Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Goodwill And Intangible Assets Disclosure [Abstract] | |||
| Amortization expense | $ 6,337 | $ 6,730 | $ 2,524 |