Fair Value Measurements (Details) - USD ($) $ in Millions	Jun. 30, 2024	Sep. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Investment	$ 15.5	$ 13.0
Derivative Asset	11.1	25.6
Assets, Fair Value Disclosure	26.6	38.6
Deferred Compensation Liabilities	45.4	36.8
Derivative Liability	9.7	16.1
Other Liabilities, Fair Value Disclosure	55.1	52.9
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Investment	15.5	13.0
Derivative Asset	0.0	0.0
Assets, Fair Value Disclosure	15.5	13.0
Deferred Compensation Liabilities	0.0	0.0
Derivative Liability	0.0	0.0
Other Liabilities, Fair Value Disclosure	0.0	0.0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred Compensation Investment	0.0	0.0
Derivative Asset	11.1	25.6
Assets, Fair Value Disclosure	11.1	25.6
Deferred Compensation Liabilities	45.4	36.8
Derivative Liability	9.7	16.1
Other Liabilities, Fair Value Disclosure	55.1	52.9
Debt, Fair Value	5,904.7	5,491.5
Level 2 | 2.50% convertible senior notes | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt, Fair Value	$ 632.8	$ 572.6