Guarantor Consolidating Financial Statements Guarantor Income Statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Income Statements, Captions [Line Items]
Financial charge income									$ 2,563	$ 1,594	$ 1,247
Leased vehicle income									595	289	98
Other income									186	77	65
Equity In Income Of Affiliates										0	0
Revenues	1,101	867	836	540	528	515	487	431	3,344	1,960	1,410
Salaries and benefits									448	298	254
Other operating expenses									322	100	85
Total operating expenses									770	398	339
Leased vehicle expenses									453	211	67
Provision for loan losses									475	304	178
Interest expense									721	283	204
Acquisition and integration expenses									42	20
Costs and Expenses									2,461	1,216	788
Income before income taxes	210	239	264	170	146	201	217	181	883	744	622
Income Tax provision									(317)	(281)	(236)
Net income	121	161	178	106	91	124	136	112	566	463	386
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									580	467	377
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Other income									56	45	51
Equity In Income Of Affiliates									584	489	405
Revenues									640	534	456
Other operating expenses									(100)	15	18
Total operating expenses									(100)	15	18
Interest expense									180	67	60
Costs and Expenses									80	82	78
Income before income taxes									560	452	378
Income Tax provision									6	11	8
Net income									566	463	386
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										467	377
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Financial charge income									140	150	107
Other income									433	194	295
Equity In Income Of Affiliates									551	599	489
Revenues									1,124	943	891
Salaries and benefits									216	201	174
Other operating expenses									228	(115)	(85)
Total operating expenses									444	86	89
Provision for loan losses									239	231	158
Interest expense									37	166	307
Costs and Expenses									720	483	554
Income before income taxes									404	460	337
Income Tax provision									42	41	51
Net income									446	501	388
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										501	388
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Financial charge income									2,423	1,444	1,140
Leased vehicle income									595	289	98
Other income									105	250	509
Revenues									3,123	1,983	1,747
Salaries and benefits									232	97	80
Other operating expenses									441	200	152
Total operating expenses									673	297	232
Leased vehicle expenses									453	211	67
Provision for loan losses									236	73	20
Interest expense									665	462	627
Acquisition and integration expenses									42	20
Costs and Expenses									2,069	1,063	946
Income before income taxes									1,054	920	801
Income Tax provision									(365)	(333)	295
Net income									689	587	506
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										593	450
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Other income									(408)	(412)	(790)
Equity In Income Of Affiliates									(1,135)	(1,088)	(894)
Revenues									(1,543)	(1,500)	(1,684)
Interest expense									(161)	(412)	(790)
Costs and Expenses									(408)	(412)	(790)
Income before income taxes									(1,135)	(1,088)	(894)
Net income									(1,135)	(1,088)	(894)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										$ (1,094)	$ (838)