Guarantor Condensed Consolidating Financial Statements Current Period Guarantor Balance Sheet (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 2,121	$ 2,974	$ 1,162	$ 1,074
Finance receivables, net	32,470	33,000
Leased vehicles, net	8,939	7,060
Restricted cash	1,849	2,071
Goodwill	1,243	1,244
Equity in net assets of non-consolidated affiliates	929	0
Property and equipment, net	176	172
Deferred income taxes	283	341
Related party receivables	437	384
Other assets	899	478
Due from affiliates	0	0
Investments in affiliates	0	0
Total assets	49,346	47,724
Secured debt	24,693	25,214
Unsecured debt	14,432	12,217
Accounts payable and accrued expenses	970	1,002
Deferred income	546	392
Deferred income taxes	48	20
Taxes payable	205	234
Related party taxes payable	636	636
Related party payables	450	433
Other liabilities	163	184
Due to affiliates	0	0
Total liabilities	42,143	40,332
Common stock	0	0
Additional paid-in capital	5,805	5,799
Accumulated other comprehensive (loss) income	(779)	(433)	16
Retained earnings	2,177	2,026
Total stockholders' equity	7,203	7,392
Total liabilities and shareholder's equity	49,346	47,724
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Finance receivables, net	0	0
Leased vehicles, net	0	0
Restricted cash	0	0
Goodwill	1,095	1,095
Equity in net assets of non-consolidated affiliates	0
Property and equipment, net		0
Deferred income taxes	59	28
Related party receivables	0	0
Other assets	107	94
Due from affiliates	8,346	6,787
Investments in affiliates	8,138	7,684
Total assets	17,745	15,688
Secured debt	0	0
Unsecured debt	9,744	7,500
Accounts payable and accrued expenses	85	78
Deferred income	0	0
Deferred income taxes	0	0
Taxes payable	75	79
Related party taxes payable	636	636
Related party payables	0	0
Other liabilities	2	3
Due to affiliates	0	0
Total liabilities	10,542	8,296
Common stock	0	0
Additional paid-in capital	5,805	5,799
Accumulated other comprehensive (loss) income	(779)	(433)
Retained earnings	2,177	2,026
Total stockholders' equity	7,203	7,392
Total liabilities and shareholder's equity	17,745	15,688
Guarantor [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	1,444	2,266	540	395
Finance receivables, net	3,845	2,401
Leased vehicles, net	0	0
Restricted cash	13	17
Goodwill	0	0
Equity in net assets of non-consolidated affiliates	0
Property and equipment, net	31	23
Deferred income taxes	0	0
Related party receivables	18	11
Other assets	170	18
Due from affiliates	0	0
Investments in affiliates	3,559	4,059
Total assets	9,080	8,795
Secured debt	0	0
Unsecured debt	0	0
Accounts payable and accrued expenses	166	156
Deferred income	0	0
Deferred income taxes	584	288
Taxes payable	0	0
Related party taxes payable	0	0
Related party payables	0	0
Other liabilities	11	12
Due to affiliates	4,054	4,164
Total liabilities	4,815	4,620
Common stock	0	0
Additional paid-in capital	79	79
Accumulated other comprehensive (loss) income	(122)	(64)
Retained earnings	4,308	4,160
Total stockholders' equity	4,265	4,175
Total liabilities and shareholder's equity	9,080	8,795
Non-Guarantors [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	677	708	622	679
Finance receivables, net	28,625	30,599
Leased vehicles, net	8,939	7,060
Restricted cash	1,836	2,054
Goodwill	148	149
Equity in net assets of non-consolidated affiliates	929
Property and equipment, net	145	149
Deferred income taxes	764	601
Related party receivables	419	373
Other assets	622	366
Due from affiliates	0	400
Investments in affiliates	0	0
Total assets	43,104	42,459
Secured debt	24,693	25,214
Unsecured debt	4,688	4,717
Accounts payable and accrued expenses	719	768
Deferred income	546	392
Deferred income taxes	4	20
Taxes payable	130	155
Related party taxes payable	0	0
Related party payables	450	433
Other liabilities	150	169
Due to affiliates	4,292	3,023
Total liabilities	35,672	34,891
Common stock	688	690
Additional paid-in capital	4,054	4,064
Accumulated other comprehensive (loss) income	(754)	(410)
Retained earnings	3,444	3,224
Total stockholders' equity	7,432	7,568
Total liabilities and shareholder's equity	43,104	42,459
Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Finance receivables, net	0	0
Leased vehicles, net	0	0
Restricted cash	0	0
Goodwill	0	0
Equity in net assets of non-consolidated affiliates	0
Property and equipment, net		0
Deferred income taxes	(540)	(288)
Related party receivables	0	0
Other assets	0	0
Due from affiliates	(8,346)	(7,187)
Investments in affiliates	(11,697)	(11,743)
Total assets	(20,583)	(19,218)
Secured debt	0	0
Unsecured debt	0	0
Accounts payable and accrued expenses	0	0
Deferred income	0	0
Deferred income taxes	(540)	(288)
Taxes payable	0	0
Related party taxes payable	0	0
Related party payables	0	0
Other liabilities	0	0
Due to affiliates	(8,346)	(7,187)
Total liabilities	(8,886)	(7,475)
Common stock	(688)	(690)
Additional paid-in capital	(4,133)	(4,143)
Accumulated other comprehensive (loss) income	876	474
Retained earnings	(7,752)	(7,384)
Total stockholders' equity	(11,697)	(11,743)
Total liabilities and shareholder's equity	$ (20,583)	$ (19,218)