Balance Sheet Components (Accrued liabilities) (Details) - USD ($) $ in Thousands |
Sep. 30, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Accrued liabilities | ||
| Sales returns and current portion of warranty accruals | $ 2,917 | $ 2,892 |
| Compensation accruals | 4,533 | 4,445 |
| Other accrued liabilities | 1,947 | 1,575 |
| Total accrued liabilities | $ 9,397 | $ 8,912 |