Reporting For Segments (Segment's Gross Profit And Reconciliations To Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit	$ 70,166	$ 76,062	$ 214,648	$ 233,051
Selling, general and administrative expenses	47,820	47,543	154,407	157,723
Restructuring and impairment charges	2,447	2,065	12,231	7,862
Other expense, net	5,305	6,377	14,113	21,681
Income before income taxes	14,594	20,077	33,897	45,785
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit	70,166	76,062	214,648	233,051
Functional Coatings [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit	41,906	47,275	125,842	144,812
Color Solutions [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit	28,450	29,122	89,222	87,220
Other Cost Of Sales [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit	$ (190)	$ (335)	$ (416)	$ 1,019