Other Long-Term Liabilities (Details 2) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2013 Rockefeller Development Services Agreement	Sep. 30, 2014 Rockefeller Development Services Agreement	Sep. 30, 2013 Rockefeller Development Services Agreement	Sep. 30, 2014 Rockefeller Development Services Agreement	Sep. 30, 2013 Rockefeller Development Services Agreement	May 31, 2014 Collaborative Arrangement	Sep. 30, 2014 Collaborative Arrangement	Sep. 30, 2014 Collaborative Arrangement
REVENUE
Approved project plan for the development services					$ 4,800,000
Term of the agreement					3 years					5 years
Upfront payment recognized as revenue over the term of the agreement					1,300,000					5,000,000
Contracts and Grants	$ 817,000	$ 940,000	$ 1,591,000	$ 1,040,000		$ 800,000	$ 900,000	$ 1,500,000	$ 900,000		$ 300,000	$ 400,000
Reimbursement of external costs incurred by the company (as a percent)										50.00%