Annual report pursuant to Section 13 and 15(d)

Revenue (Details)

v3.8.0.1
Revenue (Details)
$ in Thousands, £ in Millions
 1 Months Ended 12 Months Ended 44 Months Ended
Sep. 30, 2017
USD ($)
Jun. 30, 2014
USD ($)
Dec. 31, 2017
USD ($)
item
Dec. 31, 2017
USD ($)
Dec. 31, 2017
GBP (£)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Collaboration and License Agreement              
Deferred revenue           $ 38,735 $ 11,392
Collaboration and License Agreement | 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           $ 38,700  
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