Stock Based Compensation - Summary of Outstanding RSUs (Detail) - Restricted stock units (RSUs) [Member] - $ / shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
| Shares Unvested, Beginning Balance | 104,074 | ||
| Shares, Granted | 0 | 78,843 | 82,800 |
| Shares, Vested | (59,568) | ||
| Shares, Cancelled | 0 | ||
| Shares Unvested, Ending Balance | 44,506 | 104,074 | |
| Weighted Average Grant-Date Fair Value per Share, Unvested, Beginning Balance | $ 12.55 | ||
| Weighted Average Grant-Date Fair Value per Share, Granted | 0 | ||
| Weighted Average Grant-Date Fair Value per Share, Vested | 13.43 | ||
| Weighted Average Grant-Date Fair Value per Share, Cancelled | 0 | ||
| Weighted Average Grant-Date Fair Value per Share, Unvested, Ending Balance | $ 11.38 | $ 12.55 | |