v3.24.2.u1
Pensions and Other Postretirement Benefits (Details) - USD ($)
$ in Millions
 3 Months Ended
Jul. 31, 2024
Jul. 31, 2023
Components of net periodic benefit cost    
Settlement loss (gain) $ 0.0 $ 3.2
Defined Benefit Pension Plans    
Components of net periodic benefit cost    
Service cost 0.1 0.2
Interest cost 4.4 4.6
Expected return on plan assets (3.1) (4.1)
Amortization of net actuarial loss (gain) 1.1 0.9
Amortization of prior service cost (credit) 0.1 0.1
Settlement loss (gain) 0.0 3.2
Net periodic benefit cost 2.6 4.9
Other Postretirement Benefits    
Components of net periodic benefit cost    
Service cost 0.2 0.2
Interest cost 0.7 0.6
Expected return on plan assets 0.0 0.0
Amortization of net actuarial loss (gain) (0.5) (0.4)
Amortization of prior service cost (credit) (0.2) (0.1)
Settlement loss (gain) 0.0 0.0
Net periodic benefit cost $ 0.2 $ 0.3