Quarterly Financial Statements (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Quarterly Financial Statements [Abstract]
Net financing revenue (loss)	$ 611	$ 473	$ 443	$ 342	$ 286	$ 247	$ 341	$ 207	$ 1,869		$ 1,081		$ 1,306
Other revenue	481	774	762	1,012	812	385	873	827	3,029		2,897		4,416
Total net revenue (loss)	1,092	1,247	1,205	1,354	1,098	632	1,214	1,034	4,898		3,978		5,722
Provision for loan losses	92	105	34	98	(13)	57	59	85	329		188		357
Total noninterest expense	1,037	877	2,290	1,120	1,420	983	1,277	1,061	5,324		4,741		4,973
Income (loss) from continuing operations before income tax expense	(37)	265	(1,119)	136	(309)	(408)	(122)	(112)	(755)		(951)		392
Income tax expense (benefit) from continuing operations	(1,337)	43	(8)	18	10	13	9	19	(1,284)		51		104
Net income (loss) from continuing operations	1,300	222	(1,111)	118	(319)	(421)	(131)	(131)	529		(1,002)		288
Income (loss) from discontinued operations, net of tax	100	162	213	192	113	211	244	277	667		845		741
Net income (loss)	$ 1,400	$ 384	$ (898)	$ 310	$ (206)	$ (210)	$ 113	$ 146	$ 1,196		$ (157)		$ 1,029
Net income (loss) from continuing operations, Per Basic Share	$ 825	$ 16	$ (985)	$ (62)					$ (205)		$ (1,326)		$ (1,965)
Net (loss) income, Basic	$ 901	$ 137	$ (825)	$ 82					$ 296		$ (691)		$ (1,039)
Net income (loss) from continuing operations, Per Diluted Share	$ 647	$ 16	$ (985)	$ (62)					$ (205)	[1]	$ (1,326)	[1]	$ (1,965)	[1]
Net (loss) income, Diluted	$ 700	$ 137	$ (825)	$ 82					$ 296	[1]	$ (691)	[1]	$ (1,039)	[1]
Net income (loss) from continuing operations, Per Basic and Diluted Share					$ (390)	$ (467)	$ (242)	$ (227)
Net income (loss), Basic and Diluted					$ (305)	$ (308)	$ (58)	$ (19)

[1] Due to the antidilutive effect of converting the Fixed Rate Cumulative Mandatorily Convertible Preferred Stock into common shares and the net loss from continuing operations attributable to common shareholders for 2012, 2011, and 2010, respectively, 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.