v2.4.0.6
Document And Entity Information (USD $)
12 Months Ended
Dec. 31, 2011
Jun. 30, 2011
Feb. 24, 2012
Common Stock [Member]
Feb. 24, 2012
Class B Common Stock [Member]
Document Type 10-K      
Amendment Flag false      
Document Period End Date Dec. 31, 2011      
Document Fiscal Year Focus 2011      
Document Fiscal Period Focus FY      
Trading Symbol WSO      
Entity Filer Category Large Accelerated Filer      
Entity Registrant Name WATSCO INC      
Entity Central Index Key 0000105016      
Current Fiscal Year End Date --12-31      
Entity Common Stock, Shares Outstanding     28,359,924 4,660,931
Entity Voluntary Filers No      
Entity Current Reporting Status Yes      
Entity Well-known Seasoned Issuer Yes      
Entity Public Float   $ 1,712,000,000