Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Net trade sales	$ 4,725,300,000	$ 5,146,700,000	$ 5,072,600,000
Cost of goods sold	3,871,500,000	4,169,900,000	4,034,300,000
Gross profit	853,800,000	976,800,000	1,038,300,000
Selling and administrative expenses	465,400,000	427,300,000	422,100,000
Amortization of intangibles	69,000,000.0	66,800,000	67,500,000
Long-lived asset impairment	443,700,000	0	0
Net gain from disposal of assets and businesses	(20,100,000)	(2,500,000)	(29,400,000)
Other expense (income), net	(13,800,000)	200,000	(17,900,000)
Earnings (loss) before interest and income taxes	(90,400,000)	485,000,000.0	596,000,000.0
Interest expense	88,400,000	85,500,000	76,500,000
Interest income	5,400,000	4,100,000	2,600,000
Earnings (loss) before income taxes	(173,400,000)	403,600,000	522,100,000
Income taxes	(36,600,000)	93,700,000	119,500,000
Net earnings (loss)	(136,800,000)	309,900,000	402,600,000
Earnings attributable to noncontrolling interest, net of tax	0	(100,000)	(200,000)
Net earnings (loss) attributable to Leggett & Platt, Inc. common shareholders	$ (136,800,000)	$ 309,800,000	$ 402,400,000
Net earnings (loss) per share attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	$ (1.00)	$ 2.28	$ 2.95
Diluted (in dollars per share)	$ (1.00)	$ 2.27	$ 2.94