Discontinued Operations (Schedule of Business Details and Line Items Comprising Discontinued Operations on Statements of Earnings and Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings (Loss) from disposal of discontinued businesses, before income tax	$ 0.0	$ 0.0	$ (0.4)
Income tax (benefit) expense	0.0	(3.0)	1.7
(Loss) gain from disposal of discontinued businesses, net of tax	0.0	3.0	(2.1)
Net earnings (loss) from discontinued operations	$ 0.0	3.0	(2.1)
EMEA and Pacific Rim Businesses [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings (Loss) from disposal of discontinued businesses, before income tax		0.0	(0.4)
Income tax (benefit) expense		(2.0)	1.7
(Loss) gain from disposal of discontinued businesses, net of tax		2.0	(2.1)
Net earnings (loss) from discontinued operations		2.0	$ (2.1)
Armstrong Flooring Inc [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings (Loss) from disposal of discontinued businesses, before income tax		0.0
Income tax (benefit) expense		(1.0)
(Loss) gain from disposal of discontinued businesses, net of tax		1.0
Net earnings (loss) from discontinued operations		$ 1.0