Financial Instruments Financial Instruments (Effects of Derivatives Not Designated as a Hedging Instrument) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Other Income (Expense), Net
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	$ 0.7	$ (1.0)
Other Income (Expense), Net | Forward exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.7	(1.0)
Other Income (Expense), Net | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.0	0.0
Other Income (Expense), Net | De-Designated Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.0	0.0
Other Non-Operating Income (Expense), Net
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	20.9	(2.1)
Other Non-Operating Income (Expense), Net | Forward exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.0	(2.4)
Other Non-Operating Income (Expense), Net | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	1.5	0.3
Other Non-Operating Income (Expense), Net | De-Designated Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	$ 19.4	$ 0.0