XML 12 R1.htm IDEA: XBRL DOCUMENT v3.10.0.1
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2018
Nov. 02, 2018
Document And Entity Information [Abstract]    
Entity Registrant Name LEGGETT & PLATT INC  
Entity Central Index Key 0000058492  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Sep. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
Ticker Symbol LEG  
Amendment Flag false  
Emerging Growth Entity false  
Small Business Entity false  
Entity Common Stock, Shares Outstanding   130,417,754