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Mineral Property, Pland and Equipment (Net Value Carrying Values) (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | $ 2,813.3 | $ 2,753.4
Plant and Equipment [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 814.0 | 769.1
Mineral Property - Depletable [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 1,672.2 | 1,588.3
Mineral Property - Non-Depletable [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 90.7 | 75.4
Exploration and evaluation assets [member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 236.4 | 320.6
Operating segments [member] | Young-Davidson [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 1,444.3 | 1,432.0
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 | 608.9 | 589.5
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 | 744.7 | 767.1
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 | 90.7 | 75.4
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] | Mulatos [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 211.4 | 212.0
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 | 115.6 | 112.9
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 | 95.8 | 99.1
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 | 0.0 | 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] | Island Gold [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 800.1 | 774.9
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 | 79.5 | 54.8
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 | 720.6 | 720.1
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 | 0.0 | 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] | El Chanate [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 2.3 | 6.1
Operating segments [member] | El Chanate [Member] | Plant and Equipment [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 1.5 | 4.1
Operating segments [member] | El Chanate [Member] | Mineral Property - Depletable [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 0.8 | 2.0
Operating segments [member] | El Chanate [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
Operating segments [member] | El Chanate [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 | 113.5 |
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 | 3.2 |
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 | 110.3 |
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 | 241.7 | 328.4
Corporate and other [Member] | Plant and Equipment [Member] |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |
Mineral property, plant and equipment | 5.3 | 7.8
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 | $ 236.4 | $ 320.6

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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 2018-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=16&date=2018-03-01&anchor=para_73_e&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 54 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_54_a&doctype=Standard -URIDate 2018-03-16 + Details
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