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, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings from discontinued businesses before income tax			$ 0.0
Income tax benefit	$ 0.0	$ 0.0	(3.0)
Net earnings from discontinued operations, net of tax	0.0	0.0	3.0
Net earnings from discontinued operations	$ 0.0	$ 0.0	3.0
EMEA and Pacific Rim Businesses [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings from discontinued businesses before income tax			0.0
Income tax benefit			(2.0)
Net earnings from discontinued operations, net of tax			2.0
Net earnings from discontinued operations			2.0
Armstrong Flooring Inc [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnings from discontinued businesses before income tax			0.0
Income tax benefit			(1.0)
Net earnings from discontinued operations, net of tax			1.0
Net earnings from discontinued operations			$ 1.0