v3.26.1
Financial Instruments and Risk Management (Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Sep. 30, 2025
Derivative [Line Items]    
Total long-term debt, including current maturities $ 1,250.0 $ 1,390.0
Fixed rate debt    
Derivative [Line Items]    
Total long-term debt, including current maturities 1,250.0 1,250.0
Level 2 | Recurring fair value measurement    
Derivative [Line Items]    
Deferred compensation (21.2) (20.7)
Net liabilities at estimated fair value (17.1) (22.1)
Level 2 | Recurring fair value measurement | FX contract    
Derivative [Line Items]    
Estimated fair value of derivatives $ 4.1 $ (1.4)