NET INCOME PER SHARE (Tables)

12 Months Ended

Dec. 31, 2012

NET INCOME PER SHARE [Abstract]

Schedule of Calculation of Basic and Diluted Net Income Per Share

	For the year ended December 31,
	2010		2011		2012
Net income		20,628,408		39,270,319		471,278
Denominator for basic net income per share:
Weighted average number of shares outstanding		48,377,733		60,455,723		68,833,132
Dilutive effect of stock options		2,753,096		1,528,097		478,827
Dilutive effect of performance units		524,319		314,211		130,579
Dilutive effect of warrants		108		110		42
Denominator for diluted net income per share:		51,655,256		62,298,141		69,442,580
Basic net income per share		0.43		0.65		0.01
Diluted net income per share		0.40		0.63		0.01

(14) RISKS AND CONCENTRATION