Property, Plant and Equipment (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 42,481	$ 39,114
Accumulated depreciation	(24,689)	(23,287)
Total property, plant and equipment, net	17,792	15,827
Automobiles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 23	23
Automobiles | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Automobiles | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	6 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 3,676	3,542
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	4 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	20 years
Computer software and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 16,213	17,024
Computer software and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Computer software and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	7 years
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 15,961	15,178
Machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 2,792	2,295
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	20 years
Work in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 3,816	$ 1,052