Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands |
Sep. 30, 2019 |
Mar. 31, 2019 |
Jan. 01, 2019 |
Dec. 31, 2018 |
Jan. 01, 2018 |
|---|---|---|---|---|---|
| Restricted cash for the benefit of the landlords of leased properties | $ 1,700 | $ 1,800 | |||
| Restricted cash to collateralize corporate credit card | 500 | ||||
| Restricted cash (non-current) | $ 1,735 | 1,735 | |||
| Restricted cash (current) | $ 622 | ||||
| Change in fair value of the unvested awards | $ 100 | ||||
| ASU 2016-02 | |||||
| Change in fair value of the unvested awards | $ 800 | ||||
| Accumulated deficit | ASU 2016-02 | |||||
| Change in fair value of the unvested awards | $ 800 | $ 800 |