Property, Plant, and Equipment, net - Schedule of Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 48,373	$ 48,404
Accumulated depreciation	(33,768)	(32,887)
Property, plant, and equipment, net	14,605	15,517
Equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	31,701	31,658
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	1,576	1,576
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	3,220	3,220
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	9,442	9,442
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 2,434	$ 2,508