Property, Plant & Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 684,996,000	$ 614,263,000
Less accumulated depreciation	(283,323,000)	(267,833,000)
Total property, plant and equipment, net	401,673,000	346,430,000
Depreciation expense related to property, plant and equipment	28,500,000	21,600,000	19,400,000
Capital Expenditures Incurred but Not yet Paid	6,600,000
Period to maintain requirements for Economic Incentive for the construction of the Romanian facility, minimum	5 years
Reduction in property, plant and equipment	18,100,000	5,900,000
Land [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	29,026,000	27,883,000
Land improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	13,142,000	10,379,000
Buildings [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	158,984,000	137,923,000
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	310,944,000	306,151,000
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	9,647,000	8,779,000
Computer equipment and software [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	37,708,000	16,359,000
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 125,545,000	$ 106,789,000