Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Income Tax Disclosure [Abstract] | ||
| Beginning Balance | $ 3,076 | $ 2,859 |
| Additions for current year tax positions | 232 | 217 |
| Additions for prior year's tax positions | 476 | |
| Ending Balance | $ 3,784 | $ 3,076 |