Net Income (Loss) Per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares shares in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
| Antidilutive securities excluded from calculation of diluted net loss per share | 16,640 | 1,062 | 16,640 | 21,590 |
| Equity Awards to Purchase Common Stock | ||||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
| Antidilutive securities excluded from calculation of diluted net loss per share | 16,595 | 1,062 | 16,595 | 21,485 |
| Unvested Shares of Common Stock Issued Upon Early Exercise of Stock Options and Business Acquisition | ||||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
| Antidilutive securities excluded from calculation of diluted net loss per share | 45 | 45 | 105 | |