Debt (Schedule of Long-term Debt Instruments) (Details) € in Millions, $ in Millions	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Jun. 23, 2021 EUR (€)
Debt Instrument [Line Items]
Total long-term debt, including current maturities	$ 3,230.0	$ 3,376.2
Finance lease obligations	49.2	32.0
Less current portion	(12.6)	(12.3)
Less unamortized debt premium and debt issuance fees	(24.4)	(31.8)
Total long-term debt	3,193.0	3,332.1
Senior Notes | Senior Notes, 6.500%, Due 2027
Debt Instrument [Line Items]
Total long-term debt, including current maturities	$ 300.0	300.0
Stated interest rate of debt	6.50%
Senior Notes | 4.750% Senior Notes due 2028
Debt Instrument [Line Items]
Total long-term debt, including current maturities	$ 583.7	$ 583.7
Stated interest rate of debt	4.75%	4.75%
Senior Notes | 4.375% Senior Notes due 2029
Debt Instrument [Line Items]
Total long-term debt, including current maturities	$ 791.3	$ 791.3
Stated interest rate of debt	4.375%	4.375%
Senior Notes | 3.50% Senior Notes due 2029 (Euro Notes of €650.0)(1)
Debt Instrument [Line Items]
Total long-term debt, including current maturities | €			€ 650.0
Stated interest rate of debt	3.50%
Secured Debt | Senior Secured Term Loan Facility due 2027
Debt Instrument [Line Items]
Total long-term debt, including current maturities	$ 782.0	$ 982.0
Stated interest rate of debt	0.25%
Secured Debt | 3.50% Senior Notes due 2029 (Euro Notes of €650.0)(1)
Debt Instrument [Line Items]
Total long-term debt, including current maturities	$ 723.8	$ 687.2