Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment	$ 10.6	$ 0.0	$ 2.5
Cost of Sales
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment	6.3
Research and development expense
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment	$ 4.3