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Commitments (Details) oz in Millions, $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Mar. 31, 2019 oz
Commitments [Line Items] |  |  |
Capital purchases commitments | $ 44.0 | $ 24.5 |
Royalty expense | 17.4 | 21.6 |
Royal Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Extraordinary mining duty tax | 1.0 | 1.2 |
Island Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty expense | 9.9 | 6.2 |
Production Royalty [Member] | Royal Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Quantity of production subject to royalty | oz |  |  | 0
Royalty expense | 2.1 | 10.6 |
Net Smelter Royalty [Member] | AuRico Metals [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty expense | $ 4.0 | 3.5 |
Royalty rate | 1.50% |  |
Net Smelter Royalty [Member] | Island Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty rate | 2.00% |  |
Net Smelter Royalty [Member] | Third Party [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty rate | 2.00% |  |
Other Royalties [Member] | AuRico Metals [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty expense | $ 0.4 | $ 0.1 |
Lochalsh [Member] | Net Smelter Royalty [Member] | Island Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty rate | 3.00% |  |
Goudreau [Member] | Net Smelter Royalty [Member] | Island Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty rate | 4.38% |  |
Goudreau [Member] | Net Profit Interest [Member] | Island Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty rate | 15.00% |  |
Goudreau Lake [Member] | Net Profit Interest [Member] | Island Gold [Member] |  |  |
Commitments [Line Items] |  |  |
Royalty rate | 10.38% |  |

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- Definition The amount of capital commitments for which the entity has entered into a contract. [Refer: Capital commitments] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard -URIDate 2019-03-27 + Details
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- Definition The amount of expense arising from royalties. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 85 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_85&doctype=Standard -URIDate 2019-03-27 + Details
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