Revenue - Change in Contract Liabilities (Details) - USD ($) $ in Millions	6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Change In Contract With Customer, Liability [Roll Forward]
Balance, beginning of period	$ 1,701	$ 1,756
Deferred revenue	1,398	1,355
Recognition of deferred revenue	(1,334)	(1,432)
Currency translation adjustment	(21)	80
Other	(36)	(88)
Balance, end of period	$ 1,708	$ 1,671