Segment Information - Geographic Information - Property, Plant and Equipment, Net (Details 5) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Information
Property, plant and equipment, net	$ 311,019	$ 290,586	$ 266,849
United States
Segment Information
Property, plant and equipment, net	228,057	205,429	169,786
Belgium
Segment Information
Property, plant and equipment, net	47,921	52,943	64,567
United Kingdom
Segment Information
Property, plant and equipment, net	15,849	11,100	8,832
China
Segment Information
Property, plant and equipment, net	13,779	15,583	16,990
Japan
Segment Information
Property, plant and equipment, net	5,255	5,309	6,334
Singapore
Segment Information
Property, plant and equipment, net	65	86	77
Denmark
Segment Information
Property, plant and equipment, net	53	59	64
Canada
Segment Information
Property, plant and equipment, net	24	49	159
Brazil
Segment Information
Property, plant and equipment, net	14	22	28
Germany
Segment Information
Property, plant and equipment, net	$ 2	$ 6	$ 12