v2.4.0.6
Document and Entity Information
9 Months Ended
Sep. 30, 2012
Nov. 02, 2012
Common Stock
Nov. 02, 2012
Class B Common Stock
Document Information [Line Items]      
Document Type 10-Q    
Amendment Flag false    
Document Period End Date Sep. 30, 2012    
Document Fiscal Year Focus 2012    
Document Fiscal Period Focus Q3    
Trading Symbol WSO    
Entity Registrant Name WATSCO INC    
Entity Central Index Key 0000105016    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   29,774,883 4,717,653