Stock-based Compensation - Fair Value Assumptions (Details) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Expected volatility (as a percentage) | 101.10% | 82.70% |
| Risk-free interest rate (as a percentage) | 0.70% | 0.60% |
| Expected dividend yield (as a percentage) | 0.00% | 0.00% |
| Expected term (years) | 5 years 10 months 24 days | 6 years |
| 2019 ESPP | Employee Stock Purchase Plan | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Expected volatility (as a percentage) | 83.90% | 94.80% |
| Risk-free interest rate (as a percentage) | 0.10% | 0.10% |
| Expected dividend yield (as a percentage) | 0.00% | 0.00% |
| Expected term (years) | 6 months | 6 months |