Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax, from Unrealized Gains (Losses) on Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] | ||
| Total Accumulated Other Comprehensive Income (Loss), Beginning Balance | $ (35) | |
| Other comprehensive loss before reclassifications | 61 | $ (35) |
| Amount reclassified from accumulated other comprehensive income | (23) | |
| Net current period other comprehensive income (loss) | 38 | (35) |
| Total Accumulated Other Comprehensive Income (Loss), Ending Balance | $ 3 | $ (35) |