CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 989.3	$ 958.9	$ 1,949.6	$ 1,897.3
Cost of goods sold	759.2	724.9	1,493.5	1,429.7
Gross profit	230.1	234.0	456.1	467.6
Selling and administrative expenses	105.0	99.7	211.4	204.8
Amortization of intangibles	4.7	4.8	9.8	9.9
Impairments	0.1	3.7	0.1	3.7
Gain from sale of assets and businesses	(0.4)	(18.3)	(0.6)	(20.7)
Other (income) expense, net	(1.6)	(2.4)	(2.8)	(3.7)
Earnings from continuing operations before interest and income taxes	122.3	146.5	238.2	273.6
Interest expense	10.4	10.3	21.0	19.5
Interest income	1.5	1.0	3.5	1.8
Earnings from continuing operations before income taxes	113.4	137.2	220.7	255.9
Income taxes	25.8	37.7	47.0	65.4
Earnings from continuing operations	87.6	99.5	173.7	190.5
Earnings from discontinued operations, net of tax	0.0	20.3	0.0	20.4
Net earnings	87.6	119.8	173.7	210.9
Earnings attributable to noncontrolling interest, net of tax	0.0	1.4	0.0	(0.2)
Net earnings attributable to Leggett & Platt, Inc. common shareholders	$ 87.6	$ 121.2	$ 173.7	$ 210.7
Earnings per share from continuing operations attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	$ 0.64	$ 0.73	$ 1.27	$ 1.37
Diluted (in dollars per share)	0.64	0.72	1.26	1.35
Earnings per share from discontinued operations attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	0.00	0.15	0.00	0.15
Diluted (in dollars per share)	0.00	0.15	0.00	0.15
Earnings per share from continuing operations attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	0.64	0.88	1.27	1.52
Diluted (in dollars per share)	0.64	0.87	1.26	1.50
Cash dividends declared per share (in dollars per share)	$ 0.36	$ 0.34	$ 0.7	$ 0.66
Average shares outstanding
Basic (in shares)	136.0	137.8	136.4	138.4
Diluted (in shares)	137.4	140.1	137.8	140.6