v3.25.2

Investments in associates (Narrative) (Details) - USD ($) $ in Thousands |  |  |  | 12 Months Ended
--- | --- | --- | --- | ---
Aug. 31, 2025 | Jul. 31, 2025 | Sep. 30, 2024 | Dec. 31, 2025 | Dec. 31, 2024 | Sep. 30, 2024 | Dec. 31, 2023
Disclosure of associates [line items] |  |  |  |  |  |  |
Gain on deemed disposal |  |  |  | $ 54,439 | $ 0 |  |
Other comprehensive income |  |  |  | 93,345 | (57,822) |  |
Net loss on ownership dilution |  |  |  | $ 0 | $ (9,300) |  |
Osisko Development Corp [Member] |  |  |  |  |  |  |
Disclosure of associates [line items] |  |  |  |  |  |  |
Impairment of an investment in an associate |  |  |  |  |  |  | $ 48,800
Gain on deemed disposal | $ 54,400 |  |  |  |  |  |
Other comprehensive income | $ 1,100 |  |  |  |  | $ 1,440 |
Proportion of ownership interest in associate |  |  |  |  |  | 39.70% |
Osisko Development Corp [Member] | Cariboo Gold [Member] |  |  |  |  |  |  |
Disclosure of associates [line items] |  |  |  |  |  |  |
NSR royalty percentage |  |  |  |  | 5.00% |  |
Osisko Development Corp [Member] | Tintic property [Member] |  |  |  |  |  |  |
Disclosure of associates [line items] |  |  |  |  |  |  |
NSR royalty percentage |  |  |  |  | 2.50% |  |
Osisko Development Corp [Member] | Private placements [Member] |  |  |  |  |  |  |
Disclosure of associates [line items] |  |  |  |  |  |  |
Proportion of ownership interest in associate | 13.97% | 24.15% | 39.01% |  | 24.41% |  |
Net loss on ownership dilution |  |  |  |  | $ (9,300) |  |
Osisko Development Corp [Member] | Private and brokered placements [Member] |  |  |  |  |  |  |
Disclosure of associates [line items] |  |  |  |  |  |  |
Proportion of ownership interest in associate |  |  | 39.70% |  | 24.40% |  |
Net loss on ownership dilution |  |  |  |  | $ (9,300) |  |

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