Property, Plant and Equipment, net (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Cost	$ 2,681,786	$ 2,408,003
Accumulated depreciation	(1,689,145)	(1,605,126)
Total	992,641	802,877
Land [Member]
Property, Plant and Equipment [Line Items]
Cost	54,406	49,052
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	579,673	533,448
Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 2,047,707	$ 1,825,503