Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 762,187	$ 714,807
Less accumulated depreciation	(427,698)	(405,951)
Property, plant and equipment, net	334,489	308,856
Depreciation expense	43,165	39,654	$ 41,875
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	19,952	19,153
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	169,695	156,294
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 572,540	$ 539,360