Property, Plant and Equipment - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	$ 51,103	$ 49,667
Accumulated depreciation	(28,966)	(26,473)
Property, plant and equipment, net	22,137	23,194
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	6,760	6,745
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	42,664	41,243
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	$ 1,679	$ 1,679