Other Current Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Other Liabilities Disclosure [Abstract]
Unrealized losses on foreign exchange contracts	$ 16.9	$ 24.3
Product warranty obligations	18.0	20.8	$ 25.2
Taxes other than income taxes	59.8	58.5
Accrued interest	17.8	14.9
Income taxes payable	188.4	79.8
Operating lease liabilities	89.9	89.7
Other	93.6	88.5
Other current liabilities	$ 484.4	$ 376.5