Property, Plant, and Equipment, net (Schedule of Property, Plant, and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 48,840	$ 46,359
Accumulated depreciation	(29,752)	(28,143)
Property, plant, and equipment, net	19,088	18,216
Equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	37,025	36,625
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	1,109	1,109
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	2,934	2,928
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	2,089	2,049
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 5,683	$ 3,648