Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) ft²	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) ft² LeaseTerm	Sep. 30, 2014 USD ($)	Feb. 28, 2015 ft²
Operating Leased Assets [Line Items]
Total square footage of leased property					25,000
Lease expiration date			Dec. 31, 2018
Additional operating lease term			2 years
Rent expense | $	$ 0.2	$ 0.1	$ 0.4	$ 0.2
Office Laboratory Lease
Operating Leased Assets [Line Items]
Total square footage of leased property	56,452		56,452
Additional operating lease term			5 years
Description of lease			The term of the Lease commences when the landlord delivers possession of the Facility to the Company.
Operating lease initial term			12 years
Number of additional renewal terms | LeaseTerm			2
Leases renewal term description			The Company has the option to extend the Lease beyond the Initial Term for up to two renewal terms of five years each, provided that the rental rate would be subject to market adjustment at the beginning of each renewal term.
Office Laboratory Lease | Commencing January 1, 2017
Operating Leased Assets [Line Items]
Operating lease, additional space			25,600
Office Laboratory Lease | Commencing January 1, 2018
Operating Leased Assets [Line Items]
Operating lease, additional space			28,801