SHARE-BASED COMPENSATION - RSU Activity - Summary of Change (Details) - USD ($)	6 Months Ended
	Jun. 30, 2015
Number of Restricted Stock Units [Roll Forward]
RSUs beginning	1,258,685
RSUs awarded	672,277
RSUs released	(392,255)
RSUs forfeited	(45,623)
RSUs ending	1,493,084
Weighted Average Purchase Price RSUs	$ 0
Weighted Average Remaining Contractual Term (Years) RSUs	1 year 6 months
Aggregate Intrinsic Value RSUs	$ 17,051,019
Number of RSUs vested and expected to vest	1,391,251
Weighted Average Purchase Price of RSUs vested and expected to vest	$ 0
Weighted Average Remaining Contractual Term (Years) of RUSs vested and expected to vest	1 year 4 months 24 days
Aggregate Intrinsic Value RSUs vested and expected to vest	$ 14,958,724
Number of RSUs exercisable	81,380
Weighted Average Purchase Price of RUSs exercisable	$ 0
Weighted Average Remaining Contractual Term (Years) of RUSs exercisable
Aggregate Intrinsic Value RSUs exercisable	$ 929,360
Weighted average remaining recognition period in years	2 years 2 months 12 days
Unamortized compensation expense, net of estimated forfeitures	$ 9,412,152