Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 903	$ 827	$ 835
Other comprehensive income (loss), net of tax:
Currency translation adjustments	123	(94)	(27)
Cash flow hedge adjustments	(76)	30	48
Postretirement benefits adjustments	78	(77)	(6)
Net other comprehensive income (loss)	125	(141)	15
Comprehensive income	$ 1,028	$ 686	$ 850