SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) (Stock Options)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Stock Options
Estimated fair value of each option grant on the date of grant using Black-Scholes option pricing model
Expected stock price volatility, minimum (as a percent)	66.40%	65.00%
Expected stock price volatility, maximum (as a percent)	66.60%	65.20%
Expected term of options	6 years	6 years
Risk-free interest rate, minimum (as a percent)	0.75%	0.79%
Risk-free interest rate, maximum (as a percent)	0.87%	0.88%