Equity incentive plans - Schedule of stock options granted to employees and non-employees (Details) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Expected volatility | 79.00% | 79.00% |
| Expected dividend yield | 0.00% | 0.00% |
| Minimum [Member] | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Risk-free interest rate | 0.60% | 0.40% |
| Expected term (in years) | 5 years 3 months 18 days | 5 years 6 months |
| Maximum [Member] | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Risk-free interest rate | 1.40% | 0.70% |
| Expected term (in years) | 6 years 1 month 6 days | 6 years 1 month 6 days |