Guarantor Consolidating Financial Statements Guarantor Income Statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Income Statements, Captions [Line Items]
Financial charge income	$ 883	$ 647	$ 2,595	$ 1,709
Leased vehicle income	297	172	735	415
Other income	81	48	219	119
Equity In Income Of Affiliates	0	0	0	0
Revenues	1,261	867	3,549	2,243
Salaries and benefits	158	123	448	313
Other operating expenses	139	80	398	189
Total operating expenses	297	203	846	502
Leased vehicle expenses	228	133	563	314
Provision for loan losses	160	117	408	311
Interest expense	368	168	1,037	414
Acquisition and integration expenses	0	7	0	29
Costs and Expenses	1,053	628	2,854	1,570
Income before income taxes	208	239	695	673
Income Tax provision	(50)	(78)	(217)	(228)
Net income	158	161	478	445
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(114)	256	260	475
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Other income	18	42	58	91
Equity In Income Of Affiliates	242	113	601	413
Revenues	260	155	659	504
Salaries and benefits	0	0	0	0
Other operating expenses	117	(74)	112	(76)
Total operating expenses	117	(74)	112	(76)
Leased vehicle expenses	0	0	0	0
Provision for loan losses	0	0	0	0
Interest expense	56	57	155	128
Costs and Expenses	173	(17)	267	52
Income before income taxes	87	172	392	452
Income Tax provision	71	(11)	86	(7)
Net income	158	161	478	445
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(114)	256	260	475
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Financial charge income	48	37	117	106
Other income	115	85	346	209
Equity In Income Of Affiliates	139	123	408	427
Revenues	302	245	871	742
Salaries and benefits	64	56	180	158
Other operating expenses	(75)	42	(1)	(7)
Total operating expenses	(11)	98	179	151
Leased vehicle expenses	0	0	0	0
Provision for loan losses	97	53	232	180
Interest expense	8	54	27	143
Costs and Expenses	94	205	438	474
Income before income taxes	208	40	433	268
Income Tax provision	(27)	25	(11)	52
Net income	181	65	422	320
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	148	79	392	341
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Financial charge income	835	610	2,478	1,603
Leased vehicle income	297	172	735	415
Other income	46	100	126	228
Equity In Income Of Affiliates	0	0	0	0
Revenues	1,178	882	3,339	2,246
Salaries and benefits	94	67	268	155
Other operating expenses	160	112	474	272
Total operating expenses	254	179	742	427
Leased vehicle expenses	228	133	563	314
Provision for loan losses	63	64	176	131
Interest expense	339	236	979	552
Acquisition and integration expenses		7		29
Costs and Expenses	884	619	2,460	1,453
Income before income taxes	294	263	879	793
Income Tax provision	(94)	(92)	(292)	(273)
Net income	200	171	587	520
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	(71)	266	371	553
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Other income	(98)	(179)	(311)	(409)
Equity In Income Of Affiliates	(381)	(236)	(1,009)	(840)
Revenues	(479)	(415)	(1,320)	(1,249)
Salaries and benefits	0	0	0	0
Other operating expenses	(63)	0	(187)	0
Total operating expenses	(63)	0	(187)	0
Leased vehicle expenses	0	0	0	0
Provision for loan losses	0	0	0	0
Interest expense	(35)	(179)	(124)	(409)
Costs and Expenses	(98)	(179)	(311)	(409)
Income before income taxes	(381)	(236)	(1,009)	(840)
Income Tax provision	0	0	0	0
Net income	(381)	(236)	(1,009)	(840)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ (77)	$ (345)	$ (763)	$ (894)