Segment And Geographic Information (Financial Information Operating Segments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net financing revenue (loss)	$ 984	$ 916	$ 1,935	$ 1,766
Total other revenue	374	211	750	454
Total net revenue (loss)	1,358	1,127	2,685	2,220
Provision for loan losses	172	140	392	256
Total noninterest expense	773	724	1,483	1,419
Income (loss) from continuing operations before income tax expense	413	263	810	545
Assets	157,931	156,278	157,931	156,278	$ 158,581
Net Interest Income (Loss) after Provision for Loan Losses	812	776	1,543	1,510
Automotive Finance Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	929	850	1,825	1,659
Total other revenue	77	55	154	107
Total net revenue (loss)	1,006	905	1,979	1,766
Provision for loan losses	170	132	379	259
Total noninterest expense	410	400	837	828
Income (loss) from continuing operations before income tax expense	426	373	763	679
Assets	112,356	113,607	112,356	113,607
Insurance Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	16	14	30	26
Total other revenue	259	268	513	536
Total net revenue (loss)	275	282	543	562
Provision for loan losses	0	0	0	0
Total noninterest expense	293	267	511	469
Income (loss) from continuing operations before income tax expense	(18)	15	32	93
Assets	7,193	7,260	7,193	7,260
Mortgage Finance Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	26	11	46	22
Total other revenue	0	0	0	0
Total net revenue (loss)	26	11	46	22
Provision for loan losses	0	4	3	6
Total noninterest expense	17	10	32	18
Income (loss) from continuing operations before income tax expense	9	(3)	11	(2)
Assets	8,014	5,623	8,014	5,623
Corporate Finance Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	29	22	57	42
Total other revenue	4	6	10	12
Total net revenue (loss)	33	28	67	54
Provision for loan losses	3	4	9	(1)
Total noninterest expense	16	14	33	28
Income (loss) from continuing operations before income tax expense	14	10	25	27
Assets	2,989	2,132	2,989	2,132
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	(16)	19	(23)	17
Total other revenue	34	(118)	73	(201)
Total net revenue (loss)	18	(99)	50	(184)
Provision for loan losses	(1)	0	1	(8)
Total noninterest expense	37	33	70	76
Income (loss) from continuing operations before income tax expense	(18)	(132)	(21)	(252)
Assets	$ 27,379	$ 27,656	$ 27,379	$ 27,656