Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 489,535	$ 486,170
Less: accumulated depreciation	(345,090)	(337,492)
Net property, plant and equipment	144,445	148,678
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,714	2,684
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	112,650	111,762
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	364,990	361,010
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 9,181	$ 10,714