Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Financing costs, net	$ (6.6)	$ (10.6)
Total debt, net	888.1	1,342.7
Less: Current portion of long-term debt	0.0	12.0
Total long-term debt, net	888.1	1,330.7
Series B Term Loan
Debt Instrument [Line Items]
Debt instruments net of original issue discount	731.7	1,185.3
Receivables Financing Agreement
Debt Instrument [Line Items]
Debt instruments net of original issue discount	$ 163.0	$ 168.0