Earnings Per Share (Details 1) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Jul. 31, 2025	Jul. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income (loss)	$ (43.9)	$ 185.0
Net income (loss) per common share – assuming dilution	$ (0.41)	$ 1.74
Treasury Stock Method [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income (loss)	$ (43.9)	$ 185.0
Weighted-average common shares outstanding	106.6	106.3
Weighted-average common shares outstanding – assuming dilution (in shares)	106.6	106.5
Net income (loss) per common share – assuming dilution	$ (0.41)	$ 1.74
Employee stock options | Treasury Stock Method [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dilutive effect (in shares)	0.0	0.0
Restricted shares, restricted stock units, and performance units | Treasury Stock Method [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dilutive effect (in shares)	0.0	0.2