Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares shares in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
| Antidilutive securities excluded from calculation of diluted net loss per share | 13,089 | 15,699 | 20,127 |
| 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 | 13,088 | 15,668 | 20,057 |
| 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 | 1 | 31 | 70 |