STOCK-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Oct. 01, 2015
Service-based stock options
Stock-Based Compensation
Vesting period					4 years
Expiration period					10 years
Grant date fair value			$ 2.26		$ 2.23	$ 2.85
Net compensation expense related to employees and directors (in dollars)			$ 600	$ 200	$ 2,200	$ 700
Weighted average assumptions used to estimate fair value of each service-based stock option grant
Expected dividend yield (as a percent)					0.00%	0.00%
Options
Outstanding at the beginning of the period (in shares)					477,530
Granted (in shares)			162,250		2,181,100
Exercised (in shares)					3,566
Expired (in shares)					(13,217)
Forfeited (in shares)					(125,326)
Outstanding at the end of the period (in shares)	2,516,521	477,530	2,516,521		2,516,521
Exercisable at the end of the period (in shares)	537,756		537,756		537,756
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)					$ 21.74
Granted (in dollars per share)					3.12
Exercised (in dollars per share)					3.02
Expired (in dollars per share)					40.89
Forfeited (in dollars per share)					3.41
Outstanding at the end of the period (in dollars per share)	$ 6.44	$ 21.74	$ 6.44		6.44
Exercisable at the end of the period (in dollars per share)	$ 16.72		$ 16.72		$ 16.72
Weighted Average Remaining Contractual Term (Years)
Outstanding at the beginning of the period	9 years 1 day	8 years 15 days
Exercisable at the end of the period	8 years 15 days
Aggregate Intrinsic Value
Exercised					$ 1,343
Outstanding at the end of the period	$ 240		$ 240		240
Exercisable at end of period	0		0		0
Additional disclosures
Total unrecognized compensation cost (in dollars)	$ 3,200		$ 3,200		$ 3,200
Weighted average period over which unrecognized compensation is expected to be recognized (in years)					3 years 2 months 12 days
Total fair value of options vested (in dollars)					$ 1,300	$ 1,300
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)					77.60%	82.40%
Risk-free interest rate (as a percent)					1.50%	1.70%
Expected life (in years)					5 years 6 months	5 years 6 months
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%	88.20%
Risk-free interest rate (as a percent)					2.00%	2.20%
Expected life (in years)					6 years 3 months 18 days	6 years 3 months 18 days
Subsequent Event | Employee stock
Additional disclosures
Aggregate shares available for issuance under the Employee Stock Purchase Plan (in shares)							1,000,000