Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified										12 Months Ended				12 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Land owned [Member]	Dec. 31, 2011 Land owned [Member]	Dec. 31, 2012 Land under capital lease [Member]	Dec. 31, 2011 Land under capital lease [Member]	Dec. 31, 2012 Buildings and Improvements Owned [Member]	Dec. 31, 2011 Buildings and Improvements Owned [Member]	Dec. 31, 2012 Buildings and Improvements Owned [Member] Maximum [Member]	Dec. 31, 2012 Buildings and Improvements Owned [Member] Minimum [Member]	Dec. 31, 2012 Buildings under capital lease [Member]	Dec. 31, 2011 Buildings under capital lease [Member]	Dec. 31, 2012 Buildings under capital lease [Member] Maximum [Member]	Dec. 31, 2012 Machinery and Equipment [Member]	Dec. 31, 2011 Machinery and Equipment [Member]	Dec. 31, 2012 Machinery and Equipment [Member] Maximum [Member]	Dec. 31, 2012 Machinery and Equipment [Member] Minimum [Member]	Dec. 31, 2012 Construction in process [Member]	Dec. 31, 2011 Construction in process [Member]
Summary of Property, Plant and Equipment
Estimated Useful Life										40 years	15 years			20 years			12 years	3 years
Property, plant and equipment, Gross	$ 318,587	$ 298,387		$ 5,937	$ 5,851	$ 1,396	$ 1,378	$ 43,751	$ 42,634			$ 3,082	$ 3,039		$ 244,138	$ 237,051			$ 20,283	$ 8,434
Less - accumulated depreciation	198,900	177,859
Property, plant and equipment, net	$ 119,687	$ 120,528	$ 118,488