Balance Sheet Components - Summary of Inventory (Detail) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Inventory Disclosure [Abstract] | ||
| Finished goods | $ 4,199 | $ 237 |
| Work in progress | 159 | 0 |
| Raw materials | 1,103 | 529 |
| Total inventory | $ 5,461 | $ 766 |