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EXPLORATION AND EVALUATION ASSETS - Detailed information about exploration and evaluation assets (Details) - CAD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |
Beginning balance | $ 2,382 | $ 2,586
Additions | 159 | 29
Acquisition of AOSP and other assets (note 7) | 290 |
Transfers to property, plant and equipment | (198) | (211)
Disposals/derecognitions | (1) | (21)
Foreign exchange adjustments |  | (1)
Ending balance | 2,632 | 2,382
North America |  |
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |
Beginning balance | 2,306 | 2,500
Additions | 144 | 20
Acquisition of AOSP and other assets (note 7) | 31 |
Transfers to property, plant and equipment | (198) | (211)
Disposals/derecognitions | (1) | (3)
Foreign exchange adjustments |  | 0
Ending balance | 2,282 | 2,306
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 AOSP and other assets (note 7) | 0 |
Transfers to property, plant and equipment | 0 | 0
Disposals/derecognitions | 0 | 0
Foreign exchange adjustments |  | 0
Ending balance | 0 | 0
Offshore Africa |  |
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |
Beginning balance | 76 | 86
Additions | 15 | 9
Acquisition of AOSP and other assets (note 7) | 0 |
Transfers to property, plant and equipment | 0 | 0
Disposals/derecognitions | 0 | (18)
Foreign exchange adjustments |  | (1)
Ending balance | 91 | 76
Oil Sands Mining and Upgrading |  |
Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items] |  |
Beginning balance | 0 | 0
Additions | 0 | 0
Acquisition of AOSP and other assets (note 7) | 259 |
Transfers to property, plant and equipment | 0 | 0
Disposals/derecognitions | 0 | 0
Foreign exchange adjustments |  | 0
Ending balance | $ 259 | $ 0

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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 2017-01-01 -Paragraph 24 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=6&date=2017-03-01&anchor=para_24_b&doctype=Standard -URIDate 2017-03-09 + Details
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