Silver metals delivery agreement (Details) - USD ($) $ in Thousands |
9 Months Ended | 12 Months Ended | |
|---|---|---|---|
Sep. 30, 2025 |
Dec. 31, 2024 |
Dec. 19, 2024 |
|
| Statement [Line Items] | |||
| Current portion | $ 6,368 | $ 0 | |
| Non-current portion | 22,198 | 18,193 | |
| Silver Agreement | |||
| Statement [Line Items] | |||
| Net metals contract liability, beginning of year | 18,193 | ||
| Revaluation of metals contract liability | 10,373 | ||
| Net metals contract liability, end of year | 28,566 | 18,193 | |
| Current portion | 6,368 | ||
| Non-current portion | 22,198 | ||
| Total | $ 28,566 | $ 18,193 | $ 19,800 |