Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property Plant and Equipment [Abstract]
Buildings and Improvements, Gross	$ 53,068	$ 46,654
Machinery and equipment	465,106	410,559
Property, plant and equipment, gross, total	518,174	457,213
Less: Accumulated depreciation and amortization	(322,403)	(266,228)
Net	195,771	190,985
Construction in-progress	31,227	19,468
Land	16,298	14,940
Property, plant and equipment, net, total	243,296	225,393	200,745
Depreciation	$ 59,063	$ 56,927	$ 47,365