Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Income Tax Disclosure [Abstract] | ||||
| Income tax expense | $ 6,477 | $ 5,673 | $ 7,976 | $ 14,437 |