Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 324	$ 186
Other comprehensive income (loss), net of tax:
Currency translation adjustments	62	(13)
Cash flow hedge adjustments	(45)	9
Postretirement benefits adjustments	7	3
Net other comprehensive income (loss)	24	(1)
Comprehensive income	$ 348	$ 185