Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property, Plant and Equipment [Abstract]
Rental expense	$ 6,221	$ 5,830	$ 5,988
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	264,960	267,242
Less:Accumulated depreciation	(125,773)	(126,347)
Total property, plant and equipment	139,187	140,895
Future minimum lease commitments for operating leases
2012	6,291
2013	5,389
2014	4,321
2015	2,621
2016	2,700
Thereafter	7,578
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,367	4,486
Building and improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	90,360	95,923
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	163,923	161,635
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 6,310	$ 5,198