Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Property, plant and equipment [Abstract]
Property, plant and equipment, net	$ 27,945	$ 27,805
Machinery and equipment
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	42,027	41,254
Less: accumulated depreciation and amortization	(38,961)	(37,311)
Building
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	30,333	29,600
Less: accumulated depreciation and amortization	(10,465)	(9,654)
Leasehold improvements
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	5,048	4,942
Less: accumulated depreciation and amortization	(3,917)	(3,608)
Construction in progress
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 3,880	$ 2,582