Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.7.0.1
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Summary Of Significant Accounting Policies [Line Items]        
Maturity period of highly liquid investments     Three months or less  
Decrease in research and development expense $ 474,263 $ 0 $ 556,294 $ 0
Grants receivable for costs incurred 341,959   341,959  
Grants remaining to be awarded 2,673,935   2,673,935  
Level 1 [Member]        
Summary Of Significant Accounting Policies [Line Items]        
Liabilities 0   0  
Level 2 [Member]        
Summary Of Significant Accounting Policies [Line Items]        
Liabilities $ 0   $ 0