Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Cost	$ 2,358,022	$ 2,290,620
Accumulated depreciation	(1,539,292)	(1,471,757)
Total	818,730	818,863
Land [Member]
Property, Plant and Equipment [Line Items]
Cost	57,023	58,407
Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	558,102	536,143
Machinery, equipment and other [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 1,742,897	$ 1,696,070