Quarterly report pursuant to Section 13 or 15(d)

Organization and Summary of Significant Accounting Policies - Additional Information (Detail)

v3.20.2
Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Organization And Summary Of Significant Accounting Policies [Line Items]          
Reclassification from deferred revenue, current to deferred revenue, current, related party $ 5,218   $ 5,218   $ 8,780
Reclassification from deferred revenue, non-current to deferred revenue, non-current, related party         400
Reclassification from deferred revenue to deferred revenue, related party     2,154 $ 12,676  
Cash, cash equivalents, and marketable securities $ 91,000   $ 91,000    
Revenue | Credit Risk | Vertex Pharmaceuticals Inc          
Organization And Summary Of Significant Accounting Policies [Line Items]          
Percentage of total revenues 43.00% 0.00% 40.00% 0.00%  
Revenue | Credit Risk | Takeda Pharmaceuticals Inc          
Organization And Summary Of Significant Accounting Policies [Line Items]          
Percentage of total revenues 44.00% 96.00% 31.00% 93.00%  
Other Assets          
Organization And Summary Of Significant Accounting Policies [Line Items]          
Restricted cash $ 3,200   $ 3,200   $ 3,000