Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.3
Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Jan. 31, 2019
Jan. 01, 2019
Dec. 31, 2018
Organization And Summary Of Significant Accounting Policies [Line Items]              
Reclassification from other current assets to grants revenue receivable $ 5,591   $ 5,591       $ 4,329
Reclassification from in process research and development to in process research and development - held for sale             26,600
Cash, cash equivalents, and marketable securities 51,400   51,400        
Right-of-use asset 10,397   10,397   $ 7,200 $ 4,180 0
Lease liabilities 11,536   11,536   $ 7,200    
Accounts receivable 0   0       240
Takeda Pharmaceuticals Inc              
Organization And Summary Of Significant Accounting Policies [Line Items]              
Accounts receivable 0   0       200
Cancer Prevention and Research Institute of Texas              
Organization And Summary Of Significant Accounting Policies [Line Items]              
Accounts receivable $ 5,600   $ 5,600       $ 4,300
Revenue | Credit Risk | Takeda Pharmaceuticals Inc              
Organization And Summary Of Significant Accounting Policies [Line Items]              
Percentage of total revenues 80.00% 28.00% 90.00% 35.00%      
Revenue | Credit Risk | Cancer Prevention and Research Institute of Texas              
Organization And Summary Of Significant Accounting Policies [Line Items]              
Percentage of total revenues 12.00% 70.00% 8.00% 63.00%      
Other Assets              
Organization And Summary Of Significant Accounting Policies [Line Items]              
Restricted cash $ 3,000   $ 3,000        
ASU 2016-02              
Organization And Summary Of Significant Accounting Policies [Line Items]              
Right-of-use asset           4,180  
Lease liabilities           $ 4,700