Income Taxes - Reconciliation of effective tax rate (Details) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Reconciliation of the effective tax rate to the U.S. Federal statutory rate | |||
| Federal tax benefit at statutory rate | 21.00% | 21.00% | 21.00% |
| State tax, net of Federal benefit | 9.00% | 14.00% | 6.00% |
| Change in valuation allowance | (26.00%) | (24.00%) | (28.00%) |
| Research and development tax credits | 3.00% | 19.00% | 4.00% |
| Share based Compensation | (1.00%) | (10.00%) | (1.00%) |
| 162(m) covered employees compensation limitation | (6.00%) | ||
| FIN48 Reserve | (1.00%) | (161.00%) | (1.00%) |
| Deconsolidation gain | (3.00%) | 174.00% | |
| Gain on transfer of intellectual property | (20.00%) | ||
| Prior year federal true-up | (1.00%) | (7.00%) | |
| Other | (1.00%) | (1.00%) | |
| Effective income tax rate | 0.00% | 0.00% | 0.00% |