Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares shares in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2020 |
Mar. 31, 2019 |
|
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from calculation of diluted net loss per share | 15,246 | 18,516 |
| 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 | 15,227 | 18,459 |
| 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 | 19 | 57 |