STOCK-BASED COMPENSATION (Details) (USD $)	0 Months Ended		3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Aggregate Intrinsic Value
Outstanding at the end of the period	$ 1,188,678,000		$ 1,188,678,000
Exercisable at end of period	3,448,000		3,448,000
Service-based stock options
Stock-Based Compensation
Vesting period			4 years
Expiration period			10 years
Grant date fair value				$ 2.55
Net compensation expense related to employees and directors (in dollars)			900,000	300,000
Weighted average assumptions used to estimate fair value of each service-based stock option grant
Expected dividend rate (as a percent)			0.00%
Options
Outstanding at the beginning of the period (in shares)	2,392,988	477,530	477,530
Granted (in shares)			1,949,100
Exercised (in shares)			0
Expired (in shares)			(4,392)
Forfeited (in shares)			(29,250)
Outstanding at the end of the period (in shares)	2,392,988		2,392,988
Exercisable at the end of the period (in shares)	249,627		249,627
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 6.73	$ 21.74	$ 21.74
Granted (in dollars per share)			$ 2.22
Exercised (in dollars per share)			$ 0.00
Expired (in dollars per share)			$ 48.27
Forfeited (in dollars per share)			$ 3.02
Outstanding at the end of the period (in dollars per share)	$ 6.73		$ 6.73
Exercisable at the end of the period (in dollars per share)	$ 31.57		$ 31.57
Weighted Average Remaining Contractual Term (Years)
Outstanding at the beginning of the period	9 years 4 months 28 days	8 years 0 months 15 days
Outstanding at the end of the period	9 years 4 months 28 days	8 years 0 months 15 days
Exercisable at the end of the period	7 years 2 months 23 days
Additional disclosures
Total unrecognized compensation cost (in dollars)	4,200,000		4,200,000
Weighted average period over which unrecognized compensation is expected to be recognized (in years)			3 years 6 months
Total fair value of options vested (in dollars)			$ 300,000	$ 700,000
Service-based stock options | Minimum
Weighted average assumptions used to estimate fair value of each service-based stock option grant
Expected stock price volatility (as a percent)			80.30%	82.40%
Risk-free interest rate (as a percent)			1.50%	2.10%
Expected life (in years)			5 years 6 months	6 years 1 month 5 days
Service-based stock options | Maximum
Weighted average assumptions used to estimate fair value of each service-based stock option grant
Expected stock price volatility (as a percent)			88.10%	83.30%
Risk-free interest rate (as a percent)			1.90%	2.20%
Expected life (in years)			6 years 3 months 18 days	6 years 3 months 18 days