Defined Benefit Plan - Summary of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Compensation and Retirement Disclosure [Abstract] | ||||
| Service cost | $ 111 | $ 121 | $ 325 | $ 455 |
| Interest cost | 35 | 34 | 103 | 132 |
| Expected return on plan assets | 5 | (282) | 15 | (416) |
| Effect of curtailment | 0 | 37 | 0 | (864) |
| Net periodic benefit cost | $ 151 | $ (90) | $ 443 | $ (693) |