Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.19.3
Summary of Significant Accounting Policies - Additional Information (Detail)
3 Months Ended 9 Months Ended
Sep. 30, 2019
USD ($)
Sep. 30, 2018
USD ($)
Sep. 30, 2019
USD ($)
Sep. 30, 2018
USD ($)
Jan. 01, 2019
USD ($)
Dec. 31, 2018
USD ($)
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 $ 1,300,000 $ 2,400,000 $ 300,000 $ 1,100,000    
Grants receivable 1,200,000   1,200,000     $ 200,000
Grants remaining to be awarded 9,400,000   9,400,000      
Current portion of lease liabilities 628,676   628,676      
Long-term portion of lease liabilities 3,332,866   3,332,866      
Operating lease right-of use assets 3,098,179   3,098,179      
Operating lease liabilities $ 3,961,542   $ 3,961,542      
Adjustments due to the adoption of Topic 842            
Summary Of Significant Accounting Policies [Line Items]            
Current portion of lease liabilities         $ 600,000  
Long-term portion of lease liabilities         3,500,000  
Operating lease right-of use assets         3,300,000  
Operating lease liabilities         $ 4,100,000