v3.25.1
Retirement Plans (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2025
Mar. 31, 2024
Retirement Benefits [Abstract]        
Service cost $ 0.6 $ 0.4 $ 1.2 $ 0.9
Interest cost 4.5 5.4 9.0 10.7
Expected return on plan assets (5.3) (4.8) (10.7) (9.7)
Recognized net actuarial loss 0.6 0.3 1.2 0.7
Net periodic cost 0.4 1.3 0.7 2.6
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0.6 0.4 1.2 0.9
Interest cost 4.5 5.4 9.0 10.7
Defined Benefit Plan, Expected Return (Loss) on Plan Assets 5.3 4.8 10.7 9.7
Defined Benefit Plan, Amortization of Gain (Loss) (0.6) (0.3) (1.2) (0.7)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) $ 0.4 $ 1.3 $ 0.7 $ 2.6