Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Cost	$ 2,332,422		$ 2,332,422		$ 2,291,188
Accumulated depreciation	(1,508,390)		(1,508,390)		(1,454,119)
Total	824,032		824,032		837,069
Depreciation expense	38,191	$ 37,723	116,807	$ 112,548
Land [Member]
Property, Plant and Equipment [Line Items]
Cost	54,409		54,409		55,076
Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	536,881		536,881		537,474
Machinery, equipment and other [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 1,741,132		$ 1,741,132		$ 1,698,638