Reporting For Segments (Segment's Gross Profit And Reconciliations To Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit	$ 75,275	$ 76,186	$ 79,343	$ 78,012	$ 80,470	$ 79,732	$ 90,793	$ 88,740	$ 308,816	$ 339,735	$ 326,719
Selling, general and administrative expenses									212,485	219,947	217,290
Restructuring and impairment charges	$ 3,100	$ 2,100	$ 4,100	$ 1,700	$ 2,300	$ 1,500	$ 2,100	$ 1,200	10,955	7,116	8,523
Other expense, net									41,865	41,622	17,591
Income before income taxes									43,511	71,050	83,315
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other cost of sales									369	2,519	3,878
Total gross profit									308,816	339,735	326,719
Performance Colors And Glass [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit									193,508	212,364	209,147
Color Solutions [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total gross profit									$ 114,939	$ 124,852	$ 113,694