Property, Plant and Equiptment (Schedule of Plant Property and Equiptment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Land	$ 14,986	$ 15,394
Buildings and improvements	136,959	132,673
Machinery and equipment	160,843	151,023
Office equipment	34,972	34,300
Equipment in process	21,360	21,202
Property, Plant and Equipment, Gross	369,120	354,592
Accumulated depreciation	(222,189)	(205,575)
Total property, plant and equipment	$ 146,931	$ 149,017