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v3.19.1

Use of Judgements and Estimates (Narrative) (Details) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2018 $ / oz $ / T | Dec. 31, 2018 $ / oz $ / T
Disclosure Of Detailed Information About Use Of Judgements And Estimates Explanatory [line items] |  |
Discount rate (as percent) | 7.25% |
Gold Commodity Type [member] |  |
Disclosure Of Detailed Information About Use Of Judgements And Estimates Explanatory [line items] |  |
Long term prices used for reserves and resource estimates related to commodity | $ / oz |  | 1,320
Silver Commodity Type [member] |  |
Disclosure Of Detailed Information About Use Of Judgements And Estimates Explanatory [line items] |  |
Long term prices used for reserves and resource estimates related to commodity | $ / oz |  | 18.25
Lead Commodity [member] |  |
Disclosure Of Detailed Information About Use Of Judgements And Estimates Explanatory [line items] |  |
Long term prices used for reserves and resource estimates related to commodity | $ / T |  | 2,270
Zinc Commodity [member] |  |
Disclosure Of Detailed Information About Use Of Judgements And Estimates Explanatory [line items] |  |
Long term prices used for reserves and resource estimates related to commodity | $ / T |  | 2,750
Long-Term Gold Type [Member] |  |
Disclosure Of Detailed Information About Use Of Judgements And Estimates Explanatory [line items] |  |
Long term prices used for reserves and resource estimates related to commodity | $ / oz | 1,313 |
Copper Commodity Type [Member] |  |
Disclosure Of Detailed Information About Use Of Judgements And Estimates Explanatory [line items] |  |
Long term prices used for reserves and resource estimates related to commodity | $ / T | 7,391 |

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