XML 81 R51.htm IDEA: XBRL DOCUMENT
v3.8.0.1

CRITICAL ACCOUNTING ESTIMATES AND JUDGEMENTS (Details) | Dec. 31, 2017
--- | ---
Bottom of range |
Disclosure of fair value measurement of assets [line items] |
Discount Rate Used In Current Measurement Of Higher Of Fair Value Less Costs Of Disposal Or Previous Estimate Of Value In Use | 10.00%
Top of range |
Disclosure of fair value measurement of assets [line items] |
Discount Rate Used In Current Measurement Of Higher Of Fair Value Less Costs Of Disposal Or Previous Estimate Of Value In Use | 12.00%

X
- Definition Discount Rate Used In Current Measurement Of Higher Of Fair Value Less Costs Of Disposal Or Previous Estimate Of Value In Use + References No definition available. + Details
Name: | cnq_DiscountRateUsedInCurrentMeasurementOfHigherOfFairValueLessCostsOfDisposalOrPreviousEstimateOfValueInUse
Namespace Prefix: | cnq_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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
Name: | ifrs-full_DisclosureOfFairValueMeasurementOfAssetsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |