Segment And Geographic Information (Financial Information Operating Segments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net financing revenue (loss)	$ 916	$ 866	$ 1,766	$ 1,687
Other revenue	211	365	454	686
Total net revenue (loss)	1,127	1,231	2,220	2,373
Provision for loan losses	140	63	256	200
Total noninterest expense	724	821	1,419	1,534
Income (loss) from continuing operations before income tax expense	263	347	545	639
Assets	156,472	149,937	156,472	149,937	$ 151,828
Net Interest Income (Loss) after Provision for Loan Losses	776	803	1,500
Automotive finance operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	850	884	1,659	1,704
Other revenue	55	62	107	126
Total net revenue (loss)	905	946	1,766	1,830
Provision for loan losses	132	99	259	258
Total noninterest expense	372	386	775	772
Income (loss) from continuing operations before income tax expense	401	461	732	800
Assets	113,607	111,334	113,607	111,334
Insurance Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	14	16	26	31
Other revenue	268	290	536	562
Total net revenue (loss)	282	306	562	593
Provision for loan losses	0	0	0	0
Total noninterest expense	267	329	469	542
Income (loss) from continuing operations before income tax expense	15	(23)	93	51
Assets	7,260	7,232	7,260	7,232
Mortgage Operations [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	15	12	30	26
Other revenue	6	9	74	13
Total net revenue (loss)	21	21	104	39
Provision for loan losses	3	(25)	(2)	(48)
Total noninterest expense	10	19	29	43
Income (loss) from continuing operations before income tax expense	8	27	77	44
Assets	9,249	7,640	9,249	7,640
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Net financing revenue (loss)	37	(46)	51	(74)
Other revenue	(118)	4	(263)	(15)
Total net revenue (loss)	(81)	(42)	(212)	(89)
Provision for loan losses	5	(11)	(1)	(10)
Total noninterest expense	75	87	146	177
Income (loss) from continuing operations before income tax expense	(161)	(118)	(357)	(256)
Assets	26,356	23,731	26,356	23,731
Corporate Finance Operations [Member]
Segment Reporting Information [Line Items]
Assets	$ 2,100	$ 1,700	$ 2,100	$ 1,700