SHARE-BASED COMPENSATION - RSU Activity - Summary of Change (Details) (USD $)	3 Months Ended
	Mar. 31, 2014
Number of Restricted Stock Units [Roll Forward]
RSUs beginning	1,030,486
RSUs awarded	666,363
RSUs released	(270,848)
RSUs forfeited	(3,200)
RSUs ending	1,422,801
Weighted Average Purchase Price RSUs	$ 0
Weighted Average Remaining Contractual Term (Years) RSUs	1 year 8 months 12 days
Aggregate Intrinsic Value RSUs	$ 14,327,606
Number of RSUs vested and expected to vest	1,311,232
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 8 months 12 days
Aggregate Intrinsic Value RSUs vested and expected to vest	12,328,059
Number of RSUs exercisable	86,996
Weighted Average Purchase Price of RUSs exercisable	$ 0
Weighted Average Remaining Contractual Term (Years) of RUSs exercisable	0 years
Aggregate Intrinsic Value RSUs exercisable	876,050
Weighted average remaining recognition period in years	2 years 4 months 24 days
Unamortized compensation expense, net of estimated forfeitures	$ 8,748,507