Property, Plant and Equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, plant and equipment, net
Gross	$ 86,968	$ 93,022
Accumulated depreciation	(56,128)	(62,991)
Net	30,840	30,031
Depreciation expense	1,800	2,400	$ 2,400
Land and buildings
Property, plant and equipment, net
Gross	75,792	80,491
Machinery and equipment
Property, plant and equipment, net
Gross	9,472	11,080
Construction in process
Property, plant and equipment, net
Gross	$ 1,704	$ 1,451