Share-based Compensation - Stock Options Granted to Non-employees (Details) - Non-employee - Employee Stock Option - Consultant |
3 Months Ended | |
|---|---|---|
Mar. 31, 2021 |
Mar. 31, 2020 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Volatility | 60.00% | 56.00% |
| Risk-free interest rate | 1.60% | 1.60% |
| Term (in years) | 10 years | 10 years |
| Dividend yield | 0.00% | 0.00% |