Guarantor Condensed Consolidating Financial Statements Current Period Guarantor Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,602	$ 2,974	$ 1,517	$ 1,074
Finance receivables, net	35,074	33,000
Leased vehicles, net	16,915	7,060
Restricted cash	1,928	2,071
Goodwill	1,243	1,244
Equity in net assets of non-consolidated affiliates	978	0
Property and equipment, net	207	172
Deferred income taxes	236	341
Related party receivables	589	384
Other assets	774	478
Due from affiliates	0	0
Investment in affiliates	0	0
Total assets	59,546	47,724
Secured debt	28,284	25,214
Unsecured debt	19,975	12,217
Accounts payable and accrued expenses	1,094	1,002
Deferred income	1,205	392
Deferred income taxes	84	20
Related party taxes payable	649	636
Related party payables	527	433
Other liabilities	324	418
Due to affiliates	0	0
Total liabilities	52,142	40,332
Common stock	0	0
Additional paid-in capital	5,819	5,799
Accumulated other comprehensive loss	(956)	(433)	(207)
Retained earnings	2,541	2,026
Total shareholder's equity	7,404	7,392
Total liabilities and shareholder's equity	59,546	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	137	28
Related party receivables	0	0
Other assets	122	94
Due from affiliates	12,942	6,787
Investment in affiliates	8,398	7,684
Total assets	22,694	15,688
Secured debt	0	0
Unsecured debt	14,440	7,500
Accounts payable and accrued expenses	127	78
Deferred income	0	0
Deferred income taxes	0	0
Related party taxes payable	649	636
Related party payables	0	0
Other liabilities	74	82
Due to affiliates	0	0
Total liabilities	15,290	8,296
Common stock	0	0
Additional paid-in capital	5,819	5,799
Accumulated other comprehensive loss	(956)	(433)
Retained earnings	2,541	2,026
Total shareholder's equity	7,404	7,392
Total liabilities and shareholder's equity	22,694	15,688
Guarantor [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	834	2,266	809	395
Finance receivables, net	3,621	2,401
Leased vehicles, net	0	0
Restricted cash	36	17
Goodwill	0	0
Equity in net assets of non-consolidated affiliates	0
Property and equipment, net	43	23
Deferred income taxes	0	0
Related party receivables	23	11
Other assets	32	18
Due from affiliates	0	0
Investment in affiliates	7,070	4,059
Total assets	11,659	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	11	12
Due to affiliates	6,632	4,164
Total liabilities	7,115	4,620
Common stock	0	0
Additional paid-in capital	79	79
Accumulated other comprehensive loss	(154)	(64)
Retained earnings	4,619	4,160
Total shareholder's equity	4,544	4,175
Total liabilities and shareholder's equity	11,659	8,795
Non-Guarantors [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	768	708	708	679
Finance receivables, net	31,453	30,599
Leased vehicles, net	16,915	7,060
Restricted cash	1,892	2,054
Goodwill	148	149
Equity in net assets of non-consolidated affiliates	978
Property and equipment, net	164	149
Deferred income taxes	288	601
Related party receivables	566	373
Other assets	620	366
Due from affiliates	0	400
Investment in affiliates	0	0
Total assets	53,792	42,459
Secured debt	28,284	25,214
Unsecured debt	5,535	4,717
Accounts payable and accrued expenses	762	768
Deferred income	1,205	392
Deferred income taxes	6	20
Related party taxes payable	0	0
Related party payables	527	433
Other liabilities	239	324
Due to affiliates	6,310	3,023
Total liabilities	42,868	34,891
Common stock	690	690
Additional paid-in capital	7,238	4,064
Accumulated other comprehensive loss	(937)	(410)
Retained earnings	3,933	3,224
Total shareholder's equity	10,924	7,568
Total liabilities and shareholder's equity	53,792	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	(189)	(288)
Related party receivables	0	0
Other assets	0	0
Due from affiliates	(12,942)	(7,187)
Investment in affiliates	(15,468)	(11,743)
Total assets	(28,599)	(19,218)
Secured debt	0	0
Unsecured debt	0	0
Accounts payable and accrued expenses	0	0
Deferred income	0	0
Deferred income taxes	(189)	(288)
Related party taxes payable	0	0
Related party payables	0	0
Other liabilities	0	0
Due to affiliates	(12,942)	(7,187)
Total liabilities	(13,131)	(7,475)
Common stock	(690)	(690)
Additional paid-in capital	(7,317)	(4,143)
Accumulated other comprehensive loss	1,091	474
Retained earnings	(8,552)	(7,384)
Total shareholder's equity	(15,468)	(11,743)
Total liabilities and shareholder's equity	$ (28,599)	$ (19,218)