Restructuring And Cost Reduction Programs (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2019
Total restructuring charges	$ 11,000	$ 7,100	$ 7,000
Total expected restructuring charges	$ 7,576
Period expected for cash payments for employee benefits and other costs	12 months
2019 Restructuring Plan [Member]
Total expected restructuring charges				$ 7,600
Tile Coating Systems [Member]
Restructuring costs	$ 1,900	$ 6,200	$ 2,800