Goodwill And Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill And Other Intangible Asset [Line Items]
Amortization expense related to amortizable intangible assets				$ 13.0	$ 12.6	$ 10.1
Expected aggregate amortization expense 2020	$ 12.4			12.4
Expected aggregate amortization expense 2021	11.2			11.2
Expected aggregate amortization expense 2022	11.0			11.0
Expected aggregate amortization expense 2023	10.8			10.8
Expected aggregate amortization expense 2024	10.8			10.8
Quimicer, FMU And Gardenia [Member]
Goodwill And Other Intangible Asset [Line Items]
Goodwill impairment charge		$ 3.1	$ 5.9
Tile Coating Systems [Member]
Goodwill And Other Intangible Asset [Line Items]
Goodwill					$ 43.5
Goodwill impairment charge	$ 33.5
Tile Coating Systems [Member] | Performance Coatings [Member]
Goodwill And Other Intangible Asset [Line Items]
Goodwill impairment charge				$ 42.5