STOCKHOLDERS' EQUITY (Common Stock Warrants) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Jan. 06, 2016	Jul. 07, 2015	Feb. 27, 2015	Jan. 15, 2015	Dec. 31, 2014	Oct. 22, 2014	Oct. 21, 2014	Jan. 24, 2013	Dec. 31, 2012	Feb. 02, 2012
Class of Stock [Line Items]
Common stock warrants issued (in shares)	2,933,106	1,208,491
Underlying Shares	8,853,905
Various Institutional Holders; February 2017
Class of Stock [Line Items]
Underlying Shares	2,812,745
Exercise Price (in dollars per share)	$ 4.39
Affiliates of Third Security, LLC; February 2017
Class of Stock [Line Items]
Underlying Shares	427,082
Exercise Price (in dollars per share)	$ 4.39
Various Institutional Holders; January 2018
Class of Stock [Line Items]
Underlying Shares	441,655
Exercise Price (in dollars per share)	$ 9
Affiliates of Third Security, LLC; January 2018
Class of Stock [Line Items]
Underlying Shares	250,000
Exercise Price (in dollars per share)	$ 9
Various Institutional Holders; April 2020
Class of Stock [Line Items]
Underlying Shares	374,618
Exercise Price (in dollars per share)	$ 4.00
Various Institutional Holders; February 2020
Class of Stock [Line Items]
Underlying Shares	714,780
Exercise Price (in dollars per share)	$ 2.24
Various Institutional Holders; December 2020
Class of Stock [Line Items]
Underlying Shares	122,433
Exercise Price (in dollars per share)	$ 1.66
Various Institutional Holders; December 2020
Class of Stock [Line Items]
Underlying Shares	667,164
Exercise Price (in dollars per share)	$ 0.01
Various Institutional Holders; January 2021
Class of Stock [Line Items]
Underlying Shares	1,161,972
Exercise Price (in dollars per share)	$ 1.21
Affiliates of Third Security, LLC; January 2021
Class of Stock [Line Items]
Underlying Shares	161,026
Exercise Price (in dollars per share)	$ 1.21
Various Institutional Holders; January 2021
Class of Stock [Line Items]
Underlying Shares	1,720,430
Exercise Price (in dollars per share)	$ 1.21
Private Placement
Class of Stock [Line Items]
Common stock warrants issued (in shares)	1,051,650	493,711
Exercise Price (in dollars per share)			$ 4.39	$ 6.50	$ 7.56	$ 9.59	$ 10.25	$ 10.86	$ 11.73	$ 12.96	$ 15.00	$ 15.00
Offering
Class of Stock [Line Items]
Common stock warrants issued (in shares)	1,881,456	714,780