v3.10.0.1
Notes Payable to Investors - Additional Information (Detail) - USD ($)
1 Months Ended 9 Months Ended
Feb. 28, 2017
Oct. 31, 2016
Sep. 30, 2018
Dec. 31, 2016
Convertible Note Financing [Member]        
Debt Instrument [Line Items]        
Convertible notes payable       $ 9,000,000
Debt instrument, accrued interest rate     8.00%  
Gross proceeds from sale of capital stock     $ 30,000,000  
Additional Convertible Note Financings [Member]        
Debt Instrument [Line Items]        
Convertible notes payable $ 300,000 $ 3,500,000    
Maturity date Mar. 31, 2017 Mar. 31, 2017    
Debt issuance cost $ 125,935 $ 125,935