Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Financing revenues:
Operating lease	$ 2,116	$ 2,122	$ 2,114	$ 2,129	$ 2,182	$ 2,212	$ 2,197	$ 2,184	$ 8,481	$ 8,775	$ 8,694
Retail	761	749	723	672	670	661	638	589	2,905	2,558	2,235
Dealer	101	103	98	111	152	171	183	190	413	696	711
Total financing revenues	2,978	2,974	2,935	2,912	3,004	3,044	3,018	2,963	11,799	12,029	11,640
Depreciation on operating leases	1,448	1,450	1,349	1,685	1,900	1,712	1,583	1,625	5,932	6,820	6,909
Interest expense	768	491	495	548	769	755	613	697	2,302	2,834	2,747
Net financing revenues	762	1,033	1,091	679	335	577	822	641	3,565	2,375	1,984
Voluntary protection contract revenues and insurance earned premiums	242	241	238	235	241	231	232	229	956	933	904
Investment and other income, net	(35)	179	90	176	50	57	97	118	410	322	292
Net financing revenues and other revenues	969	1,453	1,419	1,090	626	865	1,151	988	4,931	3,630	3,180
Expenses:
Provision for credit losses	60	118	65	183	326	128	61	75	426	590	372
Operating and administrative	399	354	389	345	460	406	358	337	1,487	1,561	1,385
Voluntary protection contract expenses and insurance losses	104	98	92	75	111	116	115	113	369	455	446
Total expenses	563	570	546	603	897	650	534	525	2,282	2,606	2,203
Income before income taxes	406	883	873	487	(271)	215	617	463	2,649	1,024	977
Provision for income taxes	86	215	218	113	(185)	34	158	104	632	111	182
Net income	$ 320	$ 668	$ 655	$ 374	$ (86)	$ 181	$ 459	$ 359	$ 2,017	$ 913	$ 795