v3.26.1
Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Gain) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension Benefits | North America        
Components of net periodic benefit cost (gain)        
Service cost $ 0.6 $ 0.7 $ 1.9 $ 2.0
Interest cost 1.4 1.4 4.1 4.1
Expected return on plan assets (2.2) (2.1) (6.5) (6.3)
Recognized net actuarial loss (gain) (0.1) (0.1) (0.3) (0.2)
Recognized prior service cost (credit) 0.3 0.2 0.8 0.8
Net periodic benefit cost (income) 0.0 0.1 0.0 0.4
Pension Benefits | Other International        
Components of net periodic benefit cost (gain)        
Service cost 0.4 0.0 1.4 0.1
Interest cost 6.6 6.5 19.7 18.9
Expected return on plan assets (9.0) (9.2) (27.0) (26.7)
Recognized net actuarial loss (gain) 0.2 0.1 0.5 0.1
Recognized prior service cost (credit) 0.1 0.1 0.3 0.3
Net periodic benefit cost (income) (1.7) (2.5) (5.1) (7.3)
Other Postretirement Benefit Plan | North America        
Components of net periodic benefit cost (gain)        
Service cost 0.0 0.0 0.1 0.1
Interest cost 0.7 0.6 1.8 1.7
Recognized net actuarial loss (gain) (0.1) 0.0 (0.2) (0.2)
Net periodic benefit cost (income) $ 0.6 $ 0.6 $ 1.7 $ 1.6