Earnings Per Share (Details 1) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Earnings Per Share [Abstract]
Net income (loss)	$ (91.3)	$ 631.7	$ 876.3
Net income (loss) per common share - assuming dilution (in dollars per share)	$ (0.86)	$ 5.83	$ 7.79
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income (loss) per common share - assuming dilution (in dollars per share)	$ (0.86)	$ 5.83	$ 7.79
Net income (loss)	$ (91.3)	$ 631.7	$ 876.3
Treasury Stock Method
Earnings Per Share [Abstract]
Net income (loss)	$ (91.3)	$ 631.7	$ 876.3
Weighted-average common shares outstanding (in shares)	106.2	107.9	112.0
Weighted-average common shares outstanding – assuming dilution (in shares)	106.2	108.4	112.4
Net income (loss) per common share - assuming dilution (in dollars per share)	$ (0.86)	$ 5.83	$ 7.80
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income (loss) per common share - assuming dilution (in dollars per share)	$ (0.86)	$ 5.83	$ 7.80
Weighted-average common shares outstanding – assuming dilution (in shares)	106.2	108.4	112.4
Net income (loss)	$ (91.3)	$ 631.7	$ 876.3
Weighted-average common shares outstanding (in shares)	106.2	107.9	112.0
Employee Stock Option [Member] | Treasury Stock Method
Earnings Per Share [Abstract]
Add: Dilutive effect (in shares)	0.0	0.0	0.0
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Add: Dilutive effect (in shares)	0.0	0.0	0.0
Restricted shares, restricted stock units, and performance units | Treasury Stock Method
Earnings Per Share [Abstract]
Add: Dilutive effect (in shares)	0.0	0.5	0.4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Add: Dilutive effect (in shares)	0.0	0.5	0.4