SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Basis of Presentation
Number of operating segments	1
Revenue | Customer concentration
Concentration risk
Concentration risk (as a percent)		0.00%
Revenue | Customer concentration | Rockefeller
Concentration risk
Concentration risk (as a percent)	75.00%	35.00%	0.00%
Revenue | Customer concentration | BMS
Concentration risk
Concentration risk (as a percent)	20.00%	0.00%	0.00%
Revenue | Customer concentration | Glaxo
Concentration risk
Concentration risk (as a percent)	0.00%	57.00%	96.00%