Stock Plans and Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Stock-based compensation expense | $ 1,840 | $ 570 | $ 3,118 | $ 1,130 |
| President and Chief Executive Officer [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Stock-based compensation expense | $ 1,200 | $ 1,800 | ||
| 2013 Equity Incentive Plan [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Shares available for grant | 260,765 | 260,765 | ||
| Increased in shares available for issuance | 1,172,350 | |||
| 2013 Equity Incentive Plan [Member] | Employees, Directors and Consultant [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Options to purchase common stock granted | 1,490,801 | |||