Property, Plant, and equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 22,390	$ 18,190
Less accumulated depreciation	(7,390)	(5,146)
Property, Plant and Equipment, Net, Total	15,000	13,044
Depreciation and amortization expense	2,348	1,915	$ 1,842
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	6,616	6,587
Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	10,665	9,512
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	927	896
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	771	668
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	407	377
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	660
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 2,344	$ 150