Receivables - Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 74	$ 60
Provisions for losses on accounts receivable	53	3
Other adjustments to allowance and write-off's	(40)	11
Ending balance	91	74
Impact of adoption of the Credit Loss Standard
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 4	0
Ending balance		$ 4