Fair value gain (loss) on embedded derivatives - Narrative (Details) - USD ($) |
3 Months Ended | 9 Months Ended | 12 Months Ended | |||||
|---|---|---|---|---|---|---|---|---|
Sep. 30, 2026 |
Jun. 30, 2026 |
Sep. 30, 2025 |
Jun. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Embedded derivatives [Abstract] | ||||||||
| Conversion price (in dollars per share) | $ 8.00 | |||||||
| Embedded derivatives | $ 3,282,000 | $ 3,604,000 | $ 9,518,000 | $ 6,623,000 | $ 3,282,000 | $ 9,518,000 | $ 5,153,000 | $ 20,768,000 |
| Fair value gain (loss) on embedded derivatives | $ 322,000 | $ (2,895,000) | $ 1,871,000 | $ 11,250,000 | ||||
| Share price (in dollars per share) | $ 3.88 | $ 5.48 | $ 4.12 | $ 3.76 | $ 4.27 | |||