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Financial Instruments and Risk Management (Fair Value And Presentation in the Balance Sheet) (Details) - Derivatives [member] - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018
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Disclosure of detailed information about financial instruments [line items] |  |
Financial assets, at fair value |  | $ (5.2)
Financial liabilities, at fair value | $ 3.3 |
Currency Hedging Derivative Instruments [Member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Financial assets, at fair value |  | (4.7)
Financial liabilities, at fair value | 3.3 |
Fuel Options [Member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Financial assets, at fair value |  | (0.5)
Financial liabilities, at fair value | 0.0 |
Gold Options [Member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Financial assets, at fair value |  | $ (0.1)
Financial liabilities, at fair value | $ (0.7) |

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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Definition The fair value of financial assets. [Refer: At fair value [member]; Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2019-01-01 -Paragraph 25 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_25&doctype=Standard -URIDate 2019-03-27 + Details
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- Definition The fair value of financial liabilities. [Refer: At fair value [member]; Financial liabilities] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2019-01-01 -Paragraph 25 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_25&doctype=Standard -URIDate 2019-03-27 + Details
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- Details
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