v2.4.0.6
Document And Entity Information
9 Months Ended
Sep. 30, 2011
Nov. 03, 2011
Common Stock [Member]
Nov. 03, 2011
Class B Common Stock [Member]
Document Type 10-Q    
Amendment Flag false    
Document Period End Date Sep. 30, 2011    
Document Fiscal Year Focus 2011    
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   28,349,772 4,653,793