Property, Plant, and Equipment (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024	Sep. 30, 2024
Property, Plant and Equipment [Line Items]
Land	$ 18.6		$ 18.6		$ 18.9
Buildings and Improvements, Gross	148.0		148.0		147.9
Machinery and Equipment, Gross	1,125.9		1,125.9		1,132.7
Capitalized Computer Software, Gross	65.8		65.8		62.5
Construction in Progress, Gross	67.7		67.7		62.0
Property, Plant and Equipment, Gross	1,426.0		1,426.0		1,424.0
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(1,081.4)		(1,081.4)		(1,074.9)
Property, plant and equipment, net	344.6		344.6		$ 349.1
Depreciation	13.2	$ 13.4	26.1	$ 27.0
Capitalized Computer Software, Amortization	$ 0.8	$ 1.2	$ 1.9	$ 2.3

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

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Amount of expense for amortization of capitalized computer software costs.

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Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software.

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Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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Amount before accumulated depreciation of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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