Debt - Schedule of Short-Term Borrowings and Long Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Debt issuance costs and discounts	$ (6.8)	$ (5.6)
Total debt	1,075.7	1,093.8
Current portion of long-term debt	23.8	23.8
Long-term debt	1,051.9	1,070.0
Revolver
Debt Instrument [Line Items]
Total borrowing capacity remaining	475.0
Line of Credit | Revolver
Debt Instrument [Line Items]
Debt gross	120.0	125.0
Long-term debt	120.0
2031 Notes | Senior Notes
Debt Instrument [Line Items]
Debt gross	535.0	535.0
Term Loan A | Line of Credit
Debt Instrument [Line Items]
Debt gross	427.5	$ 439.4
Term Loan A | Line of Credit | Revolver
Debt Instrument [Line Items]
Total borrowing capacity remaining	351.5
Letters of credit outstanding	$ 3.5