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Financial Instruments and Risk Management (Currency Contracts) (Details) $ in Millions, $ in Millions, $ in Millions |  | 12 Months Ended |
--- | --- | --- | ---
Jan. 07, 2019 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2019 CAD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2019 MXN ($) | Dec. 31, 2019 $ / $ | Dec. 31, 2019 $ / $
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |  |
Gains (losses) on change in fair value of derivatives | $ 3.9 |  |  |  |  |  |  |
Collars and Forwards [Member] |  |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |  |
Financial assets, at fair value |  |  |  |  | $ 3.3 |  |  |
Financial liabilities, at fair value |  |  | $ 4.7 |  |  |  |  |
Gains (losses) on change in fair value of derivatives |  | $ 1.5 | $ (3.9) |  |  |  |  |
2019 [member] | Collars [Member] | Currency risk [member] |  |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |  |
Notional amount |  |  |  | $ 177.0 |  | $ 1,005.0 |  |
Bottom of range [member] | 2019 [member] | Collars [Member] | Currency risk [member] |  |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |  |
Average rate of hedging instrument |  |  |  |  |  |  | 1957.00% | 131.00%
Top of range [member] | 2019 [member] | Collars [Member] | Currency risk [member] |  |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |  |
Average rate of hedging instrument |  |  |  |  |  |  | 2212.00% | 135.00%

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- Definition The average rate of a hedging instrument. [Refer: Hedging instruments [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2019-01-01 -Paragraph 23B -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_23B_b&doctype=Standard -URIDate 2019-03-27 + 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 gains (losses) resulting from change in the fair value of derivatives recognised in profit or loss. [Refer: Derivatives [member]] + 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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