Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Stock Option Activity (Detail)

v3.6.0.2
Stockholders' Equity - Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Number of shares, Options vested and expected to vest 1,779,365  
Number of shares, Forfeited (648,864)  
Number of shares, Options vested and expected to vest 1,130,501 1,779,365
Number of shares, Exercisable as of December 31, 2016 1,105,501  
Weighted average exercise price, Options vested and expected to vest $ 4.37  
Weighted average exercise price, Forfeited 0.51  
Weighted average exercise price, Options vested and expected to vest 3.73 $ 4.37
Weighted average exercise price, Exercisable as of December 31, 2016 $ 3.71  
Total Weighted average intrinsic value, Options vested and expected to vest $ 666,396  
Total Weighted average intrinsic value, Options vested and expected to vest 602,451 $ 666,396
Total weighted average intrinsic value, Exercisable as of December 31, 2016 $ 602,451  
Weighted average remaining contractual life (years), Options vested and expected to vest 4 years 11 months 5 days 6 years 3 months 25 days
Weighted average remaining contractual life (years), Exercisable as of December 31, 2016 4 years 10 months 28 days