Balance Sheet Components (Inventories, Property and Equipment) (Details) - USD ($) $ in Thousands |
Jun. 30, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Inventories | ||
| Finished goods | $ 37,105 | $ 33,050 |
| Component parts | 4,531 | 4,025 |
| Work-in-process | 77 | 96 |
| Total inventories | 41,713 | 37,171 |
| Property and equipment, net | ||
| Property and equipment, gross | 24,042 | 23,537 |
| Less: accumulated depreciation | (16,170) | (16,200) |
| Property and equipment, net | 7,872 | 7,337 |
| Computer equipment and software | ||
| Property and equipment, net | ||
| Property and equipment, gross | 4,885 | 5,030 |
| Manufacturing tooling and test equipment | ||
| Property and equipment, net | ||
| Property and equipment, gross | 4,226 | 4,894 |
| Lab and warehouse equipment | ||
| Property and equipment, net | ||
| Property and equipment, gross | 5,259 | 4,869 |
| Leasehold improvements | ||
| Property and equipment, net | ||
| Property and equipment, gross | 4,105 | 3,960 |
| Furniture and fixtures | ||
| Property and equipment, net | ||
| Property and equipment, gross | 4,481 | 3,698 |
| Other | ||
| Property and equipment, net | ||
| Property and equipment, gross | $ 1,086 | $ 1,086 |