Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.19.1
Summary of Significant Accounting Policies - Additional Information (Detail)
3 Months Ended
Mar. 31, 2019
USD ($)
Mar. 31, 2018
USD ($)
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    
Number of securities in unrealized loss position for more than 12 months 0 0    
Grants receivable recognized $ 656,000 $ 370,000    
Grants receivable 656,000     $ 202,000
Grants remaining to be awarded 3,800,000      
Current portion of lease liabilities 622,483    
Long-term portion of lease liabilities 3,465,348    
Operating lease right-of use assets 3,202,124      
Operating lease liabilities $ 4,087,831      
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