Net Income per Share (Details) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Sep. 30, 2011	Sep. 30, 2010
Allocation of net income available to common shareholders using the two-class method
Net income	$ 26,296,447	$ 18,790,963	$ 15,939,493	$ 55,174,909	$ 40,085,526
Net income attributable to MercadoLibre, Inc. corresponding to unvested restricted shares					4,474
Less: Net Income attributable to Noncontrolling Interests	522			522
Net income attributable to MercadoLibre, Inc. corresponding to common stock, Basic	26,295,925	18,790,963		55,174,387	40,085,526
Net income attributable to MercadoLibre, Inc. corresponding to common stock, Basic					40,081,052
Net income attributable to MercadoLibre, Inc. corresponding to common stock, Diluted	$ 26,295,925	$ 18,790,963		$ 55,174,387	$ 40,081,052