Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Financing revenues:
Operating lease	$ 2,189	$ 2,212	$ 2,167	$ 2,126	$ 2,102	$ 2,068	$ 2,016	$ 1,981	$ 8,694	$ 8,167	$ 7,720
Retail	575	578	547	535	512	498	490	474	2,235	1,974	1,850
Dealer	182	178	176	175	152	140	141	143	711	576	476
Total financing revenues	2,946	2,968	2,890	2,836	2,766	2,706	2,647	2,598	11,640	10,717	10,046
Depreciation on operating leases	1,764	1,717	1,662	1,766	1,863	1,778	1,719	1,681	6,909	7,041	6,853
Interest expense	664	699	702	682	523	428	452	448	2,747	1,851	1,754
Net financing revenues	518	552	526	388	380	500	476	469	1,984	1,825	1,439
Insurance earned premiums and contract revenues	228	226	226	224	225	220	221	216	904	882	804
Investment and other income, net	128	68	56	40	47	66	56	88	292	257	396
Net financing revenues and other revenues	874	846	808	652	652	786	753	773	3,180	2,964	2,639
Expenses:
Provision for credit losses	106	110	67	89	81	108	127	85	372	401	582
Operating and administrative	366	347	348	324	384	323	337	313	1,385	1,357	1,277
Insurance losses and loss adjustment expenses	103	106	112	125	109	100	102	114	446	425	371
Total expenses	575	563	527	538	574	531	566	512	2,203	2,183	2,230
Income before income taxes	299	283	281	114	78	255	187	261	977	781	409
Provision (benefit) for income taxes	4	69	87	22	26	(2,821)	70	96	182	(2,629)	142
Net income	$ 295	$ 214	$ 194	$ 92	$ 52	$ 3,076	$ 117	$ 165	$ 795	$ 3,410	$ 267