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, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	$ 2,288	$ 5,574	$ 4,719
Cost of sales
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	1,059	767	1,320
Selling, general, and administrative expense
Restructuring Cost and Reserve [Line Items]
Total exit activity costs & asset impairments	$ 1,229	$ 4,807	$ 3,399