Supplemental Information (Net Sales by Geography) (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Geographic Areas, Revenues from External Customers [Abstract]
Net sales	$ 3,933	$ 3,461	$ 3,363
United States
Geographic Areas, Revenues from External Customers [Abstract]
Net sales	1,917	1,748	1,690
Germany
Geographic Areas, Revenues from External Customers [Abstract]
Net sales	228	206	171
Australia
Geographic Areas, Revenues from External Customers [Abstract]
Net sales	219	209	155
United Kingdom
Geographic Areas, Revenues from External Customers [Abstract]
Net sales	218	205	180
Mexico
Geographic Areas, Revenues from External Customers [Abstract]
Net sales	178	150	155
Other Countries
Geographic Areas, Revenues from External Customers [Abstract]
Net sales	$ 1,173	$ 943	$ 1,012