Discontinued Operations (Schedule of Business Details and Line Items Comprising Discontinued Operations on Statements of Operations and Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
(Loss) gain from disposal of discontinued businesses, before income tax			$ (0.4)	$ (4.2)
Gain (loss) from disposal of discontinued businesses, tax expense (benefit)			1.7	(1.4)
(Loss) gain from disposal of discontinued businesses, net of tax		$ 0.8	(2.1)	(2.8)
Net (loss) gain from discontinued operations		0.8	(2.1)	(2.8)
EMEA and Pacific Rim Business [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
(Loss) gain from disposal of discontinued businesses, before income tax	$ 0.0	0.0	(0.4)	(5.0)
Gain (loss) from disposal of discontinued businesses, tax expense (benefit)			1.7	(1.4)
(Loss) gain from disposal of discontinued businesses, net of tax			(2.1)	(3.6)
Net (loss) gain from discontinued operations			$ (2.1)	(3.6)
European Resilient Flooring [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
(Loss) gain from disposal of discontinued businesses, before income tax		0.8		0.8
(Loss) gain from disposal of discontinued businesses, net of tax		0.8		0.8
Net (loss) gain from discontinued operations		$ 0.8		$ 0.8