Consolidated Statements Of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement [Abstract]
Net sales	$ 3,720.8	$ 3,636.0	$ 3,359.1
Cost of goods sold	2,972.8	2,970.7	2,703.7
Gross profit	748.0	665.3	655.4
Selling and administrative expenses	380.4	382.1	354.3
Amortization of intangibles	25.7	18.8	19.8
Other expense (income), net	0.6	26.6	(6.7)
Earnings from continuing operations before interest and income taxes	341.3	237.8	288.0
Interest expense	43.4	38.3	37.7
Interest income	6.5	6.7	5.2
Earnings from continuing operations before income taxes	304.4	206.2	255.5
Income taxes	56.3	49.8	71.9
Earnings from continuing operations	248.1	156.4	183.6
Earnings (loss) from discontinued operations, net of tax	2.4	0	(0.8)
Net earnings	250.5	156.4	182.8
(Earnings) attributable to noncontrolling interest, net of tax	(2.3)	(3.1)	(6.2)
Net earnings attributable to Leggett & Platt, Inc. common shareholders	$ 248.2	$ 153.3	$ 176.6
Earnings per share from continuing operations attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	$ 1.70	$ 1.05	$ 1.17
Diluted (in dollars per share)	$ 1.68	$ 1.04	$ 1.16
Earnings (loss) per share from discontinued operations attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	$ 0.02	$ 0.00	$ 0.00
Diluted (in dollars per share)	$ 0.02	$ 0.00	$ (0.01)
Net earnings per share attributable to Leggett & Platt, Inc. common shareholders
Basic (in dollars per share)	$ 1.72	$ 1.05	$ 1.17
Diluted (in dollars per share)	$ 1.70	$ 1.04	$ 1.15