v2.4.0.8
Document and Entity Information
9 Months Ended
Sep. 30, 2015
Nov. 02, 2015
Common Stock
Nov. 02, 2015
Class B Common Stock
Document Information [Line Items]      
Document Type 10-Q    
Amendment Flag false    
Document Period End Date Sep. 30, 2015    
Document Fiscal Year Focus 2015    
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   30,249,084 5,034,991