Share capital - At the market equity offering (Details) SFr / shares in Units, SFr in Millions, $ in Millions |
3 Months Ended | 64 Months Ended | |||
|---|---|---|---|---|---|
|
Jun. 30, 2024
SFr / shares
shares
|
Dec. 31, 2025
CHF (SFr)
SFr / shares
shares
|
Dec. 31, 2025
USD ($)
shares
|
Sep. 30, 2020
CHF (SFr)
|
Sep. 30, 2020
USD ($)
|
|
| At the Market Equity Offering [Abstract] | |||||
| Nominal value per share (in CHF per share) | SFr / shares | SFr 0.02 | ||||
| At the market equity offering | |||||
| At the Market Equity Offering [Abstract] | |||||
| Value of shares authorized for issue in offering | SFr 64.0 | $ 80.0 | |||
| Nominal value per share (in CHF per share) | SFr / shares | SFr 0.02 | ||||
| Number of treasury share issued (in shares) | shares | 2,179,434 | 2,179,434 | |||
| Proceeds from issuance of treasury shares, net of underwriting fees and transaction costs | SFr 14.9 | $ 16.4 | |||
| Issuance costs | SFr 0.5 | $ 0.5 | |||
| Number of shares issued during the period | shares | 5,700,000 | ||||