Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net trade sales	$ 5,072.6	$ 4,280.2	$ 4,752.5
Cost of goods sold	4,034.3	3,376.1	3,728.5
Gross profit	1,038.3	904.1	1,024.0
Selling and administrative expenses	422.1	424.4	469.7
Amortization of intangibles	67.5	65.2	63.3
Impairments	0.0	29.4	7.8
Net gain on sale of assets and businesses	(29.4)	0.0	(5.0)
Other (income) expense, net	(17.9)	(22.4)	1.4
Earnings before interest and income taxes	596.0	407.5	486.8
Interest expense	76.5	82.7	90.7
Interest income	2.6	3.1	7.4
Earnings before income taxes	522.1	327.9	403.5
Income taxes	119.5	74.8	89.4
Net earnings	402.6	253.1	314.1
(Earnings) attributable to noncontrolling interest, net of tax	(0.2)	(0.1)	(0.1)
Net earnings attributable to Leggett & Platt, Inc. common shareholders	$ 402.4	$ 253.0	$ 314.0
Net earnings per share attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	$ 2.95	$ 1.86	$ 2.33
Diluted (in dollars per share)	$ 2.94	$ 1.86	$ 2.32