Earnings Per Share (Details 1) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income (loss)	$ 744.0	$ (91.3)	$ 631.7
Net income (loss) per common share - assuming dilution (in dollars per share)	$ 7.13	$ (0.86)	$ 5.83
Treasury Stock Method
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income (loss)	$ 744.0	$ (91.3)	$ 631.7
Weighted-average common shares outstanding (in shares)	104.1	106.2	107.9
Weighted-average common shares outstanding – assuming dilution (in shares)	104.4	106.2	108.4
Net income (loss) per common share - assuming dilution (in dollars per share)	$ 7.13	$ (0.86)	$ 5.83
Employee Stock Option [Member] | Treasury Stock Method
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Add: Dilutive effect (in shares)	0.1	0.0	0.0
Restricted shares, restricted stock units, and performance units | Treasury Stock Method
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Add: Dilutive effect (in shares)	0.2	0.0	0.5