Parent And Guarantor Consolidating Financial Statements (Schedule of Consolidating Statement of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	$ 1,135	$ 1,093
Interest on loans held-for-sale	16	31
Interest on trading assets	0	9
Interest and dividends on available-for-sale investment securities	68	74
Interest-bearing cash	3	2
Operating leases	734	507
Total financing revenue and other interest income	1,956	1,716
Interest on deposits	164	163
Interest on short-term borrowings	16	17
Interest on long-term debt	701	880
Total interest expense	881	1,060
Depreciation expense on operating lease assets	435	305
Net financing revenue (loss)	640	351
Nonbank subsidiaries	0	0
Servicing fees	82	122
Servicing asset valuation and hedge activities, net	(201)	(106)
Total servicing income, net	(119)	16
Insurance premiums and service revenue earned	259	270
Gain (loss) on mortgage and automotive loans, net	38	20
Other gain (loss) on investments, net	51	89
Other income, net of losses	157	210
Total other revenue	386	605
Total net revenue (loss)	1,026	956
Provision for loan losses	131	98
Compensation and benefits expense	285	303
Insurance losses and loss adjustment expenses	115	98
Other operating expenses	558	454
Total noninterest expense	958	855
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	(63)	3
Income tax expense (benefit) from continuing operations	(123)	1
Net income (loss) from continuing operations	60	2
Income (loss) from discontinued operations, net of tax	1,033	308
Undistributed income of bank subsidiaries	0	0
Undistributed income of nonbank subsidiaries	0	0
Net income (loss)	1,093	310
Other comprehensive income (loss), net of tax	(317)	187
Comprehensive income (loss)	776	497
Intercompany [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	0	0
Interest-bearing cash	0
Interest Expense, Debt	0	0
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	159	253
Interest on loans held-for-sale	0	5
Interest on trading assets		0
Interest and dividends on available-for-sale investment securities	0	0
Interest-bearing cash	1	1
Operating leases	96	52
Total financing revenue and other interest income	280	349
Interest on deposits	9	17
Interest on short-term borrowings	12	20
Interest on long-term debt	560	723
Total interest expense	580	755
Depreciation expense on operating lease assets	62	13
Net financing revenue (loss)	(362)	(419)
Nonbank subsidiaries	3,299	141
Servicing fees	44	52
Servicing asset valuation and hedge activities, net	0	0
Total servicing income, net	44	52
Insurance premiums and service revenue earned	0	0
Gain (loss) on mortgage and automotive loans, net	0	(1)
Other gain (loss) on investments, net	0	0
Other income, net of losses	51	35
Total other revenue	95	86
Total net revenue (loss)	3,032	(192)
Provision for loan losses	124	78
Compensation and benefits expense	192	213
Insurance losses and loss adjustment expenses	0	0
Other operating expenses	58	86
Total noninterest expense	250	299
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	2,658	(569)
Income tax expense (benefit) from continuing operations	(329)	(268)
Net income (loss) from continuing operations	2,987	(301)
Income (loss) from discontinued operations, net of tax	(265)	10
Undistributed income of bank subsidiaries	226	223
Undistributed income of nonbank subsidiaries	(1,855)	378
Net income (loss)	1,093	310
Other comprehensive income (loss), net of tax	(317)	187
Comprehensive income (loss)	776	497
Parent [Member] | Intercompany [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	24	38
Interest-bearing cash	0
Interest Expense, Debt	(1)	(5)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	0	0
Interest on loans held-for-sale	0	0
Interest on trading assets		0
Interest and dividends on available-for-sale investment securities	0	0
Interest-bearing cash	0	0
Operating leases	0	0
Total financing revenue and other interest income	0	1
Interest on deposits	0	0
Interest on short-term borrowings	0	0
Interest on long-term debt	0	0
Total interest expense	0	1
Depreciation expense on operating lease assets	0	0
Net financing revenue (loss)	0	0
Nonbank subsidiaries	3,254	0
Servicing fees	0	0
Servicing asset valuation and hedge activities, net	0	0
Total servicing income, net	0	0
Insurance premiums and service revenue earned	0	0
Gain (loss) on mortgage and automotive loans, net	0	0
Other gain (loss) on investments, net	0	0
Other income, net of losses	0	144
Total other revenue	0	144
Total net revenue (loss)	3,254	144
Provision for loan losses	0	0
Compensation and benefits expense	0	144
Insurance losses and loss adjustment expenses	0	0
Other operating expenses	0	0
Total noninterest expense	0	144
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	3,254	0
Income tax expense (benefit) from continuing operations	0	0
Net income (loss) from continuing operations	3,254	0
Income (loss) from discontinued operations, net of tax	13	3
Undistributed income of bank subsidiaries	226	223
Undistributed income of nonbank subsidiaries	(2,052)	85
Net income (loss)	1,441	311
Other comprehensive income (loss), net of tax	(578)	126
Comprehensive income (loss)	863	437
Guarantor Subsidiaries [Member] | Intercompany [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	0	1
Interest-bearing cash	0
Interest Expense, Debt	0	1
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	976	844
Interest on loans held-for-sale	16	26
Interest on trading assets		9
Interest and dividends on available-for-sale investment securities	68	74
Interest-bearing cash	2	1
Operating leases	638	455
Total financing revenue and other interest income	1,707	1,417
Interest on deposits	155	146
Interest on short-term borrowings	4	1
Interest on long-term debt	146	161
Total interest expense	331	353
Depreciation expense on operating lease assets	373	292
Net financing revenue (loss)	1,003	772
Nonbank subsidiaries	0	0
Servicing fees	38	70
Servicing asset valuation and hedge activities, net	(201)	(106)
Total servicing income, net	(163)	(36)
Insurance premiums and service revenue earned	259	270
Gain (loss) on mortgage and automotive loans, net	38	21
Other gain (loss) on investments, net	51	89
Other income, net of losses	425	345
Total other revenue	610	689
Total net revenue (loss)	1,613	1,461
Provision for loan losses	7	20
Compensation and benefits expense	223	90
Insurance losses and loss adjustment expenses	115	98
Other operating expenses	688	538
Total noninterest expense	1,026	726
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	580	715
Income tax expense (benefit) from continuing operations	206	269
Net income (loss) from continuing operations	374	446
Income (loss) from discontinued operations, net of tax	1,284	298
Undistributed income of bank subsidiaries	0	0
Undistributed income of nonbank subsidiaries	0	0
Net income (loss)	1,658	744
Other comprehensive income (loss), net of tax	(601)	388
Comprehensive income (loss)	1,057	1,132
Non-Guarantor Subsidiaries [Member] | Intercompany [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	5	8
Interest-bearing cash	2
Interest Expense, Debt	26	45
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	0	(4)
Interest on loans held-for-sale	0	0
Interest on trading assets		0
Interest and dividends on available-for-sale investment securities	0	0
Interest-bearing cash	0	0
Operating leases	0	0
Total financing revenue and other interest income	(31)	(51)
Interest on deposits	0	0
Interest on short-term borrowings	0	(4)
Interest on long-term debt	(5)	(4)
Total interest expense	(30)	(49)
Depreciation expense on operating lease assets	0	0
Net financing revenue (loss)	(1)	(2)
Nonbank subsidiaries	(6,553)	(141)
Servicing fees	0	0
Servicing asset valuation and hedge activities, net	0	0
Total servicing income, net	0	0
Insurance premiums and service revenue earned	0	0
Gain (loss) on mortgage and automotive loans, net	0	0
Other gain (loss) on investments, net	0	0
Other income, net of losses	(319)	(314)
Total other revenue	(319)	(314)
Total net revenue (loss)	(6,873)	(457)
Provision for loan losses	0	0
Compensation and benefits expense	(130)	(144)
Insurance losses and loss adjustment expenses	0	0
Other operating expenses	(188)	(170)
Total noninterest expense	(318)	(314)
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	(6,555)	(143)
Income tax expense (benefit) from continuing operations	0	0
Net income (loss) from continuing operations	(6,555)	(143)
Income (loss) from discontinued operations, net of tax	1	(3)
Undistributed income of bank subsidiaries	(452)	(446)
Undistributed income of nonbank subsidiaries	3,907	(463)
Net income (loss)	(3,099)	(1,055)
Other comprehensive income (loss), net of tax	1,179	(514)
Comprehensive income (loss)	(1,920)	(1,569)
Consolidation, Eliminations [Member] | Intercompany [Member]
Condensed Financial Statements, Captions [Line Items]
Interest and fees on finance receivables and loans	(29)	(47)
Interest-bearing cash	(2)
Interest Expense, Debt	$ (25)	$ (41)