Discontinued Operations (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 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	$ 0.8	$ (6.9)	$ (2.8)	$ (4.7)
Net loss due to change in carrying value of discontinued operations net assets		(6.8)	(4.2)	(4.6)
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		(6.8)	(3.6)	(4.6)
Net loss due to change in carrying value of discontinued operations net assets		$ (6.8)	(5.0)	$ (4.6)
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