Property, Plant, and Equipment, net (Schedule of Property, Plant, and Equipment) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 42,618	$ 42,459
Accumulated depreciation	(25,890)	(25,824)
Property, plant, and equipment, net	16,728	16,635
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	35,014	31,507
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	1,109	1,109
Computer hardware and software [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	2,910	2,974
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	1,789	2,330
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 1,796	$ 4,539