Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Stock-based Compensation Expense Recognized (Detail)

v3.10.0.1
Stock-based Compensation - Stock-based Compensation Expense Recognized (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total Stock based compensation $ 648,302 $ 127,440 $ 872,932 $ 422,206
Research and Development [Member]        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total Stock based compensation 73,463 (15,593) 91,511 (3,336)
General and Administrative [Member]        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Total Stock based compensation $ 574,839 $ 143,033 $ 781,421 $ 425,542