Exit Activity Costs and Asset Impairments (Summary Of Exit Activity Costs And Asset Impairments Recorded in the Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	$ 5,495	$ 13,747	$ 3,123
Cost of sales
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	911	9,922	9,381
Selling, general, and administrative expense
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	$ 4,584	$ 3,825	$ (6,258)