Annual report pursuant to Section 13 and 15(d)

Stock Option Plans (Additional Information) (Detail)

v3.19.1
Stock Option Plans (Additional Information) (Detail) - USD ($)
12 Months Ended
Jun. 13, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2014
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]          
Exercisable Options Outstanding Shares   936,406 797,861 613,665  
Weighted average exercise price per share   $ 4.66 $ 4.65 $ 4.83  
Unvested Options Outstanding, Shares   610,115 712,383 470,633  
Unvested Options Outstanding, Weighted average exercise price   $ 5.48 $ 5.80 $ 4.67  
Unvested Options Outstanding Weighted average remaining life (yrs)   8 years 10 months 24 days 8 years 8 months 12 days 8 years 4 months 24 days  
Weighted average remaining contractual term on unvested options   6 years 1 month 6 days 6 years 4 months 24 days 7 years  
Unrecognized stock compensation expense   $ 3,041,544      
Weighted average recognition period   2 years 10 months 24 days      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized   5,629,105 2,555,387 2,111,673  
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   100.00%      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value   $ 912,360 $ 2,323,312 $ 2,776,068  
2014 Plan          
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]          
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized   5,518,334 2,427,628 1,956,925 1,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum 20.00% 20.00% 10.00% 10.00%  
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage   100.00%