Property, Plant and Equipment (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 45,661	$ 39,114
Accumulated depreciation	(26,081)	(23,287)
Total property, plant and equipment, net	19,580	15,827	[1]
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	$ 3,782	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	$ 16,243	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	$ 17,234	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	$ 2,823	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	$ 5,556	$ 1,052

[1] See Note 2.