Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Details)

v3.10.0.1
Stock Based Compensation (Details)
 1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Jan. 01, 2018
$ / shares
shares
Jan. 01, 2017
shares
May 18, 2016
grant
shares
Apr. 05, 2016
USD ($)
shares
May 31, 2018
shares
Sep. 30, 2018
USD ($)
$ / shares
shares
Sep. 30, 2017
USD ($)
Sep. 30, 2018
USD ($)
$ / shares
shares
Sep. 30, 2017
USD ($)
Dec. 31, 2017
$ / shares
shares
Annual share reserve increase (as a percent)               4.00%    
Total stock-based compensation | $           $ 945,133 $ 264,247 $ 1,796,387 $ 852,210  
Research and development                    
Total stock-based compensation | $           32,202 41,323 64,077 123,883  
General and administrative                    
Total stock-based compensation | $           843,122 222,924 1,599,703 728,327  
Sales and marketing                    
Total stock-based compensation | $           $ 69,809 $ 0 $ 132,607 $ 0  
Service Based Options                    
Option Activity, Number of shares                    
Balance, beginning of period (in shares) 2,823,489             2,823,489    
Granted (in shares)               1,504,700    
Options exercises in period (in shares)               (243,115)    
Forfeitures (in shares)               (465,887)    
Balance, end of period (in shares)           3,619,187   3,619,187   2,823,489
Exercisable (in shares)           1,832,581   1,832,581    
Option Activity, Weighted-average exercise price                    
Beginning of period (in dollars per share) | $ / shares $ 3.93             $ 3.93    
Granted (in dollars per share) | $ / shares               3.88    
Exercised (in dollars per share) | $ / shares               2.08    
Forfeitures (in dollars per share) | $ / shares               2.73    
End of period (in dollars per share) | $ / shares           $ 4.18   4.18   $ 3.93
Exercisable (in dollars per share) | $ / shares           $ 4.88   $ 4.88    
Option Activity, Fair value of options granted                    
Grant date fair value of options granted | $           $ 3,475,857   $ 3,475,857    
Option Activity, Weighted-average remaining contractual term (in years)                    
Balance               7 years 11 months 19 days   7 years 3 months 15 days
Exercisable               6 years 8 months 19 days    
Aggregate intrinsic value | $           $ 4,400,000   $ 4,400,000    
Fair value of options vested in period | $               $ 943,270    
Per share weighted average fair value of options granted (in dollars per share) | $ / shares               $ 2.31    
Options vested (in shares)               476,399    
Weighted average exercise price (in dollars per share) | $ / shares           $ 3.27   $ 3.27    
Fair value assumptions                    
Expected annual dividend yield               0.00%    
Expected volatility rate, minimum               55.00%    
Expected volatility rate, maximum               65.00%    
Stock Options With Market Based Vesting Conditions                    
Option Activity, Number of shares                    
Balance, beginning of period (in shares) 0             0    
Granted (in shares)               500,000    
Options exercises in period (in shares)               0    
Forfeitures (in shares)               0    
Balance, end of period (in shares)           500,000   500,000   0
Exercisable (in shares)           0   0    
Option Activity, Weighted-average exercise price                    
Granted (in dollars per share) | $ / shares               $ 4.24    
End of period (in dollars per share) | $ / shares           $ 4.24   $ 4.24    
Option Activity, Fair value of options granted                    
Grant date fair value of options granted | $           $ 1,260,000   $ 1,260,000    
Option Activity, Weighted-average remaining contractual term (in years)                    
Balance               9 years 5 months 27 days    
Aggregate intrinsic value | $           215,000   $ 215,000    
Per share weighted average fair value of options granted (in dollars per share) | $ / shares               $ 2.52    
Compensation not yet recognized | $           1,030,068   $ 1,030,068    
Period for recognition               2 years 3 months 18 days    
Fair value assumptions                    
Expected annual dividend yield               0.00%    
Expected volatility               60.00%    
Expected term of options (in years)               10 years    
Risk-free interest rate               2.84%    
Restricted Stock Awards                    
Award vesting period               4 years    
Total stock-based compensation | $               $ 227,858    
Compensation not yet recognized | $           $ 1,670,642   $ 1,670,642    
Option Activity, Weighted-average remaining contractual term (in years)                    
Period for recognition               3 years 6 months    
Non-vested RSAs Outstanding                    
Beginning balance of Non-vested RSAs (in shares) 0             0    
RSAs granted (in shares)               445,000    
RSAs vested (in shares)               0    
RSAs forfeited (in shares)               0    
Ending balance of Non-vested RSAs (in shares)           445,000   445,000   0
Weighted average grant date fair value                    
Nonvested RSAs weighted average grant date fair value (in dollars per share) | $ / shares                   $ 0.00
Nonvested RSAs grants in period weighted average grant date fair value (in dollars per share) | $ / shares               $ 4.27    
RSAs vested in period weighted average grant date fair value (in dollars per share) | $ / shares               0.00    
Nonvested RSAs forfeitures weighted average grant date fair value (in dollars per share) | $ / shares               $ 0.00    
Employee Stock Purchase Plan (ESPP)                    
Total stock-based compensation | $               $ 31,788    
Minimum | Service Based Options                    
Fair value assumptions                    
Expected term of options (in years)               5 years    
Risk-free interest rate               2.53%    
Maximum | Service Based Options                    
Fair value assumptions                    
Expected term of options (in years)               6 years 3 months    
Risk-free interest rate               2.94%    
2016 Plan                    
Increase in number of shares reserved for issuance (in shares)     600,000   1,400,000.0          
Common stock remaining for future issuance (in shares)           730,067   730,067    
2016 Plan | Stock options                    
Award expiration period               10 years    
2015 Plan                    
Number of grants to be made | grant     0              
Common stock remaining for future issuance (in shares)     464,476              
2011 Stock Incentive Plan                    
Number of grants to be made | grant     0              
Employee Stock Purchase Plan (ESPP)                    
Common stock remaining for future issuance (in shares)           806,390   806,390    
Weighted average grant date fair value                    
Percentage of fair market value on the lower of first day or last day of the offering period at which employees may purchase stock under the ESPP       85.00%            
Maximum portion of earning an employee may contribute to the ESPP Plan       15.00%            
Maximum annual amount of fair market value of the Company's common stock that a participant may accrue the rights to purchase | $       $ 25,000            
Shares of common stock for future issuance (in shares)       500,000            
Automatic increase to shares authorized as percentage of outstanding stock at end of preceding year       1.00%            
Increase in shares available (in shares) 312,669 94,341                
Employee | 2016 Plan | Stock options                    
Award vesting period               4 years    
Director | 2016 Plan | Stock options                    
Award vesting period               3 years    
Terminated Executive                    
Total stock-based compensation | $           $ 300,000   $ 300,000