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		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings from discontinued operations before income tax	$ 0.0		$ 0.0
Loss from disposal of discontinued business, before income tax			0.0	$ (0.4)
Income tax expense (benefit)	3.0	$ 0.0	3.0	(1.7)
Net earnings from discontinued operations, net of tax	3.0		3.0
Gain (loss) from disposal of discontinued businesses, net of tax	3.0	0.0	3.0	(2.1)
Net earnings (loss) from discontinued operations	3.0	$ 0.0	3.0	(2.1)
EMEA and Pacific Rim Business [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings from discontinued operations before income tax	0.0		0.0
Loss from disposal of discontinued business, before income tax	0.0			(0.4)
Income tax expense (benefit)	2.0		2.0	(1.7)
Net earnings from discontinued operations, net of tax	2.0		2.0
Gain (loss) from disposal of discontinued businesses, net of tax				(2.1)
Net earnings (loss) from discontinued operations	2.0		2.0	$ (2.1)
Armstrong Flooring Inc [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings from discontinued operations before income tax	0.0		0.0
Income tax expense (benefit)	1.0		1.0
Net earnings from discontinued operations, net of tax	1.0		1.0
Net earnings (loss) from discontinued operations	$ 1.0		$ 1.0