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, Gross	$ 531,819	$ 506,116
Less accumulated depreciation	346,500	330,012
Property, plant and equipment, Net	185,319	176,104
Land [Member]
Property, plant and equipment, Gross	6,359	6,172
Buildings And Building Improvements [Member]
Property, plant and equipment, Gross	92,267	85,668
Machinery And Equipment [Member]
Property, plant and equipment, Gross	410,183	390,237
Furniture And Fixtures [Member]
Property, plant and equipment, Gross	7,934	6,799
Vehicles [Member]
Property, plant and equipment, Gross	174	893
Leasehold Improvements [Member]
Property, plant and equipment, Gross	14,767	14,200
Construction in Progress [Member]
Property, plant and equipment, Gross	$ 135	$ 2,147