Divestiture (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019	Jul. 31, 2020
Acquisitions and Divestiture [Abstract]
Proceeds from Divestiture of Businesses	$ 177	$ 0	$ 0
Disposal Group, Including Discontinued Operation, Assets				$ 50
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 127	$ 0	$ 0