Balance Sheet Components - Schedule of Allowance for Sales Returns (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Movement in Valuation Allowances and Reserves [Roll Forward] | ||
| Beginning balance | $ (17,739) | |
| Ending balance | (21,897) | $ (17,739) |
| Allowance for Sales Returns | ||
| Movement in Valuation Allowances and Reserves [Roll Forward] | ||
| Beginning balance | (6,907) | (6,916) |
| Charged to revenue | (17,396) | (19,089) |
| Utilization of sales return/incentive reserve | 16,968 | 19,098 |
| Ending balance | $ (7,335) | $ (6,907) |