Financial Instruments (Effects of Derivatives Not Designated as a Hedging Instrument) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Other Income (Expense), Net
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	$ (0.3)	$ (2.4)	$ 2.5	$ (2.2)
Other Income (Expense), Net | Forward exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	(0.3)	(2.4)	2.5	(2.2)
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	(0.4)	1.2	(1.2)	1.0
Other Non-Operating Income (Expense), Net | Forward exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	(0.3)	1.2	(1.6)	0.6
Other Non-Operating Income (Expense), Net | Other
Derivative Instruments, Gain (Loss) [Line Items]
Total (Gain) Loss Recognized in Income	$ (0.1)	$ 0.0	$ 0.4	$ 0.4