Goodwill And Other Intangible Assets (Details and Activity of Goodwill by Segment) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill net, beginning balance			$ 172,953	$ 157,469
Acquisitions	[1]			17,387
Foreign currency adjustment			(744)	(1,903)
Goodwill net, ending balance		$ 172,209	172,209	172,953
Performance Colors And Glass [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill net, beginning balance			122,408	114,934
Acquisitions	[1]			8,530
Foreign currency adjustment			(506)	(1,056)
Goodwill net, ending balance		121,902	121,902	122,408
Color Solutions [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill net, beginning balance			50,545	42,535
Acquisitions	[1]			8,857
Foreign currency adjustment			(238)	(847)
Goodwill net, ending balance		50,307	$ 50,307	$ 50,545
Tile Coating Systems [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Impairments		$ 33,500

[1] During 2018, the Company recorded: 1) goodwill related to the UWiZ and Diegel acquisitions within the Color Solutions segment and 2) goodwill related to the MRA acquisition and a purchase price adjustment within the measurement period for goodwill related to the Dip-Tech acquisition within the Performance Colors and Glass segment.