Property, Plant and Equipment - Major classifications and expected lives of property, plant and equipment (Details) (USD $) In Thousands, unless otherwise specified				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Land and office buildings	Dec. 31, 2011 Land and office buildings	Dec. 31, 2012 Production facilities	Dec. 31, 2011 Production facilities	Dec. 31, 2012 Production facilities Minimum	Dec. 31, 2012 Production facilities Maximum	Dec. 31, 2012 Machinery and equipment	Dec. 31, 2011 Machinery and equipment	Dec. 31, 2012 Machinery and equipment Minimum	Dec. 31, 2012 Machinery and equipment Maximum	Dec. 31, 2012 Furniture and fixtures	Dec. 31, 2011 Furniture and fixtures	Dec. 31, 2012 Furniture and fixtures Minimum	Dec. 31, 2012 Furniture and fixtures Maximum
Property, Plant and Equipment [Line Items]
Expected Life				39 years				10 years	20 years			3 years	15 years			3 years	20 years
Total	$ 46,290	$ 40,413		$ 3,354	$ 3,282	$ 8,552	$ 8,185			$ 32,869	$ 27,672			$ 1,515	$ 1,274
Less accumulated depreciation	(26,508)	(23,698)
Property, plant and equipment, net excluding construction in progress	19,782	16,715
Construction in progress	3,151	3,423
PROPERTY, PLANT AND EQUIPMENT, net	$ 22,933	$ 20,138	$ 18,952