Debt (Schedule of Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Sep. 30, 2025
Debt Instrument [Line Items]
Total	$ 1,527.0	$ 1,390.0
Unamortized debt issuance costs	6.2	6.7
Long-term debt	1,520.8	1,383.3
Revolving credit facility
Debt Instrument [Line Items]
Total	277.0	140.0
Senior Notes, Due 2028 | Senior notes
Debt Instrument [Line Items]
Total	750.0	750.0
Unamortized debt issuance costs	3.6	3.9
Senior Notes, Due 2029 | Senior notes
Debt Instrument [Line Items]
Total	500.0	500.0
Unamortized debt issuance costs	$ 2.6	$ 2.8