Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Cash paid for:
Interest	$ 308	$ 288	$ 103
Taxes on income, net of refunds (1)	197	376	63
Non-cash activities, operating
Prepaid assets acquired under long-term financing	48	209	0
Non-cash activities, investing
Capital expenditures in accounts payable and accrued expenses	45	46	43
Capital expenditures through capital lease obligations	668	664	52
Assets acquired under long-term financing	200	238	87
Increase in deferred purchase price receivable	1,489	665	595
Contingent consideration	41	0	0
Non-cash activities, financing
Dividends declared but not yet paid	53	51	20
Stock issued for the acquisition of HPES	0	9,850	0
Income tax refunds	$ 174	$ 38	$ 23