Additional Balance Sheet and Cash Flow Information (Property, Plant And Equipment, At Cost) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 3,285,322	$ 3,261,525
Accumulated depreciation	(2,317,541)	(2,279,932)
Total property, plant and equipment, net	967,781	981,593
Land and related improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	70,256	65,533
Buildings and related improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	464,454	464,200
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,890,126	1,887,269
Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	660,090	630,114
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 200,396	$ 214,409