Segment And Geographic Information (Financial Information Operating Segments) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net financing revenue (loss)	$ 737,000,000	$ 472,000,000	$ 2,005,000,000	$ 1,280,000,000
Other revenue	371,000,000	775,000,000	1,159,000,000	2,094,000,000
Total net revenue (loss)	1,108,000,000	1,247,000,000	3,164,000,000	3,374,000,000
Provision for loan losses	141,000,000	105,000,000	361,000,000	236,000,000
Total noninterest expense	762,000,000	845,000,000	2,521,000,000	2,671,000,000
Income (loss) from continuing operations before income tax expense	205,000,000	297,000,000	282,000,000	467,000,000
Assets	150,556,000,000	182,482,000,000	150,556,000,000	182,482,000,000	182,347,000,000
Net Interest Income (Loss) after Provision for Loan Losses	600,000,000	400,000,000	1,600,000,000	1,000,000,000
Automotive finance operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	800,000,000	728,000,000	2,350,000,000	2,051,000,000
Other revenue	65,000,000	75,000,000	207,000,000	264,000,000
Total net revenue (loss)	865,000,000	803,000,000	2,557,000,000	2,315,000,000
Provision for loan losses	150,000,000	101,000,000	350,000,000	194,000,000
Total noninterest expense	376,000,000	365,000,000	1,143,000,000	1,103,000,000
Income (loss) from continuing operations before income tax expense	339,000,000	337,000,000	1,064,000,000	1,018,000,000
Assets	108,609,000,000	123,252,000,000	108,609,000,000	123,252,000,000
Insurance Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	16,000,000	14,000,000	43,000,000	42,000,000
Other revenue	293,000,000	233,000,000	926,000,000	871,000,000
Total net revenue (loss)	309,000,000	247,000,000	969,000,000	913,000,000
Provision for loan losses	0	0	0	0
Total noninterest expense	226,000,000	234,000,000	780,000,000	780,000,000
Income (loss) from continuing operations before income tax expense	83,000,000	13,000,000	189,000,000	133,000,000
Assets	7,323,000,000	8,461,000,000	7,323,000,000	8,461,000,000
Mortgage Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	13,000,000	45,000,000	62,000,000	111,000,000
Other revenue	19,000,000	446,000,000	(6,000,000)	903,000,000
Total net revenue (loss)	32,000,000	491,000,000	56,000,000	1,014,000,000
Provision for loan losses	(12,000,000)	5,000,000	14,000,000	53,000,000
Total noninterest expense	48,000,000	155,000,000	293,000,000	465,000,000
Income (loss) from continuing operations before income tax expense	(4,000,000)	331,000,000	(251,000,000)	496,000,000
Assets	8,562,000,000	17,004,000,000	8,562,000,000	17,004,000,000
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	(92,000,000)	(315,000,000)	(450,000,000)	(924,000,000)
Other revenue	(6,000,000)	21,000,000	32,000,000	56,000,000
Total net revenue (loss)	(98,000,000)	(294,000,000)	(418,000,000)	(868,000,000)
Provision for loan losses	3,000,000	(1,000,000)	(3,000,000)	(11,000,000)
Total noninterest expense	112,000,000	91,000,000	305,000,000	323,000,000
Income (loss) from continuing operations before income tax expense	(213,000,000)	(384,000,000)	(720,000,000)	(1,180,000,000)
Assets	26,062,000,000	33,765,000,000	26,062,000,000	33,765,000,000
Commercial Finance Operations [Member]
Segment Reporting Information [Line Items]
Assets	$ 1,600,000,000	$ 1,300,000,000	$ 1,600,000,000	$ 1,300,000,000