Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Cost	$ 2,239,270		$ 2,232,129
Accumulated depreciation	(1,397,457)		(1,389,811)
Total	841,813		842,318
Depreciation expense	34,555	$ 32,188
Land [Member]
Property, Plant and Equipment [Line Items]
Cost	54,580		56,583
Buildings and improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	522,155		527,192
Machinery, equipment and other [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 1,662,535		$ 1,648,354