Financial Instruments and Risk Management - Offsetting Assets and Liabilities (Details) - Foreign currency contracts - USD ($) $ in Millions	Jun. 30, 2023	Sep. 30, 2022
Derivatives, Fair Value [Line Items]
Gross amounts of recognized assets	$ 1.0	$ 18.0
Gross amounts offset in the Balance Sheet	(0.6)	0.0
Net amounts of assets presented in the Balance Sheet	0.4	18.0
Gross amounts of recognized liabilities	(4.8)	(2.3)
Gross amounts offset in the Balance Sheet	(0.6)	0.0
Net amounts of liabilities presented in the Balance Sheet	$ (4.2)	$ (2.3)