Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Apr. 30, 2023	Apr. 30, 2022
Deferred tax assets:
Postretirement and other benefits	$ 75	$ 69
Accrued liabilities and other	35	36
Inventories	26	40
Lease liabilities	23	20
Loss and credit carryforwards	62	69
Total deferred tax assets	221	234
Valuation allowance	(14)	(27)
Total deferred tax assets, net of valuation allowance	207	207
Deferred tax liabilities:
Intangible assets	(323)	(219)
Property, plant, and equipment	(98)	(87)
Right-of-use assets	(23)	(20)
Derivative instruments	(3)	(11)
Other	(17)	(15)
Total deferred tax liabilities	(464)	(352)
Net deferred tax liability	$ (257)	$ (145)