Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 483,440	$ 474,768
Less accumulated depreciation	(327,818)	(318,929)
Net property, plant and equipment	155,622	155,839
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,875	2,929
Building
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	114,149	114,324
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	357,579	345,064
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 8,837	$ 12,451