Reporting For Segments (Net Sales To External Customers By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net sales	$ 241,877	$ 245,339	$ 699,004	$ 769,679
Functional Coatings [Member]
Segment Reporting Information [Line Items]
Net sales	154,218	154,744	441,325	485,462
Color Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	$ 87,659	$ 90,595	$ 257,679	$ 284,217