Property, Plant and Equipment - Components of Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 791.3	$ 779.1
Less: accumulated depreciation	(534.1)	(488.7)
Total Property, Plant and Equipment, Net	257.2	290.4
Land
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3.1	3.1
Buildings
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	121.0	121.7
Machinery, equipment and fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	595.4	607.3
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	13.2	11.9
Construction in progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 58.6	$ 35.1