Net Loss per Share - Schedule of Potentially Dilutive Shares Excluded from Calculation of Diluted Net Loss per Share (Details) - shares shares in Thousands |
6 Months Ended | |
|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| 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 | 158,253 | 158,259 |
| 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 | 12,491 | 16,963 |