OTHER LONG-TERM LIABILITIES (Details 2) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013	May 31, 2014
REVENUE
Contracts and Grants	$ 2,748,000	$ 1,617,000	$ 281,000
Rockefeller Development Services Agreement
REVENUE
Approved project plan for the development services				4,800,000
Term of the agreement				3 years
Upfront payment recognized as revenue over the term of the agreement				1,300,000
Contracts and Grants	2,700,000	1,400,000
Bristol Meyers Collaborative Arrangement
REVENUE
Term of the agreement					5 years
Upfront payment recognized as revenue over the term of the agreement					5,000,000
Contracts and Grants	$ 700,000
Reimbursement of external costs incurred by the company (as a percent)					50.00%