Quarterly report pursuant to Section 13 or 15(d)

Stock Options and Warrants - Additional Information (Detail)

v3.8.0.1
Stock Options and Warrants - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended
Jun. 14, 2017
Jan. 31, 2017
Dec. 12, 2016
Feb. 28, 2017
Sep. 30, 2016
Aug. 31, 2017
Aug. 31, 2016
Aug. 24, 2017
Jun. 19, 2017
May 31, 2017
Mar. 31, 2016
Feb. 28, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Stock options grant date fair value           $ 0.25            
Common Stock issued           152,763,243       149,468,244    
Proceeds from Issuance of Common Stock           $ 8,990,000            
Inducement interest related to warrant extensions           826,252            
Compensation expense           $ 254,953 $ 335,349          
Convertible Notes 2017                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Warrants to purchase common shares, shares                 383,333      
Minimum | Convertible Notes 2017                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Exercise price of warrants, per share $ 1.00                      
Warrant covering common stock shares purchased, percentage 25.00%                      
Maximum | Convertible Notes 2017                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Exercise price of warrants, per share $ 1.35                      
Warrant covering common stock shares purchased, percentage 50.00%                      
Placement Agent                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Warrants to purchase common shares, shares   122,799   453,652 1,066,667 350,766            
Term of warrants   5 years   5 years 5 years 5 years            
Exercise price of warrants, per share   $ 0.825   $ 0.825 $ 0.825 $ 0.825            
Investor                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Exercise price of warrants, per share           $ 0.50            
Common Stock issued           3,295,000            
Proceeds from Issuance of Common Stock           $ 1,600,000            
Securities Purchase Agreement                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Warrants to purchase common shares, shares     2,000,000   6,666,667 3,258,990            
Term of warrants     5 years   5 years 5 years            
Exercise price of warrants, per share     $ 1.00   $ 1.00 $ 1.00            
Proceeds from Issuance of Common Stock     $ 3,000,000   $ 8,990,000              
Before Inducement | Investor                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Exercise price of warrants, per share           $ 1.00            
Class of warrant or right expiration date           Jun. 30, 2017            
2012 Equity Incentive Plan                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Compensation expense           $ 255,000 335,000          
Grant date fair value of options and warrants           447,000 $ 252,000          
Unrecognized compensation expense           $ 1,357,000            
Weighted average period over which unrecognized compensation expense is expected to be recognized           1 year 7 months 28 days            
2012 Equity Incentive Plan | Stock Options                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Shares available for future stock-based grants           5,693,807            
2012 Equity Incentive Plan | Stock Options | Before Amendment                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Shares available for future issuance               8,000,000     5,000,000 3,000,000
2012 Equity Incentive Plan | Stock Options | After Amendment                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Shares available for future issuance               15,000,000     7,000,000 5,000,000
2012 Equity Incentive Plan | Stock Options | Directors                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Stock options granted, shares           450,000            
Stock options granted, exercise price           $ 0.57            
Stock options grant date fair value           $ 0.36            
2012 Equity Incentive Plan | Stock Options | Directors | Minimum                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Vesting period           1 year            
2012 Equity Incentive Plan | Stock Options | Directors | Maximum                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Vesting period           10 years            
2012 Equity Incentive Plan | Stock Options | Chief Science Officer                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Stock options granted, shares           600,000            
Stock options granted, exercise price           $ 0.57            
Vesting period           3 years            
Stock options grant date fair value           $ 0.35            
Stock options, term           10 years            
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Stock options granted, shares           800,000            
Vesting period           3 years            
Stock options grant date fair value           $ 0.35            
Stock options, term           10 years            
Stock options granted, exercise price, lower range limit           $ 0.57            
2012 Equity Incentive Plan | Warrants (equity allocation)                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Vesting period           5 years            
Warrants granted, shares           200,000            
Warrants granted, exercise price           $ 0.64            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage           25.00%            
Warrants grant date fair value           $ 0.26            
2012 Equity Incentive Plan | Warrants (equity allocation) | December 31, 2017                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage           25.00%            
2012 Equity Incentive Plan | Warrants (equity allocation) | Milestone                        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage           50.00%