Other Financial Instruments and Fair Value Measurements (Details) - USD ($) $ in Millions		Oct. 31, 2021	Apr. 30, 2021
Carrying amount and fair value of financial instruments
Total long-term debt	[1]	$ (4,308.8)	$ (4,669.7)
Carrying Amount [Member]
Carrying amount and fair value of financial instruments
Marketable securities and other investments		30.0	31.0
Derivative financial instruments – net		12.0	35.8
Total long-term debt		(4,308.8)	(4,669.7)
Fair Value [Member]
Carrying amount and fair value of financial instruments
Marketable securities and other investments		30.0	31.0
Derivative financial instruments – net		12.0	35.8
Total long-term debt		$ (4,717.6)	$ (5,034.5)

[1] Represents the carrying amount included in the Condensed Consolidated Balance Sheets, which includes the impact of capitalized debt issuance costs, offering discounts, and terminated interest rate contracts.