FAIR VALUE MEASUREMENTS - RECURRING BASIS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Liabilities that are measured at fair value on a recurring basis
Warrant liabilities	$ 455		$ 757
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2015			757
Decrease in fair value	(1,942)	$ (112)	(302)	$ 205
Balance at June 30, 2016	455		455
Recurring
Liabilities that are measured at fair value on a recurring basis
Warrant liabilities	455		757
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2015			757
Balance at June 30, 2016	455		455
Recurring | Level 2
Liabilities that are measured at fair value on a recurring basis
Warrant liabilities	455		757
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2015			757
Balance at June 30, 2016	455		455
Recurring | Level 3
Liabilities that are measured at fair value on a recurring basis
Warrant liabilities	0		0
Change in the estimated fair value of warrant liabilities
Balance at December 31, 2015			0
Balance at June 30, 2016	$ 0		$ 0