Guarantor Consolidating Financial Statements Guarantor Income Statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Condensed Income Statements, Captions [Line Items]
Financial charge income	$ 830	$ 415
Leased vehicle income	200	107
Other income	67	18
Equity In Income Of Affiliates	0	0
Revenues	1,097	540
Salaries and benefits	136	74
Other operating expenses	133	34
Total operating expenses	269	108
Leased vehicle expenses	156	80
Provision for loan losses	135	94
Interest expense	315	82
Acquisition and integration expenses	0	6
Costs and Expenses	875	370
Income before income taxes	222	170
Income Tax provision	(77)	(64)
Net income	145	106
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	150	100
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Other income	20	14
Equity In Income Of Affiliates	170	113
Revenues	190	127
Salaries and benefits	0	0
Other operating expenses	1	3
Total operating expenses	1	3
Leased vehicle expenses	0	0
Provision for loan losses	0	0
Interest expense	55	21
Costs and Expenses	56	24
Income before income taxes	134	103
Income Tax provision	11	3
Net income	145	106
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	150	100
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Financial charge income	30	39
Other income	127	41
Equity In Income Of Affiliates	116	146
Revenues	273	226
Salaries and benefits	53	48
Other operating expenses	33	(25)
Total operating expenses	86	23
Leased vehicle expenses	0	0
Provision for loan losses	60	67
Interest expense	11	35
Costs and Expenses	157	125
Income before income taxes	116	101
Income Tax provision	0	14
Net income	116	115
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	96	116
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Financial charge income	800	376
Leased vehicle income	200	107
Other income	38	47
Equity In Income Of Affiliates	0	0
Revenues	1,038	530
Salaries and benefits	83	26
Other operating expenses	161	56
Total operating expenses	244	82
Leased vehicle expenses	156	80
Provision for loan losses	75	27
Interest expense	305	110
Acquisition and integration expenses		6
Costs and Expenses	780	305
Income before income taxes	258	225
Income Tax provision	(88)	(81)
Net income	170	144
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	175	138
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Other income	(118)	(84)
Equity In Income Of Affiliates	(286)	(259)
Revenues	(404)	(343)
Salaries and benefits	0	0
Other operating expenses	(62)	0
Total operating expenses	(62)
Leased vehicle expenses	0	0
Provision for loan losses	0	0
Interest expense	(56)	(84)
Costs and Expenses	(118)	(84)
Income before income taxes	(286)	(259)
Income Tax provision	0
Net income	(286)	(259)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ (271)	$ (254)