Annual report pursuant to Section 13 and 15(d)

Stock Plans - Schedule of Stock Option Activity (Detail)

v3.20.1
Stock Plans - Schedule of Stock Option Activity (Detail) - 2014 Plan Stock Options/Stock Issuance Plan and 2017 Stock Incentive Plan [Member]
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2019
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Options, Outstanding, Beginning Balance | shares 5,154,691
Options Granted | shares 672,096
Options Exercised | shares (57,212)
Options Forfeited | shares (446,338)
Options Expired | shares (126,459)
Options, Outstanding, Ending Balance | shares 5,196,778
Options, Exercisable at December 31, 2019 | shares 3,771,201
Weighted-Average Exercise Price, Outstanding, Beginning Balance | $ / shares $ 13.78
Weighted-Average Exercise Price, Options Granted | $ / shares 5.59
Weighted-Average Exercise Price, Options Exercised | $ / shares 2.99
Weighted-Average Exercise Price, Options Forfeited | $ / shares 11.12
Weighted-Average Exercise Price, Options Expired | $ / shares 13.03
Weighted-Average Exercise Price, Outstanding, Ending Balance | $ / shares 13.09
Weighted-Average Exercise Price, Exercisable | $ / shares $ 13.98
Weighted-Average Remaining Contractual Term, Outstanding 7 years 6 months 3 days
Weighted-Average Remaining Exercisable 7 years 1 month 17 days
Weighted-Average Aggregate Intrinsic Value | $ $ 255
Weighted-Average Aggregate Intrinsic Value, Exercisable | $ $ 254