Receivables - Schedule of DFP (Details) - USD ($)	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Purchasers
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Beginning balance		$ 574,000,000
Transfers of receivables		1,214,000,000
Collections		(1,265,000,000)
Change in funding availability		2,000,000
Facility amendments		(525,000,000)
Ending balance	$ 0	$ 0
DE Purchasers
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Beginning balance	103,000,000
Transfers of receivables	417,000,000
Collections	(420,000,000)
Change in funding availability	2,000,000
Facility amendments	(102,000,000)
Ending balance	$ 0