Financial Instruments and Risk Management (Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis) (Details) - Level 2 - Recurring fair value measurement - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Derivative [Line Items]
Deferred compensation	$ (19.4)	$ (21.8)
Net liabilities at estimated fair value	(13.8)	(8.5)
FX contract
Derivative [Line Items]
Estimated fair value of derivatives	$ 5.6	$ 13.3