Acquisitions (Schedule Of Unaudited Pro Forma Financial Information From Joint Venture) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2011
Acquisitions [Abstract]
Revenues	$ 587,847
Net income	10,656
Less: net income attributable to noncontrolling interest	3,662
Net income attributable to Watsco, Inc.	$ 6,994
Diluted earnings per share for Common and Class B common stock	$ 0.19

The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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