Accumulated Other Comprehensive Loss, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 904.0	$ 767.5
Other comprehensive income	(1.4)	13.9
Ending balance	953.0	799.5
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(22.7)
Other comprehensive income	(1.3)
Ending balance	(24.0)
Pension Benefits Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2.4)
Other comprehensive income	0.0
Ending balance	(2.4)
Cash Flow Hedge
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	0.0
Other comprehensive income	(0.1)
Ending balance	(0.1)
Accumulated Other Comprehensive Loss, net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(25.1)	(40.1)
Other comprehensive income	(1.4)	13.9
Ending balance	$ (26.5)	$ (26.2)