Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 622,452	$ 611,428
Less accumulated depreciation	356,790	353,274
Net property, plant and equipment	265,662	258,154
Land
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	21,452	20,168
Building
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	89,734	86,498
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	459,244	449,805
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	14,468	13,662
Software
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	20,490	19,987
Construction in Progress
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 17,064	$ 21,308