Goodwill and Intangible Assets - Components of Goodwill (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Goodwill And Intangible Assets Disclosure [Abstract] | ||
| Beginning balance | $ 39,870 | $ 20,335 |
| Additions through acquisitions | 72,528 | 19,952 |
| Measurement period adjustments | 27 | (417) |
| Ending balance | $ 112,425 | $ 39,870 |