Guarantor Condensed Consolidating Financial Statements - Current Period Guarantor Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 4,178	$ 4,265
Finance receivables, net	43,773	42,172
Leased vehicles, net	43,444	42,882
Goodwill	1,198	1,197
Equity in net assets of non-consolidated affiliate (Note 5)	1,281	1,187
Related party receivables (Note 2)	659	309
Other assets (Note 7 VIEs)	6,489	5,003
Due from affiliates	0	0
Investment in affiliates	0	0
Total assets	101,022	97,015
Liabilities
Secured debt (Note 6; Note 7 VIEs)	39,441	39,887
Unsecured debt (Note 6)	44,079	40,830
Deferred income	3,336	3,221
Related party payables (Note 2)	132	92
Other liabilities	3,286	2,691
Due to affiliates	0	0
Total liabilities	90,274	86,721
Shareholders' equity (Note 10)
Common stock	0	0
Preferred stock	0	0
Additional paid-in capital	7,541	7,525
Accumulated other comprehensive loss	(708)	(768)
Retained earnings	3,915	3,537
Total shareholders' equity	10,748	10,294
Total liabilities and shareholders' equity	101,022	97,015
Parent Company [Member]
Assets
Cash and cash equivalents	0	0
Finance receivables, net	0	0
Leased vehicles, net	0	0
Goodwill	1,095	1,095
Equity in net assets of non-consolidated affiliate (Note 5)	0	0
Related party receivables (Note 2)	0	2
Other assets (Note 7 VIEs)	633	558
Due from affiliates	38,038	35,312
Investment in affiliates	10,436	9,870
Total assets	50,202	46,837
Liabilities
Secured debt (Note 6; Note 7 VIEs)	0	0
Unsecured debt (Note 6)	39,055	36,145
Deferred income	0	0
Related party payables (Note 2)	2	2
Other liabilities	397	396
Due to affiliates	0	0
Total liabilities	39,454	36,543
Shareholders' equity (Note 10)
Common stock	0	0
Preferred stock	0	0
Additional paid-in capital	7,541	7,525
Accumulated other comprehensive loss	(708)	(768)
Retained earnings	3,915	3,537
Total shareholders' equity	10,748	10,294
Total liabilities and shareholders' equity	50,202	46,837
Guarantor [Member]
Assets
Cash and cash equivalents	3,086	3,535
Finance receivables, net	11,114	9,569
Leased vehicles, net	0	0
Goodwill	0	0
Equity in net assets of non-consolidated affiliate (Note 5)	0	0
Related party receivables (Note 2)	91	23
Other assets (Note 7 VIEs)	2,045	1,497
Due from affiliates	23,975	22,603
Investment in affiliates	6,844	6,426
Total assets	47,155	43,653
Liabilities
Secured debt (Note 6; Note 7 VIEs)	0	0
Unsecured debt (Note 6)	0	0
Deferred income	0	0
Related party payables (Note 2)	0	0
Other liabilities	1,429	967
Due to affiliates	37,772	35,110
Total liabilities	39,201	36,077
Shareholders' equity (Note 10)
Common stock	0	0
Preferred stock	0	0
Additional paid-in capital	79	79
Accumulated other comprehensive loss	(133)	(109)
Retained earnings	8,008	7,606
Total shareholders' equity	7,954	7,576
Total liabilities and shareholders' equity	47,155	43,653
Non-Guarantors [Member]
Assets
Cash and cash equivalents	1,092	730
Finance receivables, net	32,659	32,603
Leased vehicles, net	43,444	42,882
Goodwill	103	102
Equity in net assets of non-consolidated affiliate (Note 5)	1,281	1,187
Related party receivables (Note 2)	568	284
Other assets (Note 7 VIEs)	4,899	3,920
Due from affiliates	0	0
Investment in affiliates	0	0
Total assets	84,046	81,708
Liabilities
Secured debt (Note 6; Note 7 VIEs)	39,871	40,289
Unsecured debt (Note 6)	5,024	4,685
Deferred income	3,336	3,221
Related party payables (Note 2)	130	90
Other liabilities	2,118	1,898
Due to affiliates	24,241	22,805
Total liabilities	74,720	72,988
Shareholders' equity (Note 10)
Common stock	698	698
Preferred stock	0	0
Additional paid-in capital	2,128	2,123
Accumulated other comprehensive loss	(661)	(714)
Retained earnings	7,161	6,613
Total shareholders' equity	9,326	8,720
Total liabilities and shareholders' equity	84,046	81,708
Eliminations [Member]
Assets
Cash and cash equivalents	0	0
Finance receivables, net	0	0
Leased vehicles, net	0	0
Goodwill	0	0
Equity in net assets of non-consolidated affiliate (Note 5)	0	0
Related party receivables (Note 2)	0	0
Other assets (Note 7 VIEs)	(1,088)	(972)
Due from affiliates	(62,013)	(57,915)
Investment in affiliates	(17,280)	(16,296)
Total assets	(80,381)	(75,183)
Liabilities
Secured debt (Note 6; Note 7 VIEs)	(430)	(402)
Unsecured debt (Note 6)	0	0
Deferred income	0	0
Related party payables (Note 2)	0	0
Other liabilities	(658)	(570)
Due to affiliates	(62,013)	(57,915)
Total liabilities	(63,101)	(58,887)
Shareholders' equity (Note 10)
Common stock	(698)	(698)
Preferred stock	0	0
Additional paid-in capital	(2,207)	(2,202)
Accumulated other comprehensive loss	794	823
Retained earnings	(15,169)	(14,219)
Total shareholders' equity	(17,280)	(16,296)
Total liabilities and shareholders' equity	(80,381)	(75,183)
Senior Notes [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Debt instrument, face amount	40,800	$ 37,300
6.75% Senior Notes Due June 2018 [Member] | Senior Notes [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Debt instrument, face amount	$ 500
Shareholders' equity (Note 10)
Weighted average interest rate	6.75%