Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands |
12 Months Ended | |||||
|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Jan. 01, 2019 |
Jan. 01, 2018 |
Dec. 31, 2016 |
|
| Restricted cash for the benefit of its leased properties | $ 1,700 | $ 1,700 | ||||
| Restricted cash to collateralize corporate credit card | 500 | |||||
| Restricted cash | 1,700 | 2,300 | $ 300 | |||
| Restricted cash (non-current) | 1,735 | 1,735 | ||||
| Restricted cash (current) | 622 | |||||
| Cash, Cash Equivalents and Restricted Cash | 93,633 | 309,421 | 104,572 | $ 7,068 | ||
| Change in fair value of the unvested awards | 800 | $ 100 | ||||
| Other than Temporary Impairment Losses, Investments | 0 | 0 | $ 0 | |||
| Accumulated deficit | ||||||
| Change in fair value of the unvested awards | $ 800 | $ 92 | ||||
| Accumulated deficit | ASU 2016-02 | ||||||
| Change in fair value of the unvested awards | $ 800 | |||||