Restructuring And Cost Reduction Programs (Summary of Charges Associated with Restructuring Programs by Segments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost And Reserve [Line Items]
Total Expected Charges	$ 7,576
Restructuring charges incurred	10,955	$ 7,116	$ 6,957
Cumulative charges to date	77,313
Operating Segments [Member]
Restructuring Cost And Reserve [Line Items]
Total Expected Charges	269
Restructuring charges incurred	119	171	4,994
Cumulative charges to date	31,388
Performance Colors And Glass [Member] | Operating Segments [Member]
Restructuring Cost And Reserve [Line Items]
Total Expected Charges	169
Restructuring charges incurred	(5)	23	3,744
Cumulative charges to date	26,927
Color Solutions [Member] | Operating Segments [Member]
Restructuring Cost And Reserve [Line Items]
Total Expected Charges	100
Restructuring charges incurred	124	148	1,250
Cumulative charges to date	4,461
Corporate Restructuring Charges [Member]
Restructuring Cost And Reserve [Line Items]
Total Expected Charges	7,307
Restructuring charges incurred	10,836	$ 6,945	$ 1,963
Cumulative charges to date	$ 45,925