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Exploration and Evaluation Assets - Detailed information about exploration and evaluation assets (Details) - CAD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |  |
Beginning balance | $ 2,637 | $ 2,632 |
Additions | 71 | 502 |
Acquisition of Devon assets (note 7) | 91 |  |
Transfers to property, plant and equipment | (219) | (397) |
Disposals/derecognitions and other |  | (100) |
Foreign exchange adjustments | (1) |  |
Ending balance | 2,579 | 2,637 | $ 2,632
North America |  |  |
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |  |
Beginning balance | 2,348 | 2,282 |
Additions | 38 | 245 |
Acquisition of Devon assets (note 7) | 91 |  |
Transfers to property, plant and equipment | (219) | (175) |
Disposals/derecognitions and other |  | (4) | (1)
Foreign exchange adjustments | 0 |  |
Ending balance | 2,258 | 2,348 | 2,282
North Sea |  |  |
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |  |
Beginning balance | 0 | 0 |
Additions | 0 | 0 |
Acquisition of Devon assets (note 7) | 0 |  |
Transfers to property, plant and equipment | 0 | 0 |
Disposals/derecognitions and other |  | 0 |
Foreign exchange adjustments | 0 |  |
Ending balance | 0 | 0 | 0
Offshore Africa |  |  |
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |  |
Beginning balance | 37 | 91 |
Additions | 33 | 35 |
Acquisition of Devon assets (note 7) | 0 |  |
Transfers to property, plant and equipment | 0 | 0 |
Disposals/derecognitions and other |  | (89) |
Foreign exchange adjustments | (1) |  |
Ending balance | 69 | 37 | 91
Oil Sands Mining and Upgrading |  |  |
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |  |
Beginning balance | 252 | 259 |
Additions | 0 | 222 |
Acquisition of Devon assets (note 7) | 0 |  |
Transfers to property, plant and equipment | 0 | (222) |
Disposals/derecognitions and other |  | (7) |
Foreign exchange adjustments | 0 |  |
Ending balance | $ 252 | $ 252 | $ 259

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- Definition Acquisitions Through Business Combination, Exploration For And Evaluation Of Mineral Resources + References No definition available. + Details
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- Definition [Line Items] for Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Table] + References No definition available. + Details
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- Definition The amount of assets arising from the search for mineral resources, including minerals, oil, natural gas and similar non-regenerative resources after the entity has obtained legal rights to explore in a specific area, as well as the determination of the technical feasibility and commercial viability of extracting the mineral resource. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 6 -IssueDate 2019-01-01 -Paragraph 24 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=6&code=ifrs-tx-2019-en-r&anchor=para_24_b&doctype=Standard -URIDate 2019-03-27 + Details
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