Discontinued Operations (Narrative) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
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		$ 3.0	$ (2.1)	$ (15.0)
Net loss due to change in carrying value of discontinued operations net assets		0.0	(0.4)	(16.4)
Income tax (benefit) expense		(3.0)	1.7	(1.4)
Loss from disposal of discontinued businesses, before income tax		0.0	(0.4)	(16.4)
Valuation loss on pension liabilities			11.8
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		2.0	(2.1)	(15.8)
Net loss due to change in carrying value of discontinued operations net assets		0.0	(0.4)	(17.2)
Income tax (benefit) expense		(2.0)	1.7	(1.4)
Loss from disposal of discontinued businesses, before income tax		0.0	$ (0.4)	(17.2)
Valuation loss on pension liabilities				11.4
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	[1]			$ 0.8
Armstrong Flooring Inc [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income tax (benefit) expense		$ (1.0)

[1] Represents AOCI adjustments related to accumulated foreign currency translation amounts.