CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Net trade sales	$ 1,045.5	$ 1,155.1
Cost of goods sold	822.7	922.1
Gross profit	222.8	233.0
Selling and administrative expenses	117.8	118.6
Amortization of intangibles	16.4	14.1
Impairments	3.5	2.9
Other (income) expense, net	4.4	(0.8)
Earnings before interest and income taxes	80.7	98.2
Interest expense	20.9	21.4
Interest income	0.9	1.4
Earnings before income taxes	60.7	78.2
Income taxes	15.0	17.1
Net earnings	45.7	61.1
Loss attributable to noncontrolling interest, net of tax	0.0	0.1
Net earnings attributable to Leggett & Platt, Inc. common shareholders	$ 45.7	$ 61.2
Net earnings per share attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	$ 0.34	$ 0.46
Diluted (in dollars per share)	$ 0.34	$ 0.45
Weighted average shares outstanding
Basic (in shares)	135.4	134.4
Diluted (in shares)	135.6	135.0