Debt (Details) - USD ($) $ in Millions	Dec. 31, 2024	Sep. 30, 2024
Debt Instrument [Line Items]
Total	$ 1,449.0	$ 1,284.0
Long-term debt	1,440.6	1,275.0
Notes payable	27.2	24.5
Unamortized debt issuance costs	$ 8.4	9.0
Short-Term Debt, Weighted Average Interest Rate, at Point in Time	3.80%
Senior notes | Senior Notes, Due 2028
Debt Instrument [Line Items]
Total	$ 750.0	750.0
Unamortized debt issuance costs	5.0	5.4
Senior notes | Senior Notes, Due 2029
Debt Instrument [Line Items]
Total	500.0	500.0
Unamortized debt issuance costs	3.4	3.6
Revolving credit facility
Debt Instrument [Line Items]
Total	$ 199.0	$ 34.0