XML 103 R35.htm IDEA: XBRL DOCUMENT
v3.20.1

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

X
- Definition Disclosure Of Detailed Information About Exploration And Evaluation Assets Explanatory [Table Text Block] + References No definition available. + Details
Name: | cnq_DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatoryTableTextBlock
Namespace Prefix: | cnq_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exploration For And Evaluation Of Mineral Resources [Abstract] + References No definition available. + Details
Name: | cnq_ExplorationForAndEvaluationOfMineralResourcesAbstract
Namespace Prefix: | cnq_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration