Preferred Stock, Common Stock and Stockholders' Equity - Summary of Stock Option Activity (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]    
Shares, Outstanding beginning balance 683,500  
Shares, Granted 354,000  
Shares, Outstanding ending balance 1,037,500 683,500
Shares, Vested and expected to vest at December 31, 2015 1,037,500  
Shares, Exercisable at December 31, 2015 530,079  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]    
Weighted Average Exercise Price, Outstanding beginning balance $ 7.67  
Weighted Average Exercise Price, Granted 6.25  
Weighted Average Exercise Price, Outstanding ending balance 7.19 $ 7.67
Weighted Average Exercise Price, Vested and expected to vest at December 31, 2015 7.19  
Weighted Average Exercise Price, Exercisable at December 31, 2015 $ 6.80  
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding, Weighted Average Remaining Contractual Term [Abstract]    
Weighted Average Remaining Contractual Term (Years), Outstanding 8 years 15 days 8 years 5 months 12 days
Weighted Average Remaining Contractual Term (Years), Granted 9 years 2 months 12 days  
Weighted Average Remaining Contractual Term (Years), Vested and expected to vest at December 31, 2015 8 years 15 days  
Weighted Average Remaining Contractual Term (Years), Exercisable at December 31, 2015 7 years 6 months  
Share Based Compensation Arrangement by Share Based Payment Award Options Outstanding, Aggregate Intrinsic Value [Abstract]    
Aggregate Intrinsic Value, Outstanding beginning balance $ 649,000  
Aggregate Intrinsic Value, Outstanding ending balance 342,200 $ 649,000
Aggregate Intrinsic Value, Vested and expected to vest at December 31, 2015 342,200  
Aggregate Intrinsic Value, Exercisable at December 31, 2015 $ 342,200