Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Cash paid for:
Interest	$ 371	$ 308	$ 288
Taxes on income, net of refunds	247	197	376
Non-cash activities, operating
ROU assets obtained in exchange for lease, net	411	0	0
Prepaid assets acquired under long-term financing	99	48	209
Non-cash activities, investing
Capital expenditures in accounts payable and accrued expenses	66	45	46
Capital expenditures through capital lease obligations	605	668	664
Assets acquired under long-term financing	376	200	238
(Decrease) increase in deferred purchase price receivable	(205)	1,489	665
Contingent consideration	18	41	0
Non-cash activities, financing
Dividends declared but not yet paid	55	53	51
Stock issued for the acquisition of HPES	0	0	9,850
Income tax refunds	42	$ 174	$ 38
Change in lease classification from operating to finance lease	87
Lease modifications and terminations	$ 216