular derivative contracts; therefore, we classified these contracts as Level 1.
	We also execute over-the-counter derivative contracts, such as interest rate swaps, a cross-currency swap, swaptions, foreign-currency denominated forward contracts, prepaid equity 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 over-the-counter 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 over-the-counter derivative contracts as Level 2 because all significant inputs into these models were market observable. During the three months ended March 31, 2014, we began to value our bilateral interest rate swap and interest rate cap portfolio using Overnight Index Swap discount curves. We previously valued this portfolio using London Interbank Offered Rate (LIBOR) discount curves. Because we continued to use a third-party-developed valuation model in which all significant inputs were market observable, these contracts remained classified as Level 2.
	Historically, we had a cross-currency swap and interest rate caps accounted for as derivative instruments that were classified as Level 3. However, at September 30, 2014, we do not have any positions 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 utilizes 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
	September 30, 2014 ($ in millions)		Level 1				Level 2				Level 3				Total
	Assets
	Investment securities
	Available-for-sale securities
	Debt securities
	U.S. Treasury and federal agencies		$	332			$	954			$	—			$	1,286
	U.S. State and political subdivisions		—				402				—				402
	Foreign government		10				222				—				232
	Mortgage-backed residential		—				10,884				—				10,884
	Mortgage-backed commercial		—				212				—				212
	Asset-backed		—				1,987				—				1,987
	Corporate debt securities		—				983				—				983
	Total debt securities		342				15,644				—				15,986
	Equity securities (a)		728				—				—				728
	Total available-for-sale securities		1,070				15,644				—				16,714
	Mortgage loans held-for-sale, net (b)		—				3				—				3
	Other assets
	Interests retained in financial asset sales		—				—				61				61
	Derivative contracts in a receivable position (c)
	Interest rate		38				167				—				205
	Foreign currency		—				25				—				25
	Other		5				—				—				5
	Total derivative contracts in a receivable position		43				192				—				235
	Collateral placed with counterparties		—				81				—				81
	Total assets		$	1,113			$	15,920			$	61			$	17,094
	Liabilities
	Accrued expenses and other liabilities
	Derivative contracts in a payable position
	Interest rate		$	(42	)		$	(152	)		$	—			$	(194	)
	Foreign currency		—				(96		)		—				(96		)
	Other		(3		)		(6		)		—				(9		)
	Total derivative contracts in a payable position (c)		(45		)		(254		)		—				(299		)
	Other liabilities		(95		)		—				—				(95		)
	Total liabilities		$	(140	)		$	(254	)		$	—			$	(394	)
	(a)	Our investment in any one industry did not exceed 19%.
	(b)	Carried at fair value due to fair value option elections.
	(c)	For additional information on derivative instruments and hedging activities, refer to Note 19.
			Recurring fair value measurements
	December 31, 2013 ($ in millions)		Level 1				Level 2				Level 3				Total
	Assets
	Investment securities
	Available-for-sale securities
Debt securities
U.S. Treasury and federal agencies		$	310			$	1,117			$	—			$	1,427
U.S. State and political subdivisions		—				315				—				315
Foreign government		7				281				—				288
Mortgage-backed residential		—				10,782				—				10,782
Mortgage-backed commercial		—				39				—				39
Asset-backed		—				2,219				—				2,219
Corporate debt securities		—				1,069				—				1,069
Total debt securities		317				15,822				—				16,139
Equity securities (a)		944				—				—				944
Total available-for-sale securities		1,261				15,822				—				17,083
Mortgage loans held-for-sale, net (b)		—				16				—				16
Other assets
Interests retained in financial asset sales		—				—				100				100
Derivative contracts in a receivable position (c)
Interest rate		46				207				93				346
Foreign currency		—				16				—				16
Total derivative contracts in a receivable position		46				223				93				362
Collateral placed with counterparties		—				133				—				133
Total assets		$	1,307			$	16,194			$	193			$	17,694
Liabilities
Accrued expenses and other liabilities
Derivative contracts in a payable position (c)
Interest rate		$	(15	)		$	(201	)		$	(94	)		$	(310	)
Foreign currency		—				(2		)		—				(2		)
Other		(5		)		—				—				(5		)
Total derivative contracts in a payable position		(20		)		(203		)		(94		)		(317		)
Total liabilities		$	(20	)		$	(203	)		$	(94	)		$	(317	)
(a)	Our investment in any one industry did not exceed 19%.
(b)	Carried at fair value due to fair value option elections.
(c)	For additional information on derivative instruments and hedging activities, refer to Note 19.
The following tables present the reconciliation for all Level 3 assets and liabilities measured at fair value on a recurring basis. 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																						Fair value at September 30, 2014		Net unrealized gains included in earnings still held at
				gains																								30-Sep-14
($ in millions)	Fair value at July 1, 2014			included				included			Purchases			Sales			Issuances			Settlements			Transfers out of Level 3
				in  earnings				in OCI
Assets
Other assets
Interests retained in financial asset sales	$	74		$	4		(a)	$	—		$	—		$	—		$	—		$	(17	)	$	—		$	61	$	—
Total assets	$	74		$	4			$	—		$	—		$	—		$	—		$	(17	)	$	—		$	61	$	—
(a)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
	Level 3 recurring fair value measurements
	Fair value at July 1, 2013			Net realized/unrealized							Purchases			Sales			Issuances			Settlements			Fair value at September 30, 2013			Net unrealized
				(losses) gains																						losses included in
																										earnings still held at
($ in millions)				included				included in OCI																		30-Sep-13
				in
				earnings
Assets
Other assets
Interests retained in financial asset sales	$	124		$	8		(a)	$	—		$	—		$	—		$	—		$	(11	)	$	121		$	—
Derivative contracts, net
Foreign currency	(9		)	47			(b)	—			—			—			—			19			57			47		(b)
Total derivative contracts in a receivable position, net	(9		)	47				—			—			—			—			19			57			47
Total assets	$	115		$	55			$	—		$	—		$	—		$	—		$	8		$	178		$	47
(a)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
(b)	Refer to Note 19 for information related to the location of the gains and losses on derivative instruments in the Condensed Consolidated Statement of Comprehensive Income.
	Level 3 recurring fair value measurements
				Net realized/unrealized																						Fair value at September 30, 2014		Net unrealized gains included in earnings still held at
				gains																								30-Sep-14
($ in millions)	Fair value at Jan. 1, 2014			included				included			Purchases			Sales			Issuances			Settlements			Transfers out of Level 3
				in  earnings				in OCI
Assets
Other assets
Interests retained in financial asset sales	$	100		$	9		(a)	$	—		$	—		$	—		$	—		$	(48	)	$	—		$	61	$	—
Interest rate derivative contracts, net	(1		)	—				—			—			—			—			(2		)	3			—		—
Total assets	$	99		$	9			$	—		$	—		$	—		$	—		$	(50	)	$	3		$	61	$	—
(a)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
	Level 3 recurring fair value measurements
	Fair value at Jan. 1, 2013			Net realized/unrealized							Purchases			Sales			Issuances			Settlements			Fair value at September 30, 2013			Net unrealized
				(losses) gains																						losses included in
																										earnings still held at
($ in millions)				included				included in OCI																		30-Sep-13
				in
				earnings
Assets
Mortgage servicing rights	$	952		$	(101	)	(a)	$	—		$	—		$	(911	)	$	60		$	—		$	—		$	—
Other assets
Interests retained in financial asset sales	154			19			(b)	—			—			—			—			(52		)	121			—
Derivative contracts, net
Interest rate	47			(51		)	(c)	—			—			—			—			4			—			—		(c)
Foreign currency	(2		)	40			(c)	—			—			—			—			19			57			38		(c)
Total derivative contracts in a receivable position, net	45			(11		)		—			—			—			—			23			57			38
Total assets	$	1,151		$	(93	)		$	—		$	—		$	(911	)	$	60		$	(29	)	$	178		$	38
(a)	Fair value adjustment was reported as servicing-asset valuation and hedge activities, net, in the Condensed Consolidated Statement of Comprehensive Income.
(b)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
(c)	Refer to Note 19 for information related to the location of the gains and losses on derivative instruments in the Condensed Consolidated Statement of Comprehensive 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 the assets and liabilities measured at fair value on a nonrecurring basis.
		Nonrecurring																Lower-of-cost				Total gain				Total gain
		fair value measurements																or				included in				included in
																		fair value				earnings for				earnings for
																		or valuation				the three				the nine months ended
																		reserve				months ended
September 30, 2014 ($ in millions)		Level 1				Level 2				Level 3				Total				allowance
Assets
Commercial finance receivables and loans, net (a)
Automotive		$	—			$	—			$	16			$	16			$	(1	)		n/m			(b)	n/m		(b)
Other		—				—				37				37				(14		)		n/m			(b)	n/m		(b)
Total commercial finance receivables and loans, net		—				—				53				53				(15		)		n/m			(b)	n/m		(b)
Other assets
Repossessed and foreclosed assets (c)		—				—				8				8				(3		)		n/m			(b)	n/m		(b)
Other		—				—				2				2				—				$	—			$	—
Total assets		$	—			$	—			$	63			$	63			$	(18	)		n/m				n/m
n/m =ot meaningful
(a)	Represents the portion of the portfolio specifically impaired during 2014. The related valuation allowance represents the cumulative adjustment to fair value of those specific receivables.
(b)	We consider the applicable valuation or loan loss allowance 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 or loan loss allowance.
(c)	The allowance provided for repossessed and foreclosed assets represents any cumulative valuation adjustment recognized to adjust the assets to fair value.
		Nonrecurring																Lower-of-cost				Total loss included in		Total loss
		fair value measurements																or				earnings for		included in
																		fair value				the three		earnings for
																		or valuation				months ended		the nine months ended
																		reserve
September 30, 2013 ($ in millions)		Level 1				Level 2				Level 3				Total				allowance
Assets
Loans held-for-sale		$	—			$	—			$	19			$	19			$	—			n/m	(a)	n/m	(a)
Commercial finance receivables and loans, net (b)
Automotive		—				—				95				95				(17		)		n/m	(a)	n/m	(a)
Other		—				—				63				63				(11		)		n/m	(a)	n/m	(a)
Total commercial finance receivables and loans, net		—				—				158				158				(28		)		n/m	(a)	n/m	(a)
Other assets
Repossessed and foreclosed assets (c)		—				—				7				7				(2		)		n/m	(a)	n/m	(a)
Other		—				—				2				2				—				n/m	(a)	n/m	(a)
Total assets		$	—			$	—			$	186			$	186			$	(30	)		n/m		n/m
n/m =ot meaningful
(a)	We consider the applicable valuation or loan loss allowance 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 or loan loss allowance.
(b)	Represents the portion of the portfolio specifically impaired during 2013. 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.
The following table presents quantitative information regarding the significant unobservable inputs used in significant Level 3 assets measured at fair value on a nonrecurring basis.
September 30, 2014 ($ in millions)		Level 3 nonrecurring measurements				Valuation technique		Unobservable input		Range
Assets
Commercial finance receivables and loans, net
Automotive		$	16			Fair value of collateral		Adjusted appraisal value		65.0-95.0%
Other		37				Discounted cash flow		Non-public/non-rated credits		91.0-109.0%
Fair Value Option for Financial Assets
We elected the fair value option for conforming and government-insured mortgage loans held-for-sale. We elected the fair value option to mitigate earnings volatility by better matching the accounting for the assets with the related hedges. Our intent in electing fair value measurement was to mitigate a divergence between accounting losses and economic exposure for certain assets and liabilities.
Excluded from the fair value option were conforming and government-insured loans funded on or prior to July 31, 2009, and repurchased or rerecognized. The loans funded on or prior to July 31, 2009, were ineligible because the election must be made at the time of funding. Repurchased and rerecognized conforming and government-insured loans were not elected because the election would not mitigate earning volatility. We repurchase or rerecognize loans due to representation and warranty obligations or conditional repurchase options. Typically, we will be unable to resell these assets through regular channels due to characteristics of the assets. Since the fair value of these assets is influenced by factors that cannot be hedged, we did not elect the fair value option.
We carried the fair value-elected conforming and government-insured loans as loans held-for-sale, net, on the Condensed Consolidated Balance Sheet. Our policy is to separately record interest income on the fair value-elected loans (unless they are placed on nonaccrual status); however, the accrued interest was excluded from the fair value presentation. Upfront fees and costs related to the fair value-elected loans were not deferred or capitalized. The fair value adjustment recorded for these loans was classified as gain (loss) on mortgage loans, net, in the Condensed Consolidated Statement of Comprehensive Income. In accordance with GAAP, the fair value option election is irrevocable once the asset is funded even if it is subsequently determined that a particular loan cannot be sold.
The following tables summarize the fair value option elections and information regarding the amounts recorded as earnings for each fair value option-elected item.
		Changes included in the
		Condensed Consolidated
		Statement of Comprehensive Income
Three months ended September 30, ($ in millions)		Interest				Gain (loss) on mortgage				Total
		on loans				loans, net				included in
		held-for-sale (a)								earnings
2014
Assets
Mortgage loans held-for-sale, net		$	—			$	—			$	—
2013
Assets
Mortgage loans held-for-sale, net		$	—			$	14			$	14		(b)
(a)	Interest income is measured by multiplying the unpaid principal balance on the loans by the coupon rate and the number of days of interest due.
(b)	The credit impact for loans held-for-sale is assumed to be zero because the loans are either suitable for sale or are covered by a government guarantee.
		Changes included in the
		Condensed Consolidated
		Statement of Comprehensive Income
Nine months ended September 30, ($ in millions)		Interest				Gain on mortgage				Total
		on loans				loans, net				included in
		held-for-sale (a)								earnings
2014
Assets
Mortgage loans held-for-sale, net		$	—			$	1			$	1
2013
Assets
Mortgage loans held-for-sale, net		$	19			$	(35	)		$	(16	)	(b)
(a)    Interest income is measured by multiplying the unpaid principal balance on the loans by the coupon rate and the number of days of interest due.
(b)    The credit impact for loans held-for-sale is assumed to be zero because the loans are either suitable for sale or are covered by a government guarantee.
The following table provides the aggregate fair value and the aggregate unpaid principal balance for the fair value option-elected loans.
		September 30, 2014								December 31, 2013
($ in millions)		Unpaid				Fair				Unpaid				Fair
		principal				value (a)				principal				value (a)
		balance								balance
Assets
Mortgage loans held-for-sale, net
Total loans		$	7			$	3			$	31			$	16
Nonaccrual loans		3				2				18				9
Loans 90+ days past due (b)		3				2				15				8
(a)	Excludes accrued interest receivable.
(b)	Loans 90+ days past due are also presented within the nonaccrual loan balance and the total loan balance; however, excludes government-insured loans that are still accruing interest.
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 market data to develop estimates of fair value, so the estimates are not necessarily indicative of the amounts that could be realized or would be paid in a current market exchange. The effect of using different market assumptions or estimation methodologies could be material to the estimated fair values. Fair value information presented herein was based on information available at September 30, 2014 and December 31, 2013.
					Estimated fair value
($ in millions)	Carrying				Level 1				Level 2				Level 3				Total
	value
September 30, 2014
Financial assets
Loans held-for-sale, net (a)	$	3			$	—			$	3			$	—			$	3
Finance receivables and loans, net (a)	98,405				—				—				99,733				99,733
Nonmarketable equity investments	275				—				245				51				296
Financial liabilities
Deposit liabilities	$	56,851			$	—			$	—			$	57,371			$	57,371
Short-term borrowings	5,255				—				—				5,255				5,255
Long-term debt (a)	67,299				—				26,945				43,233				70,178
December 31, 2013
Financial assets
Loans held-for-sale, net (a)	$	35			$	—			$	17			$	18			$	35
Finance receivables and loans, net (a)	99,120				—				—				100,090				100,090
Nonmarketable equity investments	337				—				308				38				346
Financial liabilities
Deposit liabilities	$	53,350			$	—			$	—			$	54,070			$	54,070
Short-term borrowings	8,545				—				—				8,545				8,545
Long-term debt (a)(b)	69,824				—				31,067				42,297				73,364
(a)	Includes financial instruments carried at fair value due to fair value option elections. Refer to the previous section of this note titled Fair Value Option for Financial Assets and Liabilities for further information about the fair value elections.
(b)	The carrying value includes deferred interest for zero-coupon bonds of $359 million at December 31, 2013.
The following describes the methodologies and assumptions used to determine fair value for the significant classes of financial instruments. In addition to the valuation methods discussed below, we also followed guidelines for determining whether a market was not active and a transaction was not distressed. As such, we assumed the price that would be received in an orderly transaction (including a market-based return) and not in forced liquidation or distressed sale.
•	Cash and cash equivalents — Included in cash and cash equivalents are highly liquid investments that are readily convertible to known amounts of cash and which are subject to an insignificant risk of change in value due to interest rate, quoted price, or penalty on withdrawal. Classified as Level 1 under the fair value hierarchy, cash and cash equivalents generally expose us to limited credit risk and have no stated maturities or have short-term maturities and carry interest rates that approximate market. As such, the carrying value approximates the fair value of these instruments.
•	Loans held-for-sale, net — Loans held-for-sale classified as Level 2 included all GSE-eligible mortgage loans valued predominantly using published forward agency prices. It also included any domestic loans where recently negotiated market prices for the loan pool existed with a counterparty (which approximated fair value) or quoted market prices for similar loans were available. Loans held-for-sale classified as Level 3 included all loans valued using internally developed valuation models because observable market prices were not available. The loans were priced on a discounted cash flow basis utilizing cash flow projections from internally developed models that utilized prepayment, default, and discount rate assumptions. To the extent available, we utilized market observable inputs such as interest rates and market spreads. If market observable inputs were not available, we were required to utilize internal inputs, such as prepayment speeds, credit losses, and discount rates.
•	Finance receivables and loans, net — With the exception of mortgage loans held-for-investment, the fair value of finance receivables and loans was based on discounted future cash flows using applicable spreads to approximate current rates applicable to each category of finance receivables and loans (an income approach using Level 3 inputs). The carrying value of commercial receivables in certain markets and certain automotive and other receivables for which interest rates reset on a short-term basis with applicable market indices are assumed to approximate fair value either because of the short-term nature or because of the interest rate adjustment feature. The fair value of commercial receivables in other markets was based on discounted future cash flows using applicable spreads to approximate current rates applicable to similar assets in those markets.
For consumer mortgage loans, we used valuation methods and assumptions similar to those used for mortgage loans held-for-sale. These valuations consider unique attributes of the loans such as geography, delinquency status, product type, and other factors. Refer to the section above titled Loans held-for-sale, net, for a description of methodologies and assumptions used to determine the fair value of mortgage loans held-for-sale.
•	Deposit liabilities — Deposit liabilities represent certain consumer and brokered bank deposits, mortgage escrow deposits, and dealer deposits. The fair value of deposits at Level 3 were estimated by discounting projected cash flows based on discount factors derived from the forward interest rate swap curve.
•	Short-term borrowings and Long-term debt — Level 2 debt was valued using quoted market prices for similar instruments, when available, or other means for substantiation with observable inputs. Debt valued using internally derived inputs, such as prepayment speeds and discount rates, was classified as Level 3.

Offsetting_Assets_and_Liabilit

Offsetting Assets and Liabilities	9 Months Ended
	Sep. 30, 2014
Offsetting [Abstract]	'
Assets and Liabilities Subject to Enforceable Master Netting Arrangements [Text Block]	'
	Offsetting Assets and Liabilities
	Our qualifying master netting agreements are written, legally enforceable bilateral agreements that (1) create a single legal obligation for all individual transactions covered by the agreement to the non-defaulting entity upon an event of default of the counterparty, including bankruptcy, insolvency, or similar proceeding, and (2) provide the non-defaulting 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. As it relates to derivative instruments, in certain instances we have the option to report derivatives that are subject to a qualifying master netting agreement on a net basis, we have elected to report these instruments as gross assets and liabilities on the Condensed Consolidated Balance Sheet.
	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 value of our total obligation to each other. Contractual terms provide for standard and customary exchange of collateral based on changes in the market value of the outstanding derivatives. The securing party posts additional collateral when their obligation rises or removes collateral when it falls, such that the net replacement cost of the non-defaulting party is covered in the event of counterparty default.
	The composition of offsetting derivative instruments, financial assets, and financial liabilities was as follows.
			Gross Amounts of Recognized Assets/(Liabilities)			Gross Amounts Offset in the Condensed Consolidated Balance Sheet		Net Amounts of Assets/(Liabilities) Presented in the Condensed Consolidated Balance Sheet
											Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet
	September 30, 2014 ($ in millions)										Financial Instruments			Collateral (a)			Net Amount
	Assets
	Derivative assets in net asset positions		$	115		$	—	$	115		$	(9	)	$	(5	)	$	101
	Derivative assets in net liability positions		120			—		120			(120		)	—			—
	Total assets (b)		$	235		$	—	$	235		$	(129	)	$	(5	)	$	101
	Liabilities
	Derivative liabilities in net liability positions		$	(284	)	$	—	$	(284	)	$	120		$	83		$	(81	)
	Derivative liabilities in net asset positions		(9		)	—		(9		)	9			—			—
	Derivative liabilities with no offsetting arrangements		(6		)	—		(6		)	—			—			(6		)
	Total derivative liabilities (b)		(299		)	—		(299		)	129			83			(87		)
	Securities sold under agreements to repurchase (c)		(579		)	—		(579		)	—			579			—
	Total liabilities		$	(878	)	$	—	$	(878	)	$	129		$	662		$	(87	)
	(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)	For additional information on derivative instruments and hedging activities, refer to Note 19.
	(c)	For additional information on securities sold under agreements to repurchase, refer to Note 12.
			Gross Amounts of Recognized Assets/(Liabilities)			Gross Amounts Offset in the Condensed Consolidated Balance Sheet		Net Amounts of Assets/(Liabilities) Presented in the Condensed Consolidated Balance Sheet
											Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet
	December 31, 2013 ($ in millions)										Financial Instruments			Collateral (a)			Net Amount
	Assets
	Derivative assets in net asset positions		$	319		$	—	$	319		$	(65	)	$	(120	)	$	134
	Derivative assets in net liability positions		43			—		43			(43		)	—			—
	Total assets (b)		$	362		$	—	$	362		$	(108	)	$	(120	)	$	134
	Liabilities
	Derivative liabilities in net liability positions		$	(252	)	$	—	$	(252	)	$	43		$	137		$	(72	)
	Derivative liabilities in net asset positions		(65		)	—		(65		)	65			—			—
	Total derivative liabilities (b)		(317		)	—		(317		)	108			137			(72		)
	Securities sold under agreements to repurchase (c)		(1,500		)	—		(1,500		)	—			1,500			—
	Total liabilities		$	(1,817	)	$	—	$	(1,817	)	$	108		$	1,637		$	(72	)
	(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)	For additional information on derivative instruments and hedging activities, refer to Note 19.
	(c)	For additional information on securities sold under agreements to repurchase, refer to Note 12.

Segment_And_Geographic_Informa

Segment And Geographic Information	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segment Reporting Disclosure [Text Block]	'
	Segment and Geographic 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 line-of-business basis through three operating segments - Automotive Finance operations, Insurance operations, and Mortgage 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 — Provides automotive financing services to consumers and automotive dealers. For consumers, we offer retail automotive financing and leasing for new and used vehicles, and through our commercial automotive financing operations, we fund dealer purchases of new and used vehicles through wholesale or floorplan financing.
	Insurance operations — Offers both consumer financial and insurance products sold primarily through the automotive dealer channel, and commercial insurance products sold to dealers. As part of our focus on offering dealers a broad range of consumer finance and insurance products, we provide vehicle service contracts, maintenance coverage, and Guaranteed Automobile Protection (GAP) products. We also underwrite selected commercial insurance coverages, which primarily insure dealers' vehicle inventories.
	Mortgage operations — Our ongoing Mortgage operations include the management of our held-for-investment mortgage portfolio.
	Corporate and Other primarily consists of Corporate Finance, centralized corporate treasury activities, such as management of the cash and corporate investment securities portfolios, short- and long-term debt, retail and brokered deposit liabilities, derivative instruments, the amortization of the discount associated with new debt issuances and bond exchanges, 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, overhead that was previously allocated to operations that have since been sold or classified as discontinued operations, and reclassifications and eliminations between the reportable operating segments.
	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 LIBOR swap 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 and geographic areas tables that follow are based in part on internal allocations, which involve management judgment.
	Financial information for our reportable operating segments is summarized as follows.
	Three months ended September 30,		Automotive Finance operations			Insurance			Mortgage operations			Corporate			Consolidated (b)
	($ in millions)					operations						and
												Other (a)
	2014
	Net financing revenue		$	850		$	16		$	9		$	14		$	889
	Other revenue		69			287			—			19			375
	Total net revenue		919			303			9			33			1,264
	Provision for loan losses		109			—			(7		)	—			102
	Total noninterest expense		395			243			19			85			742
	Income (loss) from continuing operations before income tax expense		$	415		$	60		$	(3	)	$	(52	)	$	420
	Total assets		$	110,937		$	7,178		$	7,402		$	23,678		$	149,195
	2013
	Net financing revenue (loss)		$	800		$	16		$	13		$	(92	)	$	737
	Other revenue		65			293			19			(6		)	371
	Total net revenue (loss)		865			309			32			(98		)	1,108
	Provision for loan losses		150			—			(12		)	3			141
	Total noninterest expense		376			226			48			112			762
	Income (loss) from continuing operations before income tax expense		$	339		$	83		$	(4	)	$	(213	)	$	205
	Total assets		$	108,609		$	7,323		$	8,562		$	26,062		$	150,556
	(a)	Total assets for Corporate Finance were $1.7 billion and $1.6 billion at September 30, 2014 and 2013, respectively.
	(b)	Net financing revenue after the provision for loan losses totaled $787 million and $596 million for the three months ended September 30, 2014 and 2013, respectively.
	Nine months ended September 30,		Automotive Finance operations			Insurance			Mortgage operations			Corporate			Consolidated (b)
	($ in millions)					operations						and
												Other (a)
	2014
	Net financing revenue (loss)		$	2,554		$	47		$	35		$	(60	)	$	2,576
	Other revenue		195			849			13			4			1,061
	Total net revenue (loss)		2,749			896			48			(56		)	3,637
	Provision for loan losses		367			—			(55		)	(10		)	302
	Total noninterest expense		1,167			785			62			262			2,276
	Income (loss) from continuing operations before income tax expense		$	1,215		$	111		$	41		$	(308	)	$	1,059
	Total assets		$	110,937		$	7,178		$	7,402		$	23,678		$	149,195
	2013
	Net financing revenue (loss)		$	2,350		$	43		$	62		$	(450	)	$	2,005
	Other revenue (loss)		207			926			(6		)	32			1,159
	Total net revenue (loss)		2,557			969			56			(418		)	3,164
	Provision for loan losses		350			—			14			(3		)	361
	Total noninterest expense		1,143			780			293			305			2,521
	Income (loss) from continuing operations before income tax expense		$	1,064		$	189		$	(251	)	$	(720	)	$	282
	Total assets		$	108,609		$	7,323		$	8,562		$	26,062		$	150,556
	(a)	Total assets for Corporate Finance were $1.7 billion and $1.6 billion at September 30, 2014 and 2013, respectively.
	(b)	Net financing revenue after the provision for loan losses totaled $2.3 billion and $1.6 billion for the nine months ended September 30, 2014 and 2013, respectively.
	Information concerning principal geographic areas were as follows.
	Three months ended September 30, ($ in millions)		Revenue (a)			Income (loss)			Net income(b)(c)
						from continuing
						operations
						before income
						tax expense (b)
	2014
	Canada		$	31		$	7		$	9
	Europe		—			(1		)	1
	Latin America		—			—			—
	Asia-Pacific		—			—			29
Total foreign		31			6			39
Total domestic (d)		1,233			414			384
Total		$	1,264		$	420		$	423
2013
Canada		$	40		$	14		$	13
Europe (e)		2			1			4
Latin America		—			12			26
Asia-Pacific		—			—			35
Total foreign		42			27			78
Total domestic (d)		1,066			178			13
Total		$	1,108		$	205		$	91
(a)	Revenue consists of net financing revenue and total other revenue as presented in our Condensed Consolidated Financial Statements.
(b)	The domestic amounts include original discount amortization of $51 million and $67 million for the three months ended September 30, 2014 and 2013, respectively.
(c)	Gain (loss) realized on sale of discontinued operations are allocated to the geographic area in which the business operated.
(d)	Amounts include eliminations between our domestic and foreign operations.
(e)	Amounts include eliminations between our foreign operations.
Nine months ended September 30, ($ in millions)		Revenue (a)			Income (loss)			Net income
					from continuing			(loss) (b)(c)
					operations
					before income
					tax expense (b)
2014
Canada		$	95		$	36		$	55
Europe		2			—			5
Latin America		—			—			(8		)
Asia-Pacific		—			—			95
Total foreign		97			36			147
Total domestic (d)		3,540			1,023			826
Total		$	3,637		$	1,059		$	973
2013
Canada		$	136		$	42		$	1,256
Europe (e)		(8		)	(18		)	(82		)
Latin America		—			7			300
Asia-Pacific		1			(2		)	89
Total foreign		129			29			1,563
Total domestic (d)		3,035			253			(1,306		)
Total		$	3,164		$	282		$	257
(a)	Revenue consists of net financing revenue and total other revenue as presented in our Condensed Consolidated Financial Statements.
(b)	The domestic amounts include original discount amortization of $149 million and $191 million for the nine months ended September 30, 2014 and 2013, respectively.
(c)	Gain (loss) realized on sale of discontinued operations are allocated to the geographic area in which the business operated.
(d)	Amounts include eliminations between our domestic and foreign operations.
(e)	Amounts include eliminations between our foreign operations.

Parent_And_Guarantor_Consolida

Parent And Guarantor Consolidating Financial Statements	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Condensed Guarantor Financial Statements [Text Block]	'
	Parent and Guarantor Condensed 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 September 30, 2014, 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) an elimination column for adjustments to arrive at (v) the information for the parent company, the Guarantors, and nonguarantors on a consolidated basis. The financial statements have been restated to reflect the dissolution of a former nonguarantor subsidiary, GMAC Mortgage Group LLC.
	Investments in subsidiaries are 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 the Guarantors’ investment in subsidiaries accounts. The elimination entries set forth in the following condensed consolidating financial statements eliminate distributed and undistributed income of subsidiaries, investments in subsidiaries, and intercompany balances and transactions between the parent, the Guarantors, and nonguarantors.
	Condensed Consolidating Statements of Comprehensive Income
	Three months ended September 30, 2014 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
															consolidated
	Financing revenue and other interest income
	Interest and fees on finance receivables and loans		$	16		$	—		$	1,098		$	—		$	1,114
	Interest and fees on finance receivables and loans — intercompany		10			—			21			(31		)	—
	Interest and dividends on available-for-sale investment securities		—			—			94			—			94
	Interest-bearing cash		—			—			2			—			2
	Interest-bearing cash — intercompany		—			—			1			(1		)	—
	Operating leases		1			—			898			—			899
	Total financing revenue and other interest income		27			—			2,114			(32		)	2,109
	Interest expense
	Interest on deposits		3			—			163			—			166
	Interest on short-term borrowings		10			—			2			—			12
	Interest on long-term debt		350			—			143			—			493
	Interest on intercompany debt		22			—			10			(32		)	—
	Total interest expense		385			—			318			(32		)	671
	Depreciation expense on operating lease assets		(4		)	—			553			—			549
	Net financing (loss) revenue		(354		)	—			1,243			—			889
	Dividends from subsidiaries
	Bank subsidiary		150			150			—			(300		)	—
	Nonbank subsidiaries		141			—			—			(141		)	—
	Other revenue
	Servicing fees		6			—			—			—			6
	Servicing asset valuation and hedge activities, net		—			—			—			—			—
	Total servicing income, net		6			—			—			—			6
	Insurance premiums and service revenue earned		—			—			246			—			246
	(Loss) gain on mortgage and automotive loans, net		(2		)	—			2			—			—
	Other gain on investments, net		—			—			45			—			45
	Other income, net of losses		206			—			373			(501		)	78
	Total other revenue		210			—			666			(501		)	375
	Total net revenue		147			150			1,909			(942		)	1,264
	Provision for loan losses		88			—			14			—			102
	Noninterest expense
	Compensation and benefits expense		153			—			199			(111		)	241
	Insurance losses and loss adjustment expenses		—			—			97			—			97
	Other operating expenses		252			—			542			(390		)	404
	Total noninterest expense		405			—			838			(501		)	742
	(Loss) income from continuing operations before income tax (benefit) expense and undistributed income (loss) of subsidiaries		(346		)	150			1,057			(441		)	420
	Income tax (benefit) expense from continuing operations		(68		)	—			195			—			127
	Net (loss) income from continuing operations		(278		)	150			862			(441		)	293
	Income from discontinued operations, net of tax		127			—			3			—			130
	Undistributed income (loss) of subsidiaries
	Bank subsidiary		150			150			—			(300		)	—
	Nonbank subsidiaries		424			(2		)	—			(422		)	—
	Net income		423			298			865			(1,163		)	423
	Other comprehensive loss, net of tax		(55		)	(3		)	(50		)	53			(55		)
	Comprehensive income		$	368		$	295		$	815		$	(1,110	)	$	368
	Three months ended September 30, 2013 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
															consolidated
	Financing revenue and other interest income
	Interest and fees on finance receivables and loans		$	243		$	—		$	876		$	—		$	1,119
	Interest and fees on finance receivables and loans — intercompany		12			—			21			(33		)	—
	Interest and dividends on available-for-sale investment securities		—			—			85			—			85
	Interest-bearing cash		1			—			2			—			3
	Interest-bearing cash - intercompany		—			—			2			(2		)	—
	Operating leases		141			—			691			—			832
	Total financing revenue and other interest income		397			—			1,677			(35		)	2,039
	Interest expense
Interest on deposits		5			—			158			—			163
Interest on short-term borrowings		11			—			4			—			15
Interest on long-term debt		469			—			140			—			609
Interest on intercompany debt		23			—			12			(35		)	—
Total interest expense		508			—			314			(35		)	787
Depreciation expense on operating lease assets		103			—			412			—			515
Net financing (loss) revenue		(214		)	—			951			—			737
Dividends from subsidiaries
Nonbank subsidiaries		54			—			—			(54		)	—
Other revenue
Servicing fees		36			—			(23		)	—			13
Servicing asset valuation and hedge activities, net		—			—			—			—			—
Total servicing income (loss), net		36			—			(23		)	—			13
Insurance premiums and service revenue earned		—			—			251			—			251
Gain on mortgage and automotive loans, net		—			—			15			—			15
Loss on extinguishment of debt		(42		)	—			—			—			(42		)
Other gain on investments, net		—			—			41			—			41
Other income, net of losses		51			—			350			(308		)	93
Total other revenue		45			—			634			(308		)	371
Total net (loss) revenue		(115		)	—			1,585			(362		)	1,108
Provision for loan losses		69			—			72			—			141
Noninterest expense
Compensation and benefits expense		153			—			205			(113		)	245
Insurance losses and loss adjustment expenses		—			—			85			—			85
Other operating expenses		119			—			508			(195		)	432
Total noninterest expense		272			—			798			(308		)	762
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income (loss) of subsidiaries		(456		)	—			715			(54		)	205
Income tax (benefit) expense from continuing operations		(189		)	—			217			—			28
Net (loss) income from continuing operations		(267		)	—			498			(54		)	177
Income (loss) from discontinued operations, net of tax		142			15			(243		)	—			(86		)
Undistributed income (loss) of subsidiaries
Bank subsidiary		235			235			—			(470		)	—
Nonbank subsidiaries		(19		)	5			—			14			—
Net income		91			255			255			(510		)	91
Other comprehensive income (loss), net of tax		4			(34		)	24			10			4
Comprehensive income		$	95		$	221		$	279		$	(500	)	$	95
Nine months ended September 30, 2014 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
														consolidated
Financing revenue and other interest income
Interest and fees on finance receivables and loans		$	(2	)	$	—		$	3,347		$	—		$	3,345
Interest and fees on finance receivables and loans — intercompany		26			—			64			(90		)	—
Interest on loans held-for-sale		—			—			1			—			1
Interest and dividends on available-for-sale investment securities		—			—			282			—			282
Interest-bearing cash		1			—			5			—			6
Interest-bearing — intercompany		—			—			4			(4		)	—
Operating leases		269			—			2,384			—			2,653
Total financing revenue and other interest income		294			—			6,087			(94		)	6,287
Interest expense
Interest on deposits		11			—			484			—			495
Interest on short-term borrowings		32			—			8			—			40
Interest on long-term debt		1,143			—			433			—			1,576
Interest on intercompany debt		68			—			26			(94		)	—
Total interest expense		1,254			—			951			(94		)	2,111
Depreciation expense on operating lease assets		164			—			1,436			—			1,600
Net financing (loss) revenue		(1,124		)	—			3,700			—			2,576
Dividends from subsidiaries
Bank subsidiary		1,650			1,650			—			(3,300		)	—
Nonbank subsidiaries		462			—			—			(462		)	—
Other revenue
Servicing fees		22			—			—			—			22
Servicing asset valuation and hedge activities, net		—			—			—			—			—
Total servicing income, net		22			—			—			—			22
Insurance premiums and service revenue earned		—			—			736			—			736
(Loss) gain on mortgage and automotive loans, net		(2		)	—			8			—			6
Loss on extinguishment of debt		(46		)	—			—			—			(46		)
Other gain on investments, net		—			—			129			—			129
Other income, net of losses		591			—			1,007			(1,384		)	214
Total other revenue		565			—			1,880			(1,384		)	1,061
Total net revenue		1,553			1,650			5,580			(5,146		)	3,637
Provision for loan losses		165			—			137			—			302
Noninterest expense
Compensation and benefits expense		441			—			604			(335		)	710
Insurance losses and loss adjustment expenses		—			—			353			—			353
Other operating expenses		648			—			1,614			(1,049		)	1,213
Total noninterest expense		1,089			—			2,571			(1,384		)	2,276
Income from continuing operations before income tax (benefit) expense and undistributed (loss) income of subsidiaries		299			1,650			2,872			(3,762		)	1,059
Income tax (benefit) expense from continuing operations		(309		)	—			594			—			285
Net income from continuing operations		608			1,650			2,278			(3,762		)	774
Income from discontinued operations, net of tax		172			—			27			—			199
Undistributed (loss) income of subsidiaries
Bank subsidiary		(802		)	(802		)	—			1,604			—
Nonbank subsidiaries		995			(2		)	—			(993		)	—
Net income		973			846			2,305			(3,151		)	973
Other comprehensive income, net of tax		126			116			124			(240		)	126
Comprehensive income		$	1,099		$	962		$	2,429		$	(3,391	)	$	1,099
Nine months ended September 30, 2013 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
														consolidated
Financing revenue and other interest income
Interest and fees on finance receivables and loans		$	674		$	—		$	2,719		$	—		$	3,393
Interest and fees on finance receivables and loans — intercompany		49			—			46			(95		)	—
Interest on loans held-for-sale		—			—			19			—			19
Interest and dividends on available-for-sale investment securities		—			—			229			—			229
Interest-bearing cash		3			—			5			—			8
Interest-bearing cash — intercompany		—			—			6			(6		)	—
Operating leases		355			—			1,999			—			2,354
Total financing revenue and other interest income		1,081			—			5,023			(101		)	6,003
Interest expense
Interest on deposits		20			—			469			—			489
Interest on short-term borrowings		35			—			12			—			47
Interest on long-term debt		1,593			—			425			(5		)	2,013
Interest on intercompany debt		43			—			52			(95		)	—
Total interest expense		1,691			—			958			(100		)	2,549
Depreciation expense on operating lease assets		267			—			1,182			—			1,449
Net financing (loss) revenue		(877		)	—			2,883			(1		)	2,005
Dividends from subsidiaries
Nonbank subsidiaries		5,217			3,659			—			(8,876		)	—
Other revenue
Servicing fees		118			—			(4		)	—			114
Servicing asset valuation and hedge activities, net		—			—			(213		)	—			(213		)
Total servicing income (loss), net		118			—			(217		)	—			(99		)
Insurance premiums and service revenue earned		—			—			768			—			768
Gain on mortgage and automotive loans, net		—			—			52			—			52
Loss on extinguishment of debt		(42		)	—			—			—			(42		)
Other gain on investments, net		—			—			156			—			156
Other income, net of losses		128			—			1,116			(920		)	324
Total other revenue		204			—			1,875			(920		)	1,159
Total net revenue		4,544			3,659			4,758			(9,797		)	3,164
Provision for loan losses		298			—			63			—			361
Noninterest expense
Compensation and benefits expense		505			—			622			(345		)	782
Insurance losses and loss adjustment expenses		—			—			346			—			346
Other operating expenses		274			—			1,694			(575		)	1,393
Total noninterest expense		779			—			2,662			(920		)	2,521
Income from continuing operations before income tax (benefit) expense and undistributed income (loss) of subsidiaries		3,467			3,659			2,033			(8,877		)	282
Income tax (benefit) expense from continuing operations		(748		)	—			693			—			(55		)
Net income from continuing operations		4,215			3,659			1,340			(8,877		)	337
(Loss) income from discontinued operations, net of tax		(1,365		)	(19		)	1,303			1			(80		)
Undistributed income (loss) of subsidiaries
Bank subsidiary		668			668			—			(1,336		)	—
Nonbank subsidiaries		(3,261		)	(2,395		)	—			5,656			—
Net income		257			1,913			2,643			(4,556		)	257
Other comprehensive loss, net of tax		(494		)	(753		)	(830		)	1,583			(494		)
Comprehensive (loss) income		$	(237	)	$	1,160		$	1,813		$	(2,973	)	$	(237	)
Condensed Consolidating Balance Sheet
September 30, 2014 ($ in millions)		Parent (a)			Guarantors			Nonguarantors (a)			Consolidating			Ally
											adjustments			consolidated
Assets
Cash and cash equivalents
Noninterest-bearing		$	932		$	—		$	386		$	—		$	1,318
Interest-bearing		1,300			—			3,081			—			4,381
Interest-bearing — intercompany		—			—			413			(413		)	—
Total cash and cash equivalents		2,232			—			3,880			(413		)	5,699
Investment securities		—			—			16,714			—			16,714
Loans held-for-sale, net		—			—			3			—			3
Finance receivables and loans, net
Finance receivables and loans, net		4,757			—			94,761			—			99,518
Intercompany loans to
Bank subsidiary		1,300			—			—			(1,300		)	—
Nonbank subsidiaries		5,603			—			1,777			(7,380		)	—
Allowance for loan losses		(104		)	—			(1,009		)	—			(1,113		)
Total finance receivables and loans, net		11,556			—			95,529			(8,680		)	98,405
Investment in operating leases, net		—			—			19,341			—			19,341
Intercompany receivables from
Bank subsidiary		518			—			—			(518		)	—
Nonbank subsidiaries		271			—			77			(348		)	—
Investment in subsidiaries
Bank subsidiary		15,770			15,770			—			(31,540		)	—
Nonbank subsidiaries		9,730			11			—			(9,741		)	—
Premiums receivable and other insurance assets		—			—			1,698			(20		)	1,678
Other assets		4,789			—			4,399			(2,436		)	6,752
Assets of operations held-for-sale		603			—			—			—			603
Total assets		$	45,469		$	15,781		$	141,641		$	(53,696	)	$	149,195
Liabilities
Deposit liabilities
Noninterest-bearing		$	—		$	—		$	73		$	—		$	73
Interest-bearing		368			—			56,410			—			56,778
Total deposit liabilities		368			—			56,483			—			56,851
Short-term borrowings		3,376			—			1,879			—			5,255
Long-term debt		22,777			—			44,522			—			67,299
Intercompany debt to
Nonbank subsidiaries		2,190			—			6,903			(9,093		)	—
Intercompany payables to
Bank subsidiary		170			—			—			(170		)	—
Nonbank subsidiaries		573			—			142			(715		)	—
Interest payable		279			—			263			—			542
Unearned insurance premiums and service revenue		—			—			2,369			—			2,369
Accrued expenses and other liabilities		546			82			3,497			(2,436		)	1,689
Total liabilities		30,279			82			116,058			(12,414		)	134,005
Total equity		15,190			15,699			25,583			(41,282		)	15,190
Total liabilities and equity		$	45,469		$	15,781		$	141,641		$	(53,696	)	$	149,195
(a)	Amounts presented are based upon the legal transfer of the underlying assets to VIEs in order to reflect legal ownership.
December 31, 2013 ($ in millions)		Parent (a)			Guarantors			Nonguarantors (a)			Consolidating			Ally
											adjustments			consolidated
Assets
Cash and cash equivalents
Noninterest-bearing		$	979		$	37		$	299		$	—		$	1,315
Interest-bearing		1,951			—			2,265			—			4,216
Interest-bearing — intercompany		—			—			410			(410		)	—
Total cash and cash equivalents		2,930			37			2,974			(410		)	5,531
Investment securities		—			—			17,083			—			17,083
Loans held-for-sale, net		—			—			35			—			35
Finance receivables and loans, net
Finance receivables and loans, net		6,673			—			93,655			—			100,328
Intercompany loans to
Bank subsidiary		600			—			—			(600		)	—
Nonbank subsidiaries		4,207			—			1,925			(6,132		)	—
Allowance for loan losses		(131		)	—			(1,077		)	—			(1,208		)
Total finance receivables and loans, net		11,349			—			94,503			(6,732		)	99,120
Investment in operating leases, net		3,172			—			14,508			—			17,680
Intercompany receivables from
Bank subsidiary		236			—			—			(236		)	—
Nonbank subsidiaries		439			—			588			(1,027		)	—
Investment in subsidiaries
Bank subsidiary		14,916			14,916			—			(29,832		)	—
Nonbank subsidiaries		10,029			68			—			(10,097		)	—
Premiums receivable and other insurance assets		—			—			1,634			(21		)	1,613
Other assets		4,691			—			6,880			(1,982		)	9,589
Assets of operations held-for-sale		516			—			—			—			516
Total assets		$	48,278		$	15,021		$	138,205		$	(50,337	)	$	151,167
Liabilities
Deposit liabilities
Noninterest-bearing		$	—		$	—		$	60		$	—		$	60
Interest-bearing		440			—			52,850			—			53,290
Total deposit liabilities		440			—			52,910			—			53,350
Short-term borrowings		3,225			—			5,320			—			8,545
Long-term debt		25,819			—			43,646			—			69,465
Intercompany debt to
Nonbank subsidiaries		2,334			—			4,808			(7,142		)	—
Intercompany payables to
Bank subsidiary		197			—			—			(197		)	—
Nonbank subsidiaries		666			—			421			(1,087		)	—
Interest payable		709			—			179			—			888
Unearned insurance premiums and service revenue		—			—			2,314			—			2,314
Accrued expenses and other liabilities		680			93			3,606			(1,982		)	2,397
Total liabilities		34,070			93			113,204			(10,408		)	136,959
Total equity		14,208			14,928			25,001			(39,929		)	14,208
Total liabilities and equity		$	48,278		$	15,021		$	138,205		$	(50,337	)	$	151,167
(a)	Amounts presented are based upon the legal transfer of the underlying assets to VIEs in order to reflect legal ownership.
Condensed Consolidating Statement of Cash Flows
Nine months ended September 30, 2014 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating			Ally
											adjustments			consolidated
Operating activities
Net cash provided by operating activities		$	544		$	1,639		$	4,036		$	(3,761	)	$	2,458
Investing activities
Purchases of available-for-sale securities		—			—			(4,117		)	—			(4,117		)
Proceeds from sales of available-for-sale securities		—			—			2,974			—			2,974
Proceeds from maturities and repayments of available-for-sale securities		—			—			1,877			—			1,877
Net decrease (increase) in finance receivables and loans		1,669			—			(2,936		)	—			(1,267		)
Proceeds from sales of finance receivables and loans		—			—			1,557			—			1,557
Net (increase) decrease in loans — intercompany		(104		)	—			147			(43		)	—
Net decrease (increase) in operating lease assets		146			—			(3,411		)	—			(3,265		)
Capital contributions to subsidiaries		(744		)	—			—			744			—
Returns of contributed capital		1,251			—			—			(1,251		)	—
Proceeds from sale of business units, net		46			—			1			—			47
Net change in restricted cash		—			—			2,128			—			2,128
Other, net		(17		)	—			88			—			71
Net cash provided by (used in) investing activities		2,247			—			(1,692		)	(550		)	5
Financing activities
Net change in short-term borrowings — third party		151			—			(3,449		)	—			(3,298		)
Net (decrease) increase in deposits		(72		)	—			3,573			—			3,501
Proceeds from issuance of long-term debt — third party		2,310			—			16,632			—			18,942
Repayments of long-term debt — third party		(5,535		)	—			(15,704		)	—			(21,239		)
Net change in debt — intercompany		(143		)	—			104			39			—
Dividends paid — third party		(200		)	—			—			—			(200		)
Dividends paid and returns of contributed capital — intercompany		—			(1,676		)	(3,337		)	5,013			—
Capital contributions from parent		—			—			744			(744		)	—
Net cash used in financing activities		(3,489		)	(1,676		)	(1,437		)	4,308			(2,294		)
Effect of exchange-rate changes on cash and cash equivalents		—			—			(1		)	—			(1		)
Net (decrease) increase in cash and cash equivalents		(698		)	(37		)	906			(3		)	168
Cash and cash equivalents at beginning of year		2,930			37			2,974			(410		)	5,531
Cash and cash equivalents at September 30		$	2,232		$	—		$	3,880		$	(413	)	$	5,699
Nine months ended September 30, 2013 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating			Ally
											adjustments			consolidated
Operating activities
Net cash provided by operating activities		$	5,198		$	3,514		$	4,528		$	(8,875	)	$	4,365
Investing activities
Purchases of available-for-sale securities		—			—			(12,747		)	—			(12,747		)
Proceeds from sales of available-for-sale securities		—			—			4,721			—			4,721
Proceeds from maturities and repayments of available-for-sale securities		—			—			3,893			—			3,893
Net (increase) decrease in finance receivables and loans		(3,527		)	79			6,192			—			2,744
Net decrease (increase) in loans — intercompany		342			251			(1,376		)	783			—
Net (increase) in operating lease assets		(1,111		)	—			(4,060		)	—			(5,171		)
Capital contributions to subsidiaries		(176		)	—			—			176			—
Returns of contributed capital		769			150			—			(919		)	—
Sales of mortgage servicing rights		—			—			911			—			911
Proceeds from sale of business units, net		1,123			554			5,260			—			6,937
Net change in restricted cash		—			(26		)	2,323			—			2,297
Other, net		(200		)	—			145			—			(55		)
Net cash (used in) provided by investing activities		(2,780		)	1,008			5,262			40			3,530
Financing activities
Net change in short-term borrowings — third party		105			36			(1,077		)	—			(936		)
Net (decrease) increase in deposits		(433		)	—			4,527			(37		)	4,057
Proceeds from issuance of long-term debt — third party		2,213			—			11,134			—			13,347
Repayments of long-term debt — third party		(6,331		)	(70		)	(20,324		)	—			(26,725		)
Net change in debt — intercompany		1,674			(271		)	(664		)	(739		)	—
Dividends paid — third party		(601		)	—			—			—			(601		)
Dividends paid and returns of contributed capital — intercompany		—			(4,217		)	(5,577		)	9,794			—
Capital contributions from parent		—			29			147			(176		)	—
Net cash used in financing activities		(3,373		)	(4,493		)	(11,834		)	8,842			(10,858		)
Effect of exchange-rate changes on cash and cash equivalents		—			—			47			—			47
Net (decrease) increase in cash and cash equivalents		(955		)	29			(1,997		)	7			(2,916		)
Adjustment for change in cash and cash equivalents of operations held-for-sale		—			—			1,952			—			1,952
Cash and cash equivalents at beginning of year		3,977			—			4,027			(491		)	7,513
Cash and cash equivalents at September 30		$	3,022		$	29		$	3,982		$	(484	)	$	6,549

Contingencies_And_Other_Risks

Contingencies And Other Risks	9 Months Ended
	Sep. 30, 2014
Loss Contingency [Abstract]	'
Contingencies Disclosure and Other Risks [Text Block]	'
	Contingencies and Other Risks
	In the normal course of business, we enter into transactions that expose us to varying degrees of risk. For additional information on contingencies and other risks arising from such transactions, refer to Note 29 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K.
	Legal Proceedings
	We are or may be subject to potential liability under various governmental proceedings, claims, and legal actions that are pending or otherwise asserted against us. We are named as defendants in a number of legal actions, and we are involved in governmental proceedings arising in connection with our respective businesses. Some of the pending actions purport to be class actions, and certain legal actions include claims for substantial compensatory and/or punitive damages or claims for indeterminate amounts of damages. We establish reserves for legal claims when payments associated with the claims become probable and the payments can be reasonably estimated. Given the inherent difficulty of predicting the outcome of litigation and regulatory matters, it is generally very difficult to predict what the eventual outcome will be, and when the matter will be resolved. The actual costs of resolving legal claims may be higher or lower than any amounts reserved for the claims.
	On the basis of information currently available, advice of counsel, available insurance coverage, and established reserves, it is the opinion of management that the eventual outcome of the current actions against us will not have a material adverse effect on our consolidated financial condition, results of operations, or cash flows. However, it is possible that the ultimate resolution of legal matters, if unfavorable, may be material to our consolidated financial condition, results of operations, or cash flows in a particular period.
	Regulatory Matters
	Ally and its subsidiaries, including Ally Bank, are or may become involved from time to time in reviews, investigations, and proceedings (both formal and informal), and information-gathering requests, by government and self-regulatory agencies, including the FRB, FDIC, Utah Department of Financial Institutions (UDFI), Consumer Financial Protection Bureau (CFPB), U.S. Department of Justice (DOJ), SEC, and the Federal Trade Commission regarding their respective operations. Such requests currently include subpoenas from each of the SEC and the DOJ. The subpoenas and document requests from the SEC include information covering a wide range of mortgage-related matters, and the subpoenas received from the DOJ include a broad request for documentation and other information in connection with its investigations of potential fraud and other potential legal violations related to mortgage-backed securities, as well as the origination and/or underwriting of mortgage loans. In addition, we recently received a document request from the SEC in connection with its investigation related to subprime automotive finance and related securitization activities.
	Further, in December 2013, Ally Financial Inc. and Ally Bank entered into Consent Orders issued by the CFPB and the DOJ pertaining to the allegation of disparate impact in the automotive finance business, which resulted in a $98 million charge in the fourth quarter of 2013. The Consent Orders require Ally to create a compliance plan addressing, at a minimum, the communication of Ally’s expectations of Equal Credit Opportunity Act compliance to dealers, maintenance of Ally’s existing limits on dealer finance income for contracts acquired by Ally, and monitoring for potential discrimination both at the dealer level and within our portfolio of contracts acquired across all dealers. Ally formed a compliance committee consisting of certain Ally and Ally Bank directors to oversee Ally’s execution of the Consent Orders’ terms. Failure to achieve certain remediation targets could result in the payment of additional amounts in the future.
	Investigations, proceedings, regulatory actions, or information-gathering requests that Ally is, or may become, involved in may result in material adverse consequences including without limitation, adverse judgments, settlements, fines, penalties, injunctions, or other actions.
	Loan Repurchases and Obligations Related to Loan Sales
	Representation and Warranty Obligation Reserve
	The representation and warranty reserve was $37 million at September 30, 2014 with respect to our sold and serviced loans for which we have retained representation and warranty obligation, compared to $45 million at December 31, 2013. The liability for representation and warranty obligations reflects management's best estimate of probable losses with respect to Ally Bank's mortgage loans sold to Freddie Mac and Fannie Mae.
	Other Contingencies
	We are subject to potential liability under various other exposures including tax, nonrecourse loans, self-insurance, and other miscellaneous contingencies. We establish reserves for these contingencies when the loss becomes probable and the amount can be reasonably estimated. The actual costs of resolving these items may be substantially higher or lower than the amounts reserved for any one item. Based on information currently available, it is the opinion of management that the eventual outcome of these items will not have a material adverse impact on our results of operations, financial position, or cash flows.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	Subsequent Events
	Declaration of Quarterly Dividend Payments
	On October 16, 2014, the Ally Board of Directors declared quarterly dividend payments on certain outstanding preferred stock. This included a cash dividend of $17.89 per share, or a total of $46 million, on Fixed Rate Cumulative Perpetual Preferred Stock, Series G; and a cash dividend of $0.53 per share, or a total of $22 million, on Fixed Rate/Floating Rate Perpetual Preferred Stock, Series A. The dividends are payable to shareholders of record as of November 1, 2014 and are payable on November 17, 2014.
	Tender Offer
	On October 22, 2014, we completed a tender offer to repurchase $750 million of our 8.000% Senior Notes due 2031, 8.000% Senior Guaranteed Notes due 2020, and 7.500% Senior Guaranteed Notes due 2020. We expect to record a loss on extinguishment of debt of approximately $160 million in the fourth quarter related to this transaction.

Description_Of_Business_Basis_1

Description Of Business, Basis of Presentation, And Changes in Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Income Tax, Policy [Policy Text Block]	'
	Income Taxes
	In calculating the provision for interim income taxes, in accordance with Accounting Standards Codification (ASC) 740, Income Taxes, we apply an estimated annual effective tax rate to year-to-date ordinary income. At the end of each interim period, we estimate the effective tax rate expected to be applicable for the full fiscal year. This method differs from that described in Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K, which describes our annual significant income tax accounting policy and related methodology.
Discontinued Operations, Policy [Policy Text Block]	'
	Discontinued Operations
	We classify operations as discontinued when operations and cash flows will be eliminated from our ongoing operations and we do not expect to retain any significant continuing involvement in their operations after the respective disposal transactions. For all periods presented, the operating results for these discontinued operations have been removed from continuing operations and presented separately as discontinued operations, net of tax, in the Condensed Consolidated Statement of Comprehensive Income. The Notes to the Condensed Consolidated Financial Statements have been adjusted to exclude discontinued operations unless otherwise noted.

Discontinued_and_Heldforsale_O1

Discontinued and Held-for-sale Operations (Tables)	9 Months Ended
	Sep. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	'
	Select financial information of discontinued operations is summarized below. The pretax income or loss, including direct costs to transact a sale, includes any impairment recognized to present the operations at the lower-of-cost or fair value. Fair value was based on the estimated sales price, which could differ from the ultimate sales price due to price volatility, changing interest rates, changing foreign-currency rates, and future economic conditions.
		Three months ended September 30,						Nine months ended September 30,
	($ in millions)	2014			2013			2014			2013
	Select Mortgage operations
	Total net revenue	$	—		$	—		$	—		$	—
	Pretax loss including direct costs to transact a sale (a) (b)	(1		)	(158		)	(4		)	(1,762		)
	Tax benefit (c)	(86		)	(40		)	(87		)	(573		)
	Select Insurance operations
	Total net revenue	$	—		$	—		$	—		$	190
	Pretax income including direct costs to transact a sale (a)	6			5			6			319
	Tax expense (benefit) (c)	7			3			7			(12		)
	Select Automotive Finance operations
	Total net revenue	$	29		$	119		$	95		$	544
	Pretax income including direct costs to transact a sale (a)	46			58			101			752
	Tax expense (benefit) (c)	—			28			4			(25		)
	Select Corporate and Other operations
	Total net revenue	$	—		$	—		$	—		$	—
	Pretax income	—			—			23			1
	Tax expense	—			—			3			—
	(a)	Includes certain treasury and other corporate activity recognized by Corporate and Other.
	(b)	2013 periods include amounts related to our former Residential Capital, LLC (ResCap) subsidiary.
	(c)	Includes certain income tax activity recognized by Corporate and Other.
	Held-for-sale Operations
	The assets of operations held-for-sale are summarized below.
	($ in millions)	Select
		Automotive Finance
		operations (a)
	September 30, 2014
	Assets
	Other assets	$	603
	Total assets	$	603
	December 31, 2013
	Assets
	Other assets	$	516
	Total assets	$	516
	(a)	Represents our joint venture in China that is being sold to GM Financial.

Other_Income_Net_Of_Losses_Tab

Other Income, Net Of Losses (Tables)	9 Months Ended
	Sep. 30, 2014
Other Nonoperating Income (Expense) [Abstract]	'
Schedule of Other Nonoperating Income, by Component [Table Text Block]	'
	Details of other income, net of losses, were as follows.
		Three months ended September 30,					Nine months ended September 30,
	($ in millions)	2014			2013		2014			2013
	Remarketing fees	$	28		$	20	$	85		$	59
	Late charges and other administrative fees	23			25		66			71
	Fair value adjustment on derivatives (a)	(4		)	21		(19		)	31
	Mortgage processing fees and other mortgage income	—			—		—			81
	Other, net	31			27		82			82
	Total other income, net of losses	$	78		$	93	$	214		$	324
	(a)	Refer to Note 19 for a description of derivative instruments and hedging activities.

Other_Operating_Expenses_Table

Other Operating Expenses (Tables)	9 Months Ended
	Sep. 30, 2014
Operating Expenses [Abstract]	'
Schedule of Other Operating Cost and Expense, by Component [Table Text Block]	'
	Details of other operating expenses were as follows.
		Three months ended September 30,				Nine months ended September 30,
	($ in millions)	2014		2013		2014		2013
	Insurance commissions	$	95	$	93	$	279	$	278
	Technology and communications	77		87		255		250
	Lease and loan administration	32		29		92		141
	Advertising and marketing	27		33		81		96
	Professional services	20		38		73		140
	Regulatory and licensing fees	23		25		69		87
	Premises and equipment depreciation	23		20		61		61
	Vehicle remarketing and repossession	22		15		61		42
	Occupancy	12		12		34		34
	State and local non-income taxes	12		1		32		17
	Mortgage representation and warranty obligation, net	—		22		1		103
	Other	61		57		175		144
	Total other operating expenses	$	404	$	432	$	1,213	$	1,393

Investment_Securities_Tables

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2014
Available-for-sale Securities [Abstract]	'
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	'
	Our portfolio of securities includes bonds, equity securities, asset- and mortgage-backed securities, interests in securitization trusts, and other investments. The cost, fair value, and gross unrealized gains and losses on available-for-sale securities were as follows.
			September 30, 2014															December 31, 2013
			Amortized cost			Gross unrealized								Fair				Amortized cost				Gross unrealized						Fair
	($ in millions)					gains				losses				value								gains			losses			value
	Available-for-sale securities
	Debt securities
	U.S. Treasury and federal agencies		$	1,313		$	1			$	(28	)		$	1,286			$	1,495			$	1		$	(69	)	$	1,427
	U.S. States and political subdivisions		386			16				—				402				316				—			(1		)	315
	Foreign government		226			6				—				232				287				4			(3		)	288
	Mortgage-backed residential (a)		11,018			78				(212		)		10,884				11,131				49			(398		)	10,782
	Mortgage-backed commercial		213			—				(1		)		212				39				—			—			39
	Asset-backed		1,982			8				(3		)		1,987				2,207				15			(3		)	2,219
	Corporate debt		970			18				(5		)		983				1,052				23			(6		)	1,069
	Total debt securities		16,108			127				(249		)		15,986				16,527				92			(480		)	16,139
	Equity securities		721			30				(23		)		728				898				74			(28		)	944
	Total available-for-sale securities (b)		$	16,829		$	157			$	(272	)		$	16,714			$	17,425			$	166		$	(508	)	$	17,083
	(a)	Residential mortgage-backed securities include agency-backed bonds totaling $8,175 million and $8,266 million at September 30, 2014, and December 31, 2013, respectively.
	(b)	Certain entities related to our Insurance operations are required to deposit securities with state regulatory authorities. Amounts deposited totaled $15 million and $15 million at September 30, 2014, and December 31, 2013, respectively.
Investments Classified by Contractual Maturity Date [Table Text Block]	'
	The maturity distribution of available-for-sale debt securities outstanding is summarized in the following tables. Prepayments may cause actual maturities to differ from scheduled maturities.
			Total						Due in							Due after							Due after					Due after
									one year							one year							five years					ten years (a)
									or less							through							through
																five years							ten years
	($ in millions)		Amount			Yield			Amount				Yield			Amount				Yield			Amount			Yield		Amount			Yield
	September 30, 2014
	Fair value of available-for-sale debt securities (b)
	U.S. Treasury and federal agencies		$	1,286		1.3	%		$	7			3.1	%		$	791			1.2	%		$	488		1.5	%	$	—		—	%
	U.S. States and political subdivisions		402			3.5			36				1.2			15				2			108			2.8		243			4.3
	Foreign government		232			2.7			—				—			124				2.6			108			2.9		—			—
	Mortgage-backed residential		10,884			2.8			—				—			65				2.1			—			—		10,819			2.8
	Mortgage-backed commercial		212			2.1			—				—			—				—			—			—		212			2.1
	Asset-backed		1,987			2			26				2.3			1,300				2			479			1.9		182			2.5
	Corporate debt		983			3.9			34				3.1			480				3			413			4.9		56			5.8
	Total available-for-sale debt securities		$	15,986		2.6			$	103			2.2			$	2,775			1.9			$	1,596		2.6		$	11,512		2.8
	Amortized cost of available-for-sale debt securities		$	16,108					$	102						$	2,773						$	1,596				$	11,637
	December 31, 2013
	Fair value of available-for-sale debt securities (b)
	U.S. Treasury and federal agencies		$	1,427		1.3	%		$	9			3	%		$	766			1.2	%		$	652		1.3	%	$	—		—	%
	U.S. States and political subdivisions		315			3.3			39				1.3			10				0.6			102			2.6		164			4.3
	Foreign government		288			2.7			18				2.7			105				2.4			164			2.9		1			2.7
	Mortgage-backed residential		10,782			2.7			—				—			90				2.1			3			4.2		10,689			2.7
	Mortgage-backed commercial		39			1.3			—				—			—				—			—			—		39			1.3
	Asset-backed		2,219			2			76				2.4			1,483				1.9			491			1.9		169			2.7
	Corporate debt		1,069			4.1			24				3.4			547				3			430			5.3		68			5.7
	Total available-for-sale debt securities		$	16,139		2.5			$	166			2.3			$	3,001			1.9			$	1,842		2.5		$	11,130		2.7
	Amortized cost of available-for-sale debt securities		$	16,527					$	165						$	3,000						$	1,882				$	11,480
	(a)	Investments with no stated maturities are included as contractual maturities of greater than 10 years. Actual maturities may differ due to call or prepayment options.
	(b)	Yields on tax-exempt obligations are computed on a tax-equivalent basis.
Schedule of Realized Gain (Loss) [Table Text Block]	'
	The following table presents gross gains and losses realized upon the sales of available-for-sale securities and other-than-temporary impairment.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014				2013
	Gross realized gains	$	48		$	59			$	150			$	196
	Gross realized losses	(3		)	(7		)		(11		)		(21		)
	Other-than-temporary impairment	—			(11		)		(10		)		(19		)
	Other gain on investments, net	$	45		$	41			$	129			$	156
Investment Income [Table Text Block]	'
	The following table presents interest and dividends on available-for-sale securities.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014				2013
	Taxable interest	$	87		$	79			$	256			$	210
	Taxable dividends	6			6				18				19
	Interest and dividends exempt from U.S. federal income tax	1			—				8				—
	Interest and dividends on available-for-sale securities	$	94		$	85			$	282			$	229
Schedule of Unrealized Loss on Investments [Table Text Block]	'
	The table below summarizes available-for-sale securities in an unrealized loss position in accumulated other comprehensive income. Based on the methodology described below that was applied to these securities, we believe that the unrealized losses relate to factors other than credit losses in the current market environment. As of September 30, 2014, we did not have the intent to sell the debt securities with an unrealized loss position in accumulated other comprehensive income, and it is not more likely than not that we will be required to sell these securities before recovery of their amortized cost basis. As of September 30, 2014, we had the ability and intent to hold equity securities with an unrealized loss position in accumulated other comprehensive income, and it is not more likely than not that we will be required to sell these securities before recovery of their amortized cost basis. As a result, we believe that the securities with an unrealized loss position in accumulated other comprehensive income are not considered to be other-than-temporarily impaired at September 30, 2014. Refer to Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information related to investment securities and our methodology for evaluating potential other-than-temporary impairments.
			September 30, 2014															December 31, 2013
			Less than							12 months								Less than							12 months
			12 months							or longer								12 months							or longer
	($ in millions)		Fair			Unrealized				Fair				Unrealized				Fair				Unrealized			Fair			Unrealized
			value			loss				value				loss				value				loss			value			loss
	Available-for-sale securities
	Debt securities
	U.S. Treasury and federal agencies		$	—		$	—			$	1,245			$	(28	)		$	1,405			$	(69	)	$	—		$	—
	U.S. States and political subdivisions		21			—				—				—				212				(1		)	—			—
	Foreign government		43			—				—				—				114				(3		)	—			—
	Mortgage-backed		1,428			(12		)		4,229				(201		)		7,503				(388		)	100			(10		)
	Asset-backed		699			(3		)		16				—				407				(3		)	1			—
	Corporate debt		238			(4		)		20				(1		)		310				(6		)	3			—
	Total temporarily impaired debt securities		2,429			(19		)		5,510				(230		)		9,951				(470		)	104			(10		)
	Temporarily impaired equity securities		255			(21		)		14				(2		)		167				(12		)	100			(16		)
	Total temporarily impaired available-for-sale securities		$	2,684		$	(40	)		$	5,524			$	(232	)		$	10,118			$	(482	)	$	204		$	(26	)

Finance_Receivables_And_Loans_1

Finance Receivables And Loans, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Loans and Leases Receivable, Net Reported Amount, by Category Alternative [Abstract]	'
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	'
	The composition of finance receivables and loans, net, reported at carrying value before allowance for loan losses was as follows.
	($ in millions)		September 30, 2014				December 31, 2013
	Consumer automobile (a)		$	58,675			$	56,417
	Consumer mortgage (b)(c)		7,595				8,444
	Commercial
	Commercial and industrial
	Automobile		28,453				30,948
	Other		1,756				1,664
	Commercial Real Estate — Automobile		3,039				2,855
	Total commercial		33,248				35,467
	Total finance receivables and loans (d)		$	99,518			$	100,328
	(a)	Includes $16 million and $1 million of fair value adjustment for loans in hedge accounting relationships at September 30, 2014, and December 31, 2013, respectively. Refer to Note 19 for additional information.
	(b)	Includes interest-only mortgage loans of $1.3 billion and $1.5 billion at September 30, 2014, and December 31, 2013, respectively, the majority of which are expected to start principal amortization in 2015 or beyond.
	(c)	Includes consumer mortgages at a fair value of $1 million at both September 30, 2014, and December 31, 2013, as a result of fair value option election.
	(d)	Totals are net of unearned income, unamortized premiums and discounts, and deferred fees and costs of $392 million and $595 million at September 30, 2014, and December 31, 2013, respectively
Allowance for Credit Losses on Financing Receivables [Table Text Block]	'
	The following tables present an analysis of the activity in the allowance for loan losses on finance receivables and loans.
	Three months ended September 30, 2014 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at July 1, 2014		$	729			$	302			$	140			$	1,171
	Charge-offs		(188		)		(13		)		—				(201		)
	Recoveries		51				1				—				52
	Net charge-offs		(137		)		(12		)		—				(149		)
	Provision for loan losses		112				(7		)		(3		)		102
	Other		(11		)		—				—				(11		)
	Allowance at September 30, 2014		$	693			$	283			$	137			$	1,113
	Three months ended September 30, 2013 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at July 1, 2013		$	610			$	431			$	142			$	1,183
	Charge-offs		(168		)		(16		)		—				(184		)
	Recoveries		53				5				—				58
	Net charge-offs		(115		)		(11		)		—				(126		)
	Provision for loan losses		156				(12		)		(3		)		141
	Other		—				(1		)		1				—
	Allowance at September 30, 2013		$	651			$	407			$	140			$	1,198
	Nine months ended September 30, 2014 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at January 1, 2014		$	673			$	389			$	146			$	1,208
	Charge-offs		(511		)		(38		)		(5		)		(554		)
	Recoveries		170				6				11				187
	Net charge-offs		(341		)		(32		)		6				(367		)
	Provision for loan losses		372				(55		)		(15		)		302
	Other		(11		)		(19		)		—				(30		)
	Allowance at September 30, 2014		$	693			$	283			$	137			$	1,113
	Allowance for loan losses
	Individually evaluated for impairment		$	25			$	180			$	15			$	220
	Collectively evaluated for impairment		668				103				122				893
	Loans acquired with deteriorated credit quality		—				—				—				—
	Finance receivables and loans at historical cost
	Ending balance		58,675				7,594				33,248				99,517
	Individually evaluated for impairment		289				904				73				1,266
	Collectively evaluated for impairment		58,384				6,690				33,175				98,249
	Loans acquired with deteriorated credit quality		2				—				—				2
	Nine months ended September 30, 2013 ($ in millions)		Consumer				Consumer				Commercial				Total
			automobile				mortgage
	Allowance at January 1, 2013		$	575			$	452			$	143			$	1,170
	Charge-offs		(443		)		(71		)		(3		)		(517		)
	Recoveries		155				13				6				174
	Net charge-offs		(288		)		(58		)		3				(343		)
	Provision for loan losses		355				14				(8		)		361
	Other		9				(1		)		2				10
	Allowance at September 30, 2013		$	651			$	407			$	140			$	1,198
	Allowance for loan losses
	Individually evaluated for impairment		$	22			$	199			$	28			$	249
	Collectively evaluated for impairment		629				208				112				949
	Loans acquired with deteriorated credit quality		—				—				—				—
	Finance receivables and loans at historical cost
	Ending balance		56,450				8,772				30,059				95,281
	Individually evaluated for impairment		269				916				251				1,436
	Collectively evaluated for impairment		56,170				7,856				29,808				93,834
	Loans acquired with deteriorated credit quality		11				—				—				11
Schedule Of Sales Of Financing Receivables And Loans [Table Text Block]	'
	The following table presents information about significant sales of finance receivables and loans recorded at historical cost and transfers of finance receivables and loans from held-for-investment to held-for-sale.
			Three months ended September 30,								Nine months ended September 30,
	($ in millions)		2014				2013				2014				2013
	Consumer automobile		$	1,562			$	—			$	1,562			$	—
	Consumer mortgage		—				—				40				—
	Commercial		—				2				—				47
	Total sales and transfers		$	1,562			$	2			$	1,602			$	47
Schedule of Purchases of Financing Receivables and Loans [Table Text Block]	'
	The following table presents information about significant purchases of finance receivables and loans.
			Three months ended September 30,								Nine months ended September 30,
	($ in millions)		2014				2013				2014				2013
	Consumer mortgage		$	83			$	—			$	98			$	—
	Total purchases		$	83			$	—			$	98			$	—
Past Due Financing Receivables [Table Text Block]	'
	The following table presents an analysis of our past due finance receivables and loans, net, recorded at historical cost reported at carrying value before allowance for loan losses.
	($ in millions)		30-59 days				60-89 days				90 days				Total				Current				Total finance
			past due				past due				or more				past due								receivables and loans
											past due
	September 30, 2014
	Consumer automobile		$	1,179			$	243			$	145			$	1,567			$	57,108			$	58,675
	Consumer mortgage (a)		110				41				138				289				7,305				7,594
	Commercial
	Commercial and industrial
	Automobile		—				—				—				—				28,453				28,453
	Other		—				—				—				—				1,756				1,756
	Commercial real estate — Automobile		—				—				—				—				3,039				3,039
	Total commercial		—				—				—				—				33,248				33,248
	Total consumer and commercial		$	1,289			$	284			$	283			$	1,856			$	97,661			$	99,517
	December 31, 2013
	Consumer automobile		$	1,145			$	255			$	157			$	1,557			$	54,860			$	56,417
	Consumer mortgage		82				31				124				237				8,206				8,443
	Commercial
	Commercial and industrial
	Automobile		—				—				36				36				30,912				30,948
	Other		—				—				—				—				1,664				1,664
	Commercial real estate — Automobile		—				—				6				6				2,849				2,855
	Total commercial		—				—				42				42				35,425				35,467
	Total consumer and commercial		$	1,227			$	286			$	323			$	1,836			$	98,491			$	100,327
	(a)	During the three months ended September 30, 2014, we completed a sub-servicing transfer of our mortgage held-for-investment loan portfolio. This caused what is expected to be a temporary increase in the delinquency levels at September 30, 2014, and is not believed to be indicative of a degradation in underlying credit quality.
Schedule of Financing Receivables, Non Accrual Status [Table Text Block]	'
	The following table presents the carrying value before allowance for loan losses of our finance receivables and loans recorded at historical cost on nonaccrual status.
	($ in millions)		September 30, 2014				December 31, 2013
	Consumer automobile		$	355			$	329
	Consumer mortgage		193				192
	Commercial
	Commercial and industrial
	Automobile		21				116
	Other		51				74
	Commercial real estate — Automobile		1				14
	Total commercial		73				204
	Total consumer and commercial finance receivables and loans		$	621			$	725
Financing Receivable Credit Quality Indicators [Table Text Block]	'
	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 historical cost reported at carrying value before allowance for loan losses. Nonperforming loans include finance receivables and loans on nonaccrual status when the principal or interest has been delinquent for 90 days or when full collection is determined not to be probable. Refer to Note 1 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information.
			September 30, 2014												December 31, 2013
	($ in millions)		Performing				Nonperforming				Total				Performing				Nonperforming				Total
	Consumer automobile		$	58,320			$	355			$	58,675			$	56,088			$	329			$	56,417
	Consumer mortgage		7,401				193				7,594				8,251				192				8,443
	The following table presents pass and criticized credit quality indicators based on regulatory definitions for our commercial finance receivables and loans recorded at historical cost reported at carrying value before allowance for loan losses.
			September 30, 2014												December 31, 2013
	($ in millions)		Pass				Criticized (a)				Total				Pass				Criticized (a)				Total
	Commercial
	Commercial and industrial
	Automobile		$	26,879			$	1,574			$	28,453			$	29,194			$	1,754			$	30,948
	Other		1,501				255				1,756				1,388				276				1,664
	Commercial real estate — Automobile		2,938				101				3,039				2,770				85				2,855
	Total commercial		$	31,318			$	1,930			$	33,248			$	33,352			$	2,115			$	35,467
	(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 [Table Text Block]	'
	The following table presents information about our impaired finance receivables and loans recorded at historical cost.
	($ in millions)		Unpaid principal balance				Carrying value before allowance				Impaired with no allowance				Impaired with an allowance				Allowance for impaired loans
	September 30, 2014
	Consumer automobile		$	289			$	289			$	—			$	289			$	25
	Consumer mortgage		909				904				128				776				180
	Commercial
	Commercial and industrial
	Automobile		21				21				4				17				1
	Other		51				51				—				51				14
	Commercial real estate — Automobile		1				1				1				—				—
	Total commercial		73				73				5				68				15
	Total consumer and commercial finance receivables and loans		$	1,271			$	1,266			$	133			$	1,133			$	220
	December 31, 2013
	Consumer automobile		$	281			$	281			$	—			$	281			$	23
	Consumer mortgage		924				919				128				791				199
	Commercial
	Commercial and industrial
	Automobile		116				116				57				59				7
	Other		74				74				—				74				16
	Commercial real estate — Automobile		14				14				9				5				3
	Total commercial		204				204				66				138				26
	Total consumer and commercial finance receivables and loans		$	1,409			$	1,404			$	194			$	1,210			$	248
	The following tables present average balance and interest income for our impaired finance receivables and loans.
			2014								2013
	Three months ended September 30, ($ in millions)		Average				Interest				Average				Interest
			balance				income				balance				income
	Consumer automobile		$	297			$	5			$	275			$	5
	Consumer mortgage		914				7				924				7
	Commercial
	Commercial and industrial
	Automobile		32				—				163				2
	Other		51				—				84				—
	Commercial real estate — Automobile		3				—				29				—
	Total commercial		86				—				276				2
	Total consumer and commercial finance receivables and loans		$	1,297			$	12			$	1,475			$	14
			2014								2013
	Nine months ended September 30, ($ in millions)		Average				Interest				Average				Interest
			balance				income				balance				income
	Consumer automobile		$	298			$	14			$	274			$	14
	Consumer mortgage		923				22				905				22
	Commercial
	Commercial and industrial
	Automobile		68				1				160				5
	Other		62				4				69				1
	Commercial real estate — Automobile		7				—				33				1
	Total commercial		137				5				262				7
	Total consumer and commercial finance receivables and loans		$	1,358			$	41			$	1,441			$	43
Troubled Debt Restructurings on Financing Receivables [Table Text Block]	'
	The following tables present information related to finance receivables and loans recorded at historical cost modified in connection with a TDR during the period.
			2014											2013
	Three months ended September 30,		Number of			Pre-modification				Post-modification				Number of			Pre-modification				Post-modification
	($ in millions)		loans			carrying value before				carrying value before				loans			carrying value before				carrying value before
						allowance				allowance							allowance				allowance
	Consumer automobile		4,361			$	72			$	63			4,610			$	69			$	57
	Consumer mortgage		37			7				6				121			33				32
	Commercial
	Commercial and industrial
	Automobile		—			—				—				2			5				5
	Other		—			—				—				1			27				27
	Commercial real estate — Automobile		—			—				—				1			7				7
	Total commercial		—			—				—				4			39				39
	Total consumer and commercial finance receivables and loans		4,398			$	79			$	69			4,735			$	141			$	128
			2014											2013
	Nine months ended September 30,		Number of			Pre-modification				Post-modification				Number of			Pre-modification				Post-modification
	($ in millions)		loans			carrying value before				carrying value before				loans			carrying value before				carrying value before
						allowance				allowance							allowance				allowance
	Consumer automobile		13,681			$	223			$	193			14,309			$	216			$	182
	Consumer mortgage		350			71				66				853			246				203
	Commercial
	Commercial and industrial
	Automobile		3			23				23				8			37				37
	Other		3			48				48				4			80				78
	Commercial real estate — Automobile		—			—				—				5			20				20
	Total commercial		6			71				71				17			137				135
	Total consumer and commercial finance receivables and loans		14,037			$	365			$	330			15,179			$	599			$	520
Finance receivables and loans redefaulted during the period [Table Text Block]	'
	The following tables present information about finance receivables and loans recorded at historical cost 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 to the Consolidated Financial Statements in our 2013 Annual Report on Form 10-K for additional information) except for commercial finance receivables and loans, where redefault is defined as 90 days past due.
			2014											2013
	Three months ended September 30, ($ in millions)		Number of			Carrying value				Charge-off amount				Number of			Carrying value				Charge-off amount
			loans			before allowance								loans			before allowance
	Consumer automobile		1,790			$	22			$	12			1,562			$	19			$	9
	Consumer mortgage		5			1				—				4			2				—
	Commercial
	Commercial and industrial — Automobile		—			—				—				—			—				—
	Commercial real estate — Automobile		—			—				—				—			—				—
	Total commercial		—			—				—				—			—				—
	Total consumer and commercial finance receivables and loans		1,795			$	23			$	12			1,566			$	21			$	9
			2014											2013
	Nine months ended September 30, ($ in millions)		Number of			Carrying value				Charge-off amount				Number of			Carrying value				Charge-off amount
			loans			before allowance								loans			before allowance
	Consumer automobile		5,020			$	62			$	33			4,309			$	53			$	26
	Consumer mortgage		10			2				—				16			4				—
	Commercial
	Commercial and industrial — Automobile		—			—				—				—			—				—
	Commercial real estate — Automobile		—			—				—				—			—				—
	Total commercial		—			—				—				—			—				—
	Total consumer and commercial finance receivables and loans		5,030			$	64			$	33			4,325			$	57			$	26

Investment_In_Operating_Leases1

Investment In Operating Leases, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Leases, Operating [Abstract]	'
Schedule of Property Subject to or Available for Operating Lease [Table Text Block]	'
	Investments in operating leases were as follows.
	($ in millions)		September 30, 2014				December 31, 2013
	Vehicles and other equipment		$	22,845			$	21,125
	Accumulated depreciation		(3,504		)		(3,445		)
	Investment in operating leases, net		$	19,341			$	17,680
Depreciation Expense On Operating Lease Assets [Table Text Block]	'
	Depreciation expense on operating lease assets includes remarketing gains and losses recognized on the sale of operating lease assets. The following summarizes the components of depreciation expense on operating lease assets.
		Three months ended September 30,								Nine months ended September 30,
	($ in millions)	2014				2013				2014			2013
	Depreciation expense on operating lease assets (excluding remarketing gains)	$	654			$	610			$	1,982		$	1,699
	Remarketing gains	(105		)		(95		)		(382		)	(250		)
	Depreciation expense on operating lease assets	$	549			$	515			$	1,600		$	1,449

Securitizations_And_Variable_I1

Securitizations And Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2014
Securitizations And Variable Interest Entities [Abstract]	'
Schedule of Variable Interest Entities [Table Text Block]	'
	Our involvement with consolidated and nonconsolidated VIEs in which we hold variable interests is presented below.
	($ in millions)		Consolidated				Assets of				Maximum exposure to
			involvement				nonconsolidated				loss in nonconsolidated
			with VIEs				VIEs (a)				VIEs
	September 30, 2014
	On-balance sheet variable interest entities
	Consumer automobile		$	33,331		(b)
	Commercial automobile		16,499
	Commercial other		—
	Off-balance sheet variable interest entities
	Consumer automobile		—				$	2,032			$	2,032		(c)
	Commercial other		121			(d)	—			(e)	291
	Total		$	49,951			$	2,032			$	2,323
	December 31, 2013
	On-balance sheet variable interest entities
	Consumer automobile		$	19,072
	Commercial automobile		20,511
	Commercial other		564
	Off-balance sheet variable interest entities
	Consumer automobile		—				$	899			$	899		(c)
	Commercial other		(24		)	(d)	—			(e)	40
	Total		$	40,123			$	899			$	939
	(a)	Asset values represent the current unpaid principal balance of outstanding consumer finance receivables and loans within the VIEs.
	(b)	Includes $14.3 billion of unsecuritized involvement with VIEs and thus not restricted for use as collateral to beneficial interest holders at September 30, 2014.
	(c)	Maximum exposure to loss represents the current unpaid principal balance of outstanding loans based on our customary representation and warranty provisions. This measure is based on the unlikely event that all of the loans have underwriting defects or other defects that trigger a representation and warranty provision and the collateral supporting the loans is worthless. This required disclosure is not an indication of our expected loss.
	(d)	Includes $143 million and $0 million classified as other assets, offset by $22 million and $24 million classified as accrued expenses and other liabilities at September 30, 2014, and December 31, 2013, respectively.
	(e)	Includes VIEs for which we have no management oversight and therefore we are not able to provide the total assets of the VIE.
Schedule Of Cash Flow Received And Paid To Nonconsolidated Securitization Entities [Table Text Block]	'
	The following table summarizes cash flows received and paid related to securitization entities, asset-backed financings, or other similar transfers of financial assets where the transfer is accounted for as a sale and we have a continuing involvement with the transferred assets (e.g., servicing) that were outstanding during the nine months ended September 30, 2014 and 2013. Additionally, this table contains information regarding cash flows received from and paid to nonconsolidated securitization entities that existed during each period.
	Nine months ended September 30, ($ in millions)		Consumer automobile				Consumer
							mortgage GSEs
	2014
	Cash proceeds from transfers completed during the period		$	1,557			$	—
	Servicing fees		6				—
	Representations and warranties obligations		—				(9		)
	2013
	Cash proceeds from transfers completed during the period		$	—			$	8,676
	Servicing fees		10				68
	Representations and warranties obligations		—				(65		)
	Other cash flows		—				70
Schedule of Quantitative Information and Net Credit Losses about Securitized and Other Financial Assets Managed Together [Table Text Block]	'
	The following tables represent on-balance sheet loans held-for-sale and finance receivables and loans, off-balance sheet securitizations, and whole-loan sales where we have continuing involvement. The tables present quantitative information about delinquencies and net credit losses. Refer to Note 9 for further detail on total serviced assets.
			Total Amount								Amount 60 days or more past due (a)
	($ in millions)		September 30, 2014				December 31, 2013				September 30, 2014				December 31, 2013
	On-balance sheet loans (b)
	Consumer automobile		$	58,675			$	56,417			$	388			$	412
	Consumer mortgage		7,598				8,460				181				164
	Commercial automobile		31,492				33,803				—				42
	Commercial other		1,756				1,683				—				—
	Total on-balance sheet loans		99,521				100,363				569				618
	Off-balance sheet securitization entities (c)
	Consumer automobile		2,032				899				3				3
	Total off-balance sheet securitization entities		2,032				899				3				3
	Whole-loan transactions (d)		1,238				2,848				37				69
	Total		$	102,791			$	104,110			$	609			$	690
	(a)	Includes both accruing and non-accruing loans 60 days or more past due.
	(b)	Includes current unpaid principal balance and any related unamortized deferred fees and costs.
	(c)	Asset values represent the current unpaid principal balance of outstanding consumer finance receivables and loans within the VIEs.
	(d)	Whole-loan transactions are not part of a securitization transaction, but represent consumer automobile pools of loans sold to third-party investors.
			Net credit losses
			Three months ended September 30,								Nine months ended September 30,
	($ in millions)		2014				2013				2014				2013
	On-balance sheet loans
	Consumer automobile		$	137			$	115			$	341			$	288
	Consumer mortgage		12				11				32				58
	Commercial automobile		—				—				1				—
	Commercial other		—				—				(7		)		(3		)
	Total on-balance sheet loans		149				126				367				343
	Off-balance sheet securitization entities
	Consumer automobile		—				1				1				3
	Total off-balance sheet securitization entities		—				1				1				3
	Whole-loan transactions		1				3				5				8
	Total		$	150			$	130			$	373			$	354

Servicing_Activities_Tables

Servicing Activities (Tables)	9 Months Ended
	Sep. 30, 2014
Servicing Activities [Abstract]	'
Schedule of Servicing Assets at Fair Value [Table Text Block]	'
	The following table summarizes past activity related to mortgage servicing rights (MSRs), which were carried at fair value. Management estimated fair value using our transaction data and other market data or, in periods when there were limited MSRs market transactions that were directly observable, internally developed discounted cash flow models (an income approach) were used to estimate the fair value. These internal valuation models estimated net cash flows based on internal operating assumptions that we believed would be used by market participants in orderly transactions combined with market-based assumptions for loan prepayment rates, interest rates, and discount rates that we believed approximate yields required by investors in this asset.
	Nine months ended September 30, ($ in millions)		2014			2013
	Estimated fair value at January 1,		$	—		$	952
	Additions		—			60
	Sales (a)		—			(911		)
	Changes in fair value
	Due to changes in valuation inputs or assumptions used in the valuation model		—			(32		)
	Other changes in fair value		—			(69		)
	Estimated fair value at September 30,		$	—		$	—
	(a)	Includes the sales of agency MSRs during the second quarter of 2013.
Components Of Servicing Valuation And Hedge Activities [Table Text Block]	'
	The components of servicing valuation and hedge activities, net, were as follows.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014		2013
	Change in estimated fair value of mortgage servicing rights	$	—		$	—			$	—	$	(101	)
	Change in fair value of derivative financial instruments	—			—				—		(112		)
	Servicing asset valuation and hedge activities, net	$	—		$	—			$	—	$	(213	)
Components Of Mortgage Servicing Fees [Table Text Block]	'
	The components of mortgage servicing fees were as follows.
		Three months ended September 30,							Nine months ended September 30,
	($ in millions)	2014			2013				2014		2013
	Contractual servicing fees, net of guarantee fees and including subservicing	$	—		$	—			$	—	$	61
	Late fees	—			—				—		1
	Ancillary fees	—			—				—		4
	Total mortgage servicing fees	$	—		$	—			$	—	$	66
Schedule Of Total Serviced Automobile Loans Outstanding [Table Text Block]	'
	The current unpaid principal balance and any related unamortized deferred fees and costs of total serviced automobile finance loans outstanding were as follows.
	($ in millions)	September 30, 2014			December 31, 2013
	On-balance sheet automobile finance loans and leases
	Consumer automobile	$	58,675		$	56,417
	Commercial automobile	31,492			33,803
	Operating leases	19,341			17,680
	Other	52			54
	Off-balance sheet automobile finance loans
	Loans sold to third-party investors
	Securitizations	2,052			887
	Whole-loan	1,189			2,748
	Total serviced automobile finance loans and leases	$	112,801		$	111,589

Other_Assets_Tables

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Other Assets [Abstract]	'
Schedule of Other Assets [Table Text Block]	'
	The components of other assets were as follows.
	($ in millions)	September 30, 2014			December 31, 2013
	Property and equipment at cost	$	754		$	709
	Accumulated depreciation	(529		)	(474		)
	Net property and equipment	225			235
	Deferred tax assets	1,788			2,040
	Restricted cash collections for securitization trusts (a)	1,724			3,664
	Other accounts receivable	369			290
	Cash reserve deposits held-for-securitization trusts (b)	296			402
	Nonmarketable equity securities	275			337
	Unamortized debt issuance cost	254			312
	Collateral placed with counterparties	243			328
	Fair value of derivative contracts in receivable position (c)	235			362
	Restricted cash and cash equivalents	123			205
	Other assets	1,220			1,414
	Total other assets	$	6,752		$	9,589
	(a)	Represents cash collections from customer payments on securitized receivables. These funds are distributed to investors as payments on the related secured debt.
	(b)	Represents credit enhancement in the form of cash reserves for various securitization transactions.
	(c)	For additional information on derivative instruments and hedging activities, refer to Note 19

Deposit_Liabilities_Tables

Deposit Liabilities (Tables)	9 Months Ended
	Sep. 30, 2014
Deposits [Abstract]	'
Schedule of Deposit Liabilities [Table Text Block]	'
	Deposit liabilities consisted of the following.
	($ in millions)	September 30, 2014		December 31, 2013
	Noninterest-bearing deposits	$	73	$	60
	Interest-bearing deposits
	Savings and money market checking accounts	25,383		21,210
	Certificates of deposit	31,027		31,640
	Dealer deposits	368		440
	Total deposit liabilities	$	56,851	$	53,350

ShortTerm_Borrowings_Tables

Short-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2014
Short-term Debt [Abstract]	'
Schedule of Short-term Debt [Table Text Block]	'
	The following table presents the composition of our short-term borrowings portfolio.
			September 30, 2014						December 31, 2013
	($ in millions)		Unsecured		Secured (a)		Total		Unsecured		Secured (a)		Total
	Demand notes		$	3,376	$	—	$	3,376	$	3,225	$	—	$	3,225
	Federal Home Loan Bank		—		1,300		1,300		—		3,570		3,570
	Securities sold under agreements to repurchase (b)		—		579		579		—		1,500		1,500
	Other (c)		—		—		—		—		250		250
	Total short-term borrowings		$	3,376	$	1,879	$	5,255	$	3,225	$	5,320	$	8,545
	(a)	Refer to Note 13 for further details on assets restricted as collateral for payment of the related debt.
	(b)	We periodically enter into term repurchase agreements, short-term borrowing arrangements in which we sell financial instruments to one or more investors while simultaneously committing to repurchase them at a specified future date, at the stated price plus accrued interest. The financial instruments sold under agreement to repurchase typically consist of U.S. government and agency securities.
	(c)	Other relates to secured borrowings at Corporate Finance at December 31, 2013.

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Long-term Debt, Unclassified [Abstract]	'
Long-term Debt Portfolio [Table Text Block]	'
	The following table presents the composition of our long-term debt portfolio.
			September 30, 2014									December 31, 2013
	($ in millions)		Unsecured			Secured			Total			Unsecured			Secured			Total
	Long-term debt
	Due within one year		$	6,572		$	11,798		$	18,370		$	5,321		$	11,851		$	17,172
	Due after one year (a)		17,065			31,450			48,515			21,425			30,423			51,848
	Fair value adjustment (b)		414			—			414			445			—			445
	Total long-term debt		$	24,051		$	43,248		$	67,299		$	27,191		$	42,274		$	69,465
	(a)	Includes $2.6 billion of trust preferred securities at both September 30, 2014 and December 31, 2013, respectively.
	(b)	Represents the fair value adjustment associated with the application of hedge accounting on certain of our long-term unsecured debt positions. Refer to Note 19 for additional information.
Scheduled Remaining Maturity of Long-term Debt [Table Text Block]	'
	The following table presents the scheduled remaining maturity of long-term debt, assuming no early redemptions will occur. The actual payment of secured debt may vary based on the payment activity of the related pledged assets.
	Year ended December 31, ($ in millions)		2014			2015			2016			2017			2018			2019 and			Fair value		Total
																		thereafter			adjustment
	Unsecured
	Long-term debt		$	1,746		$	4,920		$	1,934		$	4,377		$	1,278		$	10,837		$	414	$	25,506
	Original issue discount		(40		)	(58		)	(68		)	(80		)	(93		)	(1,116		)	—		(1,455		)
	Total unsecured		1,706			4,862			1,866			4,297			1,185			9,721			414		24,051
	Secured
	Long-term debt		2,848			12,832			10,408			9,699			3,778			3,683			—		43,248
	Total long-term debt		$	4,554		$	17,694		$	12,274		$	13,996		$	4,963		$	13,404		$	414	$	67,299
Pledged assets for the payment of the related secured borrowings and repurchase agreements [Table Text Block]	'
	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.
			September 30, 2014						December 31, 2013
	($ in millions)		Total			Ally Bank (a)			Total			Ally Bank (a)
	Investment securities		$	584		$	584		$	2,864		$	2,864
	Mortgage finance receivables and loans		7,708			7,708			8,524			8,524
	Consumer automobile finance receivables		33,749			12,047			32,947			12,332
	Commercial automobile finance receivables		19,286			18,770			21,249			21,249
	Investment in operating leases, net		4,925			3,967			5,810			3,190
	Other assets		—			—			563			—
	Total assets restricted as collateral (b)(c)		$	66,252		$	43,076		$	71,957		$	48,159
	Secured debt (d)		$	45,127		$	24,420		$	47,594		$	27,818
	(a)	Ally Bank is a component of the total column.
	(b)	Ally Bank has an advance agreement with the Federal Home Loan Bank of Pittsburgh (FHLB) and had assets pledged to secure borrowings that were restricted as collateral to the FHLB totaling $10.7 billion and $12.7 billion at September 30, 2014, and December 31, 2013, respectively. These assets were composed primarily of consumer mortgage finance receivables and loans, net. Ally Bank has access to the Federal Reserve Bank Discount Window. Ally Bank had assets pledged and restricted as collateral to the Federal Reserve Bank totaling $3.3 billion and $3.2 billion at September 30, 2014, and December 31, 2013, respectively. These assets were composed of consumer automobile finance receivables and loans, net and investment in operating leases, net. 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.
	(c)	Excludes restricted cash and cash reserves for securitization trusts recorded within other assets on the Condensed Consolidated Balance Sheet. Refer to Note 10 for additional information.
	(d)	Includes $1.9 billion and $5.3 billion of short-term borrowings at September 30, 2014, and December 31, 2013, respectively.
Schedule Of Committed Funding Facilities [Table Text Block]	'
			Outstanding						Unused Capacity (a)						Total Capacity
	($ in millions)		September 30, 2014			December 31, 2013			September 30, 2014			December 31, 2013			September 30, 2014			December 31, 2013
	Bank funding
	Secured		$	3,000		$	2,750		$	500		$	250		$	3,500		$	3,000
	Parent funding
	Secured (b)		14,613			15,159			4,517			6,497			19,130			21,656
	Total committed facilities		$	17,613		$	17,909		$	5,017		$	6,747		$	22,630		$	24,656
	(a)	Funding from committed secured facilities is available on request in the event excess collateral resides in certain facilities or is available to the extent incremental collateral is available and contributed to the facilities.
	(b)	Includes the secured facility of Corporate Finance at December 31, 2013.

Accrued_Expenses_and_Other_Lia1

Accrued Expenses and Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2014
Accounts Payable and Accrued Liabilities [Abstract]	'
Schedule of Accrued Liabilities [Table Text Block]	'
	The components of accrued expenses and other liabilities were as follows.
	($ in millions)	September 30, 2014		December 31, 2013
	Accounts payable	$	333	$	414
	Fair value of derivative contracts in payable position (a)	299		317
	Employee compensation and benefits	255		437
	Reserves for insurance losses and loss adjustment expenses	229		275
	Deferred revenue	147		122
	Collateral received from counterparties	17		159
	Other liabilities (b)	409		673
	Total accrued expenses and other liabilities	$	1,689	$	2,397
	(a)	For additional information on derivative instruments and hedging activities, refer to Note 19.
	(b)	Included $150 million accrual for insurance proceeds to be contributed to the ResCap estate at December 31, 2013. The outstanding accrual was paid in April 2014.

Preferred_Stock_Tables

Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2014
Preferred Stock, Including Additional Paid in Capital [Abstract]	'
Schedule of Stock by Class [Table Text Block]	'
	The following table summarizes information about our Series A and Series G preferred stock.
			September 30, 2014			December 31, 2013
	Preferred stock
	Series A preferred stock (a)
	Carrying value ($ in millions)		$	1,021		$	1,021
	Par value (per share)		0.01			0.01
	Liquidation preference (per share)		25			25
	Number of shares authorized (b)		40,870,560			160,870,560
	Number of shares issued and outstanding		40,870,560			40,870,560
	Dividend/coupon
	Prior to May 15, 2016		8.5		%	8.5		%
	On and after May 15, 2016		Three month			Three month
			LIBOR + 6.243%			LIBOR + 6.243%
	Series G preferred stock (c)
	Carrying value ($ in millions)		$	234		$	234
	Par value (per share)		0.01			0.01
	Liquidation preference (per share)		1,000			1,000
	Number of shares authorized		2,576,601			2,576,601
	Number of shares issued and outstanding		2,576,601			2,576,601
	Dividend/coupon		7		%	7		%
	(a)	Nonredeemable prior to May 15, 2016.
	(b)	Refer to Note 1 for additional information related to a change in number of shares authorized, which occurred on April 9, 2014.
	(c)	Redeemable beginning at December 31, 2011.

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
	The following table presents changes, net of tax, in each component of accumulated other comprehensive income (loss).
	($ in millions)	Unrealized gains				Translation adjustments and net investment hedges				Cash flow hedges			Defined benefit pension plans			Accumulated other comprehensive income (loss)
		(losses) on investment securities
	Balance at December 31, 2012	$	76			$	368			$	2		$	(135	)	$	311
	2013 net change	(323		)		(216		)		3			42			(494		)
	Balance at September 30, 2013	$	(247	)		$	152			$	5		$	(93	)	$	(183	)
	Balance at December 31, 2013	$	(269	)		$	65			$	5		$	(77	)	$	(276	)
	2014 net change	148				(27		)		1			4			126
	Balance at September 30, 2014	$	(121	)		$	38			$	6		$	(73	)	$	(150	)
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	'
	The following tables present the before- and after-tax changes in each component of accumulated other comprehensive income (loss).
	Three months ended September 30, 2014 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized losses arising during the period	$	(15	)		$	5			$	(10	)
	Less: Net realized gains reclassified to income from continuing operations	45			(a)	(1		)	(b)	44
	Net change	(60		)		6				(54		)
	Translation adjustments
	Net unrealized losses arising during the period	(11		)		4				(7		)
	Net investment hedges
	Net unrealized gains arising during the period	8				(3		)		5
	Cash flow hedges
	Net unrealized gains arising during the period	1				—				1
	Other comprehensive loss	$	(62	)		$	7			$	(55	)
	(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
	(b)	Includes amounts reclassified to income tax expense (benefit) from continuing operations in our Condensed Consolidated Statement of Comprehensive Income.
	Three months ended September 30, 2013 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized gains arising during the period	$	46			$	7			$	53
	Less: Net realized gains reclassified to income from continuing operations	41			(a)	—				41
	Net change	5				7				12
	Translation adjustments
	Net unrealized gains arising during the period	5				(2		)		3
	Net investment hedges
	Net unrealized losses arising during the period	(14		)		6				(8		)
	Cash flow hedges
	Net unrealized losses arising during the period	(4		)		1				(3		)
	Other comprehensive (loss) income	$	(8	)		$	12			$	4
	(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
	Nine months ended September 30, 2014 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized gains arising during the period	$	358			$	(89	)		$	269
	Less: Net realized gains reclassified to income from continuing operations	129			(a)	(8		)	(b)	121
	Net change	229				(81		)		148
	Translation adjustments
	Net unrealized losses arising during the period	(21		)		8				(13		)
	Less: Net realized gains reclassified to income from discontinued operations, net of tax	23				(3		)		20
	Net change	(44		)		11				(33		)
	Net investment hedges
	Net unrealized gains arising during the period	10				(4		)		6
	Cash flow hedges
	Net unrealized gains arising during the period	1				—				1
	Defined benefit pension plans
	Less: Net losses reclassified to income from continuing operations	(7		)	(c)	3				(4		)
	Other comprehensive income	$	203			$	(77	)		$	126
	(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
	(b)	Includes amounts reclassified to income tax expense (benefit) from continuing operations in our Condensed Consolidated Statement of Comprehensive Income.
	(c)	Includes losses reclassified to compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income.
	Nine months ended September 30, 2013 ($ in millions)	Before Tax				Tax Effect				After Tax
	Investment securities
	Net unrealized losses arising during the period	$	(289	)		$	128			$	(161	)
	Less: Net realized gains reclassified to income from continuing operations	156			(a)	(2		)	(b)	154
	Less: Net realized gains reclassified to income from discontinued operations, net of tax	10				(2		)		8
	Net change	(455		)		132				(323		)
	Translation adjustments
	Net unrealized losses arising during the period	(98		)		21				(77		)
	Less: Net realized gains reclassified to income from discontinued operations, net of tax	345				2				347
	Net change	(443		)		19				(424		)
	Net investment hedges
	Net unrealized gains arising during the period	52				(19		)		33
	Less: Net realized losses reclassified to income from discontinued operations, net of tax	(261		)		86				(175		)
	Net change	313				(105		)		208
	Cash flow hedges
	Net unrealized gains arising during the period	(1		)		—				(1		)
Less: Net realized losses reclassified to income from continuing operations	(7		)	(c)	3			(b)	(4		)
Net change	6				(3		)		3
Defined benefit pension plans
Net unrealized gains, prior service costs, and transition obligation arising during the period	2				—				2
Less: Net losses reclassified to income from continuing operations	(2		)	(d)	—				(2		)
Less: Net losses reclassified to income from discontinued operations, net of tax	(49		)		11				(38		)
Net change	53				(11		)		42
Other comprehensive loss	$	(526	)		$	32			$	(494	)
(a)	Includes gains reclassified to other gain on investments, net in our Condensed Consolidated Statement of Comprehensive Income.
(b)	Includes amounts reclassified to income tax expense (benefit) from continuing operations in our Condensed Consolidated Statement of Comprehensive Income.
(c)	Includes losses reclassified to interest on long-term debt in our Condensed Consolidated Statement of Comprehensive Income.
(d)	Includes losses reclassified to compensation and benefits expense in our Condensed Consolidated Statement of Comprehensive Income.

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	'
	The following table presents the calculation of basic and diluted earnings per common share.
			Three months ended						Nine months ended
			September 30,						September 30,
	($ in millions, except share data)		2014			2013			2014			2013
	Net income from continuing operations		$	293		$	177		$	774		$	337
	Preferred stock dividends — U.S. Department of the Treasury		—			(134		)	—			(401		)
	Preferred stock dividends		(67		)	(67		)	(200		)	(200		)
	Net income (loss) from continuing operations attributable to common shareholders		226			(24		)	574			(264		)
	Income (loss) from discontinued operations, net of tax		130			(86		)	199			(80		)
	Net income (loss) attributable to common shareholders		$	356		$	(110	)	$	773		$	(344	)
	Basic weighted-average common shares outstanding (a)		481,611,138			412,600,700			480,916,395			412,600,700
	Diluted weighted-average common shares outstanding (a) (b)		482,506,091			412,600,700			481,545,506			412,600,700
	Basic earnings per common share
	Net income (loss) from continuing operations		$	0.47		$	(0.06	)	$	1.19		$	(0.64	)
	Income (loss) from discontinued operations, net of tax		0.27			(0.21		)	0.41			(0.19		)
	Net income (loss)		$	0.74		$	(0.27	)	$	1.6		$	(0.83	)
	Diluted earnings per common share
	Net income (loss) from continuing operations		$	0.47		$	(0.06	)	$	1.19		$	(0.64	)
	Income (loss) from discontinued operations, net of tax		0.27			(0.21		)	0.41			(0.19		)
	Net income (loss)		$	0.74		$	(0.27	)	$	1.6		$	(0.83	)
	(a)	Includes shares related to share-based compensation that have vested but have not been issued for the three months and nine months ended September 30, 2014.
	(b)	Due to the antidilutive effect of converting the Fixed Rate Cumulative Mandatorily Convertible Preferred Stock into common shares for the three months and nine months ended September 30, 2013 and the net loss from continuing operations attributable to common shareholders for the three months and nine months ended September 30, 2013, net income (loss) from continuing operations attributable to common shareholders and basic weighted-average common shares outstanding were used to calculate basic and diluted earnings per share.

Regulatory_Capital_Tables

Regulatory Capital (Tables)	9 Months Ended
	Sep. 30, 2014
Regulatory Capital Requirements [Abstract]	'
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]	'
	The following table summarizes our capital ratios.
		September 30, 2014				December 31, 2013				Required			Well-capitalized
	($ in millions)	Amount		Ratio		Amount		Ratio		minimum			minimum
	Risk-based capital
	Tier 1 (to risk-weighted assets)
	Ally Financial Inc.	$	16,227	12.65	%	$	15,165	11.79	%	4	%		6	%
	Ally Bank	15,898		17.32		15,159		16.73		4			6
	Total (to risk-weighted assets)
	Ally Financial Inc.	$	17,275	13.47	%	$	16,405	12.76	%	8	%		10	%
	Ally Bank	16,493		17.97		15,809		17.45		8			10
	Tier 1 leverage (to adjusted quarterly average assets) (a)
	Ally Financial Inc.	$	16,227	10.91	%	$	15,165	10.23	%	3.00–4.00%			(b)
	Ally Bank	15,898		15.71		15,159		15.77		15		(c)	5	%
	Tier 1 common (to risk-weighted assets)
	Ally Financial Inc.	$	12,427	9.69	%	$	11,366	8.84	%	n/a			n/a
	Ally Bank	15,898		17.32		15,159		16.73		n/a			n/a
	n/a =160;not applicable
	(a)	Federal regulatory reporting guidelines require the calculation of adjusted quarterly average assets using a daily average methodology.
	(b)	There is no Tier 1 leverage component in the definition of "well-capitalized" for a bank holding company.
	(c)	Ally Bank, in accordance with the CLMA, is required to maintain a Tier 1 leverage ratio of at least 15%.

Recovered_Sheet1

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair Value Amounts of Derivative Instruments Reported On Our Condensed Consolidated Balance Sheet [Table Text Block]	'
	The following table summarizes the fair value amounts of derivative instruments reported on our Condensed Consolidated Balance Sheet. The fair value 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. At September 30, 2014 and December 31, 2013, $235 million and $362 million, respectively, of the derivative contracts in a receivable position were classified as other assets on the Condensed Consolidated Balance Sheet. At September 30, 2014 and December 31, 2013, $299 million and $317 million of derivative contracts in a liability position were classified as accrued expenses and other liabilities on the Condensed Consolidated Balance Sheet.
			September 30, 2014									December 31, 2013
			Derivative contracts in a						Notional			Derivative contracts in a					Notional
	($ in millions)		receivable			payable			amount			receivable position (a)			payable		amount
			position (a)			position (b)									position (b)
	Derivatives qualifying for hedge accounting
	Interest rate contracts
	Swaps (c)		$	71		$	51		$	19,959		$	204		$	169	$	21,606
	Foreign exchange contracts
	Forwards		3			—			304			3			—		326
	Total derivatives qualifying for hedge accounting		74			51			20,263			207			169		21,932
	Economic hedges
	Interest rate contracts
	Swaps		33			49			12,649			36			44		13,613
	Futures and forwards		6			—			12,253			11			3		29,836
	Written options		—			94			28,651			—			94		11,132
	Purchased options		95			—			30,097			95			—		22,962
	Total interest rate risk		134			143			83,650			142			141		77,543
	Foreign exchange contracts
	Swaps		15			92			1,263			12			1		1,379
	Futures and forwards		7			4			286			1			1		330
	Written options		—			—			—			—			—		17
	Purchased options		—			—			—			—			—		17
	Total foreign exchange risk		22			96			1,549			13			2		1,743
	Equity contracts
	Forwards		—			6			89			—			—		—
	Written options		—			3			1			—			5		3
	Purchased options		5			—			—			—			—		—
	Total equity risk		5			9			90			—			5		3
	Total economic hedges		161			248			85,289			155			148		79,289
	Total derivatives		$	235		$	299		$	105,552		$	362		$	317	$	101,221
	(a)	Includes accrued interest of $51 million and $120 million at September 30, 2014 and December 31, 2013, respectively.
	(b)	Includes accrued interest of $9 million and $12 million at September 30, 2014 and December 31, 2013, respectively.
	(c)	Includes fair value hedges consisting of receive-fixed swaps on fixed-rate debt obligations with $43 million and $196 million in a receivable position, $46 million and $163 million in a payable position, and of a $5.9 billion and $8.5 billion notional amount at September 30, 2014 and December 31, 2013, respectively. Other fair value hedges include pay-fixed swaps on portfolios of held-for-investment automotive loan assets with $28 million and $9 million in a receivable position, $5 million and $5 million in a payable position, and of a $14.1 billion and $12.6 billion notional amount at September 30, 2014 and December 31, 2013, respectively. Also includes cash flow hedges consisting of pay-fixed swaps on floating rate debt obligations with $1 million in a payable position, and of a $495 million notional amount at December 31, 2013.
Gains and Losses On Derivative Instruments Reported in Statement of Comprehensive Income [Table Text Block]	'
	The following table summarizes the location and amounts of gains and losses on derivative instruments reported in our Condensed Consolidated Statement of Comprehensive Income.
			Three months ended September 30,						Nine months ended September 30,
	($ in millions)		2014			2013			2014			2013
	Derivatives qualifying for hedge accounting
	Gain (loss) recognized in earnings on derivatives
	Interest rate contracts
	Interest and fees on finance receivables and loans (a)		$	28		$	3		$	22		$	3
	Interest on long-term debt (b)		(39		)	11			102			(302		)
	(Loss) gain recognized in earnings on hedged items (c)
	Interest rate contracts
	Interest and fees on finance receivables and loans		(15		)	(3		)	14			(3		)
	Interest on long-term debt		49			(15		)	(90		)	311
	Total derivatives qualifying for hedge accounting		23			(4		)	48			9
	Economic derivatives
	(Loss) gain recognized in earnings on derivatives
	Interest rate contracts
	Servicing asset valuation and hedge activities, net		—			—			—			(112		)
	Loss on mortgage and automotive loans, net		—			—			—			(37		)
	Other income, net of losses		(5		)	20			(24		)	26
	Total interest rate contracts		(5		)	20			(24		)	(123		)
	Foreign exchange contracts (d)
	Interest on long-term debt		(108		)	52			(117		)	71
	Other income, net of losses		8			(4		)	8			25
	Total foreign exchange contracts		(100		)	48			(109		)	96
	Equity contracts
	Compensation and benefits expense		(6		)	—			(6		)	—
	Total equity contracts		(6		)	—			(6		)	—
	(Loss) gain recognized in earnings on derivatives		$	(88	)	$	64		$	(91	)	$	(18	)
	(a)	Amounts exclude losses related to interest for qualifying accounting hedges of portfolios of retail automotive loans held-for-investment of $16 million and $1 million for the three months ended September 30, 2014 and 2013, respectively, and $43 million and $1 million for the nine months ended September 30, 2014 and 2013, respectively. These losses are primarily offset by the fixed coupon receipts on the retail automotive loans held-for-investment.
	(b)	Amounts exclude gains related to interest for qualifying accounting hedges of debt, which are primarily offset by the fixed coupon payment on the long-term debt. The gains were $27 million and $33 million for the three months ended September 30, 2014 and 2013, respectively, and $89 million and $94 million for the nine months ended September 30, 2014 and 2013, respectively.
	(c)	Amounts exclude gains related to amortization of deferred basis adjustments on the de-designated hedged item of $38 million and $112 million for the three months ended September 30, 2014 and 2013, respectively, and $120 million and $188 million for the nine months ended September 30, 2014 and 2013, respectively.
	(d)	Amounts exclude gains and losses related to the revaluation of the related foreign-denominated debt or receivable. Gains of $102 million and losses of $47 million were recognized for the three months ended September 30, 2014 and 2013, respectively. Gains of $112 million and losses of $94 million were recognized for the nine months ended September 30, 2014 and 2013, respectively.
Derivative Instruments Used in Cash Flow and Net Investment Hedge Accounting Relationships [Table Text Block]	'
	The following table summarizes derivative instruments used in cash flow and net investment hedge accounting relationships.
			Three months ended September 30,						Nine months ended September 30,
	($ in millions)		2014			2013			2014			2013
	Cash flow hedges
	Interest rate contracts
	Loss reclassified from accumulated other comprehensive income to interest on long-term debt (a)		$	(1	)	$	—		$	(1	)	$	(7	)
	Gain recorded directly to interest on long-term debt		—			—			—			1
	Total interest on long-term debt		$	(1	)	$	—		$	(1	)	$	(6	)
	Gain (loss) recognized in other comprehensive income		$	1		$	(4	)	$	1		$	6
	Net investment hedges
	Foreign exchange contracts
	Loss reclassified from accumulated other comprehensive income (loss) to income from discontinued operations, net		$	—		$	—		$	—		$	(261	)
	Total loss from discontinued operations, net		$	—		$	—		$	—		$	(261	)
	Gain (loss) recognized in other comprehensive income (b)		$	8		$	(14	)	$	10		$	313
	(a)	The amount represents losses reclassified from other comprehensive income (OCI) into earnings as a result of the discontinuance of hedge accounting because it is probable that the forecasted transaction will not occur.
	(b)	The amounts represent the effective portion of net investment hedges. There are offsetting amounts recognized in accumulated other comprehensive income related to the revaluation of the related net investment in foreign operations. There were losses of $10 million and gains of $9 million for the three months ended September 30, 2014 and 2013, respectively. There were losses of $37 million and $530 million for the nine months ended September 30, 2014 and 2013, respectively.

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements - Recurring Basis [Table Text Block]	'
	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
	September 30, 2014 ($ in millions)		Level 1				Level 2				Level 3				Total
	Assets
	Investment securities
	Available-for-sale securities
	Debt securities
	U.S. Treasury and federal agencies		$	332			$	954			$	—			$	1,286
	U.S. State and political subdivisions		—				402				—				402
	Foreign government		10				222				—				232
	Mortgage-backed residential		—				10,884				—				10,884
	Mortgage-backed commercial		—				212				—				212
	Asset-backed		—				1,987				—				1,987
	Corporate debt securities		—				983				—				983
	Total debt securities		342				15,644				—				15,986
	Equity securities (a)		728				—				—				728
	Total available-for-sale securities		1,070				15,644				—				16,714
	Mortgage loans held-for-sale, net (b)		—				3				—				3
	Other assets
	Interests retained in financial asset sales		—				—				61				61
	Derivative contracts in a receivable position (c)
	Interest rate		38				167				—				205
	Foreign currency		—				25				—				25
	Other		5				—				—				5
	Total derivative contracts in a receivable position		43				192				—				235
	Collateral placed with counterparties		—				81				—				81
	Total assets		$	1,113			$	15,920			$	61			$	17,094
	Liabilities
	Accrued expenses and other liabilities
	Derivative contracts in a payable position
	Interest rate		$	(42	)		$	(152	)		$	—			$	(194	)
	Foreign currency		—				(96		)		—				(96		)
	Other		(3		)		(6		)		—				(9		)
	Total derivative contracts in a payable position (c)		(45		)		(254		)		—				(299		)
	Other liabilities		(95		)		—				—				(95		)
	Total liabilities		$	(140	)		$	(254	)		$	—			$	(394	)
	(a)	Our investment in any one industry did not exceed 19%.
	(b)	Carried at fair value due to fair value option elections.
	(c)	For additional information on derivative instruments and hedging activities, refer to Note 19.
			Recurring fair value measurements
	December 31, 2013 ($ in millions)		Level 1				Level 2				Level 3				Total
	Assets
	Investment securities
	Available-for-sale securities
	Debt securities
	U.S. Treasury and federal agencies		$	310			$	1,117			$	—			$	1,427
	U.S. State and political subdivisions		—				315				—				315
	Foreign government		7				281				—				288
	Mortgage-backed residential		—				10,782				—				10,782
	Mortgage-backed commercial		—				39				—				39
	Asset-backed		—				2,219				—				2,219
	Corporate debt securities		—				1,069				—				1,069
	Total debt securities		317				15,822				—				16,139
	Equity securities (a)		944				—				—				944
	Total available-for-sale securities		1,261				15,822				—				17,083
	Mortgage loans held-for-sale, net (b)		—				16				—				16
	Other assets
	Interests retained in financial asset sales		—				—				100				100
	Derivative contracts in a receivable position (c)
	Interest rate		46				207				93				346
	Foreign currency		—				16				—				16
	Total derivative contracts in a receivable position		46				223				93				362
	Collateral placed with counterparties		—				133				—				133
Total assets		$	1,307			$	16,194			$	193			$	17,694
Liabilities
Accrued expenses and other liabilities
Derivative contracts in a payable position (c)
Interest rate		$	(15	)		$	(201	)		$	(94	)		$	(310	)
Foreign currency		—				(2		)		—				(2		)
Other		(5		)		—				—				(5		)
Total derivative contracts in a payable position		(20		)		(203		)		(94		)		(317		)
Total liabilities		$	(20	)		$	(203	)		$	(94	)		$	(317	)
(a)	Our investment in any one industry did not exceed 19%.
(b)	Carried at fair value due to fair value option elections.
(c)	For additional information on derivative instruments and hedging activities, refer to Note 19.
Fair Value Measurements - Reconciliation of Level 3 Assets and Liabilities [Table Text Block]	'
	The following tables present the reconciliation for all Level 3 assets and liabilities measured at fair value on a recurring basis. 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																						Fair value at September 30, 2014		Net unrealized gains included in earnings still held at
					gains																								30-Sep-14
	($ in millions)	Fair value at July 1, 2014			included				included			Purchases			Sales			Issuances			Settlements			Transfers out of Level 3
					in  earnings				in OCI
	Assets
	Other assets
	Interests retained in financial asset sales	$	74		$	4		(a)	$	—		$	—		$	—		$	—		$	(17	)	$	—		$	61	$	—
	Total assets	$	74		$	4			$	—		$	—		$	—		$	—		$	(17	)	$	—		$	61	$	—
	(a)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
		Level 3 recurring fair value measurements
		Fair value at July 1, 2013			Net realized/unrealized							Purchases			Sales			Issuances			Settlements			Fair value at September 30, 2013			Net unrealized
					(losses) gains																						losses included in
																											earnings still held at
	($ in millions)				included				included in OCI																		30-Sep-13
					in
					earnings
	Assets
	Other assets
	Interests retained in financial asset sales	$	124		$	8		(a)	$	—		$	—		$	—		$	—		$	(11	)	$	121		$	—
	Derivative contracts, net
	Foreign currency	(9		)	47			(b)	—			—			—			—			19			57			47		(b)
	Total derivative contracts in a receivable position, net	(9		)	47				—			—			—			—			19			57			47
	Total assets	$	115		$	55			$	—		$	—		$	—		$	—		$	8		$	178		$	47
	(a)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
	(b)	Refer to Note 19 for information related to the location of the gains and losses on derivative instruments in the Condensed Consolidated Statement of Comprehensive Income.
		Level 3 recurring fair value measurements
					Net realized/unrealized																						Fair value at September 30, 2014		Net unrealized gains included in earnings still held at
					gains																								30-Sep-14
	($ in millions)	Fair value at Jan. 1, 2014			included				included			Purchases			Sales			Issuances			Settlements			Transfers out of Level 3
					in  earnings				in OCI
	Assets
	Other assets
	Interests retained in financial asset sales	$	100		$	9		(a)	$	—		$	—		$	—		$	—		$	(48	)	$	—		$	61	$	—
	Interest rate derivative contracts, net	(1		)	—				—			—			—			—			(2		)	3			—		—
	Total assets	$	99		$	9			$	—		$	—		$	—		$	—		$	(50	)	$	3		$	61	$	—
	(a)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
		Level 3 recurring fair value measurements
		Fair value at Jan. 1, 2013			Net realized/unrealized							Purchases			Sales			Issuances			Settlements			Fair value at September 30, 2013			Net unrealized
					(losses) gains																						losses included in
																											earnings still held at
	($ in millions)				included				included in OCI																		30-Sep-13
					in
					earnings
	Assets
	Mortgage servicing rights	$	952		$	(101	)	(a)	$	—		$	—		$	(911	)	$	60		$	—		$	—		$	—
	Other assets
	Interests retained in financial asset sales	154			19			(b)	—			—			—			—			(52		)	121			—
	Derivative contracts, net
	Interest rate	47			(51		)	(c)	—			—			—			—			4			—			—		(c)
	Foreign currency	(2		)	40			(c)	—			—			—			—			19			57			38		(c)
	Total derivative contracts in a receivable position, net	45			(11		)		—			—			—			—			23			57			38
	Total assets	$	1,151		$	(93	)		$	—		$	—		$	(911	)	$	60		$	(29	)	$	178		$	38
	(a)	Fair value adjustment was reported as servicing-asset valuation and hedge activities, net, in the Condensed Consolidated Statement of Comprehensive Income.
	(b)	Reported as other income, net of losses, in the Condensed Consolidated Statement of Comprehensive Income.
	(c)	Refer to Note 19 for information related to the location of the gains and losses on derivative instruments in the Condensed Consolidated Statement of Comprehensive Income.
Fair Value Measurements - Nonrecurring Basis [Table Text Block]	'
	The following tables display the assets and liabilities measured at fair value on a nonrecurring basis.
			Nonrecurring																Lower-of-cost				Total gain				Total gain
			fair value measurements																or				included in				included in
																			fair value				earnings for				earnings for
																			or valuation				the three				the nine months ended
																			reserve				months ended
	September 30, 2014 ($ in millions)		Level 1				Level 2				Level 3				Total				allowance
	Assets
	Commercial finance receivables and loans, net (a)
	Automotive		$	—			$	—			$	16			$	16			$	(1	)		n/m			(b)	n/m		(b)
	Other		—				—				37				37				(14		)		n/m			(b)	n/m		(b)
	Total commercial finance receivables and loans, net		—				—				53				53				(15		)		n/m			(b)	n/m		(b)
	Other assets
	Repossessed and foreclosed assets (c)		—				—				8				8				(3		)		n/m			(b)	n/m		(b)
	Other		—				—				2				2				—				$	—			$	—
	Total assets		$	—			$	—			$	63			$	63			$	(18	)		n/m				n/m
	n/m =ot meaningful
	(a)	Represents the portion of the portfolio specifically impaired during 2014. The related valuation allowance represents the cumulative adjustment to fair value of those specific receivables.
	(b)	We consider the applicable valuation or loan loss allowance 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 or loan loss allowance.
	(c)	The allowance provided for repossessed and foreclosed assets represents any cumulative valuation adjustment recognized to adjust the assets to fair value.
			Nonrecurring																Lower-of-cost				Total loss included in		Total loss
			fair value measurements																or				earnings for		included in
																			fair value				the three		earnings for
																			or valuation				months ended		the nine months ended
																			reserve
	September 30, 2013 ($ in millions)		Level 1				Level 2				Level 3				Total				allowance
	Assets
	Loans held-for-sale		$	—			$	—			$	19			$	19			$	—			n/m	(a)	n/m	(a)
	Commercial finance receivables and loans, net (b)
	Automotive		—				—				95				95				(17		)		n/m	(a)	n/m	(a)
	Other		—				—				63				63				(11		)		n/m	(a)	n/m	(a)
	Total commercial finance receivables and loans, net		—				—				158				158				(28		)		n/m	(a)	n/m	(a)
	Other assets
	Repossessed and foreclosed assets (c)		—				—				7				7				(2		)		n/m	(a)	n/m	(a)
	Other		—				—				2				2				—				n/m	(a)	n/m	(a)
	Total assets		$	—			$	—			$	186			$	186			$	(30	)		n/m		n/m
	n/m =ot meaningful
	(a)	We consider the applicable valuation or loan loss allowance 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 or loan loss allowance.
	(b)	Represents the portion of the portfolio specifically impaired during 2013. 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.
Fair Value Measurements - Nonrecurring Fair Value Inputs [Table Text Block]	'
	The following table presents quantitative information regarding the significant unobservable inputs used in significant Level 3 assets measured at fair value on a nonrecurring basis.
	September 30, 2014 ($ in millions)		Level 3 nonrecurring measurements				Valuation technique		Unobservable input		Range
	Assets
	Commercial finance receivables and loans, net
	Automotive		$	16			Fair value of collateral		Adjusted appraisal value		65.0-95.0%
	Other		37				Discounted cash flow		Non-public/non-rated credits		91.0-109.0%
Fair Value Option - Summary of Changes Included in the Condensed Consolidated Statement of Income [Table Text Block]	'
	The following tables summarize the fair value option elections and information regarding the amounts recorded as earnings for each fair value option-elected item.
			Changes included in the
			Condensed Consolidated
			Statement of Comprehensive Income
	Three months ended September 30, ($ in millions)		Interest				Gain (loss) on mortgage				Total
			on loans				loans, net				included in
			held-for-sale (a)								earnings
	2014
	Assets
	Mortgage loans held-for-sale, net		$	—			$	—			$	—
	2013
	Assets
	Mortgage loans held-for-sale, net		$	—			$	14			$	14		(b)
	(a)	Interest income is measured by multiplying the unpaid principal balance on the loans by the coupon rate and the number of days of interest due.
	(b)	The credit impact for loans held-for-sale is assumed to be zero because the loans are either suitable for sale or are covered by a government guarantee.
			Changes included in the
			Condensed Consolidated
			Statement of Comprehensive Income
	Nine months ended September 30, ($ in millions)		Interest				Gain on mortgage				Total
			on loans				loans, net				included in
			held-for-sale (a)								earnings
	2014
	Assets
	Mortgage loans held-for-sale, net		$	—			$	1			$	1
	2013
	Assets
	Mortgage loans held-for-sale, net		$	19			$	(35	)		$	(16	)	(b)
	(a)    Interest income is measured by multiplying the unpaid principal balance on the loans by the coupon rate and the number of days of interest due.
	(b)    The credit impact for loans held-for-sale is assumed to be zero because the loans are either suitable for sale or are covered by a government guarantee.
Fair Value Option Election [Table Text Block]	'
	The following table provides the aggregate fair value and the aggregate unpaid principal balance for the fair value option-elected loans.
			September 30, 2014								December 31, 2013
	($ in millions)		Unpaid				Fair				Unpaid				Fair
			principal				value (a)				principal				value (a)
			balance								balance
	Assets
	Mortgage loans held-for-sale, net
	Total loans		$	7			$	3			$	31			$	16
	Nonaccrual loans		3				2				18				9
	Loans 90+ days past due (b)		3				2				15				8
	(a)	Excludes accrued interest receivable.
	(b)	Loans 90+ days past due are also presented within the nonaccrual loan balance and the total loan balance; however, excludes government-insured loans that are still accruing interest
Fair Value of Financial Intruments [Table Text Block]	'
	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 market data to develop estimates of fair value, so the estimates are not necessarily indicative of the amounts that could be realized or would be paid in a current market exchange. The effect of using different market assumptions or estimation methodologies could be material to the estimated fair values. Fair value information presented herein was based on information available at September 30, 2014 and December 31, 2013.
						Estimated fair value
	($ in millions)	Carrying				Level 1				Level 2				Level 3				Total
		value
	September 30, 2014
	Financial assets
	Loans held-for-sale, net (a)	$	3			$	—			$	3			$	—			$	3
	Finance receivables and loans, net (a)	98,405				—				—				99,733				99,733
	Nonmarketable equity investments	275				—				245				51				296
	Financial liabilities
	Deposit liabilities	$	56,851			$	—			$	—			$	57,371			$	57,371
	Short-term borrowings	5,255				—				—				5,255				5,255
	Long-term debt (a)	67,299				—				26,945				43,233				70,178
	December 31, 2013
	Financial assets
	Loans held-for-sale, net (a)	$	35			$	—			$	17			$	18			$	35
	Finance receivables and loans, net (a)	99,120				—				—				100,090				100,090
	Nonmarketable equity investments	337				—				308				38				346
	Financial liabilities
	Deposit liabilities	$	53,350			$	—			$	—			$	54,070			$	54,070
	Short-term borrowings	8,545				—				—				8,545				8,545
	Long-term debt (a)(b)	69,824				—				31,067				42,297				73,364
	(a)	Includes financial instruments carried at fair value due to fair value option elections. Refer to the previous section of this note titled Fair Value Option for Financial Assets and Liabilities for further information about the fair value elections.
	(b)	The carrying value includes deferred interest for zero-coupon bonds of $359 million at December 31, 2013.

Offsetting_Assets_and_Liabilit1

Offsetting Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2014
Offsetting [Abstract]	'
Offsetting Assets and Liabilities [Table Text Block]	'
	The composition of offsetting derivative instruments, financial assets, and financial liabilities was as follows.
			Gross Amounts of Recognized Assets/(Liabilities)			Gross Amounts Offset in the Condensed Consolidated Balance Sheet		Net Amounts of Assets/(Liabilities) Presented in the Condensed Consolidated Balance Sheet
											Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet
	September 30, 2014 ($ in millions)										Financial Instruments			Collateral (a)			Net Amount
	Assets
	Derivative assets in net asset positions		$	115		$	—	$	115		$	(9	)	$	(5	)	$	101
	Derivative assets in net liability positions		120			—		120			(120		)	—			—
	Total assets (b)		$	235		$	—	$	235		$	(129	)	$	(5	)	$	101
	Liabilities
	Derivative liabilities in net liability positions		$	(284	)	$	—	$	(284	)	$	120		$	83		$	(81	)
	Derivative liabilities in net asset positions		(9		)	—		(9		)	9			—			—
	Derivative liabilities with no offsetting arrangements		(6		)	—		(6		)	—			—			(6		)
	Total derivative liabilities (b)		(299		)	—		(299		)	129			83			(87		)
	Securities sold under agreements to repurchase (c)		(579		)	—		(579		)	—			579			—
	Total liabilities		$	(878	)	$	—	$	(878	)	$	129		$	662		$	(87	)
	(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)	For additional information on derivative instruments and hedging activities, refer to Note 19.
	(c)	For additional information on securities sold under agreements to repurchase, refer to Note 12.
			Gross Amounts of Recognized Assets/(Liabilities)			Gross Amounts Offset in the Condensed Consolidated Balance Sheet		Net Amounts of Assets/(Liabilities) Presented in the Condensed Consolidated Balance Sheet
											Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet
	December 31, 2013 ($ in millions)										Financial Instruments			Collateral (a)			Net Amount
	Assets
	Derivative assets in net asset positions		$	319		$	—	$	319		$	(65	)	$	(120	)	$	134
	Derivative assets in net liability positions		43			—		43			(43		)	—			—
	Total assets (b)		$	362		$	—	$	362		$	(108	)	$	(120	)	$	134
	Liabilities
	Derivative liabilities in net liability positions		$	(252	)	$	—	$	(252	)	$	43		$	137		$	(72	)
	Derivative liabilities in net asset positions		(65		)	—		(65		)	65			—			—
	Total derivative liabilities (b)		(317		)	—		(317		)	108			137			(72		)
	Securities sold under agreements to repurchase (c)		(1,500		)	—		(1,500		)	—			1,500			—
	Total liabilities		$	(1,817	)	$	—	$	(1,817	)	$	108		$	1,637		$	(72	)
	(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)	For additional information on derivative instruments and hedging activities, refer to Note 19.
	(c)	For additional information on securities sold under agreements to repurchase, refer to Note 12

Segment_And_Geographic_Informa1

Segment And Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Schedule of Segment Reporting Information, by Segment [Table Text Block]	'
	Financial information for our reportable operating segments is summarized as follows.
	Three months ended September 30,		Automotive Finance operations			Insurance			Mortgage operations			Corporate			Consolidated (b)
	($ in millions)					operations						and
												Other (a)
	2014
	Net financing revenue		$	850		$	16		$	9		$	14		$	889
	Other revenue		69			287			—			19			375
	Total net revenue		919			303			9			33			1,264
	Provision for loan losses		109			—			(7		)	—			102
	Total noninterest expense		395			243			19			85			742
	Income (loss) from continuing operations before income tax expense		$	415		$	60		$	(3	)	$	(52	)	$	420
	Total assets		$	110,937		$	7,178		$	7,402		$	23,678		$	149,195
	2013
	Net financing revenue (loss)		$	800		$	16		$	13		$	(92	)	$	737
	Other revenue		65			293			19			(6		)	371
	Total net revenue (loss)		865			309			32			(98		)	1,108
	Provision for loan losses		150			—			(12		)	3			141
	Total noninterest expense		376			226			48			112			762
	Income (loss) from continuing operations before income tax expense		$	339		$	83		$	(4	)	$	(213	)	$	205
	Total assets		$	108,609		$	7,323		$	8,562		$	26,062		$	150,556
	(a)	Total assets for Corporate Finance were $1.7 billion and $1.6 billion at September 30, 2014 and 2013, respectively.
	(b)	Net financing revenue after the provision for loan losses totaled $787 million and $596 million for the three months ended September 30, 2014 and 2013, respectively.
	Nine months ended September 30,		Automotive Finance operations			Insurance			Mortgage operations			Corporate			Consolidated (b)
	($ in millions)					operations						and
												Other (a)
	2014
	Net financing revenue (loss)		$	2,554		$	47		$	35		$	(60	)	$	2,576
	Other revenue		195			849			13			4			1,061
	Total net revenue (loss)		2,749			896			48			(56		)	3,637
	Provision for loan losses		367			—			(55		)	(10		)	302
	Total noninterest expense		1,167			785			62			262			2,276
	Income (loss) from continuing operations before income tax expense		$	1,215		$	111		$	41		$	(308	)	$	1,059
	Total assets		$	110,937		$	7,178		$	7,402		$	23,678		$	149,195
	2013
	Net financing revenue (loss)		$	2,350		$	43		$	62		$	(450	)	$	2,005
	Other revenue (loss)		207			926			(6		)	32			1,159
	Total net revenue (loss)		2,557			969			56			(418		)	3,164
	Provision for loan losses		350			—			14			(3		)	361
	Total noninterest expense		1,143			780			293			305			2,521
	Income (loss) from continuing operations before income tax expense		$	1,064		$	189		$	(251	)	$	(720	)	$	282
	Total assets		$	108,609		$	7,323		$	8,562		$	26,062		$	150,556
	(a)	Total assets for Corporate Finance were $1.7 billion and $1.6 billion at September 30, 2014 and 2013, respectively.
	(b)	Net financing revenue after the provision for loan losses totaled $2.3 billion and $1.6 billion for the nine months ended September 30, 2014 and 2013, respectively.
Information Concerning Principal Geographic Areas [Table Text Block]	'
	Information concerning principal geographic areas were as follows.
	Three months ended September 30, ($ in millions)		Revenue (a)			Income (loss)			Net income(b)(c)
						from continuing
						operations
						before income
						tax expense (b)
	2014
	Canada		$	31		$	7		$	9
	Europe		—			(1		)	1
	Latin America		—			—			—
	Asia-Pacific		—			—			29
	Total foreign		31			6			39
	Total domestic (d)		1,233			414			384
	Total		$	1,264		$	420		$	423
	2013
	Canada		$	40		$	14		$	13
	Europe (e)		2			1			4
	Latin America		—			12			26
	Asia-Pacific		—			—			35
	Total foreign		42			27			78
	Total domestic (d)		1,066			178			13
	Total		$	1,108		$	205		$	91
	(a)	Revenue consists of net financing revenue and total other revenue as presented in our Condensed Consolidated Financial Statements.
	(b)	The domestic amounts include original discount amortization of $51 million and $67 million for the three months ended September 30, 2014 and 2013, respectively.
	(c)	Gain (loss) realized on sale of discontinued operations are allocated to the geographic area in which the business operated.
	(d)	Amounts include eliminations between our domestic and foreign operations.
	(e)	Amounts include eliminations between our foreign operations.
	Nine months ended September 30, ($ in millions)		Revenue (a)			Income (loss)			Net income
						from continuing			(loss) (b)(c)
						operations
						before income
						tax expense (b)
	2014
	Canada		$	95		$	36		$	55
	Europe		2			—			5
	Latin America		—			—			(8		)
	Asia-Pacific		—			—			95
	Total foreign		97			36			147
	Total domestic (d)		3,540			1,023			826
	Total		$	3,637		$	1,059		$	973
	2013
	Canada		$	136		$	42		$	1,256
	Europe (e)		(8		)	(18		)	(82		)
	Latin America		—			7			300
	Asia-Pacific		1			(2		)	89
	Total foreign		129			29			1,563
	Total domestic (d)		3,035			253			(1,306		)
	Total		$	3,164		$	282		$	257
	(a)	Revenue consists of net financing revenue and total other revenue as presented in our Condensed Consolidated Financial Statements.
	(b)	The domestic amounts include original discount amortization of $149 million and $191 million for the nine months ended September 30, 2014 and 2013, respectively.
	(c)	Gain (loss) realized on sale of discontinued operations are allocated to the geographic area in which the business operated.
	(d)	Amounts include eliminations between our domestic and foreign operations.
	(e)	Amounts include eliminations between our foreign operations.

Parent_And_Guarantor_Consolida1

Parent And Guarantor Consolidating Financial Statements (Tables)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Condensed Income Statement [Table Text Block]	'
	Condensed Consolidating Statements of Comprehensive Income
	Three months ended September 30, 2014 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
															consolidated
	Financing revenue and other interest income
	Interest and fees on finance receivables and loans		$	16		$	—		$	1,098		$	—		$	1,114
	Interest and fees on finance receivables and loans — intercompany		10			—			21			(31		)	—
	Interest and dividends on available-for-sale investment securities		—			—			94			—			94
	Interest-bearing cash		—			—			2			—			2
	Interest-bearing cash — intercompany		—			—			1			(1		)	—
	Operating leases		1			—			898			—			899
	Total financing revenue and other interest income		27			—			2,114			(32		)	2,109
	Interest expense
	Interest on deposits		3			—			163			—			166
	Interest on short-term borrowings		10			—			2			—			12
	Interest on long-term debt		350			—			143			—			493
	Interest on intercompany debt		22			—			10			(32		)	—
	Total interest expense		385			—			318			(32		)	671
	Depreciation expense on operating lease assets		(4		)	—			553			—			549
	Net financing (loss) revenue		(354		)	—			1,243			—			889
	Dividends from subsidiaries
	Bank subsidiary		150			150			—			(300		)	—
	Nonbank subsidiaries		141			—			—			(141		)	—
	Other revenue
	Servicing fees		6			—			—			—			6
	Servicing asset valuation and hedge activities, net		—			—			—			—			—
	Total servicing income, net		6			—			—			—			6
	Insurance premiums and service revenue earned		—			—			246			—			246
	(Loss) gain on mortgage and automotive loans, net		(2		)	—			2			—			—
	Other gain on investments, net		—			—			45			—			45
	Other income, net of losses		206			—			373			(501		)	78
	Total other revenue		210			—			666			(501		)	375
	Total net revenue		147			150			1,909			(942		)	1,264
	Provision for loan losses		88			—			14			—			102
	Noninterest expense
	Compensation and benefits expense		153			—			199			(111		)	241
	Insurance losses and loss adjustment expenses		—			—			97			—			97
	Other operating expenses		252			—			542			(390		)	404
	Total noninterest expense		405			—			838			(501		)	742
	(Loss) income from continuing operations before income tax (benefit) expense and undistributed income (loss) of subsidiaries		(346		)	150			1,057			(441		)	420
	Income tax (benefit) expense from continuing operations		(68		)	—			195			—			127
	Net (loss) income from continuing operations		(278		)	150			862			(441		)	293
	Income from discontinued operations, net of tax		127			—			3			—			130
	Undistributed income (loss) of subsidiaries
	Bank subsidiary		150			150			—			(300		)	—
	Nonbank subsidiaries		424			(2		)	—			(422		)	—
	Net income		423			298			865			(1,163		)	423
	Other comprehensive loss, net of tax		(55		)	(3		)	(50		)	53			(55		)
	Comprehensive income		$	368		$	295		$	815		$	(1,110	)	$	368
	Three months ended September 30, 2013 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
															consolidated
	Financing revenue and other interest income
	Interest and fees on finance receivables and loans		$	243		$	—		$	876		$	—		$	1,119
	Interest and fees on finance receivables and loans — intercompany		12			—			21			(33		)	—
	Interest and dividends on available-for-sale investment securities		—			—			85			—			85
	Interest-bearing cash		1			—			2			—			3
	Interest-bearing cash - intercompany		—			—			2			(2		)	—
	Operating leases		141			—			691			—			832
	Total financing revenue and other interest income		397			—			1,677			(35		)	2,039
	Interest expense
	Interest on deposits		5			—			158			—			163
	Interest on short-term borrowings		11			—			4			—			15
	Interest on long-term debt		469			—			140			—			609
	Interest on intercompany debt		23			—			12			(35		)	—
Total interest expense		508			—			314			(35		)	787
Depreciation expense on operating lease assets		103			—			412			—			515
Net financing (loss) revenue		(214		)	—			951			—			737
Dividends from subsidiaries
Nonbank subsidiaries		54			—			—			(54		)	—
Other revenue
Servicing fees		36			—			(23		)	—			13
Servicing asset valuation and hedge activities, net		—			—			—			—			—
Total servicing income (loss), net		36			—			(23		)	—			13
Insurance premiums and service revenue earned		—			—			251			—			251
Gain on mortgage and automotive loans, net		—			—			15			—			15
Loss on extinguishment of debt		(42		)	—			—			—			(42		)
Other gain on investments, net		—			—			41			—			41
Other income, net of losses		51			—			350			(308		)	93
Total other revenue		45			—			634			(308		)	371
Total net (loss) revenue		(115		)	—			1,585			(362		)	1,108
Provision for loan losses		69			—			72			—			141
Noninterest expense
Compensation and benefits expense		153			—			205			(113		)	245
Insurance losses and loss adjustment expenses		—			—			85			—			85
Other operating expenses		119			—			508			(195		)	432
Total noninterest expense		272			—			798			(308		)	762
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income (loss) of subsidiaries		(456		)	—			715			(54		)	205
Income tax (benefit) expense from continuing operations		(189		)	—			217			—			28
Net (loss) income from continuing operations		(267		)	—			498			(54		)	177
Income (loss) from discontinued operations, net of tax		142			15			(243		)	—			(86		)
Undistributed income (loss) of subsidiaries
Bank subsidiary		235			235			—			(470		)	—
Nonbank subsidiaries		(19		)	5			—			14			—
Net income		91			255			255			(510		)	91
Other comprehensive income (loss), net of tax		4			(34		)	24			10			4
Comprehensive income		$	95		$	221		$	279		$	(500	)	$	95
Nine months ended September 30, 2014 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
														consolidated
Financing revenue and other interest income
Interest and fees on finance receivables and loans		$	(2	)	$	—		$	3,347		$	—		$	3,345
Interest and fees on finance receivables and loans — intercompany		26			—			64			(90		)	—
Interest on loans held-for-sale		—			—			1			—			1
Interest and dividends on available-for-sale investment securities		—			—			282			—			282
Interest-bearing cash		1			—			5			—			6
Interest-bearing — intercompany		—			—			4			(4		)	—
Operating leases		269			—			2,384			—			2,653
Total financing revenue and other interest income		294			—			6,087			(94		)	6,287
Interest expense
Interest on deposits		11			—			484			—			495
Interest on short-term borrowings		32			—			8			—			40
Interest on long-term debt		1,143			—			433			—			1,576
Interest on intercompany debt		68			—			26			(94		)	—
Total interest expense		1,254			—			951			(94		)	2,111
Depreciation expense on operating lease assets		164			—			1,436			—			1,600
Net financing (loss) revenue		(1,124		)	—			3,700			—			2,576
Dividends from subsidiaries
Bank subsidiary		1,650			1,650			—			(3,300		)	—
Nonbank subsidiaries		462			—			—			(462		)	—
Other revenue
Servicing fees		22			—			—			—			22
Servicing asset valuation and hedge activities, net		—			—			—			—			—
Total servicing income, net		22			—			—			—			22
Insurance premiums and service revenue earned		—			—			736			—			736
(Loss) gain on mortgage and automotive loans, net		(2		)	—			8			—			6
Loss on extinguishment of debt		(46		)	—			—			—			(46		)
Other gain on investments, net		—			—			129			—			129
Other income, net of losses		591			—			1,007			(1,384		)	214
Total other revenue		565			—			1,880			(1,384		)	1,061
Total net revenue		1,553			1,650			5,580			(5,146		)	3,637
Provision for loan losses		165			—			137			—			302
Noninterest expense
Compensation and benefits expense		441			—			604			(335		)	710
Insurance losses and loss adjustment expenses		—			—			353			—			353
Other operating expenses		648			—			1,614			(1,049		)	1,213
Total noninterest expense		1,089			—			2,571			(1,384		)	2,276
Income from continuing operations before income tax (benefit) expense and undistributed (loss) income of subsidiaries		299			1,650			2,872			(3,762		)	1,059
Income tax (benefit) expense from continuing operations		(309		)	—			594			—			285
Net income from continuing operations		608			1,650			2,278			(3,762		)	774
Income from discontinued operations, net of tax		172			—			27			—			199
Undistributed (loss) income of subsidiaries
Bank subsidiary		(802		)	(802		)	—			1,604			—
Nonbank subsidiaries		995			(2		)	—			(993		)	—
Net income		973			846			2,305			(3,151		)	973
Other comprehensive income, net of tax		126			116			124			(240		)	126
Comprehensive income		$	1,099		$	962		$	2,429		$	(3,391	)	$	1,099
Nine months ended September 30, 2013 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating adjustments			Ally
														consolidated
Financing revenue and other interest income
Interest and fees on finance receivables and loans		$	674		$	—		$	2,719		$	—		$	3,393
Interest and fees on finance receivables and loans — intercompany		49			—			46			(95		)	—
Interest on loans held-for-sale		—			—			19			—			19
Interest and dividends on available-for-sale investment securities		—			—			229			—			229
Interest-bearing cash		3			—			5			—			8
Interest-bearing cash — intercompany		—			—			6			(6		)	—
Operating leases		355			—			1,999			—			2,354
Total financing revenue and other interest income		1,081			—			5,023			(101		)	6,003
Interest expense
Interest on deposits		20			—			469			—			489
Interest on short-term borrowings		35			—			12			—			47
Interest on long-term debt		1,593			—			425			(5		)	2,013
Interest on intercompany debt		43			—			52			(95		)	—
Total interest expense		1,691			—			958			(100		)	2,549
Depreciation expense on operating lease assets		267			—			1,182			—			1,449
Net financing (loss) revenue		(877		)	—			2,883			(1		)	2,005
Dividends from subsidiaries
Nonbank subsidiaries		5,217			3,659			—			(8,876		)	—
Other revenue
Servicing fees		118			—			(4		)	—			114
Servicing asset valuation and hedge activities, net		—			—			(213		)	—			(213		)
Total servicing income (loss), net		118			—			(217		)	—			(99		)
Insurance premiums and service revenue earned		—			—			768			—			768
Gain on mortgage and automotive loans, net		—			—			52			—			52
Loss on extinguishment of debt		(42		)	—			—			—			(42		)
Other gain on investments, net		—			—			156			—			156
Other income, net of losses		128			—			1,116			(920		)	324
Total other revenue		204			—			1,875			(920		)	1,159
Total net revenue		4,544			3,659			4,758			(9,797		)	3,164
Provision for loan losses		298			—			63			—			361
Noninterest expense
Compensation and benefits expense		505			—			622			(345		)	782
Insurance losses and loss adjustment expenses		—			—			346			—			346
Other operating expenses		274			—			1,694			(575		)	1,393
Total noninterest expense		779			—			2,662			(920		)	2,521
Income from continuing operations before income tax (benefit) expense and undistributed income (loss) of subsidiaries		3,467			3,659			2,033			(8,877		)	282
Income tax (benefit) expense from continuing operations		(748		)	—			693			—			(55		)
Net income from continuing operations		4,215			3,659			1,340			(8,877		)	337
(Loss) income from discontinued operations, net of tax		(1,365		)	(19		)	1,303			1			(80		)
Undistributed income (loss) of subsidiaries
Bank subsidiary		668			668			—			(1,336		)	—
Nonbank subsidiaries		(3,261		)	(2,395		)	—			5,656			—
Net income		257			1,913			2,643			(4,556		)	257
Other comprehensive loss, net of tax		(494		)	(753		)	(830		)	1,583			(494		)
Comprehensive (loss) income		$	(237	)	$	1,160		$	1,813		$	(2,973	)	$	(237	)
Condensed Balance Sheet [Table Text Block]	'
	Condensed Consolidating Balance Sheet
	September 30, 2014 ($ in millions)		Parent (a)			Guarantors			Nonguarantors (a)			Consolidating			Ally
												adjustments			consolidated
	Assets
	Cash and cash equivalents
	Noninterest-bearing		$	932		$	—		$	386		$	—		$	1,318
	Interest-bearing		1,300			—			3,081			—			4,381
	Interest-bearing — intercompany		—			—			413			(413		)	—
	Total cash and cash equivalents		2,232			—			3,880			(413		)	5,699
	Investment securities		—			—			16,714			—			16,714
	Loans held-for-sale, net		—			—			3			—			3
	Finance receivables and loans, net
	Finance receivables and loans, net		4,757			—			94,761			—			99,518
	Intercompany loans to
	Bank subsidiary		1,300			—			—			(1,300		)	—
	Nonbank subsidiaries		5,603			—			1,777			(7,380		)	—
	Allowance for loan losses		(104		)	—			(1,009		)	—			(1,113		)
	Total finance receivables and loans, net		11,556			—			95,529			(8,680		)	98,405
	Investment in operating leases, net		—			—			19,341			—			19,341
	Intercompany receivables from
	Bank subsidiary		518			—			—			(518		)	—
	Nonbank subsidiaries		271			—			77			(348		)	—
	Investment in subsidiaries
	Bank subsidiary		15,770			15,770			—			(31,540		)	—
	Nonbank subsidiaries		9,730			11			—			(9,741		)	—
	Premiums receivable and other insurance assets		—			—			1,698			(20		)	1,678
	Other assets		4,789			—			4,399			(2,436		)	6,752
	Assets of operations held-for-sale		603			—			—			—			603
	Total assets		$	45,469		$	15,781		$	141,641		$	(53,696	)	$	149,195
	Liabilities
	Deposit liabilities
	Noninterest-bearing		$	—		$	—		$	73		$	—		$	73
	Interest-bearing		368			—			56,410			—			56,778
	Total deposit liabilities		368			—			56,483			—			56,851
	Short-term borrowings		3,376			—			1,879			—			5,255
	Long-term debt		22,777			—			44,522			—			67,299
	Intercompany debt to
	Nonbank subsidiaries		2,190			—			6,903			(9,093		)	—
	Intercompany payables to
	Bank subsidiary		170			—			—			(170		)	—
	Nonbank subsidiaries		573			—			142			(715		)	—
	Interest payable		279			—			263			—			542
	Unearned insurance premiums and service revenue		—			—			2,369			—			2,369
	Accrued expenses and other liabilities		546			82			3,497			(2,436		)	1,689
	Total liabilities		30,279			82			116,058			(12,414		)	134,005
	Total equity		15,190			15,699			25,583			(41,282		)	15,190
	Total liabilities and equity		$	45,469		$	15,781		$	141,641		$	(53,696	)	$	149,195
	(a)	Amounts presented are based upon the legal transfer of the underlying assets to VIEs in order to reflect legal ownership.
	December 31, 2013 ($ in millions)		Parent (a)			Guarantors			Nonguarantors (a)			Consolidating			Ally
												adjustments			consolidated
	Assets
	Cash and cash equivalents
	Noninterest-bearing		$	979		$	37		$	299		$	—		$	1,315
	Interest-bearing		1,951			—			2,265			—			4,216
	Interest-bearing — intercompany		—			—			410			(410		)	—
	Total cash and cash equivalents		2,930			37			2,974			(410		)	5,531
	Investment securities		—			—			17,083			—			17,083
	Loans held-for-sale, net		—			—			35			—			35
	Finance receivables and loans, net
	Finance receivables and loans, net		6,673			—			93,655			—			100,328
	Intercompany loans to
	Bank subsidiary		600			—			—			(600		)	—
	Nonbank subsidiaries		4,207			—			1,925			(6,132		)	—
Allowance for loan losses		(131		)	—			(1,077		)	—			(1,208		)
Total finance receivables and loans, net		11,349			—			94,503			(6,732		)	99,120
Investment in operating leases, net		3,172			—			14,508			—			17,680
Intercompany receivables from
Bank subsidiary		236			—			—			(236		)	—
Nonbank subsidiaries		439			—			588			(1,027		)	—
Investment in subsidiaries
Bank subsidiary		14,916			14,916			—			(29,832		)	—
Nonbank subsidiaries		10,029			68			—			(10,097		)	—
Premiums receivable and other insurance assets		—			—			1,634			(21		)	1,613
Other assets		4,691			—			6,880			(1,982		)	9,589
Assets of operations held-for-sale		516			—			—			—			516
Total assets		$	48,278		$	15,021		$	138,205		$	(50,337	)	$	151,167
Liabilities
Deposit liabilities
Noninterest-bearing		$	—		$	—		$	60		$	—		$	60
Interest-bearing		440			—			52,850			—			53,290
Total deposit liabilities		440			—			52,910			—			53,350
Short-term borrowings		3,225			—			5,320			—			8,545
Long-term debt		25,819			—			43,646			—			69,465
Intercompany debt to
Nonbank subsidiaries		2,334			—			4,808			(7,142		)	—
Intercompany payables to
Bank subsidiary		197			—			—			(197		)	—
Nonbank subsidiaries		666			—			421			(1,087		)	—
Interest payable		709			—			179			—			888
Unearned insurance premiums and service revenue		—			—			2,314			—			2,314
Accrued expenses and other liabilities		680			93			3,606			(1,982		)	2,397
Total liabilities		34,070			93			113,204			(10,408		)	136,959
Total equity		14,208			14,928			25,001			(39,929		)	14,208
Total liabilities and equity		$	48,278		$	15,021		$	138,205		$	(50,337	)	$	151,167
(a)	Amounts presented are based upon the legal transfer of the underlying assets to VIEs in order to reflect legal ownership.
Condensed Cash Flow Statement [Table Text Block]	'
	Condensed Consolidating Statement of Cash Flows
	Nine months ended September 30, 2014 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating			Ally
												adjustments			consolidated
	Operating activities
	Net cash provided by operating activities		$	544		$	1,639		$	4,036		$	(3,761	)	$	2,458
	Investing activities
	Purchases of available-for-sale securities		—			—			(4,117		)	—			(4,117		)
	Proceeds from sales of available-for-sale securities		—			—			2,974			—			2,974
	Proceeds from maturities and repayments of available-for-sale securities		—			—			1,877			—			1,877
	Net decrease (increase) in finance receivables and loans		1,669			—			(2,936		)	—			(1,267		)
	Proceeds from sales of finance receivables and loans		—			—			1,557			—			1,557
	Net (increase) decrease in loans — intercompany		(104		)	—			147			(43		)	—
	Net decrease (increase) in operating lease assets		146			—			(3,411		)	—			(3,265		)
	Capital contributions to subsidiaries		(744		)	—			—			744			—
	Returns of contributed capital		1,251			—			—			(1,251		)	—
	Proceeds from sale of business units, net		46			—			1			—			47
	Net change in restricted cash		—			—			2,128			—			2,128
	Other, net		(17		)	—			88			—			71
	Net cash provided by (used in) investing activities		2,247			—			(1,692		)	(550		)	5
	Financing activities
	Net change in short-term borrowings — third party		151			—			(3,449		)	—			(3,298		)
	Net (decrease) increase in deposits		(72		)	—			3,573			—			3,501
	Proceeds from issuance of long-term debt — third party		2,310			—			16,632			—			18,942
	Repayments of long-term debt — third party		(5,535		)	—			(15,704		)	—			(21,239		)
	Net change in debt — intercompany		(143		)	—			104			39			—
	Dividends paid — third party		(200		)	—			—			—			(200		)
	Dividends paid and returns of contributed capital — intercompany		—			(1,676		)	(3,337		)	5,013			—
	Capital contributions from parent		—			—			744			(744		)	—
	Net cash used in financing activities		(3,489		)	(1,676		)	(1,437		)	4,308			(2,294		)
	Effect of exchange-rate changes on cash and cash equivalents		—			—			(1		)	—			(1		)
	Net (decrease) increase in cash and cash equivalents		(698		)	(37		)	906			(3		)	168
	Cash and cash equivalents at beginning of year		2,930			37			2,974			(410		)	5,531
	Cash and cash equivalents at September 30		$	2,232		$	—		$	3,880		$	(413	)	$	5,699
	Nine months ended September 30, 2013 ($ in millions)		Parent			Guarantors			Nonguarantors			Consolidating			Ally
												adjustments			consolidated
	Operating activities
	Net cash provided by operating activities		$	5,198		$	3,514		$	4,528		$	(8,875	)	$	4,365
	Investing activities
	Purchases of available-for-sale securities		—			—			(12,747		)	—			(12,747		)
	Proceeds from sales of available-for-sale securities		—			—			4,721			—			4,721
	Proceeds from maturities and repayments of available-for-sale securities		—			—			3,893			—			3,893
	Net (increase) decrease in finance receivables and loans		(3,527		)	79			6,192			—			2,744
	Net decrease (increase) in loans — intercompany		342			251			(1,376		)	783			—
	Net (increase) in operating lease assets		(1,111		)	—			(4,060		)	—			(5,171		)
	Capital contributions to subsidiaries		(176		)	—			—			176			—
	Returns of contributed capital		769			150			—			(919		)	—
	Sales of mortgage servicing rights		—			—			911			—			911
	Proceeds from sale of business units, net		1,123			554			5,260			—			6,937
	Net change in restricted cash		—			(26		)	2,323			—			2,297
	Other, net		(200		)	—			145			—			(55		)
	Net cash (used in) provided by investing activities		(2,780		)	1,008			5,262			40			3,530
	Financing activities
	Net change in short-term borrowings — third party		105			36			(1,077		)	—			(936		)
	Net (decrease) increase in deposits		(433		)	—			4,527			(37		)	4,057
	Proceeds from issuance of long-term debt — third party		2,213			—			11,134			—			13,347
	Repayments of long-term debt — third party		(6,331		)	(70		)	(20,324		)	—			(26,725		)
	Net change in debt — intercompany		1,674			(271		)	(664		)	(739		)	—
	Dividends paid — third party		(601		)	—			—			—			(601		)
	Dividends paid and returns of contributed capital — intercompany		—			(4,217		)	(5,577		)	9,794			—
	Capital contributions from parent		—			29			147			(176		)	—
	Net cash used in financing activities		(3,373		)	(4,493		)	(11,834		)	8,842			(10,858		)
	Effect of exchange-rate changes on cash and cash equivalents		—			—			47			—			47
	Net (decrease) increase in cash and cash equivalents		(955		)	29			(1,997		)	7			(2,916		)
Adjustment for change in cash and cash equivalents of operations held-for-sale		—			—			1,952			—			1,952
Cash and cash equivalents at beginning of year		3,977			—			4,027			(491		)	7,513
Cash and cash equivalents at September 30		$	3,022		$	29		$	3,982		$	(484	)	$	6,549

Description_Of_Business_Basis_2

Description Of Business, Basis Of Presentation, And Changes In Significant Accounting Policies Initial Public Offering (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Stockholders' Equity Note, Stock Split, Conversion Ratio	310
Common Stock, Par or Stated Value Per Share	$0.01
Common Stock, Shares Authorized	1,100,000,000
Preferred Stock, Shares Authorized	41,000,000

Discontinued_and_Heldforsale_O2

Discontinued and Held-for-sale Operations (Selected Income Statement Information for Discontinued Operations) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Interest in Joint Venture	40.00%	'	40.00%	'
Mortgage Operations [Member]	'	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Total net (loss) revenue - Discontinued Operations	$0	$0	$0	$0
Pretax income (loss) including direct costs to transact a sale	-1	-158	-4	-1,762
Tax (benefit) expense - Discontinued Operations	-86	-40	-87	-573
Insurance Operations [Member]	'	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Total net (loss) revenue - Discontinued Operations	0	0	0	190
Pretax income (loss) including direct costs to transact a sale	6	5	6	319
Tax (benefit) expense - Discontinued Operations	7	3	7	-12
Automotive finance operations [Member]	'	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Total net (loss) revenue - Discontinued Operations	29	119	95	544
Pretax income (loss) including direct costs to transact a sale	46	58	101	752
Tax (benefit) expense - Discontinued Operations	0	28	4	-25
Commercial Finance Operations [Member]	'	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Total net (loss) revenue - Discontinued Operations	0	0	0	0
Pretax income (loss) including direct costs to transact a sale	0	0	23	1
Tax (benefit) expense - Discontinued Operations	$0	$0	$3	$0

Discontinued_and_Heldforsale_O3

Discontinued and Held-for-sale Operations (Select Balance Sheet Information for Held-for-sale Operations) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Millions, unless otherwise specified
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'
Other Assets	$6,752	$9,589	'
Total assets	149,195	151,167	150,556
Automotive finance operations [Member]	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'
Other Assets	603	516	'
Total assets	$603	$516	'

Other_Income_Net_Of_Losses_Sch

Other Income, Net Of Losses (Schedule of Other Income, Net Of Losses) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Nonoperating Income (Expense) [Abstract]	'	'	'	'
Remarketing Fees	$28	$20	$85	$59
Fees and Commissions, Other	23	25	66	71
Unrealized Gain (Loss) on Derivatives	-4	21	-19	31
Fees and Commissions, Mortgage Banking	0	0	0	81
Other Income	31	27	82	82
Other income, net of losses	$78	$93	$214	$324

Other_Operating_Expenses_Sched

Other Operating Expenses (Schedule Of Other Operating Expenses) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Operating Expenses [Abstract]	'	'	'	'
Insurance Commissions	$95	$93	$279	$278
Communications and Information Technology	77	87	255	250
Lease And Loan Administration	32	29	92	141
Marketing and Advertising Expense	27	33	81	96
Professional Fees	20	38	73	140
Regulatory and licensing fees	23	25	69	87
Depreciation, Nonproduction	23	20	61	61
Vehicle remarketing and repossession	22	15	61	42
Occupancy, Net	12	12	34	34
State And Local Non-Income Taxes Amount	12	1	32	17
Mortgage Representation And Warranty, Net	0	22	1	103
Other Cost and Expense, Operating	61	57	175	144
Total other operating expenses	$404	$432	$1,213	$1,393

Investment_Securities_Schedule

Investment Securities (Schedule of Available-for-sale Securities Reconciliation) (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Amortized Cost Basis	$16,829,000,000	$17,425,000,000
Available-for-sale Securities, Gross Unrealized Gains	157,000,000	166,000,000
Available-for-sale Securities, Gross Unrealized Losses	-272,000,000	-508,000,000
Available-for-sale Securities	16,714,000,000	17,083,000,000
Total agency backed bonds	8,175,000,000	8,266,000,000
Deposit Assets	15,000,000	15,000,000
Cash Equivalents, at Carrying Value	2,100,000,000	2,400,000,000
Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	16,108,000,000	16,527,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	127,000,000	92,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	-249,000,000	-480,000,000
Available-for-sale Securities, Debt Securities	15,986,000,000	16,139,000,000
US Treasury and Government [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	1,313,000,000	1,495,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	1,000,000	1,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	-28,000,000	-69,000,000
Available-for-sale Securities, Debt Securities	1,286,000,000	1,427,000,000
US States and Political Subdivisions Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	386,000,000	316,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	16,000,000	0
Available-for-sale Debt Securities, Gross Unrealized Loss	0	-1,000,000
Available-for-sale Securities, Debt Securities	402,000,000	315,000,000
Foreign Government Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	226,000,000	287,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	6,000,000	4,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	0	-3,000,000
Available-for-sale Securities, Debt Securities	232,000,000	288,000,000
Residential Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	11,018,000,000	11,131,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	78,000,000	49,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	-212,000,000	-398,000,000
Available-for-sale Securities, Debt Securities	10,884,000,000	10,782,000,000
Commercial Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	213,000,000	39,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	0	0
Available-for-sale Debt Securities, Gross Unrealized Loss	-1,000,000	0
Available-for-sale Securities, Debt Securities	212,000,000	39,000,000
Asset-backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	1,982,000,000	2,207,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	8,000,000	15,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	-3,000,000	-3,000,000
Available-for-sale Securities, Debt Securities	1,987,000,000	2,219,000,000
Corporate Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	970,000,000	1,052,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	18,000,000	23,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	-5,000,000	-6,000,000
Available-for-sale Securities, Debt Securities	983,000,000	1,069,000,000
Equity Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Equity Securities, Amortized Cost Basis	721,000,000	898,000,000
Available-for-sale Equity Securities, Gross Unrealized Gain	30,000,000	74,000,000
Available-for-sale Equity Securities, Gross Unrealized Loss	-23,000,000	-28,000,000
Available-for-sale Securities, Equity Securities	$728,000,000	$944,000,000

Investment_Securities_Investme

Investment Securities (Investments Classified by Contractual Maturity Date) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	$103	$166
Available-for-sale debt securities, Due after one year through five years, Amount	2,775	3,001
Available-for-sale debt securities, Due after five years through ten years, Amount	1,596	1,842
Available-for-sale debt securities, Due after ten years, Amount	11,512	11,130
Amortized cost of available-for-sale debt securities, Due in one year or less, Amount	102	165
Amortized cost of available-for-sale debt securities, Due after one year through five years, Amount	2,773	3,000
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Amortized Cost Basis	1,596	1,882
Amortized cost of available-for-sale debt securities, Due after ten years, Amount	11,637	11,480
Available-for-sale debt securities, Yield	2.60%	2.50%
Available-for-sale debt securities, Due in one year or less, Yield	2.20%	2.30%
Available-for-sale debt securities, Due after one year through five years, Yield	1.90%	1.90%
Available-for-sale debt securities, Due after five years through ten years, Yield	2.60%	2.50%
Available-for-sale debt securities, Due after ten years, Yield	2.80%	2.70%
Available-for-sale Debt Securities, Amortized Cost Basis	16,108	16,527
Available-for-sale Securities, Debt Securities	15,986	16,139
US Treasury and Government [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	7	9
Available-for-sale debt securities, Due after one year through five years, Amount	791	766
Available-for-sale debt securities, Due after five years through ten years, Amount	488	652
Available-for-sale debt securities, Due after ten years, Amount	0	0
Available-for-sale debt securities, Yield	1.30%	1.30%
Available-for-sale debt securities, Due in one year or less, Yield	3.10%	3.00%
Available-for-sale debt securities, Due after one year through five years, Yield	1.20%	1.20%
Available-for-sale debt securities, Due after five years through ten years, Yield	1.50%	1.30%
Available-for-sale debt securities, Due after ten years, Yield	0.00%	0.00%
Available-for-sale Debt Securities, Amortized Cost Basis	1,313	1,495
Available-for-sale Securities, Debt Securities	1,286	1,427
US States and Political Subdivisions Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	36	39
Available-for-sale debt securities, Due after one year through five years, Amount	15	10
Available-for-sale debt securities, Due after five years through ten years, Amount	108	102
Available-for-sale debt securities, Due after ten years, Amount	243	164
Available-for-sale debt securities, Yield	3.50%	3.30%
Available-for-sale debt securities, Due in one year or less, Yield	1.20%	1.30%
Available-for-sale debt securities, Due after one year through five years, Yield	2.00%	0.60%
Available-for-sale debt securities, Due after five years through ten years, Yield	2.80%	2.60%
Available-for-sale debt securities, Due after ten years, Yield	4.30%	4.30%
Available-for-sale Debt Securities, Amortized Cost Basis	386	316
Available-for-sale Securities, Debt Securities	402	315
Foreign Government Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	0	18
Available-for-sale debt securities, Due after one year through five years, Amount	124	105
Available-for-sale debt securities, Due after five years through ten years, Amount	108	164
Available-for-sale debt securities, Due after ten years, Amount	0	1
Available-for-sale debt securities, Yield	2.70%	2.70%
Available-for-sale debt securities, Due in one year or less, Yield	0.00%	2.70%
Available-for-sale debt securities, Due after one year through five years, Yield	2.60%	2.40%
Available-for-sale debt securities, Due after five years through ten years, Yield	2.90%	2.90%
Available-for-sale debt securities, Due after ten years, Yield	0.00%	2.70%
Available-for-sale Debt Securities, Amortized Cost Basis	226	287
Available-for-sale Securities, Debt Securities	232	288
Residential Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	0	0
Available-for-sale debt securities, Due after one year through five years, Amount	65	90
Available-for-sale debt securities, Due after five years through ten years, Amount	0	3
Available-for-sale debt securities, Due after ten years, Amount	10,819	10,689
Available-for-sale debt securities, Yield	2.80%	2.70%
Available-for-sale debt securities, Due in one year or less, Yield	0.00%	0.00%
Available-for-sale debt securities, Due after one year through five years, Yield	2.10%	2.10%
Available-for-sale debt securities, Due after five years through ten years, Yield	0.00%	4.20%
Available-for-sale debt securities, Due after ten years, Yield	2.80%	2.70%
Available-for-sale Debt Securities, Amortized Cost Basis	11,018	11,131
Available-for-sale Securities, Debt Securities	10,884	10,782
Commercial Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	0	0
Available-for-sale debt securities, Due after one year through five years, Amount	0	0
Available-for-sale debt securities, Due after five years through ten years, Amount	0	0
Available-for-sale debt securities, Due after ten years, Amount	212	39
Available-for-sale debt securities, Yield	2.10%	1.30%
Available-for-sale debt securities, Due in one year or less, Yield	0.00%	0.00%
Available-for-sale debt securities, Due after one year through five years, Yield	0.00%	0.00%
Available-for-sale debt securities, Due after five years through ten years, Yield	0.00%	0.00%
Available-for-sale debt securities, Due after ten years, Yield	2.10%	1.30%
Available-for-sale Debt Securities, Amortized Cost Basis	213	39
Available-for-sale Securities, Debt Securities	212	39
Asset-backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	26	76
Available-for-sale debt securities, Due after one year through five years, Amount	1,300	1,483
Available-for-sale debt securities, Due after five years through ten years, Amount	479	491
Available-for-sale debt securities, Due after ten years, Amount	182	169
Available-for-sale debt securities, Yield	2.00%	2.00%
Available-for-sale debt securities, Due in one year or less, Yield	2.30%	2.40%
Available-for-sale debt securities, Due after one year through five years, Yield	2.00%	1.90%
Available-for-sale debt securities, Due after five years through ten years, Yield	1.90%	1.90%
Available-for-sale debt securities, Due after ten years, Yield	2.50%	2.70%
Available-for-sale Debt Securities, Amortized Cost Basis	1,982	2,207
Available-for-sale Securities, Debt Securities	1,987	2,219
Corporate Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale debt securities, Due in one year or less, Amount	34	24
Available-for-sale debt securities, Due after one year through five years, Amount	480	547
Available-for-sale debt securities, Due after five years through ten years, Amount	413	430
Available-for-sale debt securities, Due after ten years, Amount	56	68
Available-for-sale debt securities, Yield	3.90%	4.10%
Available-for-sale debt securities, Due in one year or less, Yield	3.10%	3.40%
Available-for-sale debt securities, Due after one year through five years, Yield	3.00%	3.00%
Available-for-sale debt securities, Due after five years through ten years, Yield	4.90%	5.30%
Available-for-sale debt securities, Due after ten years, Yield	5.80%	5.70%
Available-for-sale Debt Securities, Amortized Cost Basis	970	1,052
Available-for-sale Securities, Debt Securities	$983	$1,069

Investment_Securities_Schedule1

Investment Securities (Schedule Of Realized Gain (Loss)) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Available-for-sale Securities [Abstract]	'	'	'	'
Available-for-sale Securities, Gross Realized Gains	$48	$59	$150	$196
Available-for-sale Securities, Gross Realized Losses	-3	-7	-11	-21
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	0	-11	-10	-19
Available-for-sale Securities, Gross Realized Gain (Loss)	$45	$41	$129	$156

Investment_Securities_Investme1

Investment Securities (Investment Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Available-for-sale Securities [Abstract]	'	'	'	'
Taxable interest	$87	$79	$256	$210
Taxable dividends	6	6	18	19
Interest and dividends exempt from U.S. federal income tax	1	0	8	0
Interest and dividends on available-for-sale investment securities	$94	$85	$282	$229

Investment_Securities_Schedule2

Investment Securities (Schedule of Unrealized Loss on Investments) (Details) (USD $)	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	$2,684	$10,118
Available-for-sale Securities, Unrealized Loss Less than 12 months	-40	-482
Available-for-sale Securities, Fair value 12 months or longer	5,524	204
Available-for-sale Securities, Unrealized Loss 12 months or longer	-232	-26
Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	2,429	9,951
Available-for-sale Securities, Unrealized Loss Less than 12 months	-19	-470
Available-for-sale Securities, Fair value 12 months or longer	5,510	104
Available-for-sale Securities, Unrealized Loss 12 months or longer	-230	-10
US Treasury and Government [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	0	1,405
Available-for-sale Securities, Unrealized Loss Less than 12 months	0	-69
Available-for-sale Securities, Fair value 12 months or longer	1,245	0
Available-for-sale Securities, Unrealized Loss 12 months or longer	-28	0
US States and Political Subdivisions Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	21	212
Available-for-sale Securities, Unrealized Loss Less than 12 months	0	-1
Available-for-sale Securities, Fair value 12 months or longer	0	0
Available-for-sale Securities, Unrealized Loss 12 months or longer	0	0
Foreign Government Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	43	114
Available-for-sale Securities, Unrealized Loss Less than 12 months	0	-3
Available-for-sale Securities, Fair value 12 months or longer	0	0
Available-for-sale Securities, Unrealized Loss 12 months or longer	0	0
Residential Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	1,428	7,503
Available-for-sale Securities, Unrealized Loss Less than 12 months	-12	-388
Available-for-sale Securities, Fair value 12 months or longer	4,229	100
Available-for-sale Securities, Unrealized Loss 12 months or longer	-201	-10
Asset-backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	699	407
Available-for-sale Securities, Unrealized Loss Less than 12 months	-3	-3
Available-for-sale Securities, Fair value 12 months or longer	16	1
Available-for-sale Securities, Unrealized Loss 12 months or longer	0	0
Corporate Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	238	310
Available-for-sale Securities, Unrealized Loss Less than 12 months	-4	-6
Available-for-sale Securities, Fair value 12 months or longer	20	3
Available-for-sale Securities, Unrealized Loss 12 months or longer	-1	0
Equity Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available-for-sale Securities, Fair value Less than 12 months	255	167
Available-for-sale Securities, Unrealized Loss Less than 12 months	-21	-12
Available-for-sale Securities, Fair value 12 months or longer	14	100
Available-for-sale Securities, Unrealized Loss 12 months or longer	($2)	($16)

Finance_Receivables_And_Loans_2

Finance Receivables And Loans, Net (Schedule of Accounts, Notes, Loans and Financing Receivables) (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Consumer Loans Auto Financing Receivable [Member]

Consumer Loans Auto Financing Receivable [Member]

Residential Mortgage [Member]

Residential Mortgage [Member]

Commercial Loan [Member]

Commercial Loan [Member]

Commercial And Industrial Automobile [Member]

Commercial And Industrial Automobile [Member]

Commercial And Industrial Other [Member]

Commercial And Industrial Other [Member]

Commercial Real Estate Automobile [Member]

Commercial Real Estate Automobile [Member]

loans held-for-investment [Member]

loans held-for-investment [Member]

Designated as Hedging Instrument [Member]

Designated as Hedging Instrument [Member]

Designated as Hedging Instrument [Member]

Designated as Hedging Instrument [Member]

Fair Value Option Election, Fair Value [Member]

Fair Value Option Election, Fair Value [Member]

Fair Value Option Election, Fair Value [Member]

Fair Value Option Election, Fair Value [Member]

Gain (Loss) Recognized in Earnings on Hedged Item [Member]

Gain (Loss) Recognized in Earnings on Hedged Item [Member]

Gain (Loss) Recognized in Earnings on Hedged Item [Member]

Gain (Loss) Recognized in Earnings on Hedged Item [Member]

Designated as Hedging Instrument [Member]

Designated as Hedging Instrument [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Gain (Loss) Recognized in Earnings on Hedged Item [Member]

Gain (Loss) Recognized in Earnings on Hedged Item [Member]

Interest Rate Contract [Member]

Interest Rate Contract [Member]

Accounts, Notes, Loans and Financing Receivable [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finance receivables and loans, net

$99,518,000,000

$95,281,000,000

$99,518,000,000

$95,281,000,000

$100,328,000,000

$58,675,000,000

$56,417,000,000

$7,595,000,000

$8,444,000,000

$33,248,000,000

$35,467,000,000

$28,453,000,000

$30,948,000,000

$1,756,000,000

$1,664,000,000

$3,039,000,000

$2,855,000,000

'

'

'

'

'

'

$99,518,000,000

$100,328,000,000

'

'

Interest and Fee Income, Loans and Leases

1,114,000,000

1,119,000,000

3,345,000,000

3,393,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-15,000,000

-3,000,000

14,000,000

-3,000,000

'

'

16,000,000

1,000,000

Held For Investment Mortgage Finance Receivables Interest Only Mortgage Loans

1,300,000,000

'

1,300,000,000

'

1,500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loans Receivable, Fair Value Disclosure

1,000,000

'

1,000,000

'

1,000,000

'

'

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$392,000,000

$595,000,000

'

'

'

'

'

'

'

'

Finance_Receivables_And_Loans_3

Finance Receivables And Loans, Net (Allowance For Credit Losses On Financing Receivables) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]	'	'	'	'	'
Loans and Leases Receivable, Allowance, Beginning Balance	$1,171	$1,183	$1,208	$1,170	'
Allowance for Loan and Lease Losses, Write-offs	-201	-184	-554	-517	'
Allowance for Loan and Lease Loss, Recovery of Bad Debts	52	58	187	174	'
Allowance for Loan and Lease Losses Write-offs, Net	-149	-126	-367	-343	'
Allowance for Loan and Lease Losses, Provision for Loss, Net	102	141	302	361	'
Allowance for Loan and Lease Losses, Adjustments, Net	-11	0	-30	10	'
Loans and Leases Receivable, Allowance, Ending Balance	1,113	1,198	1,113	1,198	'
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]	'	'	'	'	'
Allowance for loan losses, Individually evaluated for impairment	220	249	220	249	'
Allowance for loan losses, Collectively evaluated for impairment	893	949	893	949	'
Allowance for loan losses, Loans acquired with deteriorated credit quality	0	0	0	0	'
Finance receivables and loans, net	99,518	95,281	99,518	95,281	100,328
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	99,517	'	99,517	'	100,327
Financing Receivable, Individually Evaluated for Impairment	1,266	1,436	1,266	1,436	'
Financing receivable, Collectively evaluated for impairment	98,249	93,834	98,249	93,834	'
Financing receivable, Loans acquired with deteriorated credit quality	2	11	2	11	'
Consumer Loans Auto Financing Receivable [Member]	'	'	'	'	'
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]	'	'	'	'	'
Loans and Leases Receivable, Allowance, Beginning Balance	729	610	673	575	'
Allowance for Loan and Lease Losses, Write-offs	-188	-168	-511	-443	'
Allowance for Loan and Lease Loss, Recovery of Bad Debts	51	53	170	155	'
Allowance for Loan and Lease Losses Write-offs, Net	-137	-115	-341	-288	'
Allowance for Loan and Lease Losses, Provision for Loss, Net	112	156	372	355	'
Allowance for Loan and Lease Losses, Adjustments, Net	-11	0	-11	9	'
Loans and Leases Receivable, Allowance, Ending Balance	693	651	693	651	'
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]	'	'	'	'	'
Allowance for loan losses, Individually evaluated for impairment	25	22	25	22	'
Allowance for loan losses, Collectively evaluated for impairment	668	629	668	629	'
Allowance for loan losses, Loans acquired with deteriorated credit quality	0	0	0	0	'
Finance receivables and loans, net	58,675	56,450	58,675	56,450	'
Financing Receivable, Individually Evaluated for Impairment	289	269	289	269	'
Financing receivable, Collectively evaluated for impairment	58,384	56,170	58,384	56,170	'
Financing receivable, Loans acquired with deteriorated credit quality	2	11	2	11	'
Residential Mortgage [Member]	'	'	'	'	'
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]	'	'	'	'	'
Loans and Leases Receivable, Allowance, Beginning Balance	302	431	389	452	'
Allowance for Loan and Lease Losses, Write-offs	-13	-16	-38	-71	'
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1	5	6	13	'
Allowance for Loan and Lease Losses Write-offs, Net	-12	-11	-32	-58	'
Allowance for Loan and Lease Losses, Provision for Loss, Net	-7	-12	-55	14	'
Allowance for Loan and Lease Losses, Adjustments, Net	0	-1	-19	-1	'
Loans and Leases Receivable, Allowance, Ending Balance	283	407	283	407	'
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]	'	'	'	'	'
Allowance for loan losses, Individually evaluated for impairment	180	199	180	199	'
Allowance for loan losses, Collectively evaluated for impairment	103	208	103	208	'
Allowance for loan losses, Loans acquired with deteriorated credit quality	0	0	0	0	'
Finance receivables and loans, net	7,594	8,772	7,594	8,772	'
Financing Receivable, Individually Evaluated for Impairment	904	916	904	916	'
Financing receivable, Collectively evaluated for impairment	6,690	7,856	6,690	7,856	'
Financing receivable, Loans acquired with deteriorated credit quality	0	0	0	0	'
Commercial Loan [Member]	'	'	'	'	'
Financing Receivable, Allowance for Loan and Lease Losses [Roll Forward]	'	'	'	'	'
Loans and Leases Receivable, Allowance, Beginning Balance	140	142	146	143	'
Allowance for Loan and Lease Losses, Write-offs	0	0	-5	-3	'
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	0	11	6	'
Allowance for Loan and Lease Losses Write-offs, Net	0	0	6	3	'
Allowance for Loan and Lease Losses, Provision for Loss, Net	-3	-3	-15	-8	'
Allowance for Loan and Lease Losses, Adjustments, Net	0	1	0	2	'
Loans and Leases Receivable, Allowance, Ending Balance	137	140	137	140	'
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]	'	'	'	'	'
Allowance for loan losses, Individually evaluated for impairment	15	28	15	28	'
Allowance for loan losses, Collectively evaluated for impairment	122	112	122	112	'
Allowance for loan losses, Loans acquired with deteriorated credit quality	0	0	0	0	'
Finance receivables and loans, net	33,248	30,059	33,248	30,059	'
Financing Receivable, Individually Evaluated for Impairment	73	251	73	251	'
Financing receivable, Collectively evaluated for impairment	33,175	29,808	33,175	29,808	'
Financing receivable, Loans acquired with deteriorated credit quality	$0	$0	$0	$0	'

Finance_Receivables_And_Loans_4

Finance Receivables And Loans, Net (Schedule Of Sales Of Financing Receivables And Loans) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Financing Receivable, Significant Sales	$1,562	$2	$1,602	$47
Consumer Loans Auto Financing Receivable [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Financing Receivable, Significant Sales	1,562	0	1,562	0
Residential Mortgage [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Financing Receivable, Significant Sales	0	0	40	0
Commercial Loan [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Financing Receivable, Significant Sales	$0	$2	$0	$47

Finance_Receivables_And_Loans_5

Finance Receivables And Loans, Net Finance Receivables And Loans, Net (Schedule of Purchases of Financing Receivables and Loans) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Financing Receivable, Significant Purchases	$83	$0	$98	$0
Residential Mortgage [Member]	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'
Financing Receivable, Significant Purchases	$83	$0	$98	$0

Finance_Receivables_And_Loans_6

Finance Receivables And Loans, Net (Past Due Financing Receivables And Loans) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Millions, unless otherwise specified
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'	'
30 - 59 days past due	$1,289	$1,227	'
60 - 89 days past due	284	286	'
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	283	323	'
Total past due	1,856	1,836	'
Current	97,661	98,491	'
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	99,517	100,327	'
Finance receivables and loans, net	99,518	100,328	95,281
Consumer Loans Auto Financing Receivable [Member]	'	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'	'
30 - 59 days past due	1,179	1,145	'
60 - 89 days past due	243	255	'
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	145	157	'
Total past due	1,567	1,557	'
Current	57,108	54,860	'
Finance receivables and loans, net	58,675	56,417	'
Residential Mortgage [Member]	'	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'	'
30 - 59 days past due	110	82	'
60 - 89 days past due	41	31	'
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	138	124	'
Total past due	289	237	'
Current	7,305	8,206	'
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	7,594	8,443	'
Finance receivables and loans, net	7,595	8,444	'
Commercial Loan [Member]	'	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'	'
30 - 59 days past due	0	0	'
60 - 89 days past due	0	0	'
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	42	'
Total past due	0	42	'
Current	33,248	35,425	'
Finance receivables and loans, net	33,248	35,467	'
Commercial And Industrial Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'	'
30 - 59 days past due	0	0	'
60 - 89 days past due	0	0	'
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	36	'
Total past due	0	36	'
Current	28,453	30,912	'
Finance receivables and loans, net	28,453	30,948	'
Commercial And Industrial Other [Member]	'	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'	'
30 - 59 days past due	0	0	'
60 - 89 days past due	0	0	'
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	0	'
Total past due	0	0	'
Current	1,756	1,664	'
Finance receivables and loans, net	1,756	1,664	'
Commercial Real Estate Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'	'
30 - 59 days past due	0	0	'
60 - 89 days past due	0	0	'
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	6	'
Total past due	0	6	'
Current	3,039	2,849	'
Finance receivables and loans, net	$3,039	$2,855	'

Finance_Receivables_And_Loans_7

Finance Receivables And Loans, Net (Schedule of Financing Receivables, Non Accrual Status) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Finance receivables and loans on nonaccrual status	$621	$725
Consumer Loans Auto Financing Receivable [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Finance receivables and loans on nonaccrual status	355	329
Residential Mortgage [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Finance receivables and loans on nonaccrual status	193	192
Commercial Loan [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Finance receivables and loans on nonaccrual status	73	204
Commercial And Industrial Automobile [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Finance receivables and loans on nonaccrual status	21	116
Commercial And Industrial Other [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Finance receivables and loans on nonaccrual status	51	74
Commercial Real Estate Automobile [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Finance receivables and loans on nonaccrual status	$1	$14

Finance_Receivables_And_Loans_8

Finance Receivables And Loans, Net (Financing Receivable Credit Quality Indicators) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Millions, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	$99,518	$100,328	$95,281
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	99,517	100,327	'
Consumer Loans Auto Financing Receivable [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	58,675	56,417	'
Consumer Loans Auto Financing Receivable [Member] | Performing Financing Receivable [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	58,320	56,088	'
Consumer Loans Auto Financing Receivable [Member] | Nonperforming Financing Receivable [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	355	329	'
Residential Mortgage [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	7,595	8,444	'
Loans and Leases Receivable, Gross, Excluding Fair Value Option Election	7,594	8,443	'
Residential Mortgage [Member] | Performing Financing Receivable [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	7,401	8,251	'
Residential Mortgage [Member] | Nonperforming Financing Receivable [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	$193	$192	'

Finance_Receivables_And_Loans_9

Finance Receivables And Loans, Net (Schedule Of Pass And Criticized Credit Quality Indicators Of Finance Receivables) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Millions, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	$99,518	$100,328	$95,281
Commercial Loan [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	33,248	35,467	'
Commercial And Industrial Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	28,453	30,948	'
Commercial And Industrial Other [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	1,756	1,664	'
Commercial Real Estate Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	3,039	2,855	'
Pass [Member] | Commercial Loan [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	31,318	33,352	'
Pass [Member] | Commercial And Industrial Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	26,879	29,194	'
Pass [Member] | Commercial And Industrial Other [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	1,501	1,388	'
Pass [Member] | Commercial Real Estate Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	2,938	2,770	'
Criticized Member | Commercial Loan [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	1,930	2,115	'
Criticized Member | Commercial And Industrial Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	1,574	1,754	'
Criticized Member | Commercial And Industrial Other [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	255	276	'
Criticized Member | Commercial Real Estate Automobile [Member]	'	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'	'
Finance receivables and loans, net	$101	$85	'

Recovered_Sheet2

Finance Receivables And Loans, Net (Impaired Financing Receivables) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Financing Receivable, Impaired [Line Items]	'	'
Impaired Financing Receivable, Unpaid Principal Balance	$1,271	$1,409
Carrying value before allowance	1,266	1,404
Impaired Financing Receivable, Related Allowance	220	248
Consumer Loans Auto Financing Receivable [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired Financing Receivable, Unpaid Principal Balance	289	281
Carrying value before allowance	289	281
Impaired Financing Receivable, Related Allowance	25	23
Residential Mortgage [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired Financing Receivable, Unpaid Principal Balance	909	924
Carrying value before allowance	904	919
Impaired Financing Receivable, Related Allowance	180	199
Commercial Loan [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired Financing Receivable, Unpaid Principal Balance	73	204
Carrying value before allowance	73	204
Impaired Financing Receivable, Related Allowance	15	26
Commercial And Industrial Automobile [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired Financing Receivable, Unpaid Principal Balance	21	116
Carrying value before allowance	21	116
Impaired Financing Receivable, Related Allowance	1	7
Commercial And Industrial Other [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired Financing Receivable, Unpaid Principal Balance	51	74
Carrying value before allowance	51	74
Impaired Financing Receivable, Related Allowance	14	16
Commercial Real Estate Automobile [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired Financing Receivable, Unpaid Principal Balance	1	14
Carrying value before allowance	1	14
Impaired Financing Receivable, Related Allowance	0	3
Impaired With No Allowance Member	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	133	194
Impaired With No Allowance Member | Consumer Loans Auto Financing Receivable [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	0	0
Impaired With No Allowance Member | Residential Mortgage [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	128	128
Impaired With No Allowance Member | Commercial Loan [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	5	66
Impaired With No Allowance Member | Commercial And Industrial Automobile [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	4	57
Impaired With No Allowance Member | Commercial And Industrial Other [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	0	0
Impaired With No Allowance Member | Commercial Real Estate Automobile [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	1	9
Impaired With Allowance Member	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	1,133	1,210
Impaired With Allowance Member | Consumer Loans Auto Financing Receivable [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	289	281
Impaired With Allowance Member | Residential Mortgage [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	776	791
Impaired With Allowance Member | Commercial Loan [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	68	138
Impaired With Allowance Member | Commercial And Industrial Automobile [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	17	59
Impaired With Allowance Member | Commercial And Industrial Other [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	51	74
Impaired With Allowance Member | Commercial Real Estate Automobile [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Carrying value before allowance	$0	$5

Recovered_Sheet3

Finance Receivables And Loans, Net (Average Balance And Interest Income Of Impaired Finance Receivables) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Financing Receivable, Impaired [Line Items]	'	'	'	'
Impaired Financing Receivable, Average Recorded Investment	$1,297	$1,475	$1,358	$1,441
Impaired Financing Receivable, Interest Income, Accrual Method	12	14	41	43
Consumer Loans Auto Financing Receivable [Member]	'	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'	'
Impaired Financing Receivable, Average Recorded Investment	297	275	298	274
Impaired Financing Receivable, Interest Income, Accrual Method	5	5	14	14
Residential Mortgage [Member]	'	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'	'
Impaired Financing Receivable, Average Recorded Investment	914	924	923	905
Impaired Financing Receivable, Interest Income, Accrual Method	7	7	22	22
Commercial Loan [Member]	'	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'	'
Impaired Financing Receivable, Average Recorded Investment	86	276	137	262
Impaired Financing Receivable, Interest Income, Accrual Method	0	2	5	7
Commercial And Industrial Automobile [Member]	'	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'	'
Impaired Financing Receivable, Average Recorded Investment	32	163	68	160
Impaired Financing Receivable, Interest Income, Accrual Method	0	2	1	5
Commercial And Industrial Other [Member]	'	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'	'
Impaired Financing Receivable, Average Recorded Investment	51	84	62	69
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	4	1
Commercial Real Estate Automobile [Member]	'	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'	'
Impaired Financing Receivable, Average Recorded Investment	3	29	7	33
Impaired Financing Receivable, Interest Income, Accrual Method	$0	$0	$0	$1

Recovered_Sheet4

Finance Receivables and Loans, Net (Troubled Debt Restructurings) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Financing Receivable, Modifications [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Recorded Investment	$1,300,000,000	'	$1,300,000,000	'	$1,300,000,000
Financing Receivable, Modifications, Number of Contracts	4,398	4,735	14,037	15,179	'
Financing Receivable, Modifications, Pre-Modification Recorded Investment	79,000,000	141,000,000	365,000,000	599,000,000	'
Financing Receivable, Modifications, Post-Modification Recorded Investment	69,000,000	128,000,000	330,000,000	520,000,000	'
Consumer Loans Auto Financing Receivable [Member]	'	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Number of Contracts	4,361	4,610	13,681	14,309	'
Financing Receivable, Modifications, Pre-Modification Recorded Investment	72,000,000	69,000,000	223,000,000	216,000,000	'
Financing Receivable, Modifications, Post-Modification Recorded Investment	63,000,000	57,000,000	193,000,000	182,000,000	'
Residential Mortgage [Member]	'	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Number of Contracts	37	121	350	853	'
Financing Receivable, Modifications, Pre-Modification Recorded Investment	7,000,000	33,000,000	71,000,000	246,000,000	'
Financing Receivable, Modifications, Post-Modification Recorded Investment	6,000,000	32,000,000	66,000,000	203,000,000	'
Commercial Loan [Member]	'	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Number of Contracts	0	4	6	17	'
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	39,000,000	71,000,000	137,000,000	'
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	39,000,000	71,000,000	135,000,000	'
Commercial And Industrial Automobile [Member]	'	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Number of Contracts	0	2	3	8	'
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	5,000,000	23,000,000	37,000,000	'
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	5,000,000	23,000,000	37,000,000	'
Commercial And Industrial Other [Member]	'	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Number of Contracts	0	1	3	4	'
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	27,000,000	48,000,000	80,000,000	'
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	27,000,000	48,000,000	78,000,000	'
Commercial Real Estate Automobile [Member]	'	'	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Number of Contracts	0	1	0	5	'
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0	7,000,000	0	20,000,000	'
Financing Receivable, Modifications, Post-Modification Recorded Investment	$0	$7,000,000	$0	$20,000,000	'

Recovered_Sheet5

Finance Receivables And Loans, Net (Redefaults) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1,795	1,566	5,030	4,325	'
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$23	$21	$64	$57	'
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	12	9	33	26	'
Loans and Leases Receivable, Impaired, Commitment to Lend	4	'	4	'	26
Consumer Loans Auto Financing Receivable [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1,790	1,562	5,020	4,309	'
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	22	19	62	53	'
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	12	9	33	26	'
Residential Mortgage [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	5	4	10	16	'
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	1	2	2	4	'
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	0	0	0	0	'
Commercial Loan [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0	0	0	'
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0	'
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	0	0	0	0	'
Commercial And Industrial Automobile [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0	0	0	'
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0	'
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	0	0	0	0	'
Commercial Real Estate [Member]	'	'	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'	'	'
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0	0	0	'
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0	'
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$0	$0	$0	$0	'

Investment_In_Operating_Leases2

Investment In Operating Leases, Net (Investments In Operating Leases) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Leases, Operating [Abstract]	'	'
Property Subject to or Available for Operating Lease, Gross	$22,845	$21,125
Property Subject to or Available for Operating Lease, Accumulated Depreciation	-3,504	-3,445
Property Subject to or Available for Operating Lease, Net	$19,341	$17,680

Investment_In_Operating_Leases3

Investment In Operating Leases, Net (Schedule Of Depreciation Expense On Operating Lease Assets) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Leases, Operating [Abstract]	'	'	'	'
Depreciation Expense On Operating Lease Assets	$654	$610	$1,982	$1,699
Gross Remarketing (Gains) Losses	-105	-95	-382	-250
Depreciation expense on operating lease assets	$549	$515	$1,600	$1,449

Securitizations_And_Variable_I2

Securitizations And Variable Interest Entities (Schedule Of Variable Interest Entities) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]	'	'
Assets of nonconsolidated variable interest entities	$2,032	$899
Maximum exposure to loss in nonconsolidated VIEs	2,323	939
Total consoldiated involvement with VIEs	49,951	40,123
Other Assets	6,752	9,589
Consumer Loans Auto Financing Receivable [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Variable Interest Entity, Consolidated, Carrying Amount, Assets	33,331	19,072
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	0	0
Assets of nonconsolidated variable interest entities	2,032	899
Maximum exposure to loss in nonconsolidated VIEs	2,032	899
Continuing Involvement with Continued to be Recognized Transferred Financial Assets, Amount Outstanding	14,300	'
Commercial Automobile [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Variable Interest Entity, Consolidated, Carrying Amount, Assets	16,499	20,511
Commercial Other [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Variable Interest Entity, Consolidated, Carrying Amount, Assets	0	564
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	121	-24
Assets of nonconsolidated variable interest entities	0	0
Maximum exposure to loss in nonconsolidated VIEs	291	40
Other Assets	143	0
Accrued Liabilities	$22	$24

Securitizations_And_Variable_I3

Securitizations And Variable Interest Entities (Schedule Of Cash Flow Received and Paid To Nonconsolidated Securitization Entities) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Consumer Loans Auto Financing Receivable [Member]	'	'
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]	'	'
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	$1,557	$0
Cash Flows Between Transferor and Transferee, Servicing Fees	6	10
Representations and warranties obligations	0	0
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	'	0
US Government-sponsored Enterprises [Member]	'	'
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]	'	'
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	0	8,676
Cash Flows Between Transferor and Transferee, Servicing Fees	0	68
Representations and warranties obligations	-9	-65
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	'	$70

Securitizations_And_Variable_I4

Securitizations And Variable Interest Entities (Schedule Of Quantitative Information and Net Credit Losses about Securitized and Other Financial Assets Managed Together) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	$102,791	'	$102,791	'	$104,110
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	609	'	609	'	690
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	150	130	373	354	'
On-Balance Sheet Loans [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	99,521	'	99,521	'	100,363
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	569	'	569	'	618
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	149	126	367	343	'
On-Balance Sheet Loans [Member] | Consumer Loans Auto Financing Receivable [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	58,675	'	58,675	'	56,417
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	388	'	388	'	412
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	137	115	341	288	'
On-Balance Sheet Loans [Member] | Residential Mortgage [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	7,598	'	7,598	'	8,460
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	181	'	181	'	164
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	12	11	32	58	'
On-Balance Sheet Loans [Member] | Commercial Automobile [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	31,492	'	31,492	'	33,803
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	0	'	0	'	42
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	0	0	1	0	'
On-Balance Sheet Loans [Member] | Commercial Other [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	1,756	'	1,756	'	1,683
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	0	'	0	'	0
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	0	0	-7	-3	'
Off-Balance Sheet Loans [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	2,032	'	2,032	'	899
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	3	'	3	'	3
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	0	1	1	3	'
Off-Balance Sheet Loans [Member] | Consumer Loans Auto Financing Receivable [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	2,032	'	2,032	'	899
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	3	'	3	'	3
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	0	1	1	3	'
Whole-Loan Transactions [Member]	'	'	'	'	'
Quantitative Information about Securitized and Other Financial Assets Managed Together [Line Items]	'	'	'	'	'
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	1,238	'	1,238	'	2,848
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	37	'	37	'	69
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	$1	$3	$5	$8	'

Servicing_Activities_Schedule_

Servicing Activities (Schedule Of Servicing Assets at Fair Value) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Servicing Activities [Abstract]	'	'
Estimated fair value, Beginning Balance	$0	$952
Servicing Asset at Fair Value, Additions	0	60
Servicing Asset at Fair Value, Disposals	0	-911
Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions	0	-32
Servicing Asset at Fair Value, Other Changes in Fair Value	0	-69
Estimated fair value, Ending Balance	$0	$0

Servicing_Activities_Component

Servicing Activities (Components Of Servicing Valuation And Hedge Activities) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Components of Servicing Valuation and Hedge Activities [Line Items]	'	'	'	'
Net realized/unrealized gains (losses) included in earnings, Assets	$4	$55	$9	($93)
Servicing asset valuation and hedge activities, net	0	0	0	-213
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]	'	'	'	'
Components of Servicing Valuation and Hedge Activities [Line Items]	'	'	'	'
Servicing asset valuation and hedge activities, net	0	0	0	-112
Mortgage Servicing Rights [Member]	'	'	'	'
Components of Servicing Valuation and Hedge Activities [Line Items]	'	'	'	'
Net realized/unrealized gains (losses) included in earnings, Assets	$0	$0	$0	($101)

Servicing_Activities_Component1

Servicing Activities (Components Of Mortgage Servicing Fees) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Servicing Activities [Abstract]	'	'	'	'
Contractual servicing fees, net of guarantee fees and including subservicing	$0	$0	$0	$61
Late fees	0	0	0	1
Ancillary fees	0	0	0	4
Total mortgage servicing fees	$0	$0	$0	$66

Servicing_Activities_Narrative

Servicing Activities (Narrative - Automobile Servicing Activities) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Servicing Activities [Abstract]	'	'	'	'
Automobile Servicing Fees	$6	$13	$22	$48

Servicing_Activities_Schedule_1

Servicing Activities (Schedule Of Total Serviced Automobile Loans Outstanding) (Details) (Automobile Member, USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Automobile Serviced Assets [Line Items]	'	'
Total Primary Serviced Assets	$112,801	$111,589
On-Balance Sheet Loans [Member] | Consumer Loans Auto Financing Receivable [Member]	'	'
Automobile Serviced Assets [Line Items]	'	'
Total Primary Serviced Assets	58,675	56,417
On-Balance Sheet Loans [Member] | Commercial Automobile [Member]	'	'
Automobile Serviced Assets [Line Items]	'	'
Total Primary Serviced Assets	31,492	33,803
On-Balance Sheet Loans [Member] | Operating Leases [Member]	'	'
Automobile Serviced Assets [Line Items]	'	'
Total Primary Serviced Assets	19,341	17,680
On-Balance Sheet Loans [Member] | Other Assets [Member]	'	'
Automobile Serviced Assets [Line Items]	'	'
Total Primary Serviced Assets	52	54
Off-Balance Sheet Loans [Member] | Securitizations [Member]	'	'
Automobile Serviced Assets [Line Items]	'	'
Total Primary Serviced Assets	2,052	887
Off-Balance Sheet Loans [Member] | Whole-Loan Transactions [Member]	'	'
Automobile Serviced Assets [Line Items]	'	'
Total Primary Serviced Assets	$1,189	$2,748

Other_Assets_Schedule_Of_Other

Other Assets (Schedule Of Other Assets) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other Assets [Abstract]	'	'
Property, Plant and Equipment, Gross	$754	$709
Accumulated depreciation	-529	-474
Property, Plant and Equipment, Net	225	235
Deferred Tax Assets, State Taxes	1,788	2,040
Restricted cash collections for securitization trusts	1,724	3,664
Other accounts receivable	369	290
Cash reserve deposits held for securitization trusts	296	402
Nonmarketable equity securities	275	337
Unamortized Debt Issuance Expense	254	312
Cash and securities collateral placed with counterparties	243	328
Derivative Asset, Fair Value, Gross Asset	235	362
Restricted cash and cash equivalents	123	205
Other Assets, Miscellaneous	1,220	1,414
Other Assets	$6,752	$9,589

Deposit_Liabilities_Schedule_O

Deposit Liabilities (Schedule Of Deposit Liabilities) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Deposits [Abstract]	'	'
Noninterest-bearing deposit liabilities	$73,000,000	$60,000,000
Interest-bearing Deposit Liabilities, by Component [Abstract]	'	'
Deposits, Savings Deposits	25,383,000,000	21,210,000,000
Time Deposits	31,027,000,000	31,640,000,000
Deposits, Retail	368,000,000	440,000,000
Total deposit liabilities	56,851,000,000	53,350,000,000
Time Deposits, $100,000 or More	$13,100,000,000	$13,100,000,000

ShortTerm_Borrowings_Schedule_

Short-Term Borrowings (Schedule of Short-term Debt) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Short-term Debt [Line Items]	'	'
Demand Notes	$3,376	$3,225
Federal Home Loan Bank, Advances, Short-term	1,300	3,570
Securities Sold under Agreements to Repurchase, Gross	579	1,500
Other Short-term Borrowings	0	250
Short-term borrowings	5,255	8,545
Unsecured Debt [Member]	'	'
Short-term Debt [Line Items]	'	'
Demand Notes	3,376	3,225
Federal Home Loan Bank, Advances, Short-term	0	0
Securities Sold under Agreements to Repurchase, Gross	0	0
Other Short-term Borrowings	0	0
Short-term borrowings	3,376	3,225
Secured Debt [Member]	'	'
Short-term Debt [Line Items]	'	'
Demand Notes	0	0
Federal Home Loan Bank, Advances, Short-term	1,300	3,570
Securities Sold under Agreements to Repurchase, Gross	579	1,500
Other Short-term Borrowings	0	250
Short-term borrowings	$1,879	$5,320

LongTerm_Debt_LongTerm_Debt_Po

Long-Term Debt (Long-Term Debt Portfolio) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'
Long-term Debt, Current Maturities	$18,370	$17,172
Long-term Debt, Excluding Current Maturities	48,515	51,848
Derivative, Amount of Hedged Item	414	445
Long-term debt	67,299	69,465
Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Current Maturities	6,572	5,321
Long-term Debt, Excluding Current Maturities	17,065	21,425
Derivative, Amount of Hedged Item	414	445
Long-term debt	24,051	27,191
Secured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Current Maturities	11,798	11,851
Long-term Debt, Excluding Current Maturities	31,450	30,423
Derivative, Amount of Hedged Item	0	0
Long-term debt	43,248	42,274
Trust Preferred Securities Subject to Mandatory Redemption [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term Debt, Excluding Current Maturities	$2,600	$2,600

LongTerm_Debt_Scheduled_Remain

Long-Term Debt (Scheduled Remaining Maturity Of Long-Term Debt) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'
2014	$4,554	'
2015	17,694	'
2016	12,274	'
2017	13,996	'
2018	4,963	'
2019 and thereafter	13,404	'
Derivative, Amount of Hedged Item	414	445
Long-term debt	67,299	69,465
Unsecured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
2014	1,706	'
2015	4,862	'
2016	1,866	'
2017	4,297	'
2018	1,185	'
2019 and thereafter	9,721	'
Derivative, Amount of Hedged Item	414	445
Long-term debt	24,051	27,191
Unsecured Debt [Member] | Long-term Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
2014	1,746	'
2015	4,920	'
2016	1,934	'
2017	4,377	'
2018	1,278	'
2019 and thereafter	10,837	'
Derivative, Amount of Hedged Item	414	'
Long-term debt	25,506	'
Unsecured Debt [Member] | Original Issue Discount [Member]	'	'
Debt Instrument [Line Items]	'	'
2014	-40	'
2015	-58	'
2016	-68	'
2017	-80	'
2018	-93	'
2019 and thereafter	-1,116	'
Derivative, Amount of Hedged Item	0	'
Long-term debt	-1,455	'
Secured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Derivative, Amount of Hedged Item	0	0
Long-term debt	43,248	42,274
Secured Debt [Member] | Long-term Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
2014	2,848	'
2015	12,832	'
2016	10,408	'
2017	9,699	'
2018	3,778	'
2019 and thereafter	3,683	'
Derivative, Amount of Hedged Item	0	'
Long-term debt	$43,248	'

LongTerm_Debt_Pledged_Assets_R

Long-Term Debt (Pledged Assets Related to Secured Borrowings And Repurchase Agreement) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Financial Instruments, Not Separately Reported, Other Debt Securities Available-for-sale or Held-for-investment	$584	$2,864
Pledged Assets, Mortgage assets held for investment	7,708	8,524
Pledged Assets, Investment in operating leases	4,925	5,810
Pledged Assets, Not Separately Reported, Other	0	563
Pledged Assets, Other, Not Separately Reported on Statement of Financial Position	66,252	71,957
Secured Debt	45,127	47,594
Short-term borrowings	5,255	8,545
Ally Bank [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Financial Instruments, Not Separately Reported, Other Debt Securities Available-for-sale or Held-for-investment	584	2,864
Pledged Assets, Mortgage assets held for investment	7,708	8,524
Pledged Assets, Investment in operating leases	3,967	3,190
Pledged Assets, Not Separately Reported, Other	0	0
Pledged Assets, Other, Not Separately Reported on Statement of Financial Position	43,076	48,159
Secured Debt	24,420	27,818
Pledged assets for Federal Home Loan Bank [Member] | Ally Bank [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Assets, Other, Not Separately Reported on Statement of Financial Position	10,700	12,700
Pledged assets for Federal Reserve Bank [Member] | Ally Bank [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Assets, Other, Not Separately Reported on Statement of Financial Position	3,300	3,200
Secured Debt [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Short-term borrowings	1,879	5,320
Consumer Loans Auto Financing Receivable [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Assets, Not Separately Reported, Finance Receivables	33,749	32,947
Consumer Loans Auto Financing Receivable [Member] | Ally Bank [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Assets, Not Separately Reported, Finance Receivables	12,047	12,332
Commercial Automobile [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Assets, Not Separately Reported, Finance Receivables	19,286	21,249
Commercial Automobile [Member] | Ally Bank [Member]	'	'
Pledged Assets related to secured borrowings [Line Items]	'	'
Pledged Assets, Not Separately Reported, Finance Receivables	$18,770	$21,249

LongTerm_Debt_Committed_Fundin

Long-Term Debt (Committed Funding Facilities) (Details) (Committed Funding Facilities [Member], USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'
Outstanding	$17,613	$17,909
Unused capacity	5,017	6,747
Total capacity	22,630	24,656
Bank Funding Member | Secured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Outstanding	3,000	2,750
Unused capacity	500	250
Total capacity	3,500	3,000
Nonbank Funding [Member] | Secured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Outstanding	14,613	15,159
Unused capacity	4,517	6,497
Total capacity	19,130	21,656
Revolving secured funding facilities [Member]	'	'
Debt Instrument [Line Items]	'	'
Total capacity	20,900	'
Revolving secured funding facilities 1 year or greater [Member]	'	'
Debt Instrument [Line Items]	'	'
Total capacity	$15,100	'

Accrued_Expenses_and_Other_Lia2

Accrued Expenses and Other Liabilities (Schedule of Accrued Expenses and Other Liabilities) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Accounts Payable and Accrued Liabilities [Abstract]	'	'
Accounts Payable	$333	$414
Derivative Liability, Fair Value, Gross Liability	299	317
Accrued Employee Benefits	255	437
Liability for Claims and Claims Adjustment Expense	229	275
Deferred Revenue	147	122
Cash collateral received from counterparties	17	159
Other Accrued Liabilities	409	673
Accrued expenses and other liabilities	1,689	2,397
ResCap settlement accrual for insurance proceeds	'	$150

Preferred_Stock_Schedule_Of_Pr

Preferred Stock (Schedule Of Preferred Stock) (Details) (USD $)	9 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Capitalization, Equity [Line Items]	'	'
Preferred stock	$1,255	$1,255
Preferred Stock, Shares Authorized	41,000,000	'
Series A Preferred Stock [Member]	'	'
Schedule of Capitalization, Equity [Line Items]	'	'
Preferred stock	1,021	1,021
Preferred stock par value (per share)	$0.01	$0.01
Liquidation preference (per share)	$25	$25
Preferred Stock, Shares Authorized	40,870,560	160,870,560
Preferred Stock, Shares Issued and Outstanding	40,870,560	40,870,560
Preferred Stock, Dividend Rate, Percentage	8.50%	8.50%
Preferred Stock, Dividend Payment Rate, Variable	'Three month LIBORB +B 6.243%	'Three month LIBORB +B 6.243%
Series G Preferred Stock [Member]	'	'
Schedule of Capitalization, Equity [Line Items]	'	'
Preferred stock	$234	$234
Preferred stock par value (per share)	$0.01	$0.01
Liquidation preference (per share)	$1,000	$1,000
Preferred Stock, Shares Authorized	2,576,601	2,576,601
Preferred Stock, Shares Issued and Outstanding	2,576,601	2,576,601
Preferred Stock, Dividend Rate, Percentage	7.00%	7.00%

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) Rollforward (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract]	'	'	'	'
Beginning Balance Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	'	'	($269)	$76
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	-54	12	148	-323
Ending Balance Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	-121	-247	-121	-247
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]	'	'	'	'
Beginning Balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	'	'	65	368
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	'	'	-27	-216
Ending Balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	38	152	38	152
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]	'	'	'	'
Beginning Balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	'	'	5	2
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	'	'	1	3
Ending Balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	6	5	6	5
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract]	'	'	'	'
Beginning Balance Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	'	'	-77	-135
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	'	'	4	42
Ending Balance Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	-73	-93	-73	-93
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'	'	'	'
Beginning Balance Accumulated Other Comprehensive Income (Loss), Net of Tax	'	'	-276	311
Other comprehensive income (loss), net of tax	-55	4	126	-494
Ending Balance Accumulated Other Comprehensive Income (Loss), Net of Tax	($150)	($183)	($150)	($183)

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Loss) Before and After Tax (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	($15)	$46	$358	($289)
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax	45	41	129	156
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Discontinued Operations, before Tax	'	'	'	10
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, Portion Attributable to Parent	-60	5	229	-455
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	5	7	-89	128
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Tax	-1	0	-8	-2
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Discontinued Operations, Tax	'	'	'	-2
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax, Portion Attributable to Parent	6	7	-81	132
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	-10	53	269	-161
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	44	41	121	154
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Discontinued Operations, Net of Tax	'	'	'	8
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	-54	12	148	-323
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	-11	5	-21	-98
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, before Tax	'	'	23	345
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent	'	'	-44	-443
Other Comprehensive Income Unrealized Gain Loss On Net Investment Hedges Arising During the Period, Before Tax	8	-14	10	52
Other Comprehensive Income (Loss), Reclassification Adjustment for Net Investment Hedges Included in Net Income, Discontinued Operation, before Tax	'	'	'	-261
Other Comprehensive Income (Loss), Net Investment Hedges Attributable to Parent, before Tax	'	'	'	313
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	4	-2	8	21
Other Comprehensive Income (Loss), Foreign Currency Translation Reclassification Adjustment Realized upon Sale or Liquidation, Tax	'	'	-3	2
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent	'	'	11	19
Other Comprehensive Income Unrealized Gain Loss On Net Investment Hedges Arising During the Period, Tax	-3	6	-4	-19
Other Comprehensive Income (Loss), Reclassification Adjustment for Net Investment Hedges Included in Net Income, Discontinued Operation, Tax	'	'	'	86
Other Comprehensive Income (Loss), Net Investment Hedges Attributable to Parent, Tax	'	'	'	-105
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	-7	3	-13	-77
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, Net of Tax	'	'	20	347
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	'	'	-33	-424
Other Comprehensive Income Unrealized Gain Loss On Net Investment Hedges Arising During the Period Net of Tax	5	-8	6	33
Other Comprehensive Income (Loss), Reclassification Adjustment for Net Investment Hedges Included in Net Income, Discontinued Operation, Net of Tax	'	'	'	-175
Other Comprehensive Income (Loss), Net Investment Hedges Attributable to Parent, Net of Tax	'	'	'	208
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	1	-4	1	-1
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	'	'	'	-7
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	'	'	'	6
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Effect [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	0	1	0	0
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax	'	'	'	3
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	'	'	'	-3
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	1	-3	1	-1
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	'	'	'	-4
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	'	'	1	3
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	'	'	'	2
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	'	'	-7	-2
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans Included in Net Income, Discontinued Operations, before Tax	'	'	'	-49
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent	'	'	'	53
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax	'	'	'	0
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Tax	'	'	3	0
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans Included in Net Income, Discontinued Operations, Tax	'	'	'	11
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax, Portion Attributable to Parent	'	'	'	-11
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	'	'	'	2
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax	'	'	-4	-2
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans Included in Net Income, Discontinued Operations, Net of Tax	'	'	'	-38
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	'	'	4	42
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	-62	-8	203	-526
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	7	12	-77	32
Other comprehensive income (loss), net of tax	($55)	$4	$126	($494)

Earnings_Per_Common_Share_Sche

Earnings Per Common Share (Schedule Of Basic And Diluted Earnings Per Common Share) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income (loss) from continuing operations	$293	$177	$774	$337
Preferred stock dividends - U.S. Department of Treasury	0	-134	0	-401
Preferred stock dividends	-67	-67	-200	-200
Net income (loss) from continuing operations attributable to common shareholders	226	-24	574	-264
Income (loss) from discontinued operations, net of tax	130	-86	199	-80
Net income (loss) attributable to common shareholders	$356	($110)	$773	($344)
Basic weighted-average common shares outstanding	481,611,138	412,600,700	480,916,395	412,600,700
Diluted weighted-average common shares outstanding	482,506,091	412,600,700	481,545,506	412,600,700
Earnings Per Share, Basic [Abstract]	'	'	'	'
Net income (loss) from continuing operations, Per Basic Share	$0.47	($0.06)	$1.19	($0.64)
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	$0.27	($0.21)	$0.41	($0.19)
Net (loss) income, Basic	$0.74	($0.27)	$1.60	($0.83)
Earnings Per Share, Diluted [Abstract]	'	'	'	'
Net income (loss) from continuing operations, Per Diluted Share	$0.47	($0.06)	$1.19	($0.64)
Income (loss) from discontinued operations, net of tax, Diluted	$0.27	($0.21)	$0.41	($0.19)
Net (loss) income, Diluted	$0.74	($0.27)	$1.60	($0.83)
Potential common shares excluded from diluted earnings per share calculation	'	178,000,000	'	'

Regulatory_Capital_Schedule_Of

Regulatory Capital (Schedule Of Regulatory Capital Amount And Ratios) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
assets greater than $50 billion	$50,000,000,000	'
Minimum [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier 1 common (to risk-weighted assets), Ratio	5.00%	'
Parent Company [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier 1 (to risk-weighted assets), Amount	16,227,000,000	15,165,000,000
Tier 1 (to risk-weighted assets), Ratio	12.65%	11.79%
Tier 1 (to risk-weighted assets), Required minimum	4.00%	'
Tier 1 (to risk-weighted assets), Well-capitalized minimum	6.00%	'
Total (to risk-weighted assets), Amount	17,275,000,000	16,405,000,000
Total (to risk-weighted assets), Ratio	13.47%	12.76%
Total (to risk-weighted assets), Required minimum	8.00%	'
Total (to risk-weighted assets), Well-capitalized minimum	10.00%	'
Tier 1 leverage (to adjusted average assets), Amount	16,227,000,000	15,165,000,000
Tier 1 leverage (to adjusted average assets), Ratio	10.91%	10.23%
Tier 1 common (to risk-weighted assets), Amount	12,427,000,000	11,366,000,000
Tier 1 common (to risk-weighted assets), Ratio	9.69%	8.84%
Parent Company [Member] | Minimum [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	3.00%	'
Parent Company [Member] | Maximum [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	'
Ally Bank [Member]	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Tier 1 (to risk-weighted assets), Amount	15,898,000,000	15,159,000,000
Tier 1 (to risk-weighted assets), Ratio	17.32%	16.73%
Tier 1 (to risk-weighted assets), Required minimum	4.00%	'
Tier 1 (to risk-weighted assets), Well-capitalized minimum	6.00%	'
Total (to risk-weighted assets), Amount	16,493,000,000	15,809,000,000
Total (to risk-weighted assets), Ratio	17.97%	17.45%
Total (to risk-weighted assets), Required minimum	8.00%	'
Total (to risk-weighted assets), Well-capitalized minimum	10.00%	'
Tier 1 leverage (to adjusted average assets), Amount	15,898,000,000	15,159,000,000
Tier 1 leverage (to adjusted average assets), Ratio	15.71%	15.77%
Tier 1 Leverage To Average Assets For Ally Bank	15.00%	'
Tier 1 leverage (to adjusted average assets), Well-capitalized minimum	5.00%	'
Tier 1 common (to risk-weighted assets), Amount	$15,898,000,000	$15,159,000,000
Tier 1 common (to risk-weighted assets), Ratio	17.32%	16.73%

Derivative_Instruments_And_Hed1

Derivative Instruments And Hedging Activities (Narrative) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Forward Contract Indexed to Issuer's Equity [Line Items]	'	'
Cash and securities collateral placed with counterparties	$243	$328
Non-derivative collateral placed with counterparties	18	18
Cash collateral received from counterparties	17	159
noncash collateral received	7	18
Other Assets [Member]	'	'
Forward Contract Indexed to Issuer's Equity [Line Items]	'	'
Prepaid Expense	$89	'

Derivative_Instruments_And_Hed2

Derivative Instruments And Hedging Activities (Fair Value Amounts Of Derivative Instruments Reported On Our Condensed Consolidated Balance Sheet) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	$235,000,000	$362,000,000
Derivative Liability, Fair Value, Gross Liability	299,000,000	317,000,000
Notional amount	105,552,000,000	101,221,000,000
Accrued Interest [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	51,000,000	120,000,000
Derivative Liability, Fair Value, Gross Liability	9,000,000	12,000,000
Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	74,000,000	207,000,000
Derivative Liability, Fair Value, Gross Liability	51,000,000	169,000,000
Notional amount	20,263,000,000	21,932,000,000
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	71,000,000	204,000,000
Derivative Liability, Fair Value, Gross Liability	51,000,000	169,000,000
Notional amount	19,959,000,000	21,606,000,000
Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	3,000,000	3,000,000
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	304,000,000	326,000,000
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Receive-fixed Swaps, Fair Value, Gross Asset	43,000,000	196,000,000
Receive-fixed Swaps, Fair Value, Gross Liability	46,000,000	163,000,000
Receive-fixed Swaps, Notional Amount	5,900,000,000	8,500,000,000
Pay-fixed Swaps, Fair Value, Gross Asset	28,000,000	9,000,000
Pay-fixed Swaps, Fair Value, Gross Liability	5,000,000	5,000,000
Pay-fixed Swaps, Notional Amount	14,100,000,000	12,600,000,000
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Pay-fixed Swaps, Fair Value, Gross Liability	'	1,000,000
Pay-fixed Swaps, Notional Amount	'	495,000,000
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	134,000,000	142,000,000
Derivative Liability, Fair Value, Gross Liability	143,000,000	141,000,000
Notional amount	83,650,000,000	77,543,000,000
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	22,000,000	13,000,000
Derivative Liability, Fair Value, Gross Liability	96,000,000	2,000,000
Notional amount	1,549,000,000	1,743,000,000
Equity Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	5,000,000	0
Derivative Liability, Fair Value, Gross Liability	9,000,000	5,000,000
Notional amount	90,000,000	3,000,000
Interest Rate Swap [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	33,000,000	36,000,000
Derivative Liability, Fair Value, Gross Liability	49,000,000	44,000,000
Notional amount	12,649,000,000	13,613,000,000
Futures and Forwards [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	6,000,000	11,000,000
Derivative Liability, Fair Value, Gross Liability	0	3,000,000
Notional amount	12,253,000,000	29,836,000,000
Written Options [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	94,000,000	94,000,000
Notional amount	28,651,000,000	11,132,000,000
Written Options [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	0	17,000,000
Written Options [Member] | Equity Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	3,000,000	5,000,000
Notional amount	1,000,000	3,000,000
Purchased Options [Member] | Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	95,000,000	95,000,000
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	30,097,000,000	22,962,000,000
Purchased Options [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	0	17,000,000
Purchased Options [Member] | Equity Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	5,000,000	0
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	0	0
Forward Contracts [Member] | Equity Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	6,000,000	0
Notional amount	89,000,000	0
Swap [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	15,000,000	12,000,000
Derivative Liability, Fair Value, Gross Liability	92,000,000	1,000,000
Notional amount	1,263,000,000	1,379,000,000
Foreign Exchange Forward [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	7,000,000	1,000,000
Derivative Liability, Fair Value, Gross Liability	4,000,000	1,000,000
Notional amount	286,000,000	330,000,000
Other Trading [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	161,000,000	155,000,000
Derivative Liability, Fair Value, Gross Liability	248,000,000	148,000,000
Notional amount	$85,289,000,000	$79,289,000,000

Derivative_Instruments_And_Hed3

Derivative Instruments And Hedging Activities (Statement Of Gains and Losses on Derivative Instruments Reported in Statement of Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Interest and Fee Income, Loans and Leases	$1,114	$1,119	$3,345	$3,393
Interest on long-term debt	-493	-609	-1,576	-2,013
Servicing asset valuation and hedge activities, net	0	0	0	-213
Gain (loss) on mortgage and automotive loans, net	0	15	6	52
Other income, net of losses	78	93	214	324
Gain (Loss) on Equity Forward Contract Not Designated as Hedging Instruments	-6	0	-6	0
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments	-5	20	-24	-123
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	-100	48	-109	96
Gain (Loss) on Derivative Instruments, Net, Pretax	-88	64	-91	-18
Interest Gain For Qualifying Accounting Hedges Of Debt	27	33	89	94
Gains on amortization of deferred basis adjustments on the hedged items	38	112	120	188
Gain (Loss) from Revaulation of Foreign-Denominated Debt or Receivable	102	-47	112	-94
Designated as Hedging Instrument [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	23	-4	48	9
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Gain (Loss) Recognized in Earnings on Derivatives [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Interest and Fee Income, Loans and Leases	28	3	22	3
Interest on long-term debt	-39	11	102	-302
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Gain (Loss) Recognized in Earnings on Hedged Item [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Interest and Fee Income, Loans and Leases	-15	-3	14	-3
Interest on long-term debt	49	-15	-90	311
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Gain (loss) Excluded from Earnings on Derivatives [Domain]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Interest and Fee Income, Loans and Leases	16	1	43	1
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Servicing asset valuation and hedge activities, net	0	0	0	-112
Gain (loss) on mortgage and automotive loans, net	0	0	0	-37
Other income, net of losses	-5	20	-24	26
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Interest on long-term debt	-108	52	-117	71
Other income, net of losses	8	-4	8	25
Forward Contracts [Member] | Not Designated as Hedging Instrument [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Other income, net of losses	($6)	$0	($6)	$0

Derivative_Instruments_And_Hed4

Derivative Instruments And Hedging Activities (Derivative Instruments Used In Net Investment Hedge Accounting Relationships) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Cumulative Translation Adjustment, Net of Tax, Period Increase (Decrease)	($10)	$9	($37)	($530)
Interest Rate Contract [Member] | Cash Flow Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	-1	0	-1	-7
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0	0	0	1
Cash flow hedges, total interest on long-term debt	-1	0	-1	-6
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	1	-4	1	6
Foreign Exchange Contract [Member] | Net Investment Hedging [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0	0	-261
Net Investment Hedges - Total Other Income, Net of Losses	0	0	0	-261
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$8	($14)	$10	$313

Income_Taxes_Income_Tax_Expens

Income Taxes (Income Tax Expense) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'	'	'	'
Income tax expense (benefit) from continuing operations	$127	$28	$285	($55)

Sharebased_Compensation_Plans_1

Share-based Compensation Plans (Details) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Apr. 10, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
			Restricted Stock Units (RSUs) [Member]	Restricted Stock Units (RSUs) [Member]	Deferred Stock Unit [Member]	Deferred Stock Unit [Member]	Incentive Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'
Share-based Compensation	'	'	$9	$35	$11	$27	($3)
Share Price	$23.14	$23.98	'	'	'	'	'
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition	$62	'	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	'	'	4,000,000	4,000,000	3,000,000	3,000,000	1,000,000
Pecent of TARP obligation that must be paid to receive 25% IRSU compensation	25.00%	'	'	'	'	'	'
TARP Repayment	75.00%	'	'	'	'	'	'

Fair_Value_Fair_Value_Measurme

Fair Value (Fair Value Measurment - Recurring Basis) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	$16,714	$17,083
Available-for-sale, Equity Investment in Any One Industry Did Not Exceed Percentage	19.00%	19.00%
Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	16,714	17,083
Mortgage loans held-for-sale, net	3	16
Retained Interest, Fair Value Disclosure	61	100
Derivative Assets	235	362
Securities Held as Collateral, at Fair Value	81	133
Assets, Fair Value Disclosure	17,094	17,694
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-299	-317
Liabilities, Fair Value Disclosure	-394	-317
Fair Value, Measurements, Recurring [Member] | Other Liabilities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-95	'
Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-194	-310
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-96	-2
Fair Value, Measurements, Recurring [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-9	-5
Fair Value, Measurements, Recurring [Member] | Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	15,986	16,139
Fair Value, Measurements, Recurring [Member] | US Treasury and Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	1,286	1,427
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	402	315
Fair Value, Measurements, Recurring [Member] | Foreign Government Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	232	288
Fair Value, Measurements, Recurring [Member] | Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	10,884	10,782
Fair Value, Measurements, Recurring [Member] | Commercial Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	212	39
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	1,987	2,219
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	983	1,069
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	728	944
Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	205	346
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	25	16
Fair Value, Measurements, Recurring [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	5	'
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	1,070	1,261
Mortgage loans held-for-sale, net	0	0
Retained Interest, Fair Value Disclosure	0	0
Derivative Assets	43	46
Securities Held as Collateral, at Fair Value	0	0
Assets, Fair Value Disclosure	1,113	1,307
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-45	-20
Liabilities, Fair Value Disclosure	-140	-20
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Liabilities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-95	'
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-42	-15
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-3	-5
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	342	317
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury and Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	332	310
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	10	7
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	728	944
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	38	46
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	5	'
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	15,644	15,822
Mortgage loans held-for-sale, net	3	16
Retained Interest, Fair Value Disclosure	0	0
Derivative Assets	192	223
Securities Held as Collateral, at Fair Value	81	133
Assets, Fair Value Disclosure	15,920	16,194
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-254	-203
Liabilities, Fair Value Disclosure	-254	-203
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Liabilities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	'
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-152	-201
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-96	-2
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	-6	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	15,644	15,822
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury and Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	954	1,117
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	402	315
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Government Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	222	281
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	10,884	10,782
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	212	39
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	1,987	2,219
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	983	1,069
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	167	207
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	25	16
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	0	'
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Mortgage loans held-for-sale, net	0	0
Retained Interest, Fair Value Disclosure	61	100
Derivative Assets	0	93
Securities Held as Collateral, at Fair Value	0	0
Assets, Fair Value Disclosure	61	193
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	-94
Liabilities, Fair Value Disclosure	0	-94
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Liabilities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	'
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	-94
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury and Government [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	0	93
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Exchange Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets	$0	'

Fair_Value_Fair_Value_Measurem

Fair Value (Fair Value Measurement - Reconciliation of Level 3 Assets And Liabilities) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, Assets, Beginning balance	$74	$115	$99	$1,151
Net realized/unrealized gains (losses) included in earnings, Assets	4	55	9	-93
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0	0	0
Purchases, Assets	0	0	0	0
Sales, Assets	0	0	0	-911
Issuances, Assets	0	0	0	60
Settlements, Assets	-17	8	-50	-29
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	'	3	'
Fair Value, Assets, Ending balance	61	178	61	178
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	47	0	38
Mortgage Servicing Rights [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, Assets, Beginning balance	'	'	'	952
Net realized/unrealized gains (losses) included in earnings, Assets	0	0	0	-101
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	'	'	'	0
Purchases, Assets	'	'	'	0
Sales, Assets	'	'	'	-911
Issuances, Assets	'	'	'	60
Settlements, Assets	'	'	'	0
Fair Value, Assets, Ending balance	'	0	'	0
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	'	'	'	0
Retained Interest [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, Assets, Beginning balance	74	124	100	154
Net realized/unrealized gains (losses) included in earnings, Assets	4	8	9	19
Net realized/unrealized gains (losses) included in other comprehensive income, Assets	0	0	0	0
Purchases, Assets	0	0	0	0
Sales, Assets	0	0	0	0
Issuances, Assets	0	0	0	0
Settlements, Assets	-17	-11	-48	-52
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	0	'	0	'
Fair Value, Assets, Ending balance	61	121	61	121
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Derivative Financial Instruments, Assets [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, Net Derivative Asset (Liability), Beginning balance	'	-9	'	45
Gain (Loss) Included in Earnings, Net Derivative Asset (Liability)	'	47	'	-11
Gain (Loss) Included in Other Comprehensive Income (Loss), Net Derivative Asset (Liability)	'	0	'	0
Purchases, Net Derivative Asset (Liability)	'	0	'	0
Sales, Net Derivative Asset (Liability)	'	0	'	0
Issuances, Net Derivative Asset (Liability)	'	0	'	0
Settlements, Net Derivative Asset (Liability)	'	19	'	23
Fair Value, Net Derivative Asset (Liability), Ending balance	'	57	'	57
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	'	47	'	38
Interest Rate Contract [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, Net Derivative Asset (Liability), Beginning balance	'	'	-1	47
Gain (Loss) Included in Earnings, Net Derivative Asset (Liability)	'	'	0	-51
Gain (Loss) Included in Other Comprehensive Income (Loss), Net Derivative Asset (Liability)	'	'	0	0
Purchases, Net Derivative Asset (Liability)	'	'	0	0
Sales, Net Derivative Asset (Liability)	'	'	0	0
Issuances, Net Derivative Asset (Liability)	'	'	0	0
Settlements, Net Derivative Asset (Liability)	'	'	-2	4
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	'	'	78	'
Transfers out of Level 3, Net Derivative Asset (Liability)	'	'	3	'
Fair Value, Net Derivative Asset (Liability), Ending balance	0	0	0	0
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	'	'	0	0
Foreign Exchange Contract [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, Net Derivative Asset (Liability), Beginning balance	'	-9	'	-2
Gain (Loss) Included in Earnings, Net Derivative Asset (Liability)	'	47	'	40
Gain (Loss) Included in Other Comprehensive Income (Loss), Net Derivative Asset (Liability)	'	0	'	0
Purchases, Net Derivative Asset (Liability)	'	0	'	0
Sales, Net Derivative Asset (Liability)	'	0	'	0
Issuances, Net Derivative Asset (Liability)	'	0	'	0
Settlements, Net Derivative Asset (Liability)	'	19	'	19
Fair Value, Net Derivative Asset (Liability), Ending balance	'	57	'	57
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	'	47	'	38
Fair Value, Inputs, Level 3 [Member] | Mortgage Servicing Rights [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Net realized/unrealized gains (losses) included in earnings, Assets	'	'	'	-101
Interest Rate Contract [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3	'	'	$81	'

Fair_Value_Fair_Value_Measurem1

Fair Value (Fair Value Measurement - Nonrecurring Basis) (Details) (Fair Value, Measurements, Nonrecurring [Member], USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Loans Held-for-sale, Other	'	'	$19
Lower of cost or fair value or valuation reserve allowance	'	'	0
Total Income (Loss) Included In Earnings	0	0	'
Commercial Finance Receivables And Loans, Automotive [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	16	16	95
Lower of cost or fair value or valuation reserve allowance	-1	-1	-17
Commercial Finance Receivables And Loans, Other [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	37	37	63
Lower of cost or fair value or valuation reserve allowance	-14	-14	-11
Commercial Loan [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	53	53	158
Lower of cost or fair value or valuation reserve allowance	-15	-15	-28
Repossessed And Foreclosed Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	8	8	7
Lower of cost or fair value or valuation reserve allowance	-3	-3	-2
Other Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	2	2	2
Lower of cost or fair value or valuation reserve allowance	0	0	0
Assets, Total [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Assets, Fair Value Disclosure	63	63	186
Lower of cost or fair value or valuation reserve allowance	-18	-18	-30
Fair Value, Inputs, Level 1 [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Loans Held-for-sale, Other	'	'	0
Fair Value, Inputs, Level 1 [Member] | Commercial Finance Receivables And Loans, Automotive [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	0	0	0
Fair Value, Inputs, Level 1 [Member] | Commercial Finance Receivables And Loans, Other [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	0	0	0
Fair Value, Inputs, Level 1 [Member] | Commercial Loan [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	0	0	0
Fair Value, Inputs, Level 1 [Member] | Repossessed And Foreclosed Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	0	0	0
Fair Value, Inputs, Level 1 [Member] | Other Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	0	0	0
Fair Value, Inputs, Level 1 [Member] | Assets, Total [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Assets, Fair Value Disclosure	0	0	0
Fair Value, Inputs, Level 2 [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Loans Held-for-sale, Other	'	'	0
Fair Value, Inputs, Level 2 [Member] | Commercial Finance Receivables And Loans, Automotive [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	0	0	0
Fair Value, Inputs, Level 2 [Member] | Commercial Finance Receivables And Loans, Other [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	0	0	0
Fair Value, Inputs, Level 2 [Member] | Commercial Loan [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	0	0	0
Fair Value, Inputs, Level 2 [Member] | Repossessed And Foreclosed Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	0	0	0
Fair Value, Inputs, Level 2 [Member] | Other Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	0	0	0
Fair Value, Inputs, Level 2 [Member] | Assets, Total [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Assets, Fair Value Disclosure	0	0	0
Fair Value, Inputs, Level 3 [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Loans Held-for-sale, Other	'	'	19
Fair Value, Inputs, Level 3 [Member] | Commercial Finance Receivables And Loans, Automotive [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	16	16	95
Fair Value, Inputs, Level 3 [Member] | Commercial Finance Receivables And Loans, Other [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	37	37	63
Fair Value, Inputs, Level 3 [Member] | Commercial Loan [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Commercial Finance Receivables and Loans, Net, Fair Value	53	53	158
Fair Value, Inputs, Level 3 [Member] | Repossessed And Foreclosed Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	8	8	7
Fair Value, Inputs, Level 3 [Member] | Other Assets [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other Assets, Fair Value Disclosure	2	2	2
Fair Value, Inputs, Level 3 [Member] | Assets, Total [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Assets, Fair Value Disclosure	$63	$63	$186

Fair_Value_Fair_Value_Measurem2

Fair Value (Fair Value Measurements - Nonrecurring Fair Value Inputs) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]	'
Fair value inputs, Quantitative Information [Line Items]	'
Commercial automobile finance receivables	16
Commercial Other Finance Receivables and Loans	37
Commercial Finance Receivables And Loans, Automotive [Member] | Fair Value of Collateral [Member] | Minimum [Member]	'
Fair value inputs, Quantitative Information [Line Items]	'
Fair Value Inputs, Adjusted Appraisal Value	65.00%
Commercial Finance Receivables And Loans, Automotive [Member] | Fair Value of Collateral [Member] | Maximum [Member]	'
Fair value inputs, Quantitative Information [Line Items]	'
Fair Value Inputs, Adjusted Appraisal Value	95.00%
Other Commercial Finance Receivables and Loans [Member] | Fair Value of Collateral [Member] | Minimum [Member]	'
Fair value inputs, Quantitative Information [Line Items]	'
Fair Value Inputs, Adjusted Appraisal Value	91.00%
Other Commercial Finance Receivables and Loans [Member] | Fair Value of Collateral [Member] | Maximum [Member]	'
Fair value inputs, Quantitative Information [Line Items]	'
Fair Value Inputs, Adjusted Appraisal Value	109.00%

Fair_Value_Fair_Value_Option_S

Fair Value (Fair Value Option - Summary Of Changes Included In The Condensed Consolidated Statement Of Income) (Details) (Mortgage Loans Held-For-Sale [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'	'	'
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$0	$14	$1	($16)
Interest on loans held-for-sale [Member]	'	'	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'	'	'
Fair Value, Option, Changes in Fair Value, Gain (Loss)	0	0	0	19
Gain on mortgage loans, net [Member]	'	'	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'	'	'
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$0	$14	$1	($35)

Fair_Value_Fair_Value_Option_E

Fair Value (Fair Value Option Election) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value Option Election, Unpaid Principal Balance [Member]	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Mortgages Held-for-sale, Fair Value Disclosure	$7	$31
Fair Value Option Election, Unpaid Principal Balance [Member] | Mortgage Loans Held For Sale, Net [Member]	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Fair Value, Option, Loans Held as Assets, Aggregate Amount in Nonaccrual Status	3	18
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due	3	15
Fair Value Option Election, Fair Value [Member]	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Mortgages Held-for-sale, Fair Value Disclosure	3	16
Fair Value Option Election, Fair Value [Member] | Mortgage Loans Held For Sale, Net [Member]	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Fair Value, Option, Loans Held as Assets, Aggregate Amount in Nonaccrual Status	2	9
Fair Value, Option, Loans Held as Assets, 90 Days or More Past Due	$2	$8

Fair_Value_Fair_Value_of_Finan

Fair Value (Fair Value of Financial Instruments) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Loans held-for-sale, net	$3	$35
Total finance receivables and loans, net	98,405	99,120
Nonmarketable equity securities	275	337
Deposit liabilities	56,851	53,350
Short-term borrowings	5,255	8,545
Long-term debt	67,299	69,465
Deferred interest for zero coupon bonds	'	359
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Loans held-for-sale, net	0	0
Total finance receivables and loans, net	0	0
Nonmarketable equity securities	0	0
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Loans held-for-sale, net	3	17
Total finance receivables and loans, net	0	0
Nonmarketable equity securities	245	308
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	26,945	31,067
Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Loans held-for-sale, net	0	18
Total finance receivables and loans, net	99,733	100,090
Nonmarketable equity securities	51	38
Deposit liabilities	57,371	54,070
Short-term borrowings	5,255	8,545
Long-term debt	43,233	42,297
Reported Value Measurement [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Loans held-for-sale, net	3	35
Total finance receivables and loans, net	98,405	99,120
Nonmarketable equity securities	275	337
Deposit liabilities	56,851	53,350
Short-term borrowings	5,255	8,545
Long-term debt	67,299	69,824
Estimate of Fair Value Measurement [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Loans held-for-sale, net	3	35
Total finance receivables and loans, net	99,733	100,090
Nonmarketable equity securities	296	346
Deposit liabilities	57,371	54,070
Short-term borrowings	5,255	8,545
Long-term debt	$70,178	$73,364

Offsetting_Assets_and_Liabilit2

Offsetting Assets and Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	$235	$362
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	-129	-108
Derivative, Collateral, Right to Reclaim Cash	-5	-120
Derivative Liability, Fair Value, Gross Liability	-299	-317
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	129	108
Derivative, Collateral, Obligation to Return Cash	83	137
Securities Sold under Agreements to Repurchase, Gross	-579	-1,500
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral	0	0
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral, Net	-579	-1,500
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	0	0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash	579	1,500
Securities Sold under Agreements to Repurchase	0	0
Net Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	115	319
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	-9	-65
Derivative, Collateral, Right to Reclaim Cash	-5	-120
Derivative assets in net liability positions [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	120	43
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	-120	-43
Derivative, Collateral, Right to Reclaim Cash	0	0
Net liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Fair Value, Gross Liability	-284	-252
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	120	43
Derivative, Collateral, Obligation to Return Cash	83	137
Derivative liabilities in net asset positions [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Fair Value, Gross Liability	-9	-65
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	9	65
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative liabilities with no offsetting arrangements [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Fair Value, Gross Liability	-6	'
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	'
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	'
Derivative, Collateral, Obligation to Return Cash	0	'
Assets [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Fair Value, Amount Offset Against Collateral, Net	235	362
Derivative Assets	101	134
Assets [Member] | Net Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Fair Value, Amount Offset Against Collateral, Net	115	319
Derivative Assets	101	134
Assets [Member] | Derivative assets in net liability positions [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Fair Value, Amount Offset Against Collateral, Net	120	43
Derivative Assets	0	0
Liabilities, Total [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Fair Value, Amount Offset Against Collateral, Net	-299	-317
Derivative Liability	-87	-72
Gross Amounts of Recognized Liabilities	-878	-1,817
Gross Amounts Offset in the Condensed Consolidated Balance Sheet	0	0
Net Amounts of Liabilities Presented in the Condensed Consolidated Balance Sheet	-878	-1,817
Gross Amounts Not Offset Against Collateral	129	108
Obligation to Return Cash	662	1,637
Net Amount	-87	-72
Liabilities, Total [Member] | Net liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Fair Value, Amount Offset Against Collateral, Net	-284	-252
Derivative Liability	-81	-72
Liabilities, Total [Member] | Derivative liabilities in net asset positions [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Fair Value, Amount Offset Against Collateral, Net	-9	-65
Derivative Liability	0	0
Liabilities, Total [Member] | Derivative liabilities with no offsetting arrangements [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Fair Value, Amount Offset Against Collateral, Net	-6	'
Derivative Liability	($6)	'

Segment_And_Geographic_Informa2

Segment And Geographic Information (Financial Information Operating Segments) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]	'	'	'	'	'
Net financing revenue (loss)	$889,000,000	$737,000,000	$2,576,000,000	$2,005,000,000	'
Other revenue	375,000,000	371,000,000	1,061,000,000	1,159,000,000	'
Total net revenue (loss)	1,264,000,000	1,108,000,000	3,637,000,000	3,164,000,000	'
Provision for loan losses	102,000,000	141,000,000	302,000,000	361,000,000	'
Total noninterest expense	742,000,000	762,000,000	2,276,000,000	2,521,000,000	'
Income (loss) from continuing operations before income tax expense	420,000,000	205,000,000	1,059,000,000	282,000,000	'
Assets	149,195,000,000	150,556,000,000	149,195,000,000	150,556,000,000	151,167,000,000
Net Interest Income (Loss) after Provision for Loan Losses	800,000,000	600,000,000	2,300,000,000	1,600,000,000	'
Automotive finance operations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Net financing revenue (loss)	850,000,000	800,000,000	2,554,000,000	2,350,000,000	'
Other revenue	69,000,000	65,000,000	195,000,000	207,000,000	'
Total net revenue (loss)	919,000,000	865,000,000	2,749,000,000	2,557,000,000	'
Provision for loan losses	109,000,000	150,000,000	367,000,000	350,000,000	'
Total noninterest expense	395,000,000	376,000,000	1,167,000,000	1,143,000,000	'
Income (loss) from continuing operations before income tax expense	415,000,000	339,000,000	1,215,000,000	1,064,000,000	'
Assets	110,937,000,000	108,609,000,000	110,937,000,000	108,609,000,000	'
Insurance Operations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Net financing revenue (loss)	16,000,000	16,000,000	47,000,000	43,000,000	'
Other revenue	287,000,000	293,000,000	849,000,000	926,000,000	'
Total net revenue (loss)	303,000,000	309,000,000	896,000,000	969,000,000	'
Provision for loan losses	0	0	0	0	'
Total noninterest expense	243,000,000	226,000,000	785,000,000	780,000,000	'
Income (loss) from continuing operations before income tax expense	60,000,000	83,000,000	111,000,000	189,000,000	'
Assets	7,178,000,000	7,323,000,000	7,178,000,000	7,323,000,000	'
Mortgage Operations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Net financing revenue (loss)	9,000,000	13,000,000	35,000,000	62,000,000	'
Other revenue	0	19,000,000	13,000,000	-6,000,000	'
Total net revenue (loss)	9,000,000	32,000,000	48,000,000	56,000,000	'
Provision for loan losses	-7,000,000	-12,000,000	-55,000,000	14,000,000	'
Total noninterest expense	19,000,000	48,000,000	62,000,000	293,000,000	'
Income (loss) from continuing operations before income tax expense	-3,000,000	-4,000,000	41,000,000	-251,000,000	'
Assets	7,402,000,000	8,562,000,000	7,402,000,000	8,562,000,000	'
Corporate And Other [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Net financing revenue (loss)	14,000,000	-92,000,000	-60,000,000	-450,000,000	'
Other revenue	19,000,000	-6,000,000	4,000,000	32,000,000	'
Total net revenue (loss)	33,000,000	-98,000,000	-56,000,000	-418,000,000	'
Provision for loan losses	0	3,000,000	-10,000,000	-3,000,000	'
Total noninterest expense	85,000,000	112,000,000	262,000,000	305,000,000	'
Income (loss) from continuing operations before income tax expense	-52,000,000	-213,000,000	-308,000,000	-720,000,000	'
Assets	23,678,000,000	26,062,000,000	23,678,000,000	26,062,000,000	'
Commercial Finance Operations [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Assets	$1,700,000,000	$1,600,000,000	$1,700,000,000	$1,600,000,000	'

Segment_And_Geographic_Informa3

Segment And Geographic Information (Information Concerning Principal Geographic Areas) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total net revenue (loss)	$1,264	$1,108	$3,637	$3,164
Income (loss) from continuing operations before income tax expense	420	205	1,059	282
Net income (loss)	423	91	973	257
Foreign [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total net revenue (loss)	31	42	97	129
Income (loss) from continuing operations before income tax expense	6	27	36	29
Net income (loss)	39	78	147	1,563
Canada [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total net revenue (loss)	31	40	95	136
Income (loss) from continuing operations before income tax expense	7	14	36	42
Net income (loss)	9	13	55	1,256
Europe [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total net revenue (loss)	0	2	2	-8
Income (loss) from continuing operations before income tax expense	-1	1	0	-18
Net income (loss)	1	4	5	-82
Latin America [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total net revenue (loss)	0	0	0	0
Income (loss) from continuing operations before income tax expense	0	12	0	7
Net income (loss)	0	26	-8	300
Asia-Pacific [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total net revenue (loss)	0	0	0	1
Income (loss) from continuing operations before income tax expense	0	0	0	-2
Net income (loss)	29	35	95	89
Domestic [Member]	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'
Total net revenue (loss)	1,233	1,066	3,540	3,035
Income (loss) from continuing operations before income tax expense	414	178	1,023	253
Net income (loss)	384	13	826	-1,306
Amortization of Debt Discount (Premium)	$51	$67	$149	$191

Parent_And_Guarantor_Consolida2

Parent And Guarantor Consolidating Financial Statements (Schedule of Consolidating Statement of Income) (Details) (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	$1,114	$1,119	$3,345	$3,393
Interest on loans held-for-sale	'	0	0	1	19
Interest and dividends on available-for-sale investment securities	'	94	85	282	229
Interest-bearing cash	'	2	3	6	8
Operating leases	'	899	832	2,653	2,354
Total financing revenue and other interest income	'	2,109	2,039	6,287	6,003
Interest on deposits	'	166	163	495	489
Interest on short-term borrowings	'	12	15	40	47
Interest on long-term debt	'	493	609	1,576	2,013
Interest Expense, Debt	'	0	0	0	0
Total interest expense	'	671	787	2,111	2,549
Depreciation expense on operating lease assets	'	549	515	1,600	1,449
Net financing revenue (loss)	'	889	737	2,576	2,005
Bank Subsidiary	'	0	'	0	'
Nonbank subsidiaries	'	0	0	0	0
Servicing fees	'	6	13	22	114
Servicing asset valuation and hedge activities, net	'	0	0	0	-213
Total servicing income, net	'	6	13	22	-99
Insurance premiums and service revenue earned	'	246	251	736	768
Gain (loss) on mortgage and automotive loans, net	'	0	15	6	52
Gains (Losses) on Extinguishment of Debt	-160	0	-42	-46	-42
Other gain (loss) on investments, net	'	45	41	129	156
Other income, net of losses	'	78	93	214	324
Total other revenue	'	375	371	1,061	1,159
Total net revenue (loss)	'	1,264	1,108	3,637	3,164
Provision for loan losses	'	102	141	302	361
Compensation and benefits expense	'	241	245	710	782
Insurance losses and loss adjustment expenses	'	97	85	353	346
Other operating expenses	'	404	432	1,213	1,393
Total noninterest expense	'	742	762	2,276	2,521
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	'	420	205	1,059	282
Income tax expense (benefit) from continuing operations	'	127	28	285	-55
Net income (loss) from continuing operations	'	293	177	774	337
Income (loss) from discontinued operations, net of tax	'	130	-86	199	-80
Undistributed income of bank subsidiaries	'	0	0	0	0
Undistributed income of nonbank subsidiaries	'	0	0	0	0
Net income (loss)	'	423	91	973	257
Other comprehensive income (loss), net of tax	'	-55	4	126	-494
Comprehensive income (loss)	'	368	95	1,099	-237
Parent [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	16	243	-2	674
Interest on loans held-for-sale	'	'	'	0	0
Interest and dividends on available-for-sale investment securities	'	0	0	0	0
Interest-bearing cash	'	0	1	1	3
Operating leases	'	1	141	269	355
Total financing revenue and other interest income	'	27	397	294	1,081
Interest on deposits	'	3	5	11	20
Interest on short-term borrowings	'	10	11	32	35
Interest on long-term debt	'	350	469	1,143	1,593
Interest Expense, Debt	'	22	23	68	43
Total interest expense	'	385	508	1,254	1,691
Depreciation expense on operating lease assets	'	-4	103	164	267
Net financing revenue (loss)	'	-354	-214	-1,124	-877
Bank Subsidiary	'	150	'	1,650	'
Nonbank subsidiaries	'	141	54	462	5,217
Servicing fees	'	6	36	22	118
Servicing asset valuation and hedge activities, net	'	0	0	0	0
Total servicing income, net	'	6	36	22	118
Insurance premiums and service revenue earned	'	0	0	0	0
Gain (loss) on mortgage and automotive loans, net	'	-2	0	-2	0
Gains (Losses) on Extinguishment of Debt	'	'	-42	-46	-42
Other gain (loss) on investments, net	'	0	0	0	0
Other income, net of losses	'	206	51	591	128
Total other revenue	'	210	45	565	204
Total net revenue (loss)	'	147	-115	1,553	4,544
Provision for loan losses	'	88	69	165	298
Compensation and benefits expense	'	153	153	441	505
Insurance losses and loss adjustment expenses	'	0	0	0	0
Other operating expenses	'	252	119	648	274
Total noninterest expense	'	405	272	1,089	779
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	'	-346	-456	299	3,467
Income tax expense (benefit) from continuing operations	'	-68	-189	-309	-748
Net income (loss) from continuing operations	'	-278	-267	608	4,215
Income (loss) from discontinued operations, net of tax	'	127	142	172	-1,365
Undistributed income of bank subsidiaries	'	150	235	-802	668
Undistributed income of nonbank subsidiaries	'	424	-19	995	-3,261
Net income (loss)	'	423	91	973	257
Other comprehensive income (loss), net of tax	'	-55	4	126	-494
Comprehensive income (loss)	'	368	95	1,099	-237
Guarantor Subsidiaries [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	0	0	0	0
Interest on loans held-for-sale	'	'	'	0	0
Interest and dividends on available-for-sale investment securities	'	0	0	0	0
Interest-bearing cash	'	0	0	0	0
Operating leases	'	0	0	0	0
Total financing revenue and other interest income	'	0	0	0	0
Interest on deposits	'	0	0	0	0
Interest on short-term borrowings	'	0	0	0	0
Interest on long-term debt	'	0	0	0	0
Interest Expense, Debt	'	0	0	0	0
Total interest expense	'	0	0	0	0
Depreciation expense on operating lease assets	'	0	0	0	0
Net financing revenue (loss)	'	0	0	0	0
Bank Subsidiary	'	150	'	1,650	'
Nonbank subsidiaries	'	0	0	0	3,659
Servicing fees	'	0	0	0	0
Servicing asset valuation and hedge activities, net	'	0	0	0	0
Total servicing income, net	'	0	0	0	0
Insurance premiums and service revenue earned	'	0	0	0	0
Gain (loss) on mortgage and automotive loans, net	'	0	0	0	0
Gains (Losses) on Extinguishment of Debt	'	'	0	0	0
Other gain (loss) on investments, net	'	0	0	0	0
Other income, net of losses	'	0	0	0	0
Total other revenue	'	0	0	0	0
Total net revenue (loss)	'	150	0	1,650	3,659
Provision for loan losses	'	0	0	0	0
Compensation and benefits expense	'	0	0	0	0
Insurance losses and loss adjustment expenses	'	0	0	0	0
Other operating expenses	'	0	0	0	0
Total noninterest expense	'	0	0	0	0
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	'	150	0	1,650	3,659
Income tax expense (benefit) from continuing operations	'	0	0	0	0
Net income (loss) from continuing operations	'	150	0	1,650	3,659
Income (loss) from discontinued operations, net of tax	'	0	15	0	-19
Undistributed income of bank subsidiaries	'	150	235	-802	668
Undistributed income of nonbank subsidiaries	'	-2	5	-2	-2,395
Net income (loss)	'	298	255	846	1,913
Other comprehensive income (loss), net of tax	'	-3	-34	116	-753
Comprehensive income (loss)	'	295	221	962	1,160
Non-Guarantor Subsidiaries [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	1,098	876	3,347	2,719
Interest on loans held-for-sale	'	'	'	1	19
Interest and dividends on available-for-sale investment securities	'	94	85	282	229
Interest-bearing cash	'	2	2	5	5
Operating leases	'	898	691	2,384	1,999
Total financing revenue and other interest income	'	2,114	1,677	6,087	5,023
Interest on deposits	'	163	158	484	469
Interest on short-term borrowings	'	2	4	8	12
Interest on long-term debt	'	143	140	433	425
Interest Expense, Debt	'	10	12	26	52
Total interest expense	'	318	314	951	958
Depreciation expense on operating lease assets	'	553	412	1,436	1,182
Net financing revenue (loss)	'	1,243	951	3,700	2,883
Bank Subsidiary	'	0	'	0	'
Nonbank subsidiaries	'	0	0	0	0
Servicing fees	'	0	-23	0	-4
Servicing asset valuation and hedge activities, net	'	0	0	0	-213
Total servicing income, net	'	0	-23	0	-217
Insurance premiums and service revenue earned	'	246	251	736	768
Gain (loss) on mortgage and automotive loans, net	'	2	15	8	52
Gains (Losses) on Extinguishment of Debt	'	'	0	0	0
Other gain (loss) on investments, net	'	45	41	129	156
Other income, net of losses	'	373	350	1,007	1,116
Total other revenue	'	666	634	1,880	1,875
Total net revenue (loss)	'	1,909	1,585	5,580	4,758
Provision for loan losses	'	14	72	137	63
Compensation and benefits expense	'	199	205	604	622
Insurance losses and loss adjustment expenses	'	97	85	353	346
Other operating expenses	'	542	508	1,614	1,694
Total noninterest expense	'	838	798	2,571	2,662
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	'	1,057	715	2,872	2,033
Income tax expense (benefit) from continuing operations	'	195	217	594	693
Net income (loss) from continuing operations	'	862	498	2,278	1,340
Income (loss) from discontinued operations, net of tax	'	3	-243	27	1,303
Undistributed income of bank subsidiaries	'	0	0	0	0
Undistributed income of nonbank subsidiaries	'	0	0	0	0
Net income (loss)	'	865	255	2,305	2,643
Other comprehensive income (loss), net of tax	'	-50	24	124	-830
Comprehensive income (loss)	'	815	279	2,429	1,813
Consolidation, Eliminations [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	0	0	0	0
Interest on loans held-for-sale	'	'	'	0	0
Interest and dividends on available-for-sale investment securities	'	0	0	0	0
Interest-bearing cash	'	0	0	0	0
Operating leases	'	0	0	0	'
Total financing revenue and other interest income	'	-32	-35	-94	-101
Interest on deposits	'	0	0	0	0
Interest on short-term borrowings	'	0	0	0	0
Interest on long-term debt	'	0	0	0	-5
Interest Expense, Debt	'	-32	-35	-94	-95
Total interest expense	'	-32	-35	-94	-100
Depreciation expense on operating lease assets	'	0	0	0	0
Net financing revenue (loss)	'	0	0	0	-1
Bank Subsidiary	'	-300	'	-3,300	'
Nonbank subsidiaries	'	-141	-54	-462	-8,876
Servicing fees	'	0	0	0	0
Servicing asset valuation and hedge activities, net	'	0	0	0	0
Total servicing income, net	'	0	0	0	0
Insurance premiums and service revenue earned	'	0	0	0	0
Gain (loss) on mortgage and automotive loans, net	'	0	0	0	0
Gains (Losses) on Extinguishment of Debt	'	'	0	0	0
Other gain (loss) on investments, net	'	0	0	0	0
Other income, net of losses	'	-501	-308	-1,384	-920
Total other revenue	'	-501	-308	-1,384	-920
Total net revenue (loss)	'	-942	-362	-5,146	-9,797
Provision for loan losses	'	0	0	0	0
Compensation and benefits expense	'	-111	-113	-335	-345
Insurance losses and loss adjustment expenses	'	0	0	0	0
Other operating expenses	'	-390	-195	-1,049	-575
Total noninterest expense	'	-501	-308	-1,384	-920
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	'	-441	-54	-3,762	-8,877
Income tax expense (benefit) from continuing operations	'	0	0	0	0
Net income (loss) from continuing operations	'	-441	-54	-3,762	-8,877
Income (loss) from discontinued operations, net of tax	'	0	0	0	1
Undistributed income of bank subsidiaries	'	-300	-470	1,604	-1,336
Undistributed income of nonbank subsidiaries	'	-422	14	-993	5,656
Net income (loss)	'	-1,163	-510	-3,151	-4,556
Other comprehensive income (loss), net of tax	'	53	10	-240	1,583
Comprehensive income (loss)	'	-1,110	-500	-3,391	-2,973
Intercompany [Member] | Consolidation, Eliminations [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Operating leases	'	'	'	'	0
Affiliated Entity [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	0	0	0	0
Interest-bearing cash	'	0	0	0	0
Affiliated Entity [Member] | Parent [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	10	12	26	49
Interest-bearing cash	'	0	0	0	0
Affiliated Entity [Member] | Guarantor Subsidiaries [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	0	0	0	0
Interest-bearing cash	'	0	0	0	0
Affiliated Entity [Member] | Non-Guarantor Subsidiaries [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	21	21	64	46
Interest-bearing cash	'	1	2	4	6
Affiliated Entity [Member] | Consolidation, Eliminations [Member]	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'
Interest and fees on finance receivables and loans	'	-31	-33	-90	-95
Interest-bearing cash	'	($1)	($2)	($4)	($6)

Parent_And_Guarantor_Consolida3

Parent And Guarantor Consolidating Financial Statements (Schedule Of Condensed Consolidating Balance Sheet) (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Cash and Due from Banks	$1,318	'	$1,315	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	4,381	'	4,216	'	'	'
Total cash and cash equivalents	5,699	'	5,531	6,549	'	7,513
Investment securities	16,714	'	17,083	'	'	'
Loans held-for-sale, net	3	'	35	'	'	'
Finance receivables and loans, net	99,518	'	100,328	95,281	'	'
Loans to bank subsidiary	0	'	0	'	'	'
Loans to nonbank subsidiary	0	'	0	'	'	'
Allowance for loan losses	-1,113	-1,171	-1,208	-1,198	-1,183	-1,170
Total finance receivables and loans, net	98,405	'	99,120	'	'	'
Investment in operating leases, net	19,341	'	17,680	'	'	'
Receivables from bank subsidiary	0	'	0	'	'	'
Receivables from nonbank subsidiary	0	'	0	'	'	'
Investment in bank subsidiaries	0	'	0	'	'	'
Investment in nonbank subsidiaries	0	'	0	'	'	'
Premiums receivable and other insurance assets	1,678	'	1,613	'	'	'
Other Assets	6,752	'	9,589	'	'	'
Assets of operations held-for-sale	603	'	516	'	'	'
Total assets	149,195	'	151,167	150,556	'	'
Noninterest-bearing deposit liabilities	73	'	60	'	'	'
Interest-bearing deposit liabilities	56,778	'	53,290	'	'	'
Total deposit liabilities	56,851	'	53,350	'	'	'
Short-term borrowings	5,255	'	8,545	'	'	'
Long-term debt	67,299	'	69,465	'	'	'
Debt Payable To Nonbank Subsidiaries	0	'	0	'	'	'
Payables to Bank Subsidiaries	0	'	0	'	'	'
Payables to Nonbank Subsidiaries	0	'	0	'	'	'
Interest payable	542	'	888	'	'	'
Unearned insurance premiums and service revenue	2,369	'	2,314	'	'	'
Accrued expenses and other liabilities	1,689	'	2,397	'	'	'
Total liabilities	134,005	'	136,959	'	'	'
Total equity	15,190	'	14,208	19,061	'	19,898
Total liabilities and equity	149,195	'	151,167	'	'	'
Parent [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Cash and Due from Banks	932	'	979	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	1,300	'	1,951	'	'	'
Total cash and cash equivalents	2,232	'	2,930	3,022	'	3,977
Investment securities	0	'	0	'	'	'
Loans held-for-sale, net	0	'	0	'	'	'
Finance receivables and loans, net	4,757	'	6,673	'	'	'
Loans to bank subsidiary	1,300	'	600	'	'	'
Loans to nonbank subsidiary	5,603	'	4,207	'	'	'
Allowance for loan losses	-104	'	-131	'	'	'
Total finance receivables and loans, net	11,556	'	11,349	'	'	'
Investment in operating leases, net	0	'	3,172	'	'	'
Receivables from bank subsidiary	518	'	236	'	'	'
Receivables from nonbank subsidiary	271	'	439	'	'	'
Investment in bank subsidiaries	15,770	'	14,916	'	'	'
Investment in nonbank subsidiaries	9,730	'	10,029	'	'	'
Premiums receivable and other insurance assets	0	'	0	'	'	'
Other Assets	4,789	'	4,691	'	'	'
Assets of operations held-for-sale	603	'	516	'	'	'
Total assets	45,469	'	48,278	'	'	'
Noninterest-bearing deposit liabilities	0	'	0	'	'	'
Interest-bearing deposit liabilities	368	'	440	'	'	'
Total deposit liabilities	368	'	440	'	'	'
Short-term borrowings	3,376	'	3,225	'	'	'
Long-term debt	22,777	'	25,819	'	'	'
Debt Payable To Nonbank Subsidiaries	2,190	'	2,334	'	'	'
Payables to Bank Subsidiaries	170	'	197	'	'	'
Payables to Nonbank Subsidiaries	573	'	666	'	'	'
Interest payable	279	'	709	'	'	'
Unearned insurance premiums and service revenue	0	'	0	'	'	'
Accrued expenses and other liabilities	546	'	680	'	'	'
Total liabilities	30,279	'	34,070	'	'	'
Total equity	15,190	'	14,208	'	'	'
Total liabilities and equity	45,469	'	48,278	'	'	'
Guarantor Subsidiaries [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Cash and Due from Banks	0	'	37	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	0	'	0	'	'	'
Total cash and cash equivalents	0	'	37	29	'	0
Investment securities	0	'	0	'	'	'
Loans held-for-sale, net	0	'	0	'	'	'
Finance receivables and loans, net	0	'	0	'	'	'
Loans to bank subsidiary	0	'	0	'	'	'
Loans to nonbank subsidiary	0	'	0	'	'	'
Allowance for loan losses	0	'	0	'	'	'
Total finance receivables and loans, net	0	'	0	'	'	'
Investment in operating leases, net	0	'	0	'	'	'
Receivables from bank subsidiary	0	'	0	'	'	'
Receivables from nonbank subsidiary	0	'	0	'	'	'
Investment in bank subsidiaries	15,770	'	14,916	'	'	'
Investment in nonbank subsidiaries	11	'	68	'	'	'
Premiums receivable and other insurance assets	0	'	0	'	'	'
Other Assets	0	'	0	'	'	'
Assets of operations held-for-sale	0	'	0	'	'	'
Total assets	15,781	'	15,021	'	'	'
Noninterest-bearing deposit liabilities	0	'	0	'	'	'
Interest-bearing deposit liabilities	0	'	0	'	'	'
Total deposit liabilities	0	'	0	'	'	'
Short-term borrowings	0	'	0	'	'	'
Long-term debt	0	'	0	'	'	'
Debt Payable To Nonbank Subsidiaries	0	'	0	'	'	'
Payables to Bank Subsidiaries	0	'	0	'	'	'
Payables to Nonbank Subsidiaries	0	'	0	'	'	'
Interest payable	0	'	0	'	'	'
Unearned insurance premiums and service revenue	0	'	0	'	'	'
Accrued expenses and other liabilities	82	'	93	'	'	'
Total liabilities	82	'	93	'	'	'
Total equity	15,699	'	14,928	'	'	'
Total liabilities and equity	15,781	'	15,021	'	'	'
Non-Guarantor Subsidiaries [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Cash and Due from Banks	386	'	299	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	3,081	'	2,265	'	'	'
Total cash and cash equivalents	3,880	'	2,974	3,982	'	4,027
Investment securities	16,714	'	17,083	'	'	'
Loans held-for-sale, net	3	'	35	'	'	'
Finance receivables and loans, net	94,761	'	93,655	'	'	'
Loans to bank subsidiary	0	'	0	'	'	'
Loans to nonbank subsidiary	1,777	'	1,925	'	'	'
Allowance for loan losses	-1,009	'	-1,077	'	'	'
Total finance receivables and loans, net	95,529	'	94,503	'	'	'
Investment in operating leases, net	19,341	'	14,508	'	'	'
Receivables from bank subsidiary	0	'	0	'	'	'
Receivables from nonbank subsidiary	77	'	588	'	'	'
Investment in bank subsidiaries	0	'	0	'	'	'
Investment in nonbank subsidiaries	0	'	0	'	'	'
Premiums receivable and other insurance assets	1,698	'	1,634	'	'	'
Other Assets	4,399	'	6,880	'	'	'
Assets of operations held-for-sale	0	'	0	'	'	'
Total assets	141,641	'	138,205	'	'	'
Noninterest-bearing deposit liabilities	73	'	60	'	'	'
Interest-bearing deposit liabilities	56,410	'	52,850	'	'	'
Total deposit liabilities	56,483	'	52,910	'	'	'
Short-term borrowings	1,879	'	5,320	'	'	'
Long-term debt	44,522	'	43,646	'	'	'
Debt Payable To Nonbank Subsidiaries	6,903	'	4,808	'	'	'
Payables to Bank Subsidiaries	0	'	0	'	'	'
Payables to Nonbank Subsidiaries	142	'	421	'	'	'
Interest payable	263	'	179	'	'	'
Unearned insurance premiums and service revenue	2,369	'	2,314	'	'	'
Accrued expenses and other liabilities	3,497	'	3,606	'	'	'
Total liabilities	116,058	'	113,204	'	'	'
Total equity	25,583	'	25,001	'	'	'
Total liabilities and equity	141,641	'	138,205	'	'	'
Consolidation, Eliminations [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Cash and Due from Banks	0	'	0	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	0	'	0	'	'	'
Total cash and cash equivalents	-413	'	-410	-484	'	-491
Investment securities	0	'	0	'	'	'
Loans held-for-sale, net	0	'	0	'	'	'
Finance receivables and loans, net	0	'	0	'	'	'
Loans to bank subsidiary	-1,300	'	-600	'	'	'
Loans to nonbank subsidiary	-7,380	'	-6,132	'	'	'
Allowance for loan losses	0	'	0	'	'	'
Total finance receivables and loans, net	-8,680	'	-6,732	'	'	'
Investment in operating leases, net	0	'	0	'	'	'
Receivables from bank subsidiary	-518	'	-236	'	'	'
Receivables from nonbank subsidiary	-348	'	-1,027	'	'	'
Investment in bank subsidiaries	-31,540	'	-29,832	'	'	'
Investment in nonbank subsidiaries	-9,741	'	-10,097	'	'	'
Premiums receivable and other insurance assets	-20	'	-21	'	'	'
Other Assets	-2,436	'	-1,982	'	'	'
Assets of operations held-for-sale	0	'	0	'	'	'
Total assets	-53,696	'	-50,337	'	'	'
Noninterest-bearing deposit liabilities	0	'	0	'	'	'
Interest-bearing deposit liabilities	0	'	0	'	'	'
Total deposit liabilities	0	'	0	'	'	'
Short-term borrowings	0	'	0	'	'	'
Long-term debt	0	'	0	'	'	'
Debt Payable To Nonbank Subsidiaries	-9,093	'	-7,142	'	'	'
Payables to Bank Subsidiaries	-170	'	-197	'	'	'
Payables to Nonbank Subsidiaries	-715	'	-1,087	'	'	'
Interest payable	0	'	0	'	'	'
Unearned insurance premiums and service revenue	0	'	0	'	'	'
Accrued expenses and other liabilities	-2,436	'	-1,982	'	'	'
Total liabilities	-12,414	'	-10,408	'	'	'
Total equity	-41,282	'	-39,929	'	'	'
Total liabilities and equity	-53,696	'	-50,337	'	'	'
Fair Value Option Election, Fair Value [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Finance receivables and loans, net	99,518	'	100,328	'	'	'
Affiliated Entity [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	0	'	0	'	'	'
Affiliated Entity [Member] | Parent [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	0	'	0	'	'	'
Affiliated Entity [Member] | Guarantor Subsidiaries [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	0	'	0	'	'	'
Affiliated Entity [Member] | Non-Guarantor Subsidiaries [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	413	'	410	'	'	'
Affiliated Entity [Member] | Consolidation, Eliminations [Member]	'	'	'	'	'	'
Condensed Balance Sheet Statements, Captions [Line Items]	'	'	'	'	'	'
Interest-bearing Deposits in Banks and Other Financial Institutions	($413)	'	($410)	'	'	'

Parent_And_Guarantor_Consolida4

Parent And Guarantor Consolidating Financial Statements (Schedule Of Condensed Consolidating Statement of Cash Flow) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net cash provided by (used in) operating activities	$2,458		$4,365
Purchases of available-for-sale securities	-4,117		-12,747
Proceeds from sales of available-for-sale securities	2,974		4,721
Proceeds from maturities of available-for-sale securities	1,877		3,893
Net (increase) decrease in finance receivables and loans	-1,267		2,744
Proceeds from Sale of Loans Held-for-sale	1,557		'
Net (increase) decrease in operating lease assets	-3,265		-5,171
Capital contributions to subsidiaries	0		0
Returns of contributed capital	0		0
Proceeds from Sale of Mortgage Servicing Rights (MSR)	0		911
Proceeds from sale of business units, net	47	[1]	6,937	[1]
Increase (Decrease) in Restricted Cash	2,128		2,297
Other, net	71		-55
Net cash (used in) provided by investing activities	5		3,530
Net change in short-term borrowings	-3,298		-936
Net increase in bank deposits	3,501		4,057
Proceeds from issuance of long-term debt	18,942		13,347
Repayments of long-term debt	-21,239		-26,725
Net Change in Debt, Intercompany	0		0
Dividends paid	-200		-601
Dividends paid and returns of contributed capital, Intercompany	0		0
Capital contributions from parent	0		0
Net cash provided by (used in) financing activities	-2,294		-10,858
Effect of exchange-rate changes on cash and cash equivalents	-1		47
Cash and Cash Equivalents, Period Increase (Decrease)	168		-2,916
Net Cash Provided by (Used in) Discontinued Operations	0	[1],[2]	1,952	[1],[2]
Cash and cash equivalents at beginning of period	5,531		7,513
Cash and cash equivalents at end of period	5,699		6,549
Parent [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net cash provided by (used in) operating activities	544		5,198
Purchases of available-for-sale securities	0		0
Proceeds from sales of available-for-sale securities	0		0
Proceeds from maturities of available-for-sale securities	0		0
Net (increase) decrease in finance receivables and loans	1,669		-3,527
Proceeds from Sale of Loans Held-for-sale	0		'
Net (increase) decrease in operating lease assets	146		-1,111
Capital contributions to subsidiaries	-744		-176
Returns of contributed capital	1,251		769
Proceeds from Sale of Mortgage Servicing Rights (MSR)	'		0
Proceeds from sale of business units, net	46		1,123
Increase (Decrease) in Restricted Cash	0		0
Other, net	-17		-200
Net cash (used in) provided by investing activities	2,247		-2,780
Net change in short-term borrowings	151		105
Net increase in bank deposits	-72		-433
Proceeds from issuance of long-term debt	2,310		2,213
Repayments of long-term debt	-5,535		-6,331
Net Change in Debt, Intercompany	-143		1,674
Dividends paid	-200		-601
Dividends paid and returns of contributed capital, Intercompany	0		0
Capital contributions from parent	0		0
Net cash provided by (used in) financing activities	-3,489		-3,373
Effect of exchange-rate changes on cash and cash equivalents	0		0
Cash and Cash Equivalents, Period Increase (Decrease)	-698		-955
Net Cash Provided by (Used in) Discontinued Operations	'		0
Cash and cash equivalents at beginning of period	2,930		3,977
Cash and cash equivalents at end of period	2,232		3,022
Guarantor Subsidiaries [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net cash provided by (used in) operating activities	1,639		3,514
Purchases of available-for-sale securities	0		0
Proceeds from sales of available-for-sale securities	0		0
Proceeds from maturities of available-for-sale securities	0		0
Net (increase) decrease in finance receivables and loans	0		79
Proceeds from Sale of Loans Held-for-sale	0		'
Net (increase) decrease in operating lease assets	0		0
Capital contributions to subsidiaries	0		0
Returns of contributed capital	0		150
Proceeds from Sale of Mortgage Servicing Rights (MSR)	'		0
Proceeds from sale of business units, net	0		554
Increase (Decrease) in Restricted Cash	0		-26
Other, net	0		0
Net cash (used in) provided by investing activities	0		1,008
Net change in short-term borrowings	0		36
Net increase in bank deposits	0		0
Proceeds from issuance of long-term debt	0		0
Repayments of long-term debt	0		-70
Net Change in Debt, Intercompany	0		-271
Dividends paid	0		0
Dividends paid and returns of contributed capital, Intercompany	-1,676		-4,217
Capital contributions from parent	0		29
Net cash provided by (used in) financing activities	-1,676		-4,493
Effect of exchange-rate changes on cash and cash equivalents	0		0
Cash and Cash Equivalents, Period Increase (Decrease)	-37		29
Net Cash Provided by (Used in) Discontinued Operations	'		0
Cash and cash equivalents at beginning of period	37		0
Cash and cash equivalents at end of period	0		29
Non-Guarantor Subsidiaries [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net cash provided by (used in) operating activities	4,036		4,528
Purchases of available-for-sale securities	-4,117		-12,747
Proceeds from sales of available-for-sale securities	2,974		4,721
Proceeds from maturities of available-for-sale securities	1,877		3,893
Net (increase) decrease in finance receivables and loans	-2,936		6,192
Proceeds from Sale of Loans Held-for-sale	1,557		'
Net (increase) decrease in operating lease assets	-3,411		-4,060
Capital contributions to subsidiaries	0		0
Returns of contributed capital	0		0
Proceeds from Sale of Mortgage Servicing Rights (MSR)	'		911
Proceeds from sale of business units, net	1		5,260
Increase (Decrease) in Restricted Cash	2,128		2,323
Other, net	88		145
Net cash (used in) provided by investing activities	-1,692		5,262
Net change in short-term borrowings	-3,449		-1,077
Net increase in bank deposits	3,573		4,527
Proceeds from issuance of long-term debt	16,632		11,134
Repayments of long-term debt	-15,704		-20,324
Net Change in Debt, Intercompany	104		-664
Dividends paid	0		0
Dividends paid and returns of contributed capital, Intercompany	-3,337		-5,577
Capital contributions from parent	744		147
Net cash provided by (used in) financing activities	-1,437		-11,834
Effect of exchange-rate changes on cash and cash equivalents	-1		47
Cash and Cash Equivalents, Period Increase (Decrease)	906		-1,997
Net Cash Provided by (Used in) Discontinued Operations	'		1,952
Cash and cash equivalents at beginning of period	2,974		4,027
Cash and cash equivalents at end of period	3,880		3,982
Consolidation, Eliminations [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net cash provided by (used in) operating activities	-3,761		-8,875
Purchases of available-for-sale securities	0		0
Proceeds from sales of available-for-sale securities	0		0
Proceeds from maturities of available-for-sale securities	0		0
Net (increase) decrease in finance receivables and loans	0		0
Proceeds from Sale of Loans Held-for-sale	0		'
Net (increase) decrease in operating lease assets	0		0
Capital contributions to subsidiaries	744		176
Returns of contributed capital	-1,251		-919
Proceeds from Sale of Mortgage Servicing Rights (MSR)	'		0
Proceeds from sale of business units, net	0		0
Increase (Decrease) in Restricted Cash	0		0
Other, net	0		0
Net cash (used in) provided by investing activities	-550		40
Net change in short-term borrowings	0		0
Net increase in bank deposits	0		-37
Proceeds from issuance of long-term debt	0		0
Repayments of long-term debt	0		0
Net Change in Debt, Intercompany	39		-739
Dividends paid	0		0
Dividends paid and returns of contributed capital, Intercompany	5,013		9,794
Capital contributions from parent	-744		-176
Net cash provided by (used in) financing activities	4,308		8,842
Effect of exchange-rate changes on cash and cash equivalents	0		0
Cash and Cash Equivalents, Period Increase (Decrease)	-3		7
Net Cash Provided by (Used in) Discontinued Operations	'		0
Cash and cash equivalents at beginning of period	-410		-491
Cash and cash equivalents at end of period	-413		-484
Affiliated Entity [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net (increase) decrease in finance receivables and loans	0		0
Affiliated Entity [Member] | Parent [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net (increase) decrease in finance receivables and loans	-104		342
Affiliated Entity [Member] | Guarantor Subsidiaries [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net (increase) decrease in finance receivables and loans	0		251
Affiliated Entity [Member] | Non-Guarantor Subsidiaries [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net (increase) decrease in finance receivables and loans	147		-1,376
Affiliated Entity [Member] | Consolidation, Eliminations [Member]	'		'
Condensed Cash Flow Statements, Captions [Line Items]	'		'
Net (increase) decrease in finance receivables and loans	($43)		$783
[1]	The amount at SeptemberB 30, 2013, is net of cash and cash equivalents of $1,418 million of business units at the time of disposition.
[2]	Cash flows of discontinued operations are reflected within operating, investing, and financing activities in the Condensed Consolidated Statement of Cash Flows. The cash balance of these operations is reported as assets of operations held-for-sale on the Condensed Consolidated Balance Sheet.

Contingencies_and_Other_Risks_

Contingencies and Other Risks - Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2014
Contingencies and Other Risks [Abstract]	'	'
CFPB Settlement	$98	'
Representation And Warranty Obligations Reserve Balance	$45	$37

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended			9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Oct. 22, 2014	Oct. 16, 2014	Oct. 16, 2014
							Subsequent Event [Member]	Subsequent Event [Member]
							Series G Preferred Stock [Member]	Series A Preferred Stock [Member]
Subsequent Event [Line Items]	'	'	'	'	'	'	'	'
Dividends Payable, Amount Per Share	'	'	'	'	'	'	$17.89	$0.53
Dividends Payable	'	'	'	'	'	'	$46	$22
Debt Instrument, Repurchase Amount	'	'	'	'	'	750	'	'
Gains (Losses) on Extinguishment of Debt	($160)	$0	($42)	($46)	($42)	'	'	'