Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property, plant and equipment [Abstract]
Property, plant and equipment, net	$ 65,174	$ 46,530
Machinery and equipment
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	47,536	44,549
Less: accumulated depreciation and amortization	(41,419)	(40,845)
Building
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	32,058	32,461
Less: accumulated depreciation and amortization	(11,908)	(11,501)
Leasehold improvements
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	5,488	5,539
Less: accumulated depreciation and amortization	(4,447)	(4,288)
Construction in progress
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	37,866	20,615
Construction in progress Dingxin location
Property, plant and equipment [Abstract]
Property, plant and equipment, gross		14,800
Construction in progress Dingxin and Chaoyang locations
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	26,800
Construction in progress manufacturing equipment purchases
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	4,100	3,600
Construction in progress other consolidated subsidiaries
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 7,000	$ 2,200