Other Current Liabilities - Schedule of Other Current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2021	Sep. 30, 2020
Other current liabilities
Unrealized losses on foreign exchange contracts	$ 35.4	$ 24.3
Product warranty obligations	18.6	20.8
Taxes other than income taxes	90.1	58.5
Accrued interest	15.1	14.9
Income taxes payable	64.5	79.8
Operating lease liabilities	92.1	89.7
Other	105.8	88.5
Other current liabilities	$ 421.6	$ 376.5