Income Taxes - U.S. and International Components of Income from Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Operating Loss Carryforwards [Line Items]
U.S.	$ 50.0	$ 37.3	$ 88.8
Income from operations, before tax	277.2	154.1	206.7
Australia
Operating Loss Carryforwards [Line Items]
Non-U.S.	8.7	7.8	1.4
Brazil
Operating Loss Carryforwards [Line Items]
Non-U.S.	25.3	13.7	7.6
Germany
Operating Loss Carryforwards [Line Items]
Non-U.S.	27.8	17.2	10.4
Singapore
Operating Loss Carryforwards [Line Items]
Non-U.S.	19.4	16.0	20.5
United Kingdom
Operating Loss Carryforwards [Line Items]
Non-U.S.	104.8	41.4	58.5
Other international
Operating Loss Carryforwards [Line Items]
Non-U.S.	$ 41.2	$ 20.7	$ 19.5