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Mineral Property, Plant and Equipment (Net Value Carrying Values) (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
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Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | $ 4,618.0 | $ 3,360.1
Mineral Property, Plant and Equipment |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 4,618.0 | 3,360.1
Capital Additions |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 420.4 | 367.9
Corporate/Other | Mineral Property, Plant and Equipment |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 229.6 | 169.1
Corporate/Other | Capital Additions |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 26.6 | 21.1
Operating segments | Young-Davidson | Mineral Property, Plant and Equipment |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 1,563.3 | 1,500.3
Operating segments | Young-Davidson | Capital Additions |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 87.5 | 73.5
Operating segments | Island Gold | Mineral Property, Plant and Equipment |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 1,596.5 | 1,397.7
Operating segments | Island Gold | Capital Additions |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 258.0 | 243.4
Operating segments | Mulatos | Mineral Property, Plant and Equipment |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 232.7 | 293.0
Operating segments | Mulatos | Capital Additions |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 19.9 | 29.9
Operating segments | Magino | Mineral Property, Plant and Equipment |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | 995.9 | 0.0
Operating segments | Magino | Capital Additions |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Property, plant and equipment | $ 28.4 | $ 0.0

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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
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- Definition The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period. Note that right-of-use assets are not included. [Contrast: Property, plant and equipment including right-of-use assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2024-01-01 -Paragraph 73 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2024-en-r&anchor=para_73_e&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 54 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_54_a&doctype=Standard -URIDate 2024-03-27 + Details
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