Defined Contribution Plan - Additional Information (Detail) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Compensation And Retirement Disclosure [Abstract] | |||
| Contribution of employee compensation (in percent) | 100.00% | ||
| Contributions to Retirement Plan | $ 0 | $ 0 | $ 0 |