Segmented Information (Segment assets and liabilities) (Details) - USD ($) $ in Millions |
Dec. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|
| Disclosure of operating segments [line items] | ||
| Total Assets | $ 5,336.1 | $ 4,001.2 |
| Total liabilities | 1,751.9 | 1,077.7 |
| Corporate/Other | ||
| Disclosure of operating segments [line items] | ||
| Total Assets | 280.0 | 222.9 |
| Total liabilities | 559.3 | 46.8 |
| Operating segments | Young-Davidson | ||
| Disclosure of operating segments [line items] | ||
| Total Assets | 1,758.6 | 1,693.2 |
| Total liabilities | 459.8 | 381.8 |
| Operating segments | Island Gold | ||
| Disclosure of operating segments [line items] | ||
| Total Assets | 1,683.1 | 1,453.6 |
| Total liabilities | 534.5 | 476.4 |
| Operating segments | Magino | ||
| Disclosure of operating segments [line items] | ||
| Total Assets | 1,073.5 | 0.0 |
| Total liabilities | 37.9 | 0.0 |
| Operating segments | Mulatos | ||
| Disclosure of operating segments [line items] | ||
| Total Assets | 540.9 | 631.5 |
| Total liabilities | $ 160.4 | $ 172.7 |