Discontinued Operations (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net loss due to change in carrying value of discontinued operations net assets	$ (0.2)		$ (22.3)	$ (3.0)	$ (27.0)
Net loss due to change in carrying value of discontinued operations net assets			(27.3)	(4.4)	(31.9)
EMEA and Pacific Rim Business [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net loss due to change in carrying value of discontinued operations net assets	(0.2)		(27.3)	(3.8)	(31.9)
Net loss due to change in carrying value of discontinued operations net assets	$ (0.2)		$ (27.3)	(5.2)	$ (31.9)
European Resilient Flooring [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain related to accumulated other comprehensive income adjustment from discontinued foreign entity		$ 0.8		$ 0.8