Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.20.1
Summary of Significant Accounting Policies - Additional Information (Detail)
$ in Thousands
1 Months Ended 12 Months Ended
Aug. 31, 2013
USD ($)
Dec. 31, 2019
USD ($)
Segment
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Subsidiary, Sale of Stock [Line Items]        
Cash, cash equivalents, and restricted cash   $ 42,193 $ 11,767 $ 11,469
Upfront payment received $ 1,500      
Deferred revenue estimated performance period 70 months      
Revenue recognized from upfront payments   $ 121 257  
Operating segments (number) | Segment   1    
License and Service        
Subsidiary, Sale of Stock [Line Items]        
Revenue recognized from upfront payments   $ 100 $ 300  
6.0% Convertible Senior Notes due 2025        
Subsidiary, Sale of Stock [Line Items]        
Interest rate   6.00%    
Collaboration Revenue | R-Pharm, CJSC | Customer Concentration Risk        
Subsidiary, Sale of Stock [Line Items]        
Percentage of total revenue   100.00% 100.00%