Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of Stock Option Activity (Detail)

v3.8.0.1
Stockholders' Equity - Summary of Stock Option Activity (Detail)
9 Months Ended
Sep. 30, 2017
$ / shares
shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Total Options, Beginning balance | shares 3,393,813
Total Options, Granted | shares 1,702,600
Total Options, Exercised | shares (62,944)
Total Options, Cancelled | shares (122,912)
Total Options, Ending balance | shares 4,910,557
Weighted-Average Exercise Price, Beginning balance | $ / shares $ 5.10
Weighted-Average Exercise Price, Granted | $ / shares 4.91
Weighted-Average Exercise Price, Exercised | $ / shares 1.19
Weighted-Average Exercise Price, Cancelled | $ / shares 4.67
Weighted-Average Exercise Price, Ending balance | $ / shares $ 5.10