Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Cash paid for:
Interest	$ 334	$ 371	$ 308
Taxes on income, net of refunds	798	247	197
Non-cash activities, operating
ROU assets obtained in exchange for lease, net	530	411	0
Prepaid assets acquired under long-term financing	46	99	48
Non-cash activities, investing
Capital expenditures in accounts payable and accrued expenses	341	66	45
Capital expenditures through finance lease obligations	348	605	668
Assets acquired under long-term financing	35	376	200
(Decrease) increase in deferred purchase price receivable	(52)	(205)	1,489
Contingent consideration	3	18	41
Non-cash activities, financing
Dividends declared but not yet paid	0	55	53
Income tax refunds	70	42	$ 174
Lease modifications and terminations	$ 763	216
Change in lease classification from operating to finance lease		$ 87