Annual report pursuant to Section 13 and 15(d)

Revenue - Revenue from contracts with customers (Details)

v3.20.4
Revenue - Revenue from contracts with customers (Details)
12 Months Ended
Jan. 01, 2020
USD ($)
Dec. 31, 2020
USD ($)
contract
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Revenue        
Revenue   $ 3,958,000 $ 1,122,000 $ 59,505,000
Number of contracts with customers | contract   2    
Increase (decrease) in deferred revenue $ 49,964,000 $ 47,973,000 2,095,000 (38,221,000)
Deferred revenue $ 2,128,000 52,092,000    
Development revenue        
Revenue        
Revenue   3,958,000 1,122,000 20,391,000
License revenue        
Revenue        
Revenue       $ 39,114,000
GlaxoSmithKline Intellectual Property Development Ltd | Astellas Collaboration Agreement        
Revenue        
Revenue recognized in the period   $ 1,887,000    
Deferred revenue     $ 2,128,000