FAIR VALUE MEASUREMENTS - RECURRING BASIS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Liabilities that are measured at fair value on a recurring basis
Warrants	$ 190
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2016	190
Decrease in fair value	(107)	$ 1,640
Balance at March 31, 2017	190
Warrants
Liabilities that are measured at fair value on a recurring basis
Warrants	757
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2016	757
Decrease in fair value	(107)
Balance at March 31, 2017	650
Warrants | Recurring
Liabilities that are measured at fair value on a recurring basis
Warrants	757
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2016	757
Balance at March 31, 2017	650
Warrants | Recurring | Level 2
Liabilities that are measured at fair value on a recurring basis
Warrants	757
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2016	757
Balance at March 31, 2017	650
Warrants | Recurring | Level 3
Liabilities that are measured at fair value on a recurring basis
Warrants	0
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2016	0
Balance at March 31, 2017	$ 0