Net Loss per Share - Schedule of Potentially Dilutive Shares 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 |
|
| Stock Options | |||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
| Anti-dilutive securities excluded from calculation of diluted net loss per share | 5,624 | 10,262 | 16,291 |
| Unvested Restricted Stock Units And Restricted Stock Awards Not Subject To A Performance Condition | |||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
| Anti-dilutive securities excluded from calculation of diluted net loss per share | 131,172 | 148,797 | 158,264 |
| Convertible Notes (If Converted) | |||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
| Anti-dilutive securities excluded from calculation of diluted net loss per share | 101,591 | 55,468 | |