Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Cost	$ 3,006,675	$ 2,907,248
Accumulated depreciation	(1,857,891)	(1,740,196)
Total	1,148,784	1,167,052
Land [Member]
Property, Plant and Equipment [Line Items]
Cost	65,587	70,079
Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	603,962	605,448
Machinery, equipment and other [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 2,337,126	$ 2,231,721