Parent And Guarantor Consolidating Financial Statements (Schedule of Consolidating Statement of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									$ 4,457	$ 4,529	$ 4,539
Interest on loans held-for-sale									1	20	98
Interest on trading assets									0	0	10
Interest and dividends on available-for-sale investment securities									367	325	292
Interest-bearing cash									8	10	24
Operating leases									3,558	3,209	2,379
Total financing revenue and other interest income									8,391	8,093	7,342
Interest on deposits									664	654	645
Interest on short-term borrowings									52	63	71
Interest on long-term debt									2,067	2,602	3,336
Interest Expense, Related Party									0	0	0
Total interest expense									2,783	3,319	4,052
Depreciation expense on operating lease assets									2,233	1,995	1,399
Net financing revenue (loss)	799	889	866	821	774	737	628	640	3,375	2,779	1,891
Dividends from Bank Subsidiary									0
Nonbank subsidiaries									0	0	0
Servicing fees									31	126	409
Servicing asset valuation and hedge activities, net									0	(213)	(4)
Total servicing income, net									31	(87)	405
Insurance premiums and service revenue earned									979	1,012	1,055
Gain (loss) on mortgage and automotive loans, net									7	55	379
Gain (loss) on extinguishment of debt									(202)	(59)	(148)
Other gain (loss) on investments, net									181	180	146
Other income, net of losses									280	383	737
Total other revenue	215	375	365	321	325	371	402	386	1,276	1,484	2,574
Total net revenue (loss)	1,014	1,264	1,231	1,142	1,099	1,108	1,030	1,026	4,651	4,263	4,465
Provision for loan losses	155	102	63	137	140	141	89	131	457	501	329
Compensation and benefits expense									947	1,019	1,106
Insurance losses and loss adjustment expenses									410	405	454
Other operating expenses									1,591	1,981	2,062
Total noninterest expense	672	742	821	713	884	762	801	958	2,948	3,405	3,622
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries	187	420	347	292	75	205	140	(63)	1,246	357	514
Income tax expense (benefit) from continuing operations	36	127	64	94	(4)	28	40	(123)	321	(59)	(856)
Net income (loss) from continuing operations	151	293	283	198	79	177	100	60	925	416	1,370
Income (loss) from discontinued operations, net of tax	26	130	40	29	25	(86)	(1,027)	1,033	225	(55)	(174)
Undistributed income of bank subsidiaries									0	0	0
Undistributed income of nonbank subsidiaries									0	0	0
Net income (loss)	177	423	323	227	104	91	(927)	1,093	1,150	361	1,196
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									210	(587)	224
Comprehensive income (loss)									1,360	(226)	1,420
Parent [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									(14)	771	852
Interest on loans held-for-sale									0	0	15
Interest on trading assets											0
Interest and dividends on available-for-sale investment securities									0	0	0
Interest-bearing cash									1	3	16
Operating leases									269	500	232
Total financing revenue and other interest income									293	1,333	1,219
Interest on deposits									15	25	58
Interest on short-term borrowings									43	46	60
Interest on long-term debt									1,492	2,039	2,676
Interest Expense, Related Party									88	66	(1)
Total interest expense									1,638	2,176	2,793
Depreciation expense on operating lease assets									161	369	113
Net financing revenue (loss)									(1,506)	(1,212)	(1,687)
Dividends from Bank Subsidiary									1,800
Nonbank subsidiaries									651	5,732	1,074
Servicing fees									1,071	152	191
Servicing asset valuation and hedge activities, net									0	0	0
Total servicing income, net									1,071	152	191
Insurance premiums and service revenue earned									0	0	0
Gain (loss) on mortgage and automotive loans, net									(5)	0	(2)
Gain (loss) on extinguishment of debt									(202)	(61)	0
Other gain (loss) on investments, net									0	0	0
Other income, net of losses									208	157	173
Total other revenue									1,072	248	362
Total net revenue (loss)									2,017	4,768	(251)
Provision for loan losses									250	196	81
Compensation and benefits expense									586	640	812
Insurance losses and loss adjustment expenses									0	0	0
Other operating expenses									1,267	501	1,532
Total noninterest expense									1,853	1,141	2,344
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries									(86)	3,431	(2,676)
Income tax expense (benefit) from continuing operations									(457)	(969)	(2,389)
Net income (loss) from continuing operations									371	4,400	(287)
Income (loss) from discontinued operations, net of tax									193	(1,321)	49
Undistributed income of bank subsidiaries									(680)	883	859
Undistributed income of nonbank subsidiaries									1,266	(3,601)	575
Net income (loss)									1,150	361	1,196
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									210	(587)	224
Comprehensive income (loss)									1,360	(226)	1,420
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									0	0	0
Interest on loans held-for-sale									0	0	0
Interest on trading assets											0
Interest and dividends on available-for-sale investment securities									0	0	0
Interest-bearing cash									0	0	0
Operating leases									0	0	0
Total financing revenue and other interest income									0	0	0
Interest on deposits									0	0	0
Interest on short-term borrowings									0	0	0
Interest on long-term debt									0	0	0
Interest Expense, Related Party									0	0	1
Total interest expense									0	0	1
Depreciation expense on operating lease assets									0	0	0
Net financing revenue (loss)									0	0	(1)
Dividends from Bank Subsidiary									1,800
Nonbank subsidiaries									0	3,659	448
Servicing fees									0	0	0
Servicing asset valuation and hedge activities, net									0	0	0
Total servicing income, net									0	0	0
Insurance premiums and service revenue earned									0	0	0
Gain (loss) on mortgage and automotive loans, net									0	0	0
Gain (loss) on extinguishment of debt									0	0	0
Other gain (loss) on investments, net									0	0	0
Other income, net of losses									0	0	474
Total other revenue									0	0	474
Total net revenue (loss)									1,800	3,659	921
Provision for loan losses									0	0	0
Compensation and benefits expense									0	0	473
Insurance losses and loss adjustment expenses									0	0	0
Other operating expenses									0	0	1
Total noninterest expense									0	0	474
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries									1,800	3,659	447
Income tax expense (benefit) from continuing operations									0	0	0
Net income (loss) from continuing operations									1,800	3,659	447
Income (loss) from discontinued operations, net of tax									0	(19)	(93)
Undistributed income of bank subsidiaries									(680)	883	859
Undistributed income of nonbank subsidiaries									(1)	(2,393)	(105)
Net income (loss)									1,119	2,130	1,108
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									188	(812)	149
Comprehensive income (loss)									1,307	1,318	1,257
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									4,471	3,758	3,687
Interest on loans held-for-sale									1	20	83
Interest on trading assets											10
Interest and dividends on available-for-sale investment securities									367	325	292
Interest-bearing cash									7	7	8
Operating leases									3,289	2,709	2,147
Total financing revenue and other interest income									8,223	6,894	6,265
Interest on deposits									649	629	587
Interest on short-term borrowings									9	17	11
Interest on long-term debt									575	568	677
Interest Expense, Related Party									37	62	120
Total interest expense									1,270	1,276	1,395
Depreciation expense on operating lease assets									2,072	1,626	1,286
Net financing revenue (loss)									4,881	3,992	3,584
Dividends from Bank Subsidiary									0
Nonbank subsidiaries									0	0	0
Servicing fees									792	(26)	218
Servicing asset valuation and hedge activities, net									0	(213)	(4)
Total servicing income, net									792	(239)	214
Insurance premiums and service revenue earned									979	1,012	1,055
Gain (loss) on mortgage and automotive loans, net									12	55	381
Gain (loss) on extinguishment of debt									0	2	(148)
Other gain (loss) on investments, net									181	180	146
Other income, net of losses									507	1,438	1,280
Total other revenue									2,471	2,448	2,928
Total net revenue (loss)									7,352	6,440	6,512
Provision for loan losses									207	305	248
Compensation and benefits expense									793	821	297
Insurance losses and loss adjustment expenses									410	405	454
Other operating expenses									2,159	2,250	1,243
Total noninterest expense									3,362	3,476	1,994
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries									3,783	2,659	4,270
Income tax expense (benefit) from continuing operations									778	910	1,533
Net income (loss) from continuing operations									3,005	1,749	2,737
Income (loss) from discontinued operations, net of tax									32	1,284	(130)
Undistributed income of bank subsidiaries									0	0	0
Undistributed income of nonbank subsidiaries									0	0	0
Net income (loss)									3,037	3,033	2,607
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									212	(873)	463
Comprehensive income (loss)									3,249	2,160	3,070
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									0	0	0
Interest on loans held-for-sale									0	0	0
Interest on trading assets											0
Interest and dividends on available-for-sale investment securities									0	0	0
Interest-bearing cash									0	0	0
Operating leases									0	0	0
Total financing revenue and other interest income									(125)	(134)	(142)
Interest on deposits									0	0	0
Interest on short-term borrowings									0	0	0
Interest on long-term debt									0	(5)	(17)
Interest Expense, Related Party									(125)	(128)	(120)
Total interest expense									(125)	(133)	(137)
Depreciation expense on operating lease assets									0	0	0
Net financing revenue (loss)									0	(1)	(5)
Dividends from Bank Subsidiary									(3,600)
Nonbank subsidiaries									(651)	(9,391)	(1,522)
Servicing fees									(1,832)	0	0
Servicing asset valuation and hedge activities, net									0	0	0
Total servicing income, net									(1,832)	0	0
Insurance premiums and service revenue earned									0	0	0
Gain (loss) on mortgage and automotive loans, net									0	0	0
Gain (loss) on extinguishment of debt									0	0	0
Other gain (loss) on investments, net									0	0	0
Other income, net of losses									(435)	(1,212)	(1,190)
Total other revenue									(2,267)	(1,212)	(1,190)
Total net revenue (loss)									(6,518)	(10,604)	(2,717)
Provision for loan losses									0	0	0
Compensation and benefits expense									(432)	(442)	(476)
Insurance losses and loss adjustment expenses									0	0	0
Other operating expenses									(1,835)	(770)	(714)
Total noninterest expense									(2,267)	(1,212)	(1,190)
(Loss) income from continuing operations before income tax (benefit) expense and undistributed income of subsidiaries									(4,251)	(9,392)	(1,527)
Income tax expense (benefit) from continuing operations									0	0	0
Net income (loss) from continuing operations									(4,251)	(9,392)	(1,527)
Income (loss) from discontinued operations, net of tax									0	1	0
Undistributed income of bank subsidiaries									1,360	(1,766)	(1,718)
Undistributed income of nonbank subsidiaries									(1,265)	5,994	(470)
Net income (loss)									(4,156)	(5,163)	(3,715)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent									(400)	1,685	(612)
Comprehensive income (loss)									(4,556)	(3,478)	(4,327)
Affiliated Entity [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									0	0	0
Interest-bearing cash									0	0	0
Affiliated Entity [Member] | Parent [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									37	59	104
Interest-bearing cash									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
Interest-bearing cash									0	0	0
Affiliated Entity [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									82	68	22
Interest-bearing cash									6	7	16
Affiliated Entity [Member] | Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Interest and fees on finance receivables and loans									(119)	(127)	(126)
Interest-bearing cash									$ (6)	$ (7)	$ (16)