Property, Plant, and Equipment, net - Schedule of Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2021	Mar. 31, 2021	Sep. 30, 2020
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 53,398	$ 53,398	$ 53,286
Accumulated depreciation	(34,218)	(34,218)	(32,234)
Property, plant, and equipment, net	19,180	19,180	21,052
Loss on sale of equipment	(200)	200
Equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	35,435	35,435	35,218
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	1,125	1,125	1,125
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	3,584	3,584	3,473
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	6,589	6,589	3,169
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 6,665	$ 6,665	$ 10,301

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 of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

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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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