Net Income Per Share - Net Income Per Share of Common Stock (Detail) (USD $)	3 Months Ended												12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income attributable to MercadoLibre, Inc. per common share
Net income attributable to MercadoLibre, Inc. per common share, Basic	$ 0.93	$ 0.66	$ 0.67	$ 0.40	$ 0.69	$ 0.59	$ 0.57	$ 0.45	$ 0.47	$ 0.60	$ 0.34	$ 0.32	$ 2.66	$ 2.30	$ 1.73
Net income attributable to MercadoLibre, Inc. per common share, Diluted	$ 0.93	$ 0.66	$ 0.67	$ 0.40	$ 0.69	$ 0.59	$ 0.57	$ 0.45	$ 0.47	$ 0.60	$ 0.34	$ 0.32	$ 2.66	$ 2.30	$ 1.73
Numerator:
Net income attributable to MercadoLibre, Inc., Basic													$ 117,517,082	$ 101,606,696	$ 76,169,200
Net income attributable to MercadoLibre, Inc., Diluted													$ 117,517,082	$ 101,606,696	$ 76,169,200
Denominator:
Weighted average of common stock outstanding for Basic earnings per share	44,153,185	44,152,933	44,152,933	44,151,323	44,150,920	44,150,387	44,147,999	44,142,076	44,142,020	44,141,925	44,138,105	44,131,383	44,152,600	44,147,861	44,138,397
Weighted average of common stock outstanding for Diluted earnings per share													44,152,600	44,147,861	44,138,397
Adjustment for stock options														1,977	8,089
Adjustment for shares granted under LTRP															4,951
Adjusted weighted average of common stock outstanding for Diluted earnings per share	44,153,185	44,152,933	44,152,933	44,151,357	44,152,895	44,157,321	44,152,133	44,147,796	44,152,658	44,151,218	44,152,296	44,147,667	44,152,600	44,149,838	44,151,437