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Mineral Property, Plant and Equipment (Net Value Carrying Values) (Details) $ in Millions | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2019 CAD ($)
--- | --- | --- | ---
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | $ 3,101.3 | $ 2,933.4 |
Plant and Equipment [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 888.7 | 750.9 |
Mineral Property - Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 1,909.0 | 1,824.4 |
Mineral Property - Non-Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 16.9 | 104.9 |
Exploration and evaluation assets [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 286.7 | 253.2 |
Operating segments [member] | Young-Davidson [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 1,507.5 | 1,467.2 |
Operating segments [member] | Young-Davidson [Member] | Plant and Equipment [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 684.7 | 555.3 |
Operating segments [member] | Young-Davidson [Member] | Mineral Property - Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 822.8 | 807.0 |
Operating segments [member] | Young-Davidson [Member] | Mineral Property - Non-Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 | 104.9 |
Operating segments [member] | Young-Davidson [Member] | Exploration and evaluation assets [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 | 0.0 |
Operating segments [member] | Island Gold [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 912.0 | 824.3 |
Operating segments [member] | Island Gold [Member] | Plant and Equipment [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 88.4 | 77.3 |
Operating segments [member] | Island Gold [Member] | Mineral Property - Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 818.7 | 747.0 |
Operating segments [member] | Island Gold [Member] | Mineral Property - Non-Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 4.9 | 0.0 |
Operating segments [member] | Island Gold [Member] | Exploration and evaluation assets [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 | 0.0 |
Operating segments [member] | Mulatos [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 246.5 | 245.8 |
Operating segments [member] | Mulatos [Member] | Plant and Equipment [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 107.8 | 109.7 |
Operating segments [member] | Mulatos [Member] | Mineral Property - Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 126.7 | 136.1 |
Operating segments [member] | Mulatos [Member] | Mineral Property - Non-Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 12.0 | 0.0 |
Operating segments [member] | Mulatos [Member] | Exploration and evaluation assets [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 | 0.0 |
Operating segments [member] | Kirazli Segment [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 141.1 |  | $ 134,600,000
Operating segments [member] | Kirazli Segment [Member] | Plant and Equipment [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.3 |  | 300,000
Operating segments [member] | Kirazli Segment [Member] | Mineral Property - Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 140.8 |  | $ 134,300,000
Operating segments [member] | Kirazli Segment [Member] | Mineral Property - Non-Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 |  |
Operating segments [member] | Kirazli Segment [Member] | Exploration and evaluation assets [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 |  |
Corporate and other [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 294.2 | 261.5 |
Corporate and other [Member] | Plant and Equipment [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 7.5 | 8.3 |
Corporate and other [Member] | Mineral Property - Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 | 0.0 |
Corporate and other [Member] | Mineral Property - Non-Depletable [Member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | 0.0 | 0.0 |
Corporate and other [Member] | Exploration and evaluation assets [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Mineral property, plant and equipment | $ 286.7 | $ 253.2 |

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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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 54 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_54_a&doctype=Standard -URIDate 2020-01-01 + Details
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