Property And Equipment (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 480,601	$ 477,155
Less allowance for depreciation	(381,015)	(371,006)
Property and Equipment, net	99,586	106,149
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	360,402	358,061
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	91,570	91,389
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	13,013	12,774
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 15,616	$ 14,931