Summary of Unrecognized Tax Benefits (Detail) $ in Thousands |
12 Months Ended |
|---|---|
|
Dec. 31, 2016
USD ($)
| |
| Income Tax Disclosure [Abstract] | |
| Beginning balance | $ 568 |
| Additions for tax positions related to the prior year | 0 |
| Lapse of statute of limitations | 0 |
| Ending balance | $ 568 |