Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.21.2
Summary of Significant Accounting Policies - Additional Information (Detail)
3 Months Ended 6 Months Ended
Jun. 30, 2021
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
Jun. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Summary Of Significant Accounting Policies [Line Items]          
Maturity period of highly liquid investments     three months or less    
Realized gains or losses on marketable securities $ 0 $ 0 $ 0 $ 0  
Number of securities in unrealized loss position for more than 12 months 0   0   0
Grants receivable recognized $ 3,000,000.0 $ 1,000,000.0 $ 4,000,000.0 $ 2,400,000  
Government grants receivable 3,800,000   3,800,000   $ 1,100,000
Grant award funding remaining $ 14,200,000   $ 14,200,000