Guarantor Condensed Consolidating Financial Statements Current Period Guarantor Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 2,070	$ 2,974	$ 1,412	$ 1,074
Finance receivables, net	34,385	33,000
Leased vehicles, net	12,904	7,060
Restricted cash	1,856	2,071
Goodwill	1,243	1,244
Equity in net assets of non-consolidated affiliates	978	0
Property and equipment, net	202	172
Deferred income taxes	283	341
Related party receivables	588	384
Other assets	821	478
Due from affiliates	0	0
Investment in affiliates	0	0
Total assets	55,330	47,724
Secured debt	26,617	25,214
Unsecured debt	17,713	12,217
Accounts payable and accrued expenses	1,138	1,002
Deferred income	844	392
Deferred income taxes	70	20
Related party taxes payable	636	636
Related party payables	429	433
Other liabilities	380	418
Due to affiliates	0	0
Total liabilities	47,827	40,332
Common stock	0	0
Additional paid-in capital	5,815	5,799
Accumulated other comprehensive loss	(674)	(433)	65
Retained earnings	2,362	2,026
Total shareholder's equity	7,503	7,392
Total liabilities and shareholder's equity	55,330	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	0
Deferred income taxes	97	28
Related party receivables	0	0
Other assets	118	94
Due from affiliates	10,754	6,787
Investment in affiliates	8,424	7,684
Total assets	20,488	15,688
Secured debt	0	0
Unsecured debt	12,141	7,500
Accounts payable and accrued expenses	130	78
Deferred income	0	0
Deferred income taxes	0	0
Related party taxes payable	636	636
Related party payables	0	0
Other liabilities	72	82
Due to affiliates	6	0
Total liabilities	12,985	8,296
Common stock	0	0
Additional paid-in capital	5,815	5,799
Accumulated other comprehensive loss	(674)	(433)
Retained earnings	2,362	2,026
Total shareholder's equity	7,503	7,392
Total liabilities and shareholder's equity	20,488	15,688
Guarantor [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	1,161	2,266	699	395
Finance receivables, net	4,152	2,401
Leased vehicles, net	0	0
Restricted cash	30	17
Goodwill	0	0
Equity in net assets of non-consolidated affiliates	0
Property and equipment, net	35	23
Deferred income taxes	0	0
Related party receivables	22	11
Other assets	61	18
Due from affiliates	0	0
Investment in affiliates	4,660	4,059
Total assets	10,121	8,795
Secured debt	0	0
Unsecured debt	0	0
Accounts payable and accrued expenses	205	156
Deferred income	0	0
Deferred income taxes	267	288
Related party taxes payable	0	0
Related party payables	0	0
Other liabilities	24	12
Due to affiliates	5,221	4,164
Total liabilities	5,717	4,620
Common stock	0	0
Additional paid-in capital	79	79
Accumulated other comprehensive loss	(108)	(64)
Retained earnings	4,433	4,160
Total shareholder's equity	4,404	4,175
Total liabilities and shareholder's equity	10,121	8,795
Non-Guarantors [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	909	708	713	679
Finance receivables, net	30,233	30,599
Leased vehicles, net	12,904	7,060
Restricted cash	1,826	2,054
Goodwill	148	149
Equity in net assets of non-consolidated affiliates	978
Property and equipment, net	167	149
Deferred income taxes	388	601
Related party receivables	566	373
Other assets	642	366
Due from affiliates	0	400
Investment in affiliates	0	0
Total assets	48,761	42,459
Secured debt	26,617	25,214
Unsecured debt	5,572	4,717
Accounts payable and accrued expenses	803	768
Deferred income	844	392
Deferred income taxes	5	20
Related party taxes payable	0	0
Related party payables	429	433
Other liabilities	284	324
Due to affiliates	5,527	3,023
Total liabilities	40,081	34,891
Common stock	690	690
Additional paid-in capital	4,948	4,064
Accumulated other comprehensive loss	(655)	(410)
Retained earnings	3,697	3,224
Total shareholder's equity	8,680	7,568
Total liabilities and shareholder's equity	48,761	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	0
Deferred income taxes	(202)	(288)
Related party receivables	0	0
Other assets	0	0
Due from affiliates	(10,754)	(7,187)
Investment in affiliates	(13,084)	(11,743)
Total assets	(24,040)	(19,218)
Secured debt	0	0
Unsecured debt	0	0
Accounts payable and accrued expenses	0	0
Deferred income	0	0
Deferred income taxes	(202)	(288)
Related party taxes payable	0	0
Related party payables	0	0
Other liabilities	0	0
Due to affiliates	(10,754)	(7,187)
Total liabilities	(10,956)	(7,475)
Common stock	(690)	(690)
Additional paid-in capital	(5,027)	(4,143)
Accumulated other comprehensive loss	763	474
Retained earnings	(8,130)	(7,384)
Total shareholder's equity	(13,084)	(11,743)
Total liabilities and shareholder's equity	$ (24,040)	$ (19,218)