SHARE-BASED COMPENSATION 1 (Details) (USD $)	3 Months Ended
	Mar. 31, 2012 number	Mar. 31, 2011
Number of Restricted Stock Units [Roll Forward]
RSUs beginning	1,860,577
RSUs awarded	283,056
RSUs released	(127,767)
RSUs forfeited	(1,265)
RSUs ending	2,014,601
Weighted Average Purchase Price RSUs	$ 0
Weighted Average Remaining Contractual Term (Years) RSUs	1.5
Aggregate Intrinsic Value RSUs	$ 13,074,760
Number of RSUs vested and expected to vest	1,837,739
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	1.5
Aggregate Intrinsic Value RSUs vested and expected to vest	11,362,322
Number of RSUs exercisable	86,996
Weighted Average Purchase Price of RUSs exercisable	$ 0
Weighted Average Remaining Contractual Term (Years) of RUSs exercisable	0.0
Aggregate Intrinsic Value RSUs exercisable	564,604
Weighted average remaining recognition period in years	2.2
Unamortized compensation expense, net of estimated forfeitures	9,045,749
Other Options Disclosure [Abstract]
Intrinsic value of options exercised	84,000	458,000
Tax benefit from options exercised, before impact of valuation allowance	34,000	181,000
Cash received from exercise price of options exercised	$ 54,000	$ 57,000