Financial Instruments (Effects of Derivatives Not Designated as a Hedging Instrument) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Other Income (Expense), Net
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	$ (0.7)	$ (2.8)	$ (0.2)	$ (6.7)
Other Income (Expense), Net | Forward exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	(0.7)	(2.8)	(0.2)	(6.7)
Other Income (Expense), Net | De-designated interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.0	0.0	0.0	0.0
Other Income (Expense), Net | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.0	0.0	0.0	0.0
Other non‑operating income (expense), net
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.5	12.6	(1.3)	(29.8)
Other non‑operating income (expense), net | Forward exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.2	1.1	(0.2)	(0.8)
Other non‑operating income (expense), net | De-designated interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	0.0	11.5	(1.9)	(27.3)
Other non‑operating income (expense), net | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	$ 0.3	$ 0.0	$ 0.8	$ (1.7)