EARNINGS PER SHARE (EPS) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net earnings
Net earnings	$ 53.5	$ 90.4
(Earnings) attributable to noncontrolling interest, net of tax	0.0	0.0
Net earnings attributable to Leggett & Platt, Inc. common shareholders	$ 53.5	$ 90.4
Weighted average number of shares (in millions)
Weighted average number of common shares used in basic EPS (in shares)	135.9	136.6
Dilutive effect of stock-based compensation (in shares)	0.4	0.3
Weighted average number of common shares and dilutive potential common shares used in diluted EPS (in shares)	136.3	136.9
Basic and diluted EPS
Basic EPS attributable to Leggett & Platt, Inc. common shareholders (in usd per share)	$ 0.39	$ 0.66
Diluted EPS attributable to Leggett & Platt, Inc. common shareholders (in usd per share)	$ 0.39	$ 0.66
Other information
Anti-dilutive shares excluded from diluted EPS computation (in shares)	0.5	0.4
Cash dividends declared per share (in usd per share)	$ 0.44	$ 0.42