Property, Plant, and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 480,400	$ 457,744
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(327,645)	(310,279)
Property, Plant and Equipment, Net	152,755	147,465
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,835	5,267
Building
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	110,534	107,082
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	349,667	334,951
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 16,364	$ 10,444