Segment Information - Schedule of Segment Reporting Information by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016
Segment Reporting Information [Line Items]
Total financing revenues	$ 2,458	$ 2,255
Insurance earned premiums and contract revenues	193	174
Investment and other income, net	52	38
Total gross revenues	2,703	2,467
Depreciation on operating leases	1,589	1,360
Interest expense	307	508
Provision for credit losses	52	45
Operating and administrative expenses	279	270
Insurance losses and loss adjustment expenses	89	79
Provision for income taxes	146	70
Net income	241	135
Total assets	116,743	111,184	$ 114,592
Intercompany Eliminations [Member]
Segment Reporting Information [Line Items]
Total financing revenues	0	0
Insurance earned premiums and contract revenues	0	0
Investment and other income, net	0	0
Total gross revenues	0	0
Depreciation on operating leases	0	0
Interest expense	0	0
Provision for credit losses	0	0
Operating and administrative expenses	0	0
Insurance losses and loss adjustment expenses	0	0
Provision for income taxes	0	0
Net income	0	0
Total assets	(1,027)	(932)
Finance Operations [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total financing revenues	2,458	2,255
Insurance earned premiums and contract revenues	0	0
Investment and other income, net	34	21
Total gross revenues	2,492	2,276
Depreciation on operating leases	1,589	1,360
Interest expense	307	508
Provision for credit losses	52	45
Operating and administrative expenses	210	209
Insurance losses and loss adjustment expenses	0	0
Provision for income taxes	125	51
Net income	209	103
Total assets	113,457	108,202
Insurance Operations [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total financing revenues	0	0
Insurance earned premiums and contract revenues	193	174
Investment and other income, net	18	17
Total gross revenues	211	191
Depreciation on operating leases	0	0
Interest expense	0	0
Provision for credit losses	0	0
Operating and administrative expenses	69	61
Insurance losses and loss adjustment expenses	89	79
Provision for income taxes	21	19
Net income	32	32
Total assets	$ 4,313	$ 3,914