Quarterly report pursuant to Section 13 or 15(d)

Revenue (Details)

v3.8.0.1
Revenue (Details)
$ in Thousands, £ in Millions
 1 Months Ended 9 Months Ended
Sep. 30, 2017
USD ($)
Jun. 30, 2014
USD ($)
Sep. 30, 2017
USD ($)
item
Sep. 30, 2017
GBP (£)
Sep. 30, 2017
USD ($)
Dec. 31, 2016
USD ($)
Collaboration and License Agreement            
Deferred revenue         $ 42,592 $ 11,392
Collaborative arrangement | GlaxoSmithKline Intellectual Property Development Ltd            
Collaboration and License Agreement            
Number of Target programs | item     5      
Number of additional target peptides, that the entity has right to nominate | item     3      
Upfront payment received   $ 42,100        
Amount of non-substantive development milestones     $ 49,300      
Milestone payments received     $ 10,300      
License exercise fee, receivable       £ 30 38,000  
Option exercise fee, received $ 26,600          
Increase in revenue amortization $ 17,500          
Deferred revenue         $ 42,600  
Deferred revenue amortization period     12 months      
Written notice period required to be served for the termination of agreement for material breach (in days)     60 days      
Notice period required to be served for the termination of agreement or specific program (in days)     60 days