Revenue - Change in Contract Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Change In Contract With Customer, Liability [Roll Forward]
Balance, beginning of period	$ 1,756	$ 1,886
Deferred revenue	698	770
Recognition of deferred revenue	(719)	(717)
Currency translation adjustment	30	(5)
Other	(2)	(16)
Balance, end of period	$ 1,763	$ 1,918