Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($) $ in Millions	Jun. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 383.3	$ 378.6
Less accumulated depreciation	(95.3)	(62.5)
Property, plant and equipment, net	288.0	316.1
Accumulated depreciation related to facilities and equipment acquired under capital leases	6.6	4.9
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	50.7	51.0
Plants and buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	107.2	106.5
Facilities and equipment acquired under capital leases	13.7	13.7
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	151.6	152.8
Facilities and equipment acquired under capital leases	26.5	27.2
Software and computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	65.7	63.3
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 8.1	$ 5.0

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 leased physical assets used in the normal conduct of business to produce goods and services.

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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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