Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Stock Option Activity Under Equity Incentive Plan (Detail)

v3.5.0.2
Stock Based Compensation - Stock Option Activity Under Equity Incentive Plan (Detail)
9 Months Ended
Sep. 30, 2016
USD ($)
$ / shares
shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Number of Shares, Outstanding Beginning Balance | shares 9,032,136
Number of Shares, Granted | shares 2,945,000
Number of Shares, Exercised | shares (6,187)
Number of Shares, Forfeitures | shares (843,098)
Number of Shares, Outstanding Ending Balance | shares 11,127,851
Number of Shares, Vested and expected to vest | shares 11,048,510
Number of Shares, Exercisable | shares 7,854,716
Weighted-Average Exercise Price, Outstanding at beginning of period | $ / shares $ 3.77
Weighted-Average Exercise Price, Granted | $ / shares 0.53
Weighted-Average Exercise Price, Exercised | $ / shares 0.53
Weighted-Average Exercise Price, Forfeitures | $ / shares 2.34
Weighted-Average Exercise Price, Outstanding at end of period | $ / shares 3.03
Weighted-Average Exercise Price, Vested and expected to vest | $ / shares 3.04
Weighted-Average Exercise Price, Exercisable | $ / shares $ 3.54
Weighted-Average Remaining Contractual Term, Outstanding 5 years 7 months 13 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest 5 years 7 months 2 days
Weighted-Average Remaining Contractual Term, Exercisable 4 years 4 months 6 days
Aggregate Intrinsic Value, Outstanding | $ $ 378,524
Aggregate Intrinsic Value, Vested and expected to vest | $ 370,312
Aggregate Intrinsic Value, Exercisable | $ $ 61,500