{
 "instance": {
  "cnq-20211231.htm cnq-20211231_d2.htm": {
   "axisCustom": 3,
   "axisStandard": 33,
   "contextCount": 835,
   "dts": {
    "calculationLink": {
     "local": [
      "cnq-20211231_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "cnq-20211231_def.xml"
     ]
    },
    "inline": {
     "local": [
      "cnq-20211231.htm",
      "cnq-20211231_d2.htm"
     ]
    },
    "labelLink": {
     "local": [
      "cnq-20211231_lab.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "cnq-20211231_pre.xml"
     ]
    },
    "schema": {
     "local": [
      "cnq-20211231.xsd",
      "reference-2009-12-16.xsd"
     ],
     "remote": [
      "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xl-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xlink-2003-12-31.xsd",
      "http://www.xbrl.org/2005/xbrldt-2005.xsd",
      "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
      "http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd",
      "http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/net-2009-12-16.xsd",
      "http://xbrl.ifrs.org/taxonomy/2021-03-24/full_ifrs/full_ifrs-cor_2021-03-24.xsd",
      "https://www.xbrl.org/2020/extensible-enumerations-2.0.xsd",
      "https://www.xbrl.org/dtr/type/2020-01-21/types.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-roles-2021-01-31.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-types-2021-01-31.xsd",
      "https://xbrl.sec.gov/country/2021/country-2021.xsd",
      "https://xbrl.sec.gov/currency/2021/currency-2021.xsd",
      "https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd"
     ]
    }
   },
   "elementCount": 909,
   "entityCount": 1,
   "hidden": {
    "http://www.cnrl.com/20211231": 4,
    "http://xbrl.sec.gov/dei/2021q4": 9,
    "total": 13
   },
   "keyCustom": 204,
   "keyStandard": 337,
   "memberCustom": 121,
   "memberStandard": 50,
   "nsprefix": "cnq",
   "nsuri": "http://www.cnrl.com/20211231",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "true",
     "longName": "000010001 - Document - Cover Page",
     "role": "http://www.cnrl.com/role/CoverPage",
     "shortName": "Cover Page",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R10": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfChangesInAccountingPoliciesExplanatory",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210041002 - Disclosure - Changes in Accounting Policies",
     "role": "http://www.cnrl.com/role/ChangesinAccountingPolicies",
     "shortName": "Changes in Accounting Policies",
     "subGroupType": "",
     "uniqueAnchor": null
    },
    "R100": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:GainLossesOnChangeInFairValueOfSettledDerivatives",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240824047 - Disclosure - Financial Instruments - Net (Gains) Losses from Risk Management Activities (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsNetGainsLossesfromRiskManagementActivitiesDetails",
     "shortName": "Financial Instruments - Net (Gains) Losses from Risk Management Activities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R101": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:GainsLossesOnCashFlowHedgesNetOfTax",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240834048 - Disclosure - Financial Instruments - Foreign Currency Exchange Rate Risk Management (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
     "shortName": "Financial Instruments - Foreign Currency Exchange Rate Risk Management (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "iaa3c7a0d1ed04c8d812d30bb23b76fe1_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:NotionalAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R102": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:SensitivityAnalysisForEachTypeOfMarketRisk",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i1d0bdfd104634bf89654917f30b29e49_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnNetProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240844049 - Disclosure - Financial Instruments - Financial Instrument Sensitivities (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails",
     "shortName": "Financial Instruments - Financial Instrument Sensitivities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:SensitivityAnalysisForEachTypeOfMarketRisk",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i1d0bdfd104634bf89654917f30b29e49_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnNetProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R103": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ExpectedCreditLossRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240854050 - Disclosure - Financial Instruments - Counterparty Credit Risk Management (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails",
     "shortName": "Financial Instruments - Counterparty Credit Risk Management (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ExpectedCreditLossRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R104": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:TradeAndOtherCurrentPayablesToTradeSuppliers",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240864051 - Disclosure - Financial Instruments - Maturity Dates for Financial Liabilities (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
     "shortName": "Financial Instruments - Maturity Dates for Financial Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i6f495498e71e479c95e2944a369c247b_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:TradeAndOtherCurrentPayablesToTradeSuppliers",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R105": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ie462c8d8334442c1a37fc867e285c9fe_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CommitmentsForOilAndGasTransportationAndProcessing",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240894052 - Disclosure - Commitments and Contingencies (Details)",
     "role": "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
     "shortName": "Commitments and Contingencies (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ie462c8d8334442c1a37fc867e285c9fe_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CommitmentsForOilAndGasTransportationAndProcessing",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R106": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutCashFlowSupplementalDisclosuresTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:AdjustmentsForDecreaseIncreaseInTradeAccountReceivable",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240924053 - Disclosure - Supplemental Disclosure of Cash Flow Information - Supplemental Schedule Of Cash Flow Information (Details)",
     "role": "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails",
     "shortName": "Supplemental Disclosure of Cash Flow Information - Supplemental Schedule Of Cash Flow Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutCashFlowSupplementalDisclosuresTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:AdjustmentsForDecreaseIncreaseInTradeAccountReceivable",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R107": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:LiabilitiesArisingFromFinancingActivities",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240934054 - Disclosure - Supplemental Disclosure of Cash Flow Information - Liabilities Arising From Financing Activities (Details)",
     "role": "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails",
     "shortName": "Supplemental Disclosure of Cash Flow Information - Liabilities Arising From Financing Activities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "cnq:IncreaseDecreaseThroughFinancingCashFlowsProceedsPaymentsfromLongTermBorrowingsLiabilitiesArisingFromFinancingActivities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R108": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "cnq:NumberOfGeographicSegments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "segment",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240964055 - Disclosure - Segmented Information - Narrative (Details)",
     "role": "http://www.cnrl.com/role/SegmentedInformationNarrativeDetails",
     "shortName": "Segmented Information - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "cnq:NumberOfGeographicSegments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "segment",
      "xsiNil": "false"
     }
    },
    "R109": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:RevenueFromSaleOfOilAndGasProducts",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240974056 - Disclosure - Segmented Information - Operating Segments Earnings (Details)",
     "role": "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
     "shortName": "Segmented Information - Operating Segments Earnings (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ia6f2a619d1654cb69001c4cc705e9a4f_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:RoyaltyExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfChangesInAccountingPoliciesExplanatory",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210051003 - Disclosure - Accounting Standards Issued But Not Yet Applied",
     "role": "http://www.cnrl.com/role/AccountingStandardsIssuedButNotYetApplied",
     "shortName": "Accounting Standards Issued But Not Yet Applied",
     "subGroupType": "",
     "uniqueAnchor": null
    },
    "R110": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:NetExpendituresProceedsExplorationForAndEvaluationOfMineralResources",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240984057 - Disclosure - Segmented Information - Capital Expenditures (Details)",
     "role": "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
     "shortName": "Segmented Information - Capital Expenditures (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:NetExpendituresProceedsExplorationForAndEvaluationOfMineralResources",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R111": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:Assets",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240994058 - Disclosure - Segmented Information - Segmented Assets (Details)",
     "role": "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails",
     "shortName": "Segmented Information - Segmented Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i6f92387228e541aa82f0e6c2c8b6d659_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:Assets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R112": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "if042ae344a1a43a6a4cf949ab714889d_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:KeyManagementPersonnelCompensationShorttermEmployeeBenefits",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241024059 - Disclosure - Remuneration of Directors and Senior Management (Details)",
     "role": "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails",
     "shortName": "Remuneration of Directors and Senior Management (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "if042ae344a1a43a6a4cf949ab714889d_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:KeyManagementPersonnelCompensationShorttermEmployeeBenefits",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R113": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "cnq:DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "i37032380167d456d81182e2ed62368d7_D20210101-20211231",
      "decimals": "4",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:AverageForeignExchangeRate",
      "reportCount": 1,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241054060 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Twelve Month Average Benchmark Prices (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Twelve Month Average Benchmark Prices (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "cnq:DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "iabad72f2b1bb4a6b96139c95c3508407_D20210101-20211231",
      "decimals": "2",
      "lang": "en-US",
      "name": "cnq:TwelveMonthAverageBenchmarkPriceDollarsPerBbl",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usdPerBbl",
      "xsiNil": "false"
     }
    },
    "R114": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "srt:ScheduleOfProvedDevelopedAndUndevelopedOilAndGasReserveQuantitiesTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ib05c614c556c41b9958039ca97cdf612_I20201231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNet",
      "reportCount": 1,
      "unitRef": "mmbbls",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241064061 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Proved and Proved Developed Oil and Natural Gas Liquids, Net of Royalties (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Proved and Proved Developed Oil and Natural Gas Liquids, Net of Royalties (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "srt:ScheduleOfProvedDevelopedAndUndevelopedOilAndGasReserveQuantitiesTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "i843386b3b6a24bb8acb14209b8c0b0ba_I20181231",
      "decimals": "0",
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "mmbbls",
      "xsiNil": "false"
     }
    },
    "R115": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "if90a6cd79e134614ac6c436b1444fb25_D20210101-20211231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNetPeriodIncreaseDecrease",
      "reportCount": 1,
      "unique": true,
      "unitRef": "mmbbls",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241074062 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Oil and Natural Gas Liquids Narrative (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Oil and Natural Gas Liquids Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "if90a6cd79e134614ac6c436b1444fb25_D20210101-20211231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNetPeriodIncreaseDecrease",
      "reportCount": 1,
      "unique": true,
      "unitRef": "mmbbls",
      "xsiNil": "false"
     }
    },
    "R116": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic84a5788f0fb41f68206654c2427fdab_I20201231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNet",
      "reportCount": 1,
      "unitRef": "bcf",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241084063 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Proved and Proved Developed Natural Gas Reserve Quantities (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Proved and Proved Developed Natural Gas Reserve Quantities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "iea205b30e8fe43158cebfbdf2f75a4a5_I20181231",
      "decimals": "0",
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "bcf",
      "xsiNil": "false"
     }
    },
    "R117": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "i7051f53c0dac499db26328dc1c09bd7e_D20210101-20211231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNetPeriodIncreaseDecrease",
      "reportCount": 1,
      "unique": true,
      "unitRef": "bcf",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241094064 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Natural Gas Narrative (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Natural Gas Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "i7051f53c0dac499db26328dc1c09bd7e_D20210101-20211231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "srt:ProvedDevelopedAndUndevelopedReservesNetPeriodIncreaseDecrease",
      "reportCount": 1,
      "unique": true,
      "unitRef": "bcf",
      "xsiNil": "false"
     }
    },
    "R118": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:CapitalizedCostsRelatingToOilAndGasProducingActivitiesDisclosure1TableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CapitalizedCostsProvedProperties1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241104065 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Capitalized Costs Related to Crude Oil and Natural Gas Activities (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Capitalized Costs Related to Crude Oil and Natural Gas Activities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:CapitalizedCostsRelatingToOilAndGasProducingActivitiesDisclosure1TableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CapitalizedCostsProvedProperties1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R119": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutCostsIncurredInCrudeOilAndNaturalGasActivitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241114066 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Costs Incurred in Crude Oil and Natural Gas Activities (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Costs Incurred in Crude Oil and Natural Gas Activities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutCostsIncurredInCrudeOilAndNaturalGasActivitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "cnq:DescriptionOfManagementJudgementsInApplyingEntitysAccountingPoliciesWithSignificantEffectOnRecognisedAmountPolicyTextBlock",
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfAccountingJudgementsAndEstimatesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210061004 - Disclosure - Critical Accounting Estimates and Judgements",
     "role": "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgements",
     "shortName": "Critical Accounting Estimates and Judgements",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "cnq:DescriptionOfManagementJudgementsInApplyingEntitysAccountingPoliciesWithSignificantEffectOnRecognisedAmountPolicyTextBlock",
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfAccountingJudgementsAndEstimatesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R120": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:Revenue",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241124067 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Results of Operations from Crude Oil and Natural Gas Producing Activities (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Results of Operations from Crude Oil and Natural Gas Producing Activities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutResultsOfOperationsFromCrudeOilAndNaturalGasActivitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "i3697cacc39d6427298c36ce725a51210_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:Revenue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R121": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "srt:FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241134068 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Future Net Cash Flows Relating to Proved Crude Oil and Natural Gas Reserves (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Future Net Cash Flows Relating to Proved Crude Oil and Natural Gas Reserves (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "srt:FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R122": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "srt:ScheduleOfChangesInStandardizedMeasureOfDiscountedFutureNetCashFlowsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "srt:SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241144069 - Disclosure - Supplementary Oil And Gas Information (Unaudited) - Sources of Change in the Standardized Measure of Discounted Future Net Cash Flows (Details)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) - Sources of Change in the Standardized Measure of Discounted Future Net Cash Flows (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "srt:ScheduleOfChangesInStandardizedMeasureOfDiscountedFutureNetCashFlowsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "srt:SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfInventoriesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210081005 - Disclosure - Inventory",
     "role": "http://www.cnrl.com/role/Inventory",
     "shortName": "Inventory",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfInventoriesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfExplorationAndEvaluationAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210111006 - Disclosure - Exploration and Evaluation Assets",
     "role": "http://www.cnrl.com/role/ExplorationandEvaluationAssets",
     "shortName": "Exploration and Evaluation Assets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfExplorationAndEvaluationAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfPropertyPlantAndEquipmentExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210151007 - Disclosure - Property, Plant and Equipment",
     "role": "http://www.cnrl.com/role/PropertyPlantandEquipment",
     "shortName": "Property, Plant and Equipment",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfPropertyPlantAndEquipmentExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R16": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfLeasesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210201008 - Disclosure - Leases",
     "role": "http://www.cnrl.com/role/Leases",
     "shortName": "Leases",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfLeasesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210251009 - Disclosure - Investments",
     "role": "http://www.cnrl.com/role/Investments",
     "shortName": "Investments",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfOtherNoncurrentAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210311010 - Disclosure - Other Long-Term Assets",
     "role": "http://www.cnrl.com/role/OtherLongTermAssets",
     "shortName": "Other Long-Term Assets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfOtherNoncurrentAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfBorrowingsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210371011 - Disclosure - Long-Term Debt",
     "role": "http://www.cnrl.com/role/LongTermDebt",
     "shortName": "Long-Term Debt",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfBorrowingsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:AuditorFirmId",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "false",
     "longName": "000020002 - Document - Audit Information",
     "role": "http://www.cnrl.com/role/AuditInformation",
     "shortName": "Audit Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:AuditorFirmId",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfOtherNoncurrentLiabilitiesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210411012 - Disclosure - Other Long-Term Liabilities",
     "role": "http://www.cnrl.com/role/OtherLongTermLiabilities",
     "shortName": "Other Long-Term Liabilities",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfOtherNoncurrentLiabilitiesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfIncomeTaxExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210481013 - Disclosure - Income Taxes",
     "role": "http://www.cnrl.com/role/IncomeTaxes",
     "shortName": "Income Taxes",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfIncomeTaxExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfIssuedCapitalExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210561014 - Disclosure - Share Capital",
     "role": "http://www.cnrl.com/role/ShareCapital",
     "shortName": "Share Capital",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfIssuedCapitalExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfAnalysisOfOtherComprehensiveIncomeByItemExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210621015 - Disclosure - Accumulated Other Comprehensive (Loss) Income",
     "role": "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncome",
     "shortName": "Accumulated Other Comprehensive (Loss) Income",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfAnalysisOfOtherComprehensiveIncomeByItemExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210651016 - Disclosure - Capital Disclosures",
     "role": "http://www.cnrl.com/role/CapitalDisclosures",
     "shortName": "Capital Disclosures",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfEarningsPerShareExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210691017 - Disclosure - Net Earnings Per Common Share",
     "role": "http://www.cnrl.com/role/NetEarningsPerCommonShare",
     "shortName": "Net Earnings Per Common Share",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfEarningsPerShareExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfFinanceIncomeExpenseExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210731018 - Disclosure - Interest and Other Financing Expense",
     "role": "http://www.cnrl.com/role/InterestandOtherFinancingExpense",
     "shortName": "Interest and Other Financing Expense",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfFinanceIncomeExpenseExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfFinancialInstrumentsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210761019 - Disclosure - Financial Instruments",
     "role": "http://www.cnrl.com/role/FinancialInstruments",
     "shortName": "Financial Instruments",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfFinancialInstrumentsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210871020 - Disclosure - Commitments and Contingencies",
     "role": "http://www.cnrl.com/role/CommitmentsandContingencies",
     "shortName": "Commitments and Contingencies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfCashFlowStatementExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210901021 - Disclosure - Supplemental Disclosure of Cash Flow Information",
     "role": "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformation",
     "shortName": "Supplemental Disclosure of Cash Flow Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfCashFlowStatementExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CashAndCashEquivalents",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100010003 - Statement - Consolidated Balance Sheets",
     "role": "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
     "shortName": "Consolidated Balance Sheets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:CurrentTradeReceivables",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfEntitysReportableSegmentsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210941022 - Disclosure - Segmented Information",
     "role": "http://www.cnrl.com/role/SegmentedInformation",
     "shortName": "Segmented Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfEntitysReportableSegmentsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfInformationAboutKeyManagementPersonnelExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211001023 - Disclosure - Remuneration of Directors and Senior Management",
     "role": "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagement",
     "shortName": "Remuneration of Directors and Senior Management",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfInformationAboutKeyManagementPersonnelExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211031024 - Disclosure - Supplementary Oil And Gas Information (Unaudited)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnaudited",
     "shortName": "Supplementary Oil And Gas Information (Unaudited)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:StatementOfIFRSCompliance",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "220022001 - Disclosure - Accounting Policies (Policies)",
     "role": "http://www.cnrl.com/role/AccountingPoliciesPolicies",
     "shortName": "Accounting Policies (Policies)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:StatementOfIFRSCompliance",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutInventoriesExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230093001 - Disclosure - Inventory (Tables)",
     "role": "http://www.cnrl.com/role/InventoryTables",
     "shortName": "Inventory (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutInventoriesExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230123002 - Disclosure - Exploration and Evaluation Assets (Tables)",
     "role": "http://www.cnrl.com/role/ExplorationandEvaluationAssetsTables",
     "shortName": "Exploration and Evaluation Assets (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230163003 - Disclosure - Property, Plant and Equipment (Tables)",
     "role": "http://www.cnrl.com/role/PropertyPlantandEquipmentTables",
     "shortName": "Property, Plant and Equipment (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfQuantitativeInformationAboutRightofuseAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230213004 - Disclosure - Leases (Tables)",
     "role": "http://www.cnrl.com/role/LeasesTables",
     "shortName": "Leases (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfQuantitativeInformationAboutRightofuseAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230263005 - Disclosure - Investments (Tables)",
     "role": "http://www.cnrl.com/role/InvestmentsTables",
     "shortName": "Investments (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfInformationAboutOtherNonCurrentAssetsExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230323006 - Disclosure - Other Long-Term Assets (Tables)",
     "role": "http://www.cnrl.com/role/OtherLongTermAssetsTables",
     "shortName": "Other Long-Term Assets (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfInformationAboutOtherNonCurrentAssetsExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:RevenueFromSaleOfOilAndGasProducts",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100020004 - Statement - Consolidated Statements of Earnings (Loss)",
     "role": "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
     "shortName": "Consolidated Statements of Earnings (Loss)",
     "subGroupType": "",
     "uniqueAnchor": null
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230363007 - Disclosure - Long-Term Debt (Tables)",
     "role": "http://www.cnrl.com/role/LongTermDebtTables",
     "shortName": "Long-Term Debt (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230423008 - Disclosure - Other Long-Term Liabilities (Tables)",
     "role": "http://www.cnrl.com/role/OtherLongTermLiabilitiesTables",
     "shortName": "Other Long-Term Liabilities (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfMajorComponentsOfTaxExpenseIncomeTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230493009 - Disclosure - Income Taxes (Tables)",
     "role": "http://www.cnrl.com/role/IncomeTaxesTables",
     "shortName": "Income Taxes (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfMajorComponentsOfTaxExpenseIncomeTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfClassesOfShareCapitalExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230573010 - Disclosure - Share Capital (Tables)",
     "role": "http://www.cnrl.com/role/ShareCapitalTables",
     "shortName": "Share Capital (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfClassesOfShareCapitalExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutAccumulatedOtherComprehensiveIncomeExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230633011 - Disclosure - Accumulated Other Comprehensive (Loss) Income (Tables)",
     "role": "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeTables",
     "shortName": "Accumulated Other Comprehensive (Loss) Income (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutAccumulatedOtherComprehensiveIncomeExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutCapitalExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230663012 - Disclosure - Capital Disclosures (Tables)",
     "role": "http://www.cnrl.com/role/CapitalDisclosuresTables",
     "shortName": "Capital Disclosures (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutCapitalExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:EarningsPerShareExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230703013 - Disclosure - Net Earnings Per Common Share (Tables)",
     "role": "http://www.cnrl.com/role/NetEarningsPerCommonShareTables",
     "shortName": "Net Earnings Per Common Share (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:EarningsPerShareExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R47": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutFinanceIncomeCostExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230743014 - Disclosure - Interest and Other Financing Expense (Tables)",
     "role": "http://www.cnrl.com/role/InterestandOtherFinancingExpenseTables",
     "shortName": "Interest and Other Financing Expense (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutFinanceIncomeCostExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R48": {
     "firstAnchor": {
      "ancestors": [
       "ifrs-full:DisclosureOfFinancialLiabilitiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfFinancialAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230773015 - Disclosure - Financial Instruments (Tables)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsTables",
     "shortName": "Financial Instruments (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ifrs-full:DisclosureOfFinancialLiabilitiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfFinancialAssetsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R49": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutCommitmentsAndContingenciesExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230883016 - Disclosure - Commitments and Contingencies (Tables)",
     "role": "http://www.cnrl.com/role/CommitmentsandContingenciesTables",
     "shortName": "Commitments and Contingencies (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutCommitmentsAndContingenciesExplanatoryTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:EarningsPerShareExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ProfitLoss",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100030005 - Statement - Consolidated Statements of Comprehensive Income (Loss)",
     "role": "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss",
     "shortName": "Consolidated Statements of Comprehensive Income (Loss)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:ReclassificationAdjustmentsOnCashFlowHedgesNetOfTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R50": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutCashFlowSupplementalDisclosuresTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230913017 - Disclosure - Supplemental Disclosure of Cash Flow Information (Tables)",
     "role": "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationTables",
     "shortName": "Supplemental Disclosure of Cash Flow Information (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DisclosureOfDetailedInformationAboutCashFlowSupplementalDisclosuresTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R51": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfOperatingSegmentsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230953018 - Disclosure - Segmented Information (Tables)",
     "role": "http://www.cnrl.com/role/SegmentedInformationTables",
     "shortName": "Segmented Information (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfOperatingSegmentsExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R52": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231013019 - Disclosure - Remuneration of Directors and Senior Management (Tables)",
     "role": "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementTables",
     "shortName": "Remuneration of Directors and Senior Management (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R53": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "cnq:DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:ScheduleofTwelveMonthAverageBenchmarkPricesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231043020 - Disclosure - Supplementary Oil And Gas Information (Unaudited) (Tables)",
     "role": "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables",
     "shortName": "Supplementary Oil And Gas Information (Unaudited) (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "cnq:DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231_d2.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:ScheduleofTwelveMonthAverageBenchmarkPricesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R54": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ie9b96f726dc540b9a18b5a05b6571108_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:UsefulLivesOrDepreciationRatesPropertyPlantAndEquipmentPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240034001 - Disclosure - Accounting Policies - Narrative (Details)",
     "role": "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
     "shortName": "Accounting Policies - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ie9b96f726dc540b9a18b5a05b6571108_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:UsefulLivesOrDepreciationRatesPropertyPlantAndEquipmentPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R55": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i9581eaf4dd5b44209ea8c85180e902f0_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "cnq:DiscountRateUsedInCurrentMeasurementOfHigherOfFairValueLessCostsOfDisposalOrPreviousEstimateOfValueInUse",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240074002 - Disclosure - Critical Accounting Estimates and Judgements - Narrative (Details)",
     "role": "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails",
     "shortName": "Critical Accounting Estimates and Judgements - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i9581eaf4dd5b44209ea8c85180e902f0_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "cnq:DiscountRateUsedInCurrentMeasurementOfHigherOfFairValueLessCostsOfDisposalOrPreviousEstimateOfValueInUse",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R56": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutInventoriesExplanatoryTableTextBlock",
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CurrentCrudeOil",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240104003 - Disclosure - Inventory - Schedule of Inventory (Details)",
     "role": "http://www.cnrl.com/role/InventoryScheduleofInventoryDetails",
     "shortName": "Inventory - Schedule of Inventory (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutInventoriesExplanatoryTableTextBlock",
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CurrentCrudeOil",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R57": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatoryTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:AssetsArisingFromExplorationForAndEvaluationOfMineralResources",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240134004 - Disclosure - Exploration and Evaluation Assets - Detailed information about exploration and evaluation assets (Details)",
     "role": "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
     "shortName": "Exploration and Evaluation Assets - Detailed information about exploration and evaluation assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatoryTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "idcfec93b56df483ba4d0efb29c92603c_I20191231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:AssetsArisingFromExplorationForAndEvaluationOfMineralResources",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R58": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i26d2ca9232b7481bb036fa1d6c5e4e12_I20211217",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CashTransferred",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240144005 - Disclosure - Exploration and Evaluation Assets - Narrative (Details)",
     "role": "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
     "shortName": "Exploration and Evaluation Assets - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R59": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:PropertyPlantAndEquipment",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240174006 - Disclosure - Property, Plant and Equipment - Detailed information about property, plant and equipment (Details)",
     "role": "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
     "shortName": "Property, Plant and Equipment - Detailed information about property, plant and equipment (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ideb788b14e5e40ca853b6ff90d0c3f81_I20191231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:PropertyPlantAndEquipment",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:IncomeTaxRelatingToGainsLossesOnCashFlowHedgesOfOtherComprehensiveIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100040006 - Statement - Consolidated Statements of Comprehensive Income (Loss) (Parenthetical)",
     "role": "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLossParenthetical",
     "shortName": "Consolidated Statements of Comprehensive Income (Loss) (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:IncomeTaxRelatingToGainsLossesOnCashFlowHedgesOfOtherComprehensiveIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R60": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:BorrowingCostsCapitalised",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240184007 - Disclosure - Property, Plant and Equipment - Narrative (Details)",
     "role": "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
     "shortName": "Property, Plant and Equipment - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i5d69a6b0b6ae4f468ff83522a669eeef_D20200101-20201231",
      "decimals": "3",
      "lang": "en-US",
      "name": "ifrs-full:CapitalisationRateOfBorrowingCostsEligibleForCapitalisation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R61": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i26d2ca9232b7481bb036fa1d6c5e4e12_I20211217",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:PropertyPlantAndEquipmentRecognisedAsOfAcquisitionDate",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240194008 - Disclosure - Property, Plant and Equipment - Summary of Net Assets Acquired and Liablities Assumed (Details)",
     "role": "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails",
     "shortName": "Property, Plant and Equipment - Summary of Net Assets Acquired and Liablities Assumed (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i26d2ca9232b7481bb036fa1d6c5e4e12_I20211217",
      "decimals": "-6",
      "lang": "en-US",
      "name": "cnq:NetWorkingCapitalLiabilitiesRecognisedAsOfAcquisitionDate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R62": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:RightofuseAssets",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240224009 - Disclosure - Leases - Lease Assets (Details)",
     "role": "http://www.cnrl.com/role/LeasesLeaseAssetsDetails",
     "shortName": "Leases - Lease Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:DisclosureOfQuantitativeInformationAboutRightofuseAssetsExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:AdditionsToRightofuseAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R63": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:DisclosureOfQuantitativeInformationAboutRightofuseAssetsExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:RightofuseAssets",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240234010 - Disclosure - Leases - Lease Assets by Segment (Details)",
     "role": "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
     "shortName": "Leases - Lease Assets by Segment (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ib93ddbfbe8f34f48bccd142a73eeb6ea_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:RightofuseAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R64": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:LeaseLiabilities",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240244011 - Disclosure - Leases - Lease Liabilities and Expense (Details)",
     "role": "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails",
     "shortName": "Leases - Lease Liabilities and Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:CurrentLeaseLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R65": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CurrentInvestments",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240274012 - Disclosure - Investments - Summary of Investments (Details)",
     "role": "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails",
     "shortName": "Investments - Summary of Investments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ie09ac0fcae1748ed9040d66f8c560178_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:CurrentInvestments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R66": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ie09ac0fcae1748ed9040d66f8c560178_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CurrentInvestmentsNumberOfSharesHeld",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240284013 - Disclosure - Investments - Narrative (Details)",
     "role": "http://www.cnrl.com/role/InvestmentsNarrativeDetails",
     "shortName": "Investments - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ie09ac0fcae1748ed9040d66f8c560178_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CurrentInvestmentsNumberOfSharesHeld",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R67": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:GainsLossesOnInvestments",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240294014 - Disclosure - Investments - PrairieSky (Details)",
     "role": "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails",
     "shortName": "Investments - PrairieSky (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i7bef0e0eaf534aa4a92db132cbd387ac_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R68": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:GainsLossesOnInvestments",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240304015 - Disclosure - Investments - Inter Pipeline (Details)",
     "role": "http://www.cnrl.com/role/InvestmentsInterPipelineDetails",
     "shortName": "Investments - Inter Pipeline (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "if571e9ef785a447cba8f531b3e1c4892_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R69": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfInformationAboutOtherNonCurrentAssetsExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DebtInstrumentsHeld",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240334016 - Disclosure - Other Long-Term Assets - Schedule of other long-term assets (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails",
     "shortName": "Other Long-Term Assets - Schedule of other long-term assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfInformationAboutOtherNonCurrentAssetsExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DebtInstrumentsHeld",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ia39a9f8a0843412aa014707740cbfe35_I20181231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:Equity",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100050007 - Statement - Consolidated Statements of Changes in Equity",
     "role": "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
     "shortName": "Consolidated Statements of Changes in Equity",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i285c8e04ec47477c9a3cc9fc55e1c4f5_I20181231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:Equity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R70": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "cnq:TollPayerPercentForOthers",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240344017 - Disclosure - Other Long-Term Assets - Narrative (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
     "shortName": "Other Long-Term Assets - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "cnq:TollPayerPercentForOthers",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R71": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CurrentAssets",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240354018 - Disclosure - Other Long-Term Assets - Summary of Assets, Liabilities, Partners' Equity and Equity (Income) Loss (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails",
     "shortName": "Other Long-Term Assets - Summary of Assets, Liabilities, Partners' Equity and Equity (Income) Loss (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfInterestsInJointArrangementsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic74d5560e81f4e6c8cfeb31d75b92d58_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:Equity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R72": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:Borrowings",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240384019 - Disclosure - Long-Term Debt - Summary of Long-term Debt (Details)",
     "role": "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
     "shortName": "Long-Term Debt - Summary of Long-term Debt (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:ShorttermBorrowings",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R73": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:RepaymentsOfBorrowingsClassifiedAsFinancingActivities",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240394020 - Disclosure - Long-Term Debt - Narrative (Details)",
     "role": "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
     "shortName": "Long-Term Debt - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "cnq:LettersOfCreditAndGuaranteesOutstandingAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R74": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:Borrowings",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240404021 - Disclosure - Long-Term Debt - Schedule of Debt Repayments (Details)",
     "role": "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails",
     "shortName": "Long-Term Debt - Schedule of Debt Repayments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:MaturityAnalysisForNonderivativeFinancialLiabilities",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i35b7b8fcf7a34608ad8abc3e489e80ae_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:Borrowings",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R75": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ProvisionForDecommissioningRestorationAndRehabilitationCosts",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240434022 - Disclosure - Other Long-Term Liabilities - Schedule of Other Long-Term Liabilities (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails",
     "shortName": "Other Long-Term Liabilities - Schedule of Other Long-Term Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:DerivativeFinancialLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R76": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DecommissioningRestorationAndRehabilitationLiabilitiesPeriodOfAccretion",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240444023 - Disclosure - Other Long-Term Liabilities - Asset Retirement Obligations (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails",
     "shortName": "Other Long-Term Liabilities - Asset Retirement Obligations (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "cnq:DecommissioningRestorationAndRehabilitationLiabilitiesPeriodOfAccretion",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R77": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ProvisionForDecommissioningRestorationAndRehabilitationCosts",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240454024 - Disclosure - Other Long-Term Liabilities - Segmented Asset Retirement Obligations (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
     "shortName": "Other Long-Term Liabilities - Segmented Asset Retirement Obligations (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i455d8384b43648578b1e24475aa471f2_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:ProvisionForDecommissioningRestorationAndRehabilitationCosts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R78": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:LiabilitiesFromSharebasedPaymentTransactions2011",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240464025 - Disclosure - Other Long-Term Liabilities - Share-Based Compensation (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails",
     "shortName": "Other Long-Term Liabilities - Share-Based Compensation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:PaymentsOfOtherEquityInstruments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R79": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfIndirectMeasurementOfFairValueOfGoodsOrServicesReceivedShareOptionsGrantedDuringPeriodExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:WeightedAverageFairValueAtMeasurementDateShareOptionsGranted",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240474026 - Disclosure - Other Long-Term Liabilities - Weighted Average Assumptions Used to Calculate Share-Based Compensation Liability (Details)",
     "role": "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails",
     "shortName": "Other Long-Term Liabilities - Weighted Average Assumptions Used to Calculate Share-Based Compensation Liability (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfIndirectMeasurementOfFairValueOfGoodsOrServicesReceivedShareOptionsGrantedDuringPeriodExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:WeightedAverageFairValueAtMeasurementDateShareOptionsGranted",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:EarningsPerShareExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ProfitLoss",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100060008 - Statement - Consolidated Statements of Cash Flows",
     "role": "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
     "shortName": "Consolidated Statements of Cash Flows",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:AdjustmentsForDepreciationAndAmortisationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R80": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfMajorComponentsOfTaxExpenseIncomeTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CurrentOtherTaxExpenseIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240504027 - Disclosure - Income Taxes - Schedule Of Provision For Income Tax (Details)",
     "role": "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
     "shortName": "Income Taxes - Schedule Of Provision For Income Tax (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfMajorComponentsOfTaxExpenseIncomeTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:CurrentOtherTaxExpenseIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R81": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAndAverageEffectiveTaxRateTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ApplicableTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240514028 - Disclosure - Income Taxes - Schedule of Provision For Income Tax Rate Reconciliation (Details)",
     "role": "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails",
     "shortName": "Income Taxes - Schedule of Provision For Income Tax Rate Reconciliation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAndAverageEffectiveTaxRateTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:ApplicableTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R82": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DeferredTaxLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240524029 - Disclosure - Income Taxes - Summary of Major Temporary Differences (Details)",
     "role": "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
     "shortName": "Income Taxes - Summary of Major Temporary Differences (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DeferredTaxLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R83": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DeferredTaxExpenseIncomeRecognisedInProfitOrLoss",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240534030 - Disclosure - Income Taxes - Summary of Movements in Deferred Tax Assets and Liabilities (Details)",
     "role": "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails",
     "shortName": "Income Taxes - Summary of Movements in Deferred Tax Assets and Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i5a3a04186e2a431983ad56cabb5fca4c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:DeferredTaxExpenseIncomeRecognisedInProfitOrLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R84": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DeferredTaxLiabilityAsset",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240544031 - Disclosure - Income Taxes - Summary of Net Deferred Income Tax Liability (Details)",
     "role": "http://www.cnrl.com/role/IncomeTaxesSummaryofNetDeferredIncomeTaxLiabilityDetails",
     "shortName": "Income Taxes - Summary of Net Deferred Income Tax Liability (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R85": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i77ca7a4819e848eb8f6112c9268d894f_D20220101-20220101",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "cnq:ProvincialCorporateIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240554032 - Disclosure - Income Taxes - Narrative (Details)",
     "role": "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
     "shortName": "Income Taxes - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i77ca7a4819e848eb8f6112c9268d894f_D20220101-20220101",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "cnq:ProvincialCorporateIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R86": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:Equity",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240584033 - Disclosure - Share Capital - Outstanding Common Shares (Details)",
     "role": "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails",
     "shortName": "Share Capital - Outstanding Common Shares (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:DisclosureOfClassesOfShareCapitalExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ib0c29c07149c43bda380af45cd5718cf_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "ifrs-full:NumberOfShareOptionsExercisedInSharebasedPaymentArrangement",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R87": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i09cd054b3ec94900ab054939f0af7ba5_D20220302-20220302",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "cnq:PercentageOfDividendIncreasedFromPreviousQuarterlyDividend",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240594034 - Disclosure - Share Capital - Narrative (Details)",
     "role": "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
     "shortName": "Share Capital - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i09cd054b3ec94900ab054939f0af7ba5_D20220302-20220302",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "cnq:PercentageOfDividendIncreasedFromPreviousQuarterlyDividend",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R88": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfNumberAndWeightedAverageExercisePricesOfShareOptionsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:NumberOfOutstandingShareOptions",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240604035 - Disclosure - Share Capital - Stock Option Activity (Details)",
     "role": "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails",
     "shortName": "Share Capital - Stock Option Activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfNumberAndWeightedAverageExercisePricesOfShareOptionsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "ifrs-full:NumberOfShareOptionsGrantedInSharebasedPaymentArrangement",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R89": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfNumberAndWeightedAverageExercisePricesOfShareOptionsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:NumberOfOutstandingShareOptions",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240614036 - Disclosure - Share Capital - Range of Exercise Prices of Stock Options (Details)",
     "role": "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails",
     "shortName": "Share Capital - Range of Exercise Prices of Stock Options (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "lang": "en-US",
      "name": "ifrs-full:WeightedAverageRemainingContractualLifeOfOutstandingShareOptions2019",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfSummaryOfSignificantAccountingPoliciesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210011001 - Disclosure - Accounting Policies",
     "role": "http://www.cnrl.com/role/AccountingPolicies",
     "shortName": "Accounting Policies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:DisclosureOfSummaryOfSignificantAccountingPoliciesExplanatory",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R90": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutAccumulatedOtherComprehensiveIncomeExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:AccumulatedOtherComprehensiveIncomeNetOfTaxDerivativeInstrumentsDesignatedAsCashFlowHedges",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240644037 - Disclosure - Accumulated Other Comprehensive (Loss) Income (Details)",
     "role": "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeDetails",
     "shortName": "Accumulated Other Comprehensive (Loss) Income (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "cnq:DisclosureOfDetailedInformationAboutAccumulatedOtherComprehensiveIncomeExplanatoryTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:AccumulatedOtherComprehensiveIncomeNetOfTaxDerivativeInstrumentsDesignatedAsCashFlowHedges",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R91": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutCapitalExplanatoryTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "cnq:DebtToBookCapitalizationRatio",
      "reportCount": 1,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240674038 - Disclosure - Capital Disclosures - Narrative (Details)",
     "role": "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails",
     "shortName": "Capital Disclosures - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i9581eaf4dd5b44209ea8c85180e902f0_I20211231",
      "decimals": "2",
      "lang": "en-US",
      "name": "cnq:DebtToBookCapitalizationRatio",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R92": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:Borrowings",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240684039 - Disclosure - Capital Disclosures - Schedule of Debt to Book Capitalization Ratio (Details)",
     "role": "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails",
     "shortName": "Capital Disclosures - Schedule of Debt to Book Capitalization Ratio (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutCapitalExplanatoryTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "cnq:BorrowingsNetOfCashAndCashEquivalents",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R93": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:EarningsPerShareExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:WeightedAverageShares",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240714040 - Disclosure - Net Earnings Per Common Share - Schedule of Basic and Diluted Net Earnings (Loss) per Common Share (Details)",
     "role": "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails",
     "shortName": "Net Earnings Per Common Share - Schedule of Basic and Diluted Net Earnings (Loss) per Common Share (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ifrs-full:EarningsPerShareExplanatory",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:WeightedAverageShares",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R94": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "cnq:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240724041 - Disclosure - Net Earnings Per Common Share - Narrative (Details)",
     "role": "http://www.cnrl.com/role/NetEarningsPerCommonShareNarrativeDetails",
     "shortName": "Net Earnings Per Common Share - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "cnq:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R95": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutFinanceIncomeCostExplanatoryTableTextBlock",
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:InterestExpenseOnBorrowings",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240754042 - Disclosure - Interest and Other Financing Expense (Details)",
     "role": "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails",
     "shortName": "Interest and Other Financing Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "cnq:DisclosureOfDetailedInformationAboutFinanceIncomeCostExplanatoryTableTextBlock",
       "ix:continuation",
       "div",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:InterestExpenseOnBorrowings",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R96": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfFinancialAssetsExplanatory",
       "ifrs-full:DisclosureOfFinancialLiabilitiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:FinancialAssetsAtAmortisedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240784043 - Disclosure - Financial Instruments - Carrying Amounts of Financial Instruments by Category (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails",
     "shortName": "Financial Instruments - Carrying Amounts of Financial Instruments by Category (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfFinancialAssetsExplanatory",
       "ifrs-full:DisclosureOfFinancialLiabilitiesExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:FinancialAssetsAtAmortisedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R97": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ia73bd858dcb84629b8d45c43c164a546_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:FinancialLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240794044 - Disclosure - Financial Instruments - Carrying Amounts and Fair Values of Financial Instruments (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
     "shortName": "Financial Instruments - Carrying Amounts and Fair Values of Financial Instruments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ia73bd858dcb84629b8d45c43c164a546_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:FinancialLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R98": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfDetailedInformationAboutFinancialInstrumentsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CurrentDerivativeFinancialAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240804045 - Disclosure - Financial Instruments - Carrying Amounts and Reconciliation of Derivative Financial Instruments (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
     "shortName": "Financial Instruments - Carrying Amounts and Reconciliation of Derivative Financial Instruments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfDetailedInformationAboutFinancialInstrumentsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ibd1b2ad9ca2c49279ce4925837475030_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "ifrs-full:CurrentDerivativeFinancialAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    },
    "R99": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ifrs-full:DisclosureOfDetailedInformationAboutFinancialInstrumentsExplanatory",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "i79da1927cdf3430c833a0939bcdd8c92_I20201231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "cnq:DerivativeFinancialAssetsLiabilitiesNet",
      "reportCount": 1,
      "unitRef": "cad",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240814046 - Disclosure - Financial Instruments - Estimated Fair Values of Derivative Financial Instruments Included in Risk Management Asset (Details)",
     "role": "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails",
     "shortName": "Financial Instruments - Estimated Fair Values of Derivative Financial Instruments Included in Risk Management Asset (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "cnq-20211231.htm",
      "contextRef": "ic10bd32acc24409d8e89bad42a1f3c9c_D20210101-20211231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "cnq:GainLossesOnChangeInFairValueOfUnsettledDerivativesIncludingFairValueMovementOfCommodityFinancialInstruments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "cad",
      "xsiNil": "false"
     }
    }
   },
   "segmentCount": 177,
   "tag": {
    "cnq_AccrualClassifiedAsCurrentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accrual Classified As Current [Member]",
        "label": "Accrual Classified As Current [Member]",
        "terseLabel": "Accrued liabilities"
       }
      }
     },
     "localname": "AccrualClassifiedAsCurrentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_AccruedLiabilitiesAsOfAcquisitionDate": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 11.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accrued Liabilities As Of Acquisition Date",
        "label": "Accrued Liabilities As Of Acquisition Date",
        "negatedTerseLabel": "Accrued liabilities"
       }
      }
     },
     "localname": "AccruedLiabilitiesAsOfAcquisitionDate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AccumulatedOtherComprehensiveIncomeNetOfTaxDerivativeInstrumentsDesignatedAsCashFlowHedges": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_AccumulatedOtherComprehensiveIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated Other Comprehensive Income, Net Of Tax, Derivative Instruments Designated As Cash Flow Hedges",
        "label": "Accumulated Other Comprehensive Income, Net Of Tax, Derivative Instruments Designated As Cash Flow Hedges",
        "terseLabel": "Derivative financial instruments designated as cash flow hedges"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeNetOfTaxDerivativeInstrumentsDesignatedAsCashFlowHedges",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AccumulatedOtherComprehensiveIncomeNetOfTaxExchangeDifferencesOnTranslation": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_AccumulatedOtherComprehensiveIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated Other Comprehensive Income, Net Of Tax, Exchange Differences On Translation",
        "label": "Accumulated Other Comprehensive Income, Net Of Tax, Exchange Differences On Translation",
        "terseLabel": "Foreign currency translation adjustment"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeNetOfTaxExchangeDifferencesOnTranslation",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AcquisitionsThroughOtherBusinessCombinationsNetCashConsiderationPaid": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Acquisitions Through Other Business Combinations, Net Cash Consideration Paid",
        "label": "Acquisitions Through Other Business Combinations, Net Cash Consideration Paid",
        "verboseLabel": "Net cash paid for consideration for acquisition of exploration and evaluation assets"
       }
      }
     },
     "localname": "AcquisitionsThroughOtherBusinessCombinationsNetCashConsiderationPaid",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdditionsAndAcquisitionsExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additions And Acquisitions, Exploration For And Evaluation Of Mineral Resources",
        "label": "Additions And Acquisitions, Exploration For And Evaluation Of Mineral Resources",
        "terseLabel": "Additions/Acquisitions"
       }
      }
     },
     "localname": "AdditionsAndAcquisitionsExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdditionsPropertyPlantAndEquipment": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additions, Property, Plant And Equipment",
        "label": "Additions, Property, Plant And Equipment",
        "terseLabel": "Additions/Acquisitions"
       }
      }
     },
     "localname": "AdditionsPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentForDecommissioningRestorationAndRehabilitationCostsArisingFromThePassageOfTIme": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 6.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustment For Decommissioning, Restoration And Rehabilitation Costs Arising From The Passage Of TIme",
        "label": "Adjustment For Decommissioning, Restoration And Rehabilitation Costs Arising From The Passage Of TIme",
        "terseLabel": "Asset retirement obligation accretion"
       }
      }
     },
     "localname": "AdjustmentForDecommissioningRestorationAndRehabilitationCostsArisingFromThePassageOfTIme",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentForGainsLossesOnAcquisitionsOfPropertyPlantAndEquipmentExplorationAndEvaluationAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 10.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustment For Gains (Losses) On Acquisitions, Of Property, Plant And Equipment, Exploration And Evaluation Assets",
        "label": "Adjustment For Gains (Losses) On Acquisitions, Of Property, Plant And Equipment, Exploration And Evaluation Assets",
        "terseLabel": "Gain on acquisitions"
       }
      }
     },
     "localname": "AdjustmentForGainsLossesOnAcquisitionsOfPropertyPlantAndEquipmentExplorationAndEvaluationAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentsForDecreaseIncreaseInCurrentPrepaymentsAndOtherCurrentAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustments For Decrease (Increase) In Current Prepayments And Other Current Assets",
        "label": "Adjustments For Decrease (Increase) In Current Prepayments And Other Current Assets",
        "terseLabel": "Prepaids and other"
       }
      }
     },
     "localname": "AdjustmentsForDecreaseIncreaseInCurrentPrepaymentsAndOtherCurrentAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentsForDecreaseIncreaseInCurrentTaxAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustments For Decrease (Increase) In Current Tax Assets",
        "label": "Adjustments For Decrease (Increase) In Current Tax Assets",
        "terseLabel": "Current income tax (liabilities) assets"
       }
      }
     },
     "localname": "AdjustmentsForDecreaseIncreaseInCurrentTaxAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentsForDecreaseIncreaseInOtherLongTermAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 8.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustments For Decrease (Increase) In Other Long-Term Assets",
        "label": "Adjustments For Decrease (Increase) In Other Long-Term Assets",
        "terseLabel": "Other long-term assets"
       }
      }
     },
     "localname": "AdjustmentsForDecreaseIncreaseInOtherLongTermAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentsForGainLossOnInvestments": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 14.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustments For Gain (Loss) On Investments",
        "label": "Adjustments For Gain (Loss) On Investments",
        "negatedTerseLabel": "(Gain) loss from investments"
       }
      }
     },
     "localname": "AdjustmentsForGainLossOnInvestments",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentsForIncreaseDecreaseInAccruedLiabilities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 5.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustments For Increase (Decrease) In Accrued Liabilities",
        "label": "Adjustments For Increase (Decrease) In Accrued Liabilities",
        "terseLabel": "Accrued liabilities"
       }
      }
     },
     "localname": "AdjustmentsForIncreaseDecreaseInAccruedLiabilities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_AdjustmentsToIncreaseDecreaseFromSettlementOfCrossCurrencySwapsClassifiedAsOperatingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 13.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "localname": "AdjustmentsToIncreaseDecreaseFromSettlementOfCrossCurrencySwapsClassifiedAsOperatingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "monetaryItemType"
    },
    "cnq_AlbertaNaturalGasReferenceLocationMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Alberta Natural Gas Reference Location [Member]",
        "label": "Alberta Natural Gas Reference Location [Member]",
        "terseLabel": "AECO"
       }
      }
     },
     "localname": "AlbertaNaturalGasReferenceLocationMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_AlbertaPetroleumMarketingCommissionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Alberta Petroleum Marketing Commission",
        "label": "Alberta Petroleum Marketing Commission [Member]",
        "terseLabel": "Alberta Petroleum Marketing Commission"
       }
      }
     },
     "localname": "AlbertaPetroleumMarketingCommissionMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_AnalysisOfOtherComprehensiveIncomeByItemAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Analysis Of Other Comprehensive Income By Item [Abstract]",
        "label": "Analysis Of Other Comprehensive Income By Item [Abstract]",
        "terseLabel": "Analysis Of Other Comprehensive Income By Item [Abstract]"
       }
      }
     },
     "localname": "AnalysisOfOtherComprehensiveIncomeByItemAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Antidilutive Securities Excluded From Computation Of Earnings Per Share, Amount1",
        "label": "Antidilutive Securities Excluded From Computation Of Earnings Per Share, Amount1",
        "terseLabel": "Potentially anti-dilutive securities (in shares)"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/NetEarningsPerCommonShareNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "cnq_AuditorInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Auditor Information",
        "label": "Auditor Information [Abstract]"
       }
      }
     },
     "localname": "AuditorInformationAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_BitumenMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Bitumen [Member]",
        "label": "Bitumen [Member]",
        "terseLabel": "Bitumen"
       }
      }
     },
     "localname": "BitumenMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_BorrowingsAmountAuthorizedInBaseShelfProspectus": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Borrowings, Amount Authorized In Base Shelf Prospectus",
        "label": "Borrowings, Amount Authorized In Base Shelf Prospectus",
        "terseLabel": "Base shell prospectus borrowings, authorized"
       }
      }
     },
     "localname": "BorrowingsAmountAuthorizedInBaseShelfProspectus",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_BorrowingsNetOfCashAndCashEquivalents": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Borrowings, Net Of Cash And Cash Equivalents",
        "label": "Borrowings, Net Of Cash And Cash Equivalents",
        "totalLabel": "Long-term debt, net"
       }
      }
     },
     "localname": "BorrowingsNetOfCashAndCashEquivalents",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_BritishColumbiaGasProducingAssetsAndProcessingInfrastructureSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "British Columbia - Gas Producing Assets And Processing Infrastructure Segment",
        "label": "British Columbia - Gas Producing Assets And Processing Infrastructure Segment [Member]",
        "terseLabel": "British Columbia - Gas Producing Assets And Processing Infrastructure Segment"
       }
      }
     },
     "localname": "BritishColumbiaGasProducingAssetsAndProcessingInfrastructureSegmentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_BritishColumbiaWestcoastStation2Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "British Columbia Westcoast Station 2 [Member]",
        "label": "British Columbia Westcoast Station 2 [Member]",
        "terseLabel": "BC Westcoast Station 2"
       }
      }
     },
     "localname": "BritishColumbiaWestcoastStation2Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_BusinessAcquisitionProFormaOperatingIncomeLoss": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business Acquisition, Pro Forma Operating Income (Loss)",
        "label": "Business Acquisition, Pro Forma Operating Income (Loss)",
        "terseLabel": "Pro forma net operating income"
       }
      }
     },
     "localname": "BusinessAcquisitionProFormaOperatingIncomeLoss",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_BusinessAcquisitionProFormaRevenue": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business Acquisition, Pro Forma Revenue",
        "label": "Business Acquisition, Pro Forma Revenue",
        "terseLabel": "Pro forma revenue"
       }
      }
     },
     "localname": "BusinessAcquisitionProFormaRevenue",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CanadianCreditFacilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Canadian Credit Facilities [Member]",
        "label": "Canadian Credit Facilities [Member]",
        "terseLabel": "Bank credit facilities"
       }
      }
     },
     "localname": "CanadianCreditFacilitiesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CanadianDollarDenominatedDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Canadian Dollar Denominated Debt [Member]",
        "label": "Canadian Dollar Denominated Debt [Member]",
        "terseLabel": "Medium-term notes"
       }
      }
     },
     "localname": "CanadianDollarDenominatedDebtMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CanadianLightSweetMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Canadian Light Sweet [Member]",
        "label": "Canadian Light Sweet [Member]",
        "terseLabel": "Canadian Light Sweet"
       }
      }
     },
     "localname": "CanadianLightSweetMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CapitalisedCostsExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": 2.0,
       "parentTag": "cnq_CapitalisedCostsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalised Costs, Exploration For And Evaluation Of Mineral Resources",
        "label": "Capitalised Costs, Exploration For And Evaluation Of Mineral Resources",
        "terseLabel": "Capitalized \u00a0costs"
       }
      }
     },
     "localname": "CapitalisedCostsExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CapitalisedCostsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalised Costs, Exploration For And Evaluation Of Mineral Resources And Property, Plant and Equipment",
        "label": "Capitalised Costs, Exploration For And Evaluation Of Mineral Resources And Property, Plant and Equipment",
        "totalLabel": "Total capitalised costs"
       }
      }
     },
     "localname": "CapitalisedCostsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CapitalisedCostsPropertyPlantAndEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": 1.0,
       "parentTag": "cnq_CapitalisedCostsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalised Costs, Property, Plant And Equipment",
        "label": "Capitalised Costs, Property, Plant And Equipment",
        "terseLabel": "Capitalized \u00a0costs"
       }
      }
     },
     "localname": "CapitalisedCostsPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceRelatingToOilAndGasProducingActivities1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails": {
       "order": 1.0,
       "parentTag": "cnq_CapitalizedCostsOilAndGasProducingActivitiesGross1",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized Costs, Accumulated Depreciation, Depletion, Amortization And Valuation Allowance Relating To Oil And Gas Producing Activities1",
        "label": "Capitalized Costs, Accumulated Depreciation, Depletion, Amortization And Valuation Allowance Relating To Oil And Gas Producing Activities1",
        "negatedTerseLabel": "Less: accumulated depletion and depreciation"
       }
      }
     },
     "localname": "CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceRelatingToOilAndGasProducingActivities1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CapitalizedCostsOilAndGasProducingActivitiesGross1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails_1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized Costs, Oil And Gas Producing Activities, Gross1",
        "label": "Capitalized Costs, Oil And Gas Producing Activities, Gross1",
        "totalLabel": "Capitalized costs, gross"
       }
      }
     },
     "localname": "CapitalizedCostsOilAndGasProducingActivitiesGross1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CapitalizedCostsOilAndGasProducingActivitiesNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails": {
       "order": 2.0,
       "parentTag": "cnq_CapitalizedCostsOilAndGasProducingActivitiesGross1",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized Costs, Oil And Gas Producing Activities, Net",
        "label": "Capitalized Costs, Oil And Gas Producing Activities, Net",
        "terseLabel": "Net capitalized costs"
       }
      }
     },
     "localname": "CapitalizedCostsOilAndGasProducingActivitiesNet",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CapitalizedCostsProvedProperties1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails_1": {
       "order": 1.0,
       "parentTag": "cnq_CapitalizedCostsOilAndGasProducingActivitiesGross1",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized Costs, Proved Properties1",
        "label": "Capitalized Costs, Proved Properties1",
        "terseLabel": "Capitalized costs, proved properties"
       }
      }
     },
     "localname": "CapitalizedCostsProvedProperties1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CapitalizedCostsRelatingToOilAndGasProducingActivitiesByGeographicArea1LineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Capitalized Costs Relating To Oil And Gas Producing Activities, By Geographic Area1 [Table]",
        "label": "Capitalized Costs Relating To Oil And Gas Producing Activities, By Geographic Area1 [Line Items]",
        "terseLabel": "Capitalized Costs Relating To Oil And Gas Producing Activities, By Geographic Area1 [Line Items]"
       }
      }
     },
     "localname": "CapitalizedCostsRelatingToOilAndGasProducingActivitiesByGeographicArea1LineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_CapitalizedCostsRelatingToOilAndGasProducingActivitiesByGeographicArea1Table": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized Costs Relating To Oil And Gas Producing Activities, By Geographic Area1 [Table]",
        "label": "Capitalized Costs Relating To Oil And Gas Producing Activities, By Geographic Area1 [Table]",
        "terseLabel": "Capitalized Costs Relating To Oil And Gas Producing Activities, By Geographic Area1 [Table]"
       }
      }
     },
     "localname": "CapitalizedCostsRelatingToOilAndGasProducingActivitiesByGeographicArea1Table",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_CapitalizedCostsRelatingToOilAndGasProducingActivitiesDisclosure1TableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized Costs Relating To Oil And Gas Producing Activities Disclosure1 [Table Text Block]",
        "label": "Capitalized Costs Relating To Oil And Gas Producing Activities Disclosure1 [Table Text Block]",
        "terseLabel": "Schedule of Capitalized Costs Relating To Oil And Gas Producing Activities Disclosure"
       }
      }
     },
     "localname": "CapitalizedCostsRelatingToOilAndGasProducingActivitiesDisclosure1TableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_CapitalizedCostsUnprovedProperties1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails_1": {
       "order": 2.0,
       "parentTag": "cnq_CapitalizedCostsOilAndGasProducingActivitiesGross1",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized Costs, Unproved Properties1",
        "label": "Capitalized Costs, Unproved Properties1",
        "terseLabel": "Capitalized costs, unproved properties"
       }
      }
     },
     "localname": "CapitalizedCostsUnprovedProperties1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CashAndCashEquivalentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash And Cash Equivalents",
        "label": "Cash And Cash Equivalents [Member]",
        "terseLabel": "Cash and cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalentsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CashFlowsFromUsedInPropertyPlantandEquipmentClassifiedAsInvestingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 2.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash Flows From (Used In) Property, Plant and Equipment, Classified As Investing Activities",
        "label": "Cash Flows From (Used In) Property, Plant and Equipment, Classified As Investing Activities",
        "terseLabel": "Net expenditures on property, plant and equipment"
       }
      }
     },
     "localname": "CashFlowsFromUsedInPropertyPlantandEquipmentClassifiedAsInvestingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CertainExecutivesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Certain Executives",
        "label": "Certain Executives [Member]",
        "terseLabel": "Certain Executives"
       }
      }
     },
     "localname": "CertainExecutivesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CommercialPaper1Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commercial Paper1 [Member]",
        "label": "Commercial Paper1 [Member]",
        "terseLabel": "Commercial paper (December 31, 2021 \u2013 US$nil; \u2028December 31, 2020 \u2013 US$426 million)",
        "verboseLabel": "Commercial Paper"
       }
      }
     },
     "localname": "CommercialPaper1Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CommitmentsForOilAndGasTransportationAndProcessing": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments For Oil And Gas Transportation And Processing",
        "label": "Commitments For Oil And Gas Transportation And Processing",
        "terseLabel": "Product transportation"
       }
      }
     },
     "localname": "CommitmentsForOilAndGasTransportationAndProcessing",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CommitmentsForOilAndGasTransportationPeriodOfAgreement": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments For Oil And Gas Transportation, Period Of Agreement",
        "label": "Commitments For Oil And Gas Transportation, Period Of Agreement",
        "terseLabel": "Commitments for oil and gas transportation, period of agreement"
       }
      }
     },
     "localname": "CommitmentsForOilAndGasTransportationPeriodOfAgreement",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_CommitmentsForServiceToll": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments For Service Toll",
        "label": "Commitments For Service Toll",
        "terseLabel": "North West Redwater Partnership service toll"
       }
      }
     },
     "localname": "CommitmentsForServiceToll",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CommitmentsInRelationToJointVenturesInterestPayable": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments In Relation To Joint Ventures, Interest Payable",
        "label": "Commitments In Relation To Joint Ventures, Interest Payable",
        "terseLabel": "Interest payable included in service toll"
       }
      }
     },
     "localname": "CommitmentsInRelationToJointVenturesInterestPayable",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CommitmentsInRelationToJointVenturesPercentageProRataShareOfMonthlyDebtCost": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments In Relation To Joint Ventures, Percentage Pro Rata Share Of Monthly Debt Cost",
        "label": "Commitments In Relation To Joint Ventures, Percentage Pro Rata Share Of Monthly Debt Cost",
        "terseLabel": "Percent of pro rata share of debt company has committed paying to joint venture, toll payer percent"
       }
      }
     },
     "localname": "CommitmentsInRelationToJointVenturesPercentageProRataShareOfMonthlyDebtCost",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_CommitmentsInRelationToJointVenturesTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments In Relation To Joint Ventures, Term",
        "label": "Commitments In Relation To Joint Ventures, Term",
        "terseLabel": "Term of commitment to joint venture"
       }
      }
     },
     "localname": "CommitmentsInRelationToJointVenturesTerm",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_CorporateInformationAndStatementOfIFRSComplianceAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Corporate Information And Statement Of IFRS Compliance [Abstract]",
        "label": "Corporate Information And Statement Of IFRS Compliance [Abstract]",
        "terseLabel": "Corporate Information And Statement Of IFRS Compliance [Abstract]"
       }
      }
     },
     "localname": "CorporateInformationAndStatementOfIFRSComplianceAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_CostOfSalesProductionExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 7.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_GrossProfit",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cost Of Sales, Production Expense",
        "label": "Cost Of Sales, Production Expense",
        "negatedTerseLabel": "Production",
        "terseLabel": "Production"
       }
      }
     },
     "localname": "CostOfSalesProductionExpense",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CostOfSalesTransportationBlendingAndFeedstockExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 8.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_GrossProfit",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cost Of Sales, Transportation, Blending, And Feedstock Expense",
        "label": "Cost Of Sales, Transportation, Blending, And Feedstock Expense",
        "negatedTerseLabel": "Transportation",
        "terseLabel": "Transportation, blending and feedstock",
        "verboseLabel": "Transportation, blending and feedstock"
       }
      }
     },
     "localname": "CostOfSalesTransportationBlendingAndFeedstockExpense",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails": {
       "order": 1.0,
       "parentTag": "cnq_CostsIncurredOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Costs Incurred, Acquisition Of Oil And Gas Properties With Proved Reserves1",
        "label": "Costs Incurred, Acquisition Of Oil And Gas Properties With Proved Reserves1",
        "terseLabel": "Property acquisitions, proved"
       }
      }
     },
     "localname": "CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CostsIncurredAcquisitionOfUnprovedOilAndGasProperties1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails": {
       "order": 3.0,
       "parentTag": "cnq_CostsIncurredOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Costs Incurred, Acquisition Of Unproved Oil And Gas Properties1",
        "label": "Costs Incurred, Acquisition Of Unproved Oil And Gas Properties1",
        "terseLabel": "Property acquisitions, unproved"
       }
      }
     },
     "localname": "CostsIncurredAcquisitionOfUnprovedOilAndGasProperties1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CostsIncurredDevelopmentCosts1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails": {
       "order": 2.0,
       "parentTag": "cnq_CostsIncurredOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Costs Incurred, Development Costs1",
        "label": "Costs Incurred, Development Costs1",
        "terseLabel": "Development"
       }
      }
     },
     "localname": "CostsIncurredDevelopmentCosts1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CostsIncurredInOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1LineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Costs Incurred In Oil And Gas Property Acquisition, Exploration, And Development Activities1 [Table]",
        "label": "Costs Incurred In Oil And Gas Property Acquisition, Exploration, And Development Activities1 [Line Items]",
        "terseLabel": "Costs Incurred In Oil And Gas Property Acquisition, Exploration, And Development Activities1 [Line Items]"
       }
      }
     },
     "localname": "CostsIncurredInOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1LineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_CostsIncurredInOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1Table": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Costs Incurred In Oil And Gas Property Acquisition, Exploration, And Development Activities1 [Table]",
        "label": "Costs Incurred In Oil And Gas Property Acquisition, Exploration, And Development Activities1 [Table]",
        "terseLabel": "Costs Incurred In Oil And Gas Property Acquisition, Exploration, And Development Activities1 [Table]"
       }
      }
     },
     "localname": "CostsIncurredInOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1Table",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_CostsIncurredOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Costs Incurred, Oil And Gas Property Acquisition, Exploration, And Development Activities1",
        "label": "Costs Incurred, Oil And Gas Property Acquisition, Exploration, And Development Activities1",
        "totalLabel": "Costs incurred"
       }
      }
     },
     "localname": "CostsIncurredOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CreditFacilitiesAndCommercialPaperMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Credit Facilities And Commercial Paper [Member]",
        "label": "Credit Facilities And Commercial Paper [Member]",
        "terseLabel": "Credit facilities and commercial paper"
       }
      }
     },
     "localname": "CreditFacilitiesAndCommercialPaperMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CreditFacilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Credit Facilities [Member]",
        "label": "Credit Facilities [Member]",
        "terseLabel": "Bank credit facilities"
       }
      }
     },
     "localname": "CreditFacilitiesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CromerLightSourBlendMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cromer Light Sour Blend [Member]",
        "label": "Cromer Light Sour Blend [Member]",
        "terseLabel": "Cromer LSB"
       }
      }
     },
     "localname": "CromerLightSourBlendMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CrudeOilGradeAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Crude Oil Grade [Axis]",
        "label": "Crude Oil Grade [Axis]",
        "terseLabel": "Crude Oil Grade [Axis]"
       }
      }
     },
     "localname": "CrudeOilGradeAxis",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_CrudeOilGradeDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Domain] for Crude Oil Grade [Axis]",
        "label": "Crude Oil Grade [Domain]",
        "terseLabel": "Crude Oil Grade [Domain]"
       }
      }
     },
     "localname": "CrudeOilGradeDomain",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CrudeOilNaturalGasLiquidsNaturalGasOtherIncomeAndRevenueMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Crude Oil, Natural Gas Liquids, Natural Gas, Other Income And Revenue",
        "label": "Crude Oil, Natural Gas Liquids, Natural Gas, Other Income And Revenue [Member]",
        "terseLabel": "Crude Oil, Natural Gas Liquids, Natural Gas, Other Income And Revenue"
       }
      }
     },
     "localname": "CrudeOilNaturalGasLiquidsNaturalGasOtherIncomeAndRevenueMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CurrencySwapContractTermThroughMarch2038Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Currency Swap Contract, Term Through March 2038 [Member]",
        "label": "Currency Swap Contract, Term Through March 2038 [Member]",
        "terseLabel": "Currency swap contract, term through March 2038"
       }
      }
     },
     "localname": "CurrencySwapContractTermThroughMarch2038Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CurrentCorporateIncomeTaxExpenseIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_CurrentTaxExpenseIncome",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Corporate Income Tax Expense (Income)",
        "label": "Current Corporate Income Tax Expense (Income)",
        "terseLabel": "Current corporate income tax"
       }
      }
     },
     "localname": "CurrentCorporateIncomeTaxExpenseIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CurrentDerivativeFinancialAssetsLiabilities": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Derivative Financial Assets (Liabilities)",
        "label": "Current Derivative Financial Assets (Liabilities)",
        "verboseLabel": "Asset (liability), included in current portion of other long-term (liabilities) assets"
       }
      }
     },
     "localname": "CurrentDerivativeFinancialAssetsLiabilities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CurrentInvestmentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Investments [Member]",
        "label": "Current Investments [Member]",
        "terseLabel": "Investments"
       }
      }
     },
     "localname": "CurrentInvestmentsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_CurrentInvestmentsNumberOfSharesHeld": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Investments, Number Of Shares Held",
        "label": "Current Investments, Number Of Shares Held",
        "terseLabel": "Number of shares held as investment (in shares)"
       }
      }
     },
     "localname": "CurrentInvestmentsNumberOfSharesHeld",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "cnq_CurrentLiabilitiesFromShareBasedPaymentArrangements": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_LiabilitiesFromSharebasedPaymentTransactions2011",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Liabilities From Share-Based Payment Arrangements",
        "label": "Current Liabilities From Share-Based Payment Arrangements",
        "terseLabel": "Less: current portion"
       }
      }
     },
     "localname": "CurrentLiabilitiesFromShareBasedPaymentArrangements",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CurrentOtherTaxExpenseIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_CurrentTaxExpenseIncome",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Other Tax Expense (Income)",
        "label": "Current Other Tax Expense (Income)",
        "terseLabel": "Other taxes"
       }
      }
     },
     "localname": "CurrentOtherTaxExpenseIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CurrentPetroleumRevenueTaxExpenseIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_CurrentTaxExpenseIncome",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Petroleum Revenue Tax Expense (Income)",
        "label": "Current Petroleum Revenue Tax Expense (Income)",
        "negatedTerseLabel": "Current PRT - North Sea"
       }
      }
     },
     "localname": "CurrentPetroleumRevenueTaxExpenseIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CurrentRawMaterialsCurrentProductionSuppliesAndOther": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/InventoryScheduleofInventoryDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_Inventories",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Raw Materials, Current Production Supplies And Other",
        "label": "Current Raw Materials, Current Production Supplies And Other",
        "terseLabel": "Materials, supplies and other"
       }
      }
     },
     "localname": "CurrentRawMaterialsCurrentProductionSuppliesAndOther",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InventoryScheduleofInventoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_CurrentTradePayablesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Current Trade Payables [Member]",
        "label": "Current Trade Payables [Member]",
        "terseLabel": "Accounts payable"
       }
      }
     },
     "localname": "CurrentTradePayablesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_DebtInstrumentDebtToBookCapitalizationRatio": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt Instrument, Debt To Book Capitalization Ratio",
        "label": "Debt Instrument, Debt To Book Capitalization Ratio",
        "terseLabel": "Debt to book capitalization ratio"
       }
      }
     },
     "localname": "DebtInstrumentDebtToBookCapitalizationRatio",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_DebtToBookCapitalizationRatio": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt To Book Capitalization Ratio",
        "label": "Debt To Book Capitalization Ratio",
        "terseLabel": "Debt to book capitalization"
       }
      }
     },
     "localname": "DebtToBookCapitalizationRatio",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails",
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_DecommissioningRestorationAndRehabilitationAssetsRecognizedAsofAcquisitionDate": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Decommissioning, Restoration, And Rehabilitation Assets Recognized As of Acquisition Date",
        "label": "Decommissioning, Restoration, And Rehabilitation Assets Recognized As of Acquisition Date",
        "negatedTerseLabel": "Asset retirement obligations",
        "terseLabel": "Asset retirement obligations"
       }
      }
     },
     "localname": "DecommissioningRestorationAndRehabilitationAssetsRecognizedAsofAcquisitionDate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DecommissioningRestorationAndRehabilitationCostsArisingFromPassageOfTIme": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 3.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": 5.0,
       "parentTag": "ifrs-full_GrossProfit",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Decommissioning, Restoration, And Rehabilitation Costs Arising From Passage Of TIme",
        "label": "Decommissioning, Restoration, And Rehabilitation Costs Arising From Passage Of TIme",
        "negatedTerseLabel": "Asset retirement obligation accretion",
        "terseLabel": "Asset retirement obligation accretion"
       }
      }
     },
     "localname": "DecommissioningRestorationAndRehabilitationCostsArisingFromPassageOfTIme",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DecommissioningRestorationAndRehabilitationCostsProvisionUsed": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 11.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Decommissioning, Restoration And Rehabilitation Costs, Provision Used",
        "label": "Decommissioning, Restoration And Rehabilitation Costs, Provision Used",
        "negatedTerseLabel": "Abandonment expenditures"
       }
      }
     },
     "localname": "DecommissioningRestorationAndRehabilitationCostsProvisionUsed",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DecommissioningRestorationAndRehabilitationCostsRelatedTemporaryDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Decommissioning, Restoration And Rehabilitation Costs Related Temporary Differences [Member]",
        "label": "Decommissioning, Restoration And Rehabilitation Costs Related Temporary Differences [Member]",
        "terseLabel": "Asset retirement obligations"
       }
      }
     },
     "localname": "DecommissioningRestorationAndRehabilitationCostsRelatedTemporaryDifferencesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_DecommissioningRestorationAndRehabilitationLiabilitiesPeriodOfAccretion": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Decommissioning, Restoration, And Rehabilitation Liabilities, Period Of Accretion",
        "label": "Decommissioning, Restoration, And Rehabilitation Liabilities, Period Of Accretion",
        "terseLabel": "Asset retirement obligations settlement period"
       }
      }
     },
     "localname": "DecommissioningRestorationAndRehabilitationLiabilitiesPeriodOfAccretion",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_DeferredCorporateIncomeTaxExpenseIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_DeferredTaxExpenseIncome",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Corporate Income Tax Expense (Income)",
        "label": "Deferred Corporate Income Tax Expense (Income)",
        "terseLabel": "Deferred corporate income tax"
       }
      }
     },
     "localname": "DeferredCorporateIncomeTaxExpenseIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DeferredFinancingCostsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Financing Costs [Member]",
        "label": "Deferred Financing Costs [Member]",
        "terseLabel": "Transaction costs"
       }
      }
     },
     "localname": "DeferredFinancingCostsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_DeferredPetroleumRevenueTaxExpenseIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_DeferredTaxExpenseIncome",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Petroleum Revenue Tax Expense (Income)",
        "label": "Deferred Petroleum Revenue Tax Expense (Income)",
        "terseLabel": "Deferred PRT \u2013 North Sea"
       }
      }
     },
     "localname": "DeferredPetroleumRevenueTaxExpenseIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DeferredPetroleumRevenueTaxRelatedTemporaryDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Petroleum Revenue Tax Related Temporary Differences [Member]",
        "label": "Deferred Petroleum Revenue Tax Related Temporary Differences [Member]",
        "terseLabel": "Deferred PRT"
       }
      }
     },
     "localname": "DeferredPetroleumRevenueTaxRelatedTemporaryDifferencesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_DeferredPurchaseConsiderationPayableRecognisedInBusinessCombination": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Purchase Consideration Payable Recognised In Business Combination",
        "label": "Deferred Purchase Consideration Payable Recognised In Business Combination",
        "terseLabel": "Deferred purchase consideration payable"
       }
      }
     },
     "localname": "DeferredPurchaseConsiderationPayableRecognisedInBusinessCombination",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DeferredPurchaseConsiderationPayableRecognisedInBusinessCombinationPayablePeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Purchase Consideration Payable Recognised In Business Combination, Payable Period",
        "label": "Deferred Purchase Consideration Payable Recognised In Business Combination, Payable Period",
        "terseLabel": "Deferred purchase consideration payable, payable period"
       }
      }
     },
     "localname": "DeferredPurchaseConsiderationPayableRecognisedInBusinessCombinationPayablePeriod",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_DeferredPurchaseConsiderationRecognisedInBusinessCombinationInstallmentPaymentAmount": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Purchase Consideration Recognised In Business Combination, Installment Payment Amount",
        "label": "Deferred Purchase Consideration Recognised In Business Combination, Installment Payment Amount",
        "terseLabel": "Annual installment amount"
       }
      }
     },
     "localname": "DeferredPurchaseConsiderationRecognisedInBusinessCombinationInstallmentPaymentAmount",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DeferredPurchaseConsiderationRecognisedInBusinessCombinationInstallmentsPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Purchase Consideration Recognised In Business Combination, Installments Period",
        "label": "Deferred Purchase Consideration Recognised In Business Combination, Installments Period",
        "terseLabel": "Installment period"
       }
      }
     },
     "localname": "DeferredPurchaseConsiderationRecognisedInBusinessCombinationInstallmentsPeriod",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_DemandCreditFacilityMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Demand Credit Facility [Member]",
        "label": "Demand Credit Facility [Member]",
        "terseLabel": "Demand credit facility"
       }
      }
     },
     "localname": "DemandCreditFacilityMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_DerivativeFinancialAssetsLiabilitiesHeldForHedging": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails_1": {
       "order": 2.0,
       "parentTag": "cnq_DerivativeFinancialAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative Financial Assets (Liabilities) Held For Hedging",
        "label": "Derivative Financial Assets (Liabilities) Held For Hedging",
        "terseLabel": "Cash flow hedges, asset (liability)"
       }
      }
     },
     "localname": "DerivativeFinancialAssetsLiabilitiesHeldForHedging",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DerivativeFinancialAssetsLiabilitiesHeldForTrading": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails_1": {
       "order": 1.0,
       "parentTag": "cnq_DerivativeFinancialAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative Financial Assets (Liabilities) Held For Trading",
        "label": "Derivative Financial Assets (Liabilities) Held For Trading",
        "terseLabel": "Derivatives held for trading, (liability)"
       }
      }
     },
     "localname": "DerivativeFinancialAssetsLiabilitiesHeldForTrading",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DerivativeFinancialAssetsLiabilitiesNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails_1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative Financial Assets (Liabilities), Net",
        "label": "Derivative Financial Assets (Liabilities), Net",
        "periodEndLabel": "Derivative financial asset (liability), net",
        "periodStartLabel": "Derivative financial asset (liability), net",
        "terseLabel": "Derivative financial asset (liability), net",
        "totalLabel": "Derivative financial asset (liability), net"
       }
      }
     },
     "localname": "DerivativeFinancialAssetsLiabilitiesNet",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DerivativeTermOfContract1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative, Term Of Contract1",
        "label": "Derivative, Term Of Contract1",
        "terseLabel": "Derivative, term of contract"
       }
      }
     },
     "localname": "DerivativeTermOfContract1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_DescriptionOfAccountingPolicyForComprehensiveIncomeExplanatoryPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Description Of Accounting Policy For Comprehensive Income Explanatory [Policy Text Block]",
        "label": "Description Of Accounting Policy For Comprehensive Income Explanatory [Policy Text Block]",
        "terseLabel": "COMPREHENSIVE INCOME (LOSS)"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForComprehensiveIncomeExplanatoryPolicyTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DescriptionOfAccountingPolicyForCostOfSalesPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Description Of Accounting Policy For Cost Of Sales [Policy Text Block]",
        "label": "Description Of Accounting Policy For Cost Of Sales [Policy Text Block]",
        "terseLabel": "COST OF GOODS SOLD"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForCostOfSalesPolicyTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DescriptionOfAccountingPolicyForRiskManagementActivitiesExplanatoryPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Description Of Accounting Policy For Risk Management Activities Explanatory [Policy Text Block]",
        "label": "Description Of Accounting Policy For Risk Management Activities Explanatory [Policy Text Block]",
        "terseLabel": "RISK MANAGEMENT ACTIVITIES"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForRiskManagementActivitiesExplanatoryPolicyTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DescriptionOfManagementJudgementsInApplyingEntitysAccountingPoliciesWithSignificantEffectOnRecognisedAmountPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Description Of Management Judgements In Applying Entity's Accounting Policies With Significant Effect On Recognised Amount [Policy Text Block]",
        "label": "Description Of Management Judgements In Applying Entity's Accounting Policies With Significant Effect On Recognised Amount [Policy Text Block]",
        "terseLabel": "Critical Accounting Estimates and Judgements"
       }
      }
     },
     "localname": "DescriptionOfManagementJudgementsInApplyingEntitysAccountingPoliciesWithSignificantEffectOnRecognisedAmountPolicyTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DevonCanadaCorporationMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Devon Canada Corporation [Member]",
        "label": "Devon Canada Corporation [Member]",
        "terseLabel": "Devon"
       }
      }
     },
     "localname": "DevonCanadaCorporationMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_DisclosureOfCommitmentsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Disclosure Of Commitments [Table]",
        "label": "Disclosure Of Commitments [Line Items]",
        "terseLabel": "Disclosure Of Commitments [Line Items]"
       }
      }
     },
     "localname": "DisclosureOfCommitmentsLineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfCommitmentsTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Commitments [Table]",
        "label": "Disclosure Of Commitments [Table]",
        "terseLabel": "Disclosure Of Commitments [Table]"
       }
      }
     },
     "localname": "DisclosureOfCommitmentsTable",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutAccumulatedOtherComprehensiveIncomeExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Accumulated Other Comprehensive Income Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Accumulated Other Comprehensive Income Explanatory [Table Text Block]",
        "terseLabel": "Components of Accumulated Other Comprehensive (Loss) Income, Net of Taxes"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutAccumulatedOtherComprehensiveIncomeExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutCapitalExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Capital Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Capital Explanatory [Table Text Block]",
        "terseLabel": "Disclosure of detailed information about capital"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutCapitalExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutCashFlowSupplementalDisclosuresTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Cash Flow Supplemental Disclosures [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Cash Flow Supplemental Disclosures [Table Text Block]",
        "terseLabel": "Schedule of cash flow supplemental disclosures"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutCashFlowSupplementalDisclosuresTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutCommitmentsAndContingenciesExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Commitments And Contingencies Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Commitments And Contingencies Explanatory [Table Text Block]",
        "terseLabel": "Disclosure of future payments"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutCommitmentsAndContingenciesExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutCostsIncurredInCrudeOilAndNaturalGasActivitiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Costs Incurred In Crude Oil And Natural Gas Activities [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Costs Incurred In Crude Oil And Natural Gas Activities [Table Text Block]",
        "terseLabel": "Disclosure of Detailed Information About Costs Incurred In Crude Oil And Natural Gas Activities"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutCostsIncurredInCrudeOilAndNaturalGasActivitiesTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutDecommissioningRestorationAndRehabilitationCostsExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Decommissioning, Restoration And Rehabilitation Costs Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Decommissioning, Restoration And Rehabilitation Costs Explanatory [Table Text Block]",
        "terseLabel": "Summary of asset retirement obligations"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutDecommissioningRestorationAndRehabilitationCostsExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Exploration And Evaluation Assets Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Exploration And Evaluation Assets Explanatory [Table Text Block]",
        "terseLabel": "Detailed information about exploration and evaluation assets"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutExplorationForAndEvaluationOfMineralResourcesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Table]",
        "label": "Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items]",
        "terseLabel": "Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Line Items]"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutExplorationForAndEvaluationOfMineralResourcesLineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutExplorationForAndEvaluationOfMineralResourcesTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Table]",
        "label": "Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Table]",
        "terseLabel": "Disclosure Of Detailed Information About Exploration For And Evaluation Of Mineral Resources [Table]"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutExplorationForAndEvaluationOfMineralResourcesTable",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutFinanceIncomeCostExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Finance Income (Cost) Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Finance Income (Cost) Explanatory [Table Text Block]",
        "terseLabel": "Disclosure of interest and other financing expense"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutFinanceIncomeCostExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutInventoriesExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Inventories Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Inventories Explanatory [Table Text Block]",
        "terseLabel": "Schedule of Inventory"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutInventoriesExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InventoryTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Investments Other Than Investments Accounted For Using Equity Method Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Investments Other Than Investments Accounted For Using Equity Method Explanatory [Table Text Block]",
        "terseLabel": "Summary of investments"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Non-Current Liabilities Explanatory [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Non-Current Liabilities Explanatory [Table Text Block]",
        "terseLabel": "Disclosure of other long-term liabilities"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutNonCurrentLiabilitiesExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfDetailedInformationAboutResultsOfOperationsFromCrudeOilAndNaturalGasActivitiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Detailed Information About Results Of Operations From Crude Oil And Natural Gas Activities [Table Text Block]",
        "label": "Disclosure Of Detailed Information About Results Of Operations From Crude Oil And Natural Gas Activities [Table Text Block]",
        "terseLabel": "Disclosure Of Detailed Information About Results Of Operations From Crude Oil And Natural Gas Activities"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutResultsOfOperationsFromCrudeOilAndNaturalGasActivitiesTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfInformationAboutLeaseAssetsExplanatoryLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Disclosure Of Information About Lease Assets Explanatory [Table]",
        "label": "Disclosure Of Information About Lease Assets Explanatory [Line Items]",
        "terseLabel": "Disclosure Of Information About Lease Assets Explanatory [Line Items]"
       }
      }
     },
     "localname": "DisclosureOfInformationAboutLeaseAssetsExplanatoryLineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfInformationAboutLeaseAssetsExplanatoryTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Information About Lease Assets Explanatory [Table]",
        "label": "Disclosure Of Information About Lease Assets Explanatory [Table]",
        "terseLabel": "Disclosure Of Information About Lease Assets Explanatory [Table]"
       }
      }
     },
     "localname": "DisclosureOfInformationAboutLeaseAssetsExplanatoryTable",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfInformationAboutOtherNonCurrentAssetsExplanatoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Information About Other Non-Current Assets Explanatory [Table Text Block]",
        "label": "Disclosure Of Information About Other Non-Current Assets Explanatory [Table Text Block]",
        "terseLabel": "Disclosure of other long-term assets"
       }
      }
     },
     "localname": "DisclosureOfInformationAboutOtherNonCurrentAssetsExplanatoryTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfMajorComponentsOfTaxExpenseIncomeLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Disclosure Of Major Components Of Tax Expense (Income) [Table]",
        "label": "Disclosure Of Major Components Of Tax Expense (Income) [Line Items]",
        "terseLabel": "Disclosure Of Major Components Of Tax Expense (Income) [Line Items]"
       }
      }
     },
     "localname": "DisclosureOfMajorComponentsOfTaxExpenseIncomeLineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfMajorComponentsOfTaxExpenseIncomeTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Major Components Of Tax Expense (Income) [Table]",
        "label": "Disclosure Of Major Components Of Tax Expense (Income) [Table]",
        "terseLabel": "Disclosure Of Major Components Of Tax Expense (Income) [Table]"
       }
      }
     },
     "localname": "DisclosureOfMajorComponentsOfTaxExpenseIncomeTable",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_DisclosureOfMajorComponentsOfTaxExpenseIncomeTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Major Components Of Tax Expense (Income) [Table Text Block]",
        "label": "Disclosure Of Major Components Of Tax Expense (Income) [Table Text Block]",
        "terseLabel": "Schedule of provision for income tax"
       }
      }
     },
     "localname": "DisclosureOfMajorComponentsOfTaxExpenseIncomeTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfQuantitativeInformationAboutLeaseLiabilitiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Quantitative Information About Lease Liabilities [Table Text Block]",
        "label": "Disclosure Of Quantitative Information About Lease Liabilities [Table Text Block]",
        "terseLabel": "Schedule of Lease Liabilities"
       }
      }
     },
     "localname": "DisclosureOfQuantitativeInformationAboutLeaseLiabilitiesTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAndAverageEffectiveTaxRateTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Reconciliation Of Accounting Profit Multiplied By Applicable Tax Rates And Average Effective Tax Rate [Table Text Block]",
        "label": "Disclosure Of Reconciliation Of Accounting Profit Multiplied By Applicable Tax Rates And Average Effective Tax Rate [Table Text Block]",
        "terseLabel": "Schedule of provision for income tax reconciliation"
       }
      }
     },
     "localname": "DisclosureOfReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAndAverageEffectiveTaxRateTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure Of Supplementary Oil And Gas Information Explanatory [Text Block]",
        "label": "Disclosure Of Supplementary Oil And Gas Information Explanatory [Text Block]",
        "terseLabel": "Supplementary Oil And Gas Information (Unaudited)"
       }
      }
     },
     "localname": "DisclosureOfSupplementaryOilAndGasInformationExplanatoryTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnaudited"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_DisclosureofleasesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of leases [Abstract]",
        "label": "Disclosure of leases [Abstract]",
        "terseLabel": "Disclosure of leases [Abstract]"
       }
      }
     },
     "localname": "DisclosureofleasesAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_DiscountRateUsedInCurrentMeasurementOfHigherOfFairValueLessCostsOfDisposalOrPreviousEstimateOfValueInUse": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Discount Rate Used In Current Measurement Of Higher Of Fair Value Less Costs Of Disposal Or Previous Estimate Of Value In Use",
        "label": "Discount Rate Used In Current Measurement Of Higher Of Fair Value Less Costs Of Disposal Or Previous Estimate Of Value In Use",
        "terseLabel": "Discount rate used in current measurement of higher of fair value less costs of disposal or previous estimate of value in use"
       }
      }
     },
     "localname": "DiscountRateUsedInCurrentMeasurementOfHigherOfFairValueLessCostsOfDisposalOrPreviousEstimateOfValueInUse",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_DisposalsExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disposals, Exploration For And Evaluation Of Mineral Resources",
        "label": "Disposals, Exploration For And Evaluation Of Mineral Resources",
        "negatedTerseLabel": "Derecognitions and other"
       }
      }
     },
     "localname": "DisposalsExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_DisposalsOfRightOfUseAssets": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disposals Of Right-Of-Use Assets",
        "label": "Disposals Of Right-Of-Use Assets",
        "negatedTerseLabel": "Derecognitions"
       }
      }
     },
     "localname": "DisposalsOfRightOfUseAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_EdmontonC5PlusCondensateMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Edmonton C5Plus Condensate [Member]",
        "label": "Edmonton C5Plus Condensate [Member]",
        "terseLabel": "Edmonton C5+"
       }
      }
     },
     "localname": "EdmontonC5PlusCondensateMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_EmployeeStockOption1Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employee Stock Option1 [Member]",
        "label": "Employee Stock Option1 [Member]",
        "terseLabel": "Stock options"
       }
      }
     },
     "localname": "EmployeeStockOption1Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExercisePriceRangeFiveMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exercise Price Range Five [Member]",
        "label": "Exercise Price Range Five [Member]",
        "terseLabel": "$40.00 - $44.99"
       }
      }
     },
     "localname": "ExercisePriceRangeFiveMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExercisePriceRangeFourMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exercise Price Range Four [Member]",
        "label": "Exercise Price Range Four [Member]",
        "terseLabel": "$35.00 - $39.99"
       }
      }
     },
     "localname": "ExercisePriceRangeFourMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExercisePriceRangeOneMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exercise Price Range One [Member]",
        "label": "Exercise Price Range One [Member]",
        "terseLabel": "$20.76 - $24.99"
       }
      }
     },
     "localname": "ExercisePriceRangeOneMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExercisePriceRangeSevenMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exercise Price Range Seven",
        "label": "Exercise Price Range Seven [Member]",
        "terseLabel": "$50.00 - $54.24"
       }
      }
     },
     "localname": "ExercisePriceRangeSevenMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExercisePriceRangeSixMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exercise Price Range Six [Member]",
        "label": "Exercise Price Range Six [Member]",
        "terseLabel": "$45.00 - $49.99"
       }
      }
     },
     "localname": "ExercisePriceRangeSixMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExercisePriceRangeThreeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exercise Price Range Three [Member]",
        "label": "Exercise Price Range Three [Member]",
        "terseLabel": "$30.00 - $34.99"
       }
      }
     },
     "localname": "ExercisePriceRangeThreeMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExercisePriceRangeTwoMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exercise Price Range Two [Member]",
        "label": "Exercise Price Range Two [Member]",
        "terseLabel": "$25.00 - $29.99"
       }
      }
     },
     "localname": "ExercisePriceRangeTwoMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExpectedForfeitureAsPercentageShareOptionsGranted": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Expected Forfeiture As Percentage, Share Options Granted",
        "label": "Expected Forfeiture As Percentage, Share Options Granted",
        "terseLabel": "Expected forfeiture rate"
       }
      }
     },
     "localname": "ExpectedForfeitureAsPercentageShareOptionsGranted",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_ExplorationAndEvaluationAssetsRecognizedAsOfAcquisitionDate": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 7.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exploration And Evaluation Assets Recognized As Of Acquisition Date",
        "label": "Exploration And Evaluation Assets Recognized As Of Acquisition Date",
        "terseLabel": "Exploration and evaluation assets"
       }
      }
     },
     "localname": "ExplorationAndEvaluationAssetsRecognizedAsOfAcquisitionDate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ExplorationAndProductionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exploration And Production [Member]",
        "label": "Exploration And Production [Member]",
        "terseLabel": "Exploration and \u00a0\u00a0 Production"
       }
      }
     },
     "localname": "ExplorationAndProductionMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ExplorationForAndEvaluationOfMineralResourcesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Exploration For And Evaluation Of Mineral Resources [Abstract]",
        "label": "Exploration For And Evaluation Of Mineral Resources [Abstract]",
        "terseLabel": "Exploration and evaluation assets",
        "verboseLabel": "Exploration and evaluation assets"
       }
      }
     },
     "localname": "ExplorationForAndEvaluationOfMineralResourcesAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_FieldEquipmentAndPowerMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Field Equipment And Power [Member]",
        "label": "Field Equipment And Power [Member]",
        "terseLabel": "Field equipment and power"
       }
      }
     },
     "localname": "FieldEquipmentAndPowerMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_FinancialAssetsLiabilitiesAtFairValueThroughOtherComprehensiveIncomeNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 3.0,
       "parentTag": "cnq_FinancialAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial Assets (Liabilities) At Fair Value Through Other Comprehensive Income, Net",
        "label": "Financial Assets (Liabilities) At Fair Value Through Other Comprehensive Income, Net",
        "totalLabel": "Derivatives used for hedging"
       }
      }
     },
     "localname": "FinancialAssetsLiabilitiesAtFairValueThroughOtherComprehensiveIncomeNet",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_FinancialAssetsLiabilitiesAtFairValueThroughProfitOrLossNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 2.0,
       "parentTag": "cnq_FinancialAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial Assets (Liabilities) At Fair Value Through Profit Or Loss, Net",
        "label": "Financial Assets (Liabilities) At Fair Value Through Profit Or Loss, Net",
        "totalLabel": "Fair value through profit or loss"
       }
      }
     },
     "localname": "FinancialAssetsLiabilitiesAtFairValueThroughProfitOrLossNet",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_FinancialAssetsLiabilitiesNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial Assets (Liabilities), Net",
        "label": "Financial Assets (Liabilities), Net",
        "totalLabel": "Net financial assets (liabilities)"
       }
      }
     },
     "localname": "FinancialAssetsLiabilitiesNet",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_FinancialInstrumentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial Instruments [Abstract]",
        "label": "Financial Instruments [Abstract]",
        "terseLabel": "Financial Instruments [Abstract]"
       }
      }
     },
     "localname": "FinancialInstrumentsAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_FinancialLiabilitiesAtFairValueThroughOtherComprehensiveIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_FinancialLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial Liabilities At Fair Value Through Other Comprehensive Income",
        "label": "Financial Liabilities At Fair Value Through Other Comprehensive Income",
        "negatedLabel": "Financial liabilities, derivatives used for hedging"
       }
      }
     },
     "localname": "FinancialLiabilitiesAtFairValueThroughOtherComprehensiveIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ForeignCurrencyTransactionLoss1": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 7.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Foreign Currency Transaction Loss1",
        "label": "Foreign Currency Transaction Loss1",
        "terseLabel": "Realized foreign exchange loss (gain)"
       }
      }
     },
     "localname": "ForeignCurrencyTransactionLoss1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ForeignExchangeAdjustmentsAndOtherRightOfUseAssets": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Foreign Exchange Adjustments And Other, Right-Of-Use Assets",
        "label": "Foreign Exchange Adjustments And Other, Right-Of-Use Assets",
        "terseLabel": "Foreign exchange adjustments and other"
       }
      }
     },
     "localname": "ForeignExchangeAdjustmentsAndOtherRightOfUseAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_FutureNetCashFlowsRelatingtoProvedOilandGasReservesDevelopmentCostsandAssetRetirementObligations": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails": {
       "order": 3.0,
       "parentTag": "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Development Costs and Asset Retirement Obligations",
        "label": "Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Development Costs and Asset Retirement Obligations",
        "negatedTerseLabel": "Future development costs and asset retirement obligations"
       }
      }
     },
     "localname": "FutureNetCashFlowsRelatingtoProvedOilandGasReservesDevelopmentCostsandAssetRetirementObligations",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_GainLossesOnChangeInFairValueOfSettledDerivatives": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsNetGainsLossesfromRiskManagementActivitiesDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_GainsLossesOnChangeInFairValueOfDerivatives",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gain (Losses) On Change In Fair Value Of Settled Derivatives",
        "label": "Gain (Losses) On Change In Fair Value Of Settled Derivatives",
        "negatedLabel": "Risk management activities (commodity derivatives)",
        "negatedTerseLabel": "Net realized risk management loss"
       }
      }
     },
     "localname": "GainLossesOnChangeInFairValueOfSettledDerivatives",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsNetGainsLossesfromRiskManagementActivitiesDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_GainLossesOnChangeInFairValueOfUnsettledDerivatives": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsNetGainsLossesfromRiskManagementActivitiesDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_GainsLossesOnChangeInFairValueOfDerivatives",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gain (Losses) On Change In Fair Value Of Unsettled Derivatives",
        "label": "Gain (Losses) On Change In Fair Value Of Unsettled Derivatives",
        "negatedTerseLabel": "Net unrealized risk management loss (gain)"
       }
      }
     },
     "localname": "GainLossesOnChangeInFairValueOfUnsettledDerivatives",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsNetGainsLossesfromRiskManagementActivitiesDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_GainLossesOnChangeInFairValueOfUnsettledDerivativesIncludingFairValueMovementOfCommodityFinancialInstruments": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gain (Losses) On Change In Fair Value Of Unsettled Derivatives, Including Fair Value Movement Of Commodity Financial Instruments",
        "label": "Gain (Losses) On Change In Fair Value Of Unsettled Derivatives, Including Fair Value Movement Of Commodity Financial Instruments",
        "terseLabel": "Net change in fair value of outstanding derivatives financial instruments recognized in: Risk management activities"
       }
      }
     },
     "localname": "GainLossesOnChangeInFairValueOfUnsettledDerivativesIncludingFairValueMovementOfCommodityFinancialInstruments",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_GainsLossesOnAcquisitionsOfPropertyPlantAndEquipmentExplorationAndEvaluationAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 10.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gains (Losses) On Acquisitions, Of Property, Plant And Equipment, Exploration And Evaluation Assets",
        "label": "Gains (Losses) On Acquisitions, Of Property, Plant And Equipment, Exploration And Evaluation Assets",
        "negatedTerseLabel": "Gain on acquisitions"
       }
      }
     },
     "localname": "GainsLossesOnAcquisitionsOfPropertyPlantAndEquipmentExplorationAndEvaluationAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_GainsLossesOnExchangeDifferencesOnTranslationRecognisedInProfitOrLossSettledAndUnsettledDerivativeHedgingInstruments": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gains (Losses) On Exchange Differences On Translation Recognised In Profit Or Loss, Settled And Unsettled Derivative Hedging Instruments",
        "label": "Gains (Losses) On Exchange Differences On Translation Recognised In Profit Or Loss, Settled And Unsettled Derivative Hedging Instruments",
        "terseLabel": "Net change in fair value of outstanding derivatives financial instruments recognized in: Foreign exchange"
       }
      }
     },
     "localname": "GainsLossesOnExchangeDifferencesOnTranslationRecognisedInProfitOrLossSettledAndUnsettledDerivativeHedgingInstruments",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_GainsLossesOnInvestments": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 11.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": -1.0
      },
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gains (Losses) On Investments",
        "label": "Gains (Losses) On Investments",
        "negatedTerseLabel": "(Gain) loss from investments",
        "negatedTotalLabel": "(Gain) loss from investment"
       }
      }
     },
     "localname": "GainsLossesOnInvestments",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_GainsOnAcquisitionsOfPropertyPlantAndEquipment": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gains On Acquisitions Of Property, Plant And Equipment",
        "label": "Gains On Acquisitions Of Property, Plant And Equipment",
        "terseLabel": "Gains on acquisitions of property, plant and equipment, pre-tax"
       }
      }
     },
     "localname": "GainsOnAcquisitionsOfPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_HenryHubLouisianaMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Henry Hub Louisiana [Member]",
        "label": "Henry Hub Louisiana [Member]",
        "terseLabel": "Henry Hub Louisiana"
       }
      }
     },
     "localname": "HenryHubLouisianaMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_IncomeTaxRelatingToGainsLossesOnCashFlowHedgesOfOtherComprehensiveIncome": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Income Tax Relating To Gains (Losses) On Cash Flow Hedges Of Other Comprehensive Income",
        "label": "Income Tax Relating To Gains (Losses) On Cash Flow Hedges Of Other Comprehensive Income",
        "terseLabel": "Unrealized income, tax"
       }
      }
     },
     "localname": "IncomeTaxRelatingToGainsLossesOnCashFlowHedgesOfOtherComprehensiveIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLossParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncomeTaxRelatingToReclassificationAdjustmentsOnCashFlowHedgesOfOtherComprehensiveIncome": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Income Tax Relating To Reclassification Adjustments On Cash Flow Hedges Of Other Comprehensive Income",
        "label": "Income Tax Relating To Reclassification Adjustments On Cash Flow Hedges Of Other Comprehensive Income",
        "terseLabel": "Reclassification to net earnings (loss), tax"
       }
      }
     },
     "localname": "IncomeTaxRelatingToReclassificationAdjustmentsOnCashFlowHedgesOfOtherComprehensiveIncome",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLossParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncomeTaxesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Income Taxes [Abstract]",
        "label": "Income Taxes [Abstract]",
        "terseLabel": "Income Taxes [Abstract]"
       }
      }
     },
     "localname": "IncomeTaxesAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_IncreaseDecreaseInDeferredTaxLiabilityAssetDueToChangeInProvincialCorporateIncomeTaxRate": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) In Deferred Tax Liability (Asset) Due To Change In Provincial Corporate Income Tax Rate",
        "label": "Increase (Decrease) In Deferred Tax Liability (Asset) Due To Change In Provincial Corporate Income Tax Rate",
        "terseLabel": "Increase in deferred income tax liability due to change in provincial corporate income tax rate"
       }
      }
     },
     "localname": "IncreaseDecreaseInDeferredTaxLiabilityAssetDueToChangeInProvincialCorporateIncomeTaxRate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseInWorkingCapitalInvestingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 5.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) In Working Capital, Investing Activities",
        "label": "Increase (Decrease) In Working Capital, Investing Activities",
        "negatedLabel": "Net change in non-cash working capital, investing activities",
        "negatedTerseLabel": "Net change in non-cash working capital"
       }
      }
     },
     "localname": "IncreaseDecreaseInWorkingCapitalInvestingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseInWorkingCapitalOperatingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 8.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) In Working Capital, Operating Activities",
        "label": "Increase (Decrease) In Working Capital, Operating Activities",
        "negatedLabel": "Net change in non-cash working capital, operating activities",
        "negatedTerseLabel": "Net change in non-cash working capital"
       }
      }
     },
     "localname": "IncreaseDecreaseInWorkingCapitalOperatingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseThroughChangeInCostRevisionAndTimingEstimatesOtherProvisions": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) Through Change In Cost Revision And Timing Estimates, Other Provisions",
        "label": "Increase (Decrease) Through Change In Cost Revision And Timing Estimates, Other Provisions",
        "terseLabel": "Revision of cost and timing estimates"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughChangeInCostRevisionAndTimingEstimatesOtherProvisions",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseThroughExerciseOfOptionsAdditionalValueReceivedInExcessOfCash": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) Through Exercise Of Options, Additional Value Received In Excess Of Cash",
        "label": "Increase (Decrease) Through Exercise Of Options, Additional Value Received In Excess Of Cash",
        "terseLabel": "Previously recognized liability on stock options exercised for common shares"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughExerciseOfOptionsAdditionalValueReceivedInExcessOfCash",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseThroughExerciseOfOptionsCashReceived": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) Through Exercise Of Options, Cash Received",
        "label": "Increase (Decrease) Through Exercise Of Options, Cash Received",
        "terseLabel": "Issued upon exercise of stock options"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughExerciseOfOptionsCashReceived",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseThroughFinancingCashFlowsProceedsPaymentsfromLongTermBorrowingsLiabilitiesArisingFromFinancingActivities": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) Through Financing Cash Flows, Proceeds (Payments) from Long-Term Borrowings, Liabilities Arising From Financing Activities",
        "label": "Increase (Decrease) Through Financing Cash Flows, Proceeds (Payments) from Long-Term Borrowings, Liabilities Arising From Financing Activities",
        "terseLabel": "Issue (repayment) of long-term debt"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughFinancingCashFlowsProceedsPaymentsfromLongTermBorrowingsLiabilitiesArisingFromFinancingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseThroughNetExchangeDifferencesExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) Through Net Exchange Differences, Exploration For And Evaluation Of Mineral Resources",
        "label": "Increase (Decrease) Through Net Exchange Differences, Exploration For And Evaluation Of Mineral Resources",
        "terseLabel": "Foreign exchange adjustments"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughNetExchangeDifferencesExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseDecreaseThroughTransfersToPropertyPlantAndEquipmentExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) Through Transfers To Property, Plant And Equipment, Exploration For And Evaluation Of Mineral Resources",
        "label": "Increase (Decrease) Through Transfers To Property, Plant And Equipment, Exploration For And Evaluation Of Mineral Resources",
        "terseLabel": "Transfers to property, plant and equipment"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughTransfersToPropertyPlantAndEquipmentExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IncreaseThroughCapitalizationOfShortTermLeasesPropertyPlantAndEquipment": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase Through Capitalization Of Short-Term Leases, Property, Plant And Equipment",
        "label": "Increase Through Capitalization Of Short-Term Leases, Property, Plant And Equipment",
        "terseLabel": "Increase through capitalization of short-term leases, property, plant and equipment"
       }
      }
     },
     "localname": "IncreaseThroughCapitalizationOfShortTermLeasesPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_InflationRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Inflation Rate",
        "label": "Inflation Rate",
        "terseLabel": "Inflation rate"
       }
      }
     },
     "localname": "InflationRate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_InterPipelineLtd.Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Inter Pipeline Ltd. [Member]",
        "label": "Inter Pipeline Ltd. [Member]",
        "terseLabel": "Investment in Inter Pipeline Ltd."
       }
      }
     },
     "localname": "InterPipelineLtd.Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails",
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails",
      "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_InterestPaidReceivedNet": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest Paid (Received), Net",
        "label": "Interest Paid (Received), Net",
        "terseLabel": "Interest paid on long-term debt, net"
       }
      }
     },
     "localname": "InterestPaidReceivedNet",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_InventoriesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Inventories [Abstract]",
        "label": "Inventories [Abstract]",
        "terseLabel": "Inventories [Abstract]"
       }
      }
     },
     "localname": "InventoriesAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_InventoryPrepaidsAndOtherLongTermAssetsAsOfAcquisitionDate": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 10.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Inventory, Prepaids And Other Long-Term Assets Of Acquisition Date",
        "label": "Inventory, Prepaids And Other Long-Term Assets As Of Acquisition Date",
        "terseLabel": "Inventory, prepaids and other long-term assets"
       }
      }
     },
     "localname": "InventoryPrepaidsAndOtherLongTermAssetsAsOfAcquisitionDate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_InvestmentNameAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investment, Name [Axis]",
        "label": "Investment, Name [Axis]",
        "terseLabel": "Investment, Name [Axis]"
       }
      }
     },
     "localname": "InvestmentNameAxis",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails",
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails",
      "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_InvestmentNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Domain] for Investment, Name [Axis]",
        "label": "Investment, Name [Domain]",
        "terseLabel": "Investment, Name [Domain]"
       }
      }
     },
     "localname": "InvestmentNameDomain",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails",
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails",
      "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_InvestmentsAccountedForUsingEquityMethodRelatedTemporaryDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investments Accounted For Using Equity Method Related Temporary Differences [Member]",
        "label": "Investments Accounted For Using Equity Method Related Temporary Differences [Member]",
        "terseLabel": "Investment in North West Redwater Partnership"
       }
      }
     },
     "localname": "InvestmentsAccountedForUsingEquityMethodRelatedTemporaryDifferencesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_InvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodRelatedTemporaryDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investments Other Than Investments Accounted For Using Equity Method Related Temporary Differences [Member]",
        "label": "Investments Other Than Investments Accounted For Using Equity Method Related Temporary Differences [Member]",
        "terseLabel": "Investments"
       }
      }
     },
     "localname": "InvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodRelatedTemporaryDifferencesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_IssuanceRepaymentsOfLineOfCreditBorrowingsClassifiedAsFinancingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 7.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Issuance (Repayments) Of Line Of Credit Borrowings, Classified As Financing Activities",
        "label": "Issuance (Repayments) Of Line Of Credit Borrowings, Classified As Financing Activities",
        "terseLabel": "(Repayment) issuance of bank credit facilities and commercial paper, net"
       }
      }
     },
     "localname": "IssuanceRepaymentsOfLineOfCreditBorrowingsClassifiedAsFinancingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IssuanceRepaymentsOfLongTermBorrowingsClassifiedAsFinancingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 5.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Issuance (Repayments) Of Long-Term Borrowings, Classified As Financing Activities",
        "label": "Issuance (Repayments) Of Long-Term Borrowings, Classified As Financing Activities",
        "terseLabel": "(Repayment) issuance of US dollar debt securities"
       }
      }
     },
     "localname": "IssuanceRepaymentsOfLongTermBorrowingsClassifiedAsFinancingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_IssuanceRepaymentsOfMediumTermBorrowingsClassifiedAsFinancingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 3.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Issuance (Repayments) Of Medium-Term Borrowings, Classified As Financing Activities",
        "label": "Issuance (Repayments) Of Medium-Term Borrowings, Classified As Financing Activities",
        "terseLabel": "Repayment of medium-term notes"
       }
      }
     },
     "localname": "IssuanceRepaymentsOfMediumTermBorrowingsClassifiedAsFinancingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDay": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Joint Venture, Processing Agreement, Barrels Of Bitumen Feedstock Processed Per Day",
        "label": "Joint Venture, Processing Agreement, Barrels Of Bitumen Feedstock Processed Per Day",
        "terseLabel": "Barrels of bitumen feedstock processed per day"
       }
      }
     },
     "localname": "JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDay",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "cnq_JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDayPortionRelatedToCompany": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails": {
       "order": 1.0,
       "parentTag": "cnq_JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDay",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Joint Venture, Processing Agreement, Barrels Of Bitumen Feedstock Processed Per Day, Portion Related To Company",
        "label": "Joint Venture, Processing Agreement, Barrels Of Bitumen Feedstock Processed Per Day, Portion Related To Company",
        "terseLabel": "Processing agreement, barrels of bitumen feedstock per date for the Company"
       }
      }
     },
     "localname": "JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDayPortionRelatedToCompany",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "cnq_JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDayPortionRelatedToOthers": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails": {
       "order": 2.0,
       "parentTag": "cnq_JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDay",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Joint Venture, Processing Agreement, Barrels Of Bitumen Feedstock Processed Per Day, Portion Related To Others",
        "label": "Joint Venture, Processing Agreement, Barrels Of Bitumen Feedstock Processed Per Day, Portion Related To Others",
        "terseLabel": "Processing agreement, barrels of bitumen feedstock per date for others"
       }
      }
     },
     "localname": "JointVentureProcessingAgreementBarrelsOfBitumenFeedstockProcessedPerDayPortionRelatedToOthers",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "cnq_JoslynOilSandsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Joslyn Oil Sands",
        "label": "Joslyn Oil Sands [Member]",
        "terseLabel": "Joslyn Oil Sands"
       }
      }
     },
     "localname": "JoslynOilSandsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_KeyManagementPersonnelCompensationAnnualIncentivePlans": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_KeyManagementPersonnelCompensation",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Key Management Personnel Compensation, Annual Incentive Plans",
        "label": "Key Management Personnel Compensation, Annual Incentive Plans",
        "terseLabel": "Annual incentive plans"
       }
      }
     },
     "localname": "KeyManagementPersonnelCompensationAnnualIncentivePlans",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_KeyManagementPersonnelCompensationLongTermShareBasedPayment": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails": {
       "order": 4.0,
       "parentTag": "ifrs-full_KeyManagementPersonnelCompensation",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Key Management Personnel Compensation, Long-Term Share-Based Payment",
        "label": "Key Management Personnel Compensation, Long-Term Share-Based Payment",
        "terseLabel": "Long-term incentive plans"
       }
      }
     },
     "localname": "KeyManagementPersonnelCompensationLongTermShareBasedPayment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_KeyManagementPersonnelCompensationOptionsIssued": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_KeyManagementPersonnelCompensation",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Key Management Personnel Compensation, Options Issued",
        "label": "Key Management Personnel Compensation, Options Issued",
        "terseLabel": "Common stock option based awards"
       }
      }
     },
     "localname": "KeyManagementPersonnelCompensationOptionsIssued",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_KeyManagementPersonnelOfEntityOrParentNonManagementDirectorMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Key Management Personnel Of Entity Or Parent, Non-Management Director [Member]",
        "label": "Key Management Personnel Of Entity Or Parent, Non-Management Director [Member]",
        "terseLabel": "Non-management directors"
       }
      }
     },
     "localname": "KeyManagementPersonnelOfEntityOrParentNonManagementDirectorMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_KeyManagementPersonnelOfEntityOrParentSeniorManagementMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Key Management Personnel Of Entity Or Parent, Senior Management [Member]",
        "label": "Key Management Personnel Of Entity Or Parent, Senior Management [Member]",
        "terseLabel": "Senior management"
       }
      }
     },
     "localname": "KeyManagementPersonnelOfEntityOrParentSeniorManagementMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_KeystoneXLPipelineProjectMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Keystone XL Pipeline Project",
        "label": "Keystone XL Pipeline Project [Member]",
        "terseLabel": "Keystone XL Pipeline Project"
       }
      }
     },
     "localname": "KeystoneXLPipelineProjectMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LeaseAssetsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lease Assets [Member]",
        "label": "Lease Assets [Member]",
        "verboseLabel": "Lease assets"
       }
      }
     },
     "localname": "LeaseAssetsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LeasePaymentsIncludedInLiablities": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lease Payments Included In Liablities",
        "label": "Lease Payments Included In Liablities",
        "terseLabel": "Lease payments included In liablities"
       }
      }
     },
     "localname": "LeasePaymentsIncludedInLiablities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LettersOfCreditAndGuaranteesOutstandingAmount": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Letters Of Credit And Guarantees Outstanding, Amount",
        "label": "Letters Of Credit And Guarantees Outstanding, Amount",
        "terseLabel": "Letters of credit and guarantees outstanding"
       }
      }
     },
     "localname": "LettersOfCreditAndGuaranteesOutstandingAmount",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LiabilitiesFromShareBasedPaymentTransactionsTransferredToCommonSharesThroughExerciseOfOptions": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Liabilities From Share-Based Payment Transactions, Transferred To Common Shares Through Exercise Of Options",
        "label": "Liabilities From Share-Based Payment Transactions, Transferred To Common Shares Through Exercise Of Options",
        "negatedTerseLabel": "Transferred to common shares"
       }
      }
     },
     "localname": "LiabilitiesFromShareBasedPaymentTransactionsTransferredToCommonSharesThroughExerciseOfOptions",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LineOfCreditFacilityMaximumBorrowingCapacity1": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line Of Credit Facility, Maximum Borrowing Capacity1",
        "label": "Line Of Credit Facility, Maximum Borrowing Capacity1",
        "terseLabel": "Maximum credit facility"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacity1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LineOfCreditFacilityMaximumBorrowingCapacityExtendedTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line Of Credit Facility, Maximum Borrowing Capacity Extended Term",
        "label": "Line Of Credit Facility, Maximum Borrowing Capacity Extended Term",
        "terseLabel": "Maximum credit facility extended term"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacityExtendedTerm",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_LineOfCreditFacilityMaximumBorrowingCapacityIncreased": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line Of Credit Facility, Maximum Borrowing Capacity Increased",
        "label": "Line Of Credit Facility, Maximum Borrowing Capacity Increased",
        "terseLabel": "Maximum borrowing capacity increased"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacityIncreased",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LineOfCreditFacilityMaximumBorrowingCapacityNotExtended": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line Of Credit Facility, Maximum Borrowing Capacity Not Extended",
        "label": "Line Of Credit Facility, Maximum Borrowing Capacity Not Extended",
        "terseLabel": "Maximum borrowing capacity not extended"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacityNotExtended",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LineOfCreditFacilityMaximumBorrowingCapacityReDraw": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line Of Credit Facility, Maximum Borrowing Capacity Re-draw",
        "label": "Line Of Credit Facility, Maximum Borrowing Capacity Re-draw",
        "terseLabel": "Maximum credit facility re draw"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacityReDraw",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LineOfCreditFacilityMaximumBorrowingCapacityReduction": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line Of Credit Facility, Maximum Borrowing Capacity, Reduction",
        "label": "Line Of Credit Facility, Maximum Borrowing Capacity, Reduction",
        "terseLabel": "Maximum borrowing capacity reduction"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacityReduction",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LineOfCreditFacilityMaximumBorrowingCapacityTermExtended": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line Of Credit Facility, Maximum Borrowing Capacity, Term Extended",
        "label": "Line Of Credit Facility, Maximum Borrowing Capacity, Term Extended",
        "terseLabel": "Maximum borrowing capacity, term extended"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacityTermExtended",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_LongTermBorrowingsFivePointEightFivePercentDueFebruary2035Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Five Point Eight Five Percent Due February 2035 [Member]",
        "label": "Long-Term Borrowings - Five Point Eight Five Percent Due February 2035 [Member]",
        "terseLabel": "5.85% due February 1, 2035 (US$350 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsFivePointEightFivePercentDueFebruary2035Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsFourPointNineFivePercentDueJune2047Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Four Point Nine Five Percent Due June 2047 [Member]",
        "label": "Long-Term Borrowings - Four Point Nine Five Percent Due June 2047 [Member]",
        "terseLabel": "4.95% due June 1, 2047 (US$750 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsFourPointNineFivePercentDueJune2047Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsIncludingCurrentPortionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings, Including Current Portion [Member]",
        "label": "Long-Term Borrowings, Including Current Portion [Member]",
        "terseLabel": "Long-term debt",
        "verboseLabel": "Fixed rate long-term debt"
       }
      }
     },
     "localname": "LongTermBorrowingsIncludingCurrentPortionMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsSevenPointTwoZeroPercentDueJanuary2032Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Seven Point Two Zero Percent Due January 2032 [Member]",
        "label": "Long-Term Borrowings - Seven Point Two Zero Percent Due January 2032 [Member]",
        "terseLabel": "7.20% due January 15, 2032 (US$400 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsSevenPointTwoZeroPercentDueJanuary2032Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsSixPointFiveZeroPercentDueFebruary2037Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Six Point Five Zero Percent Due February 2037 [Member]",
        "label": "Long-Term Borrowings - Six Point Five Zero Percent Due February 2037 [Member]",
        "terseLabel": "6.50% due February 15, 2037 (US$450 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsSixPointFiveZeroPercentDueFebruary2037Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsSixPointFourFivePercentDueJune2033Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Six Point Four Five Percent Due June 2033 [Member]",
        "label": "Long-Term Borrowings - Six Point Four Five Percent Due June 2033 [Member]",
        "terseLabel": "6.45% due June 30, 2033 (US$350 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsSixPointFourFivePercentDueJune2033Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsSixPointSevenFivePercentDueFebruary2039Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Six Point Seven Five Percent Due February 2039 [Member]",
        "label": "Long-Term Borrowings - Six Point Seven Five Percent Due February 2039 [Member]",
        "terseLabel": "6.75% due February 1, 2039 (US$400 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsSixPointSevenFivePercentDueFebruary2039Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsSixPointTwoFivePercentDueMarch2038Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Six Point Two Five Percent Due March 2038 [Member]",
        "label": "Long-Term Borrowings - Six Point Two Five Percent Due March 2038 [Member]",
        "terseLabel": "6.25% due March 15, 2038 (US$1,100 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsSixPointTwoFivePercentDueMarch2038Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsThreePointEightFivePercentDueJune2027Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Three Point Eight Five Percent Due June 2027 [Member]",
        "label": "Long-Term Borrowings - Three Point Eight Five Percent Due June 2027 [Member]",
        "terseLabel": "3.85% due June 1, 2027 (US$1,250 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsThreePointEightFivePercentDueJune2027Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsThreePointEightZeroPercentDueApril2024Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Three Point Eight Zero Percent Due April 2024 [Member]",
        "label": "Long-Term Borrowings - Three Point Eight Zero Percent Due April 2024 [Member]",
        "terseLabel": "3.80% due April 15, 2024 (US$500 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsThreePointEightZeroPercentDueApril2024Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsThreePointFourFivePercentDueNovember2021Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Three Point Four Five Percent Due November 2021 [Member]",
        "label": "Long-Term Borrowings - Three Point Four Five Percent Due November 2021 [Member]",
        "terseLabel": "3.45% due November 15, 2021 (US$500 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsThreePointFourFivePercentDueNovember2021Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsThreePointNineZeroPercentDueFebruary2025Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Three Point Nine Zero Percent Due February 2025 [Member]",
        "label": "Long-Term Borrowings - Three Point Nine Zero Percent Due February 2025 [Member]",
        "terseLabel": "3.90% due February 1, 2025 (US$600 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsThreePointNineZeroPercentDueFebruary2025Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsTwoPointNineFivePercentDueJanuary2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Two Point Nine Five Percent Due January 2023 [Member]",
        "label": "Long-Term Borrowings - Two Point Nine Five Percent Due January 2023 [Member]",
        "terseLabel": "2.95% due January 15, 2023 (US$1,000 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsTwoPointNineFivePercentDueJanuary2023Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsTwoPointNineFivePercentDueJulyTwoThousandThirtyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Two Point Nine Five Percent Due July Two Thousand Thirty",
        "label": "Long-Term Borrowings - Two Point Nine Five Percent Due July Two Thousand Thirty [Member]",
        "terseLabel": "2.95% due July 15, 2030 (US$500 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsTwoPointNineFivePercentDueJulyTwoThousandThirtyMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermBorrowingsTwoPointZeroFivePercentDueJulyTwoThousandTwentyFiveMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Borrowings - Two Point Zero Five Percent Due July Two Thousand Twenty Five",
        "label": "Long-Term Borrowings - Two Point Zero Five Percent Due July Two Thousand Twenty Five [Member]",
        "terseLabel": "2.05% due July 15, 2025 (US$600 million)"
       }
      }
     },
     "localname": "LongTermBorrowingsTwoPointZeroFivePercentDueJulyTwoThousandTwentyFiveMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_LongTermNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Notes [Member]",
        "label": "Long-Term Notes [Member]",
        "terseLabel": "US dollar denominated debt, unsecured"
       }
      }
     },
     "localname": "LongTermNotesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MIscellaneousOtherAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails_1": {
       "order": 4.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "MIscellaneous Other Assets",
        "label": "MIscellaneous Other Assets",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "MIscellaneousOtherAssets",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_MajorBorrowingsTransactionsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Major Borrowings Transactions [Member]",
        "label": "Major Borrowings Transactions [Member]",
        "terseLabel": "Major Borrowings Transactions"
       }
      }
     },
     "localname": "MajorBorrowingsTransactionsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsExpiringAugustTwoThousandTwentyThreeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings Expiring August Two Thousand Twenty Three",
        "label": "Medium-Term Borrowings Expiring August Two Thousand Twenty Three [Member]",
        "terseLabel": "Medium-term borrowings expiring August 2023"
       }
      }
     },
     "localname": "MediumTermBorrowingsExpiringAugustTwoThousandTwentyThreeMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsFourPointEightFivePercentDebenturesDueMay2047Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - Four Point Eight Five Percent Debentures Due May 2047 [Member]",
        "label": "Medium-Term Borrowings - Four Point Eight Five Percent Debentures Due May 2047 [Member]",
        "terseLabel": "4.85% debentures due May 30, 2047"
       }
      }
     },
     "localname": "MediumTermBorrowingsFourPointEightFivePercentDebenturesDueMay2047Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsOnePointFourFivePercentDebenturesDueNovemberTwoThousandTwentyThreeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - One Point Four Five Percent Debentures Due November Two Thousand Twenty Three",
        "label": "Medium-Term Borrowings - One Point Four Five Percent Debentures Due November Two Thousand Twenty Three [Member]",
        "terseLabel": "1.45% debentures due November 16, 2023"
       }
      }
     },
     "localname": "MediumTermBorrowingsOnePointFourFivePercentDebenturesDueNovemberTwoThousandTwentyThreeMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsThreePointFiveFivePercentDebenturesDueJune2024Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - Three Point Five Five Percent Debentures Due June 2024 [Member]",
        "label": "Medium-Term Borrowings - Three Point Five Five Percent Debentures Due June 2024 [Member]",
        "terseLabel": "3.55% debentures due June 3, 2024"
       }
      }
     },
     "localname": "MediumTermBorrowingsThreePointFiveFivePercentDebenturesDueJune2024Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsThreePointFourTwoPercentDebenturesDueDecember2026Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - Three Point Four Two Percent Debentures Due December 2026 [Member]",
        "label": "Medium-Term Borrowings - Three Point Four Two Percent Debentures Due December 2026 [Member]",
        "terseLabel": "3.42% debentures due December 1, 2026"
       }
      }
     },
     "localname": "MediumTermBorrowingsThreePointFourTwoPercentDebenturesDueDecember2026Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsThreePointThreeOnePercentDebenturesDueFebruaryTwoThousandTwentyTwoMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - Three Point Three One Percent Debentures Due February Two Thousand Twenty Two [Member]",
        "label": "Medium-Term Borrowings - Three Point Three One Percent Debentures Due February Two Thousand Twenty Two [Member]",
        "terseLabel": "3.31% debentures due February 11, 2022"
       }
      }
     },
     "localname": "MediumTermBorrowingsThreePointThreeOnePercentDebenturesDueFebruaryTwoThousandTwentyTwoMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsTwoPointEightNinePercentDebenturesDueAugust2020Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - Two Point Eight Nine Percent Debentures Due August 2020 [Member]",
        "label": "Medium-Term Borrowings - Two Point Eight Nine Percent Debentures Due August 2020 [Member]",
        "terseLabel": "2.89% debentures due August 14, 2020"
       }
      }
     },
     "localname": "MediumTermBorrowingsTwoPointEightNinePercentDebenturesDueAugust2020Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsTwoPointFiveZeroPercentDebenturesDueJanuaryTwoThousandTwentyEightMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - Two Point Five Zero Percent Debentures Due January Two Thousand Twenty Eight",
        "label": "Medium-Term Borrowings - Two Point Five Zero Percent Debentures Due January Two Thousand Twenty Eight [Member]",
        "terseLabel": "2.50% debentures due January 17, 2028"
       }
      }
     },
     "localname": "MediumTermBorrowingsTwoPointFiveZeroPercentDebenturesDueJanuaryTwoThousandTwentyEightMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MediumTermBorrowingsTwoPointZeroFivePercentDebenturesDueJune2020Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Medium-Term Borrowings - Two Point Zero Five Percent Debentures Due June 2020 [Member]",
        "label": "Medium-Term Borrowings - Two Point Zero Five Percent Debentures Due June 2020 [Member]",
        "terseLabel": "2.05% debentures due June 1, 2020"
       }
      }
     },
     "localname": "MediumTermBorrowingsTwoPointZeroFivePercentDebenturesDueJune2020Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MidstreamAndRefiningSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Midstream And Refining Segment [Member]",
        "label": "Midstream And Refining Segment [Member]",
        "terseLabel": "Midstream and Refining"
       }
      }
     },
     "localname": "MidstreamAndRefiningSegmentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_MinimumLeasePaymentsPayableUnderNonCancellableLease": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Minimum Lease Payments Payable Under Non-Cancellable Lease",
        "label": "Minimum Lease Payments Payable Under Non-Cancellable Lease",
        "terseLabel": "Offshore vessels and equipment, field equipment and power"
       }
      }
     },
     "localname": "MinimumLeasePaymentsPayableUnderNonCancellableLease",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_MiscellaneousOtherLiabilities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails_1": {
       "order": 5.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Miscellaneous Other Liabilities",
        "label": "Miscellaneous Other Liabilities",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "MiscellaneousOtherLiabilities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NaturalGasHubAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Natural Gas Hub [Axis]",
        "label": "Natural Gas Hub [Axis]",
        "terseLabel": "Natural Gas Hub [Axis]"
       }
      }
     },
     "localname": "NaturalGasHubAxis",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_NaturalGasHubDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Domain] for Natural Gas Hub [Axis]",
        "label": "Natural Gas Hub [Domain]",
        "terseLabel": "Natural Gas Hub [Domain]"
       }
      }
     },
     "localname": "NaturalGasHubDomain",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NetExpendituresProceedsExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": 2.0,
       "parentTag": "cnq_NetExpendituresProceedsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Net Expenditures (Proceeds), Exploration For And Evaluation Of Mineral Resources",
        "label": "Net Expenditures (Proceeds), Exploration For And Evaluation Of Mineral Resources",
        "terseLabel": "Net expenditures"
       }
      }
     },
     "localname": "NetExpendituresProceedsExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NetExpendituresProceedsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Net Expenditures (Proceeds), Exploration For And Evaluation Of Mineral Resources And Property, Plant and Equipment",
        "label": "Net Expenditures (Proceeds), Exploration For And Evaluation Of Mineral Resources And Property, Plant and Equipment",
        "totalLabel": "Net expenditures"
       }
      }
     },
     "localname": "NetExpendituresProceedsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NetExpendituresProceedsPropertyPlantandEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": 1.0,
       "parentTag": "cnq_NetExpendituresProceedsExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Net Expenditures (Proceeds), Property, Plant and Equipment",
        "label": "Net Expenditures (Proceeds), Property, Plant and Equipment",
        "terseLabel": "Net expenditures"
       }
      }
     },
     "localname": "NetExpendituresProceedsPropertyPlantandEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NetWorkingCapitalLiabilitiesRecognisedAsOfAcquisitionDate": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 8.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Net Working Capital Liabilities Recognised As Of Acquisition Date",
        "label": "Net Working Capital Liabilities Recognised As Of Acquisition Date",
        "negatedTerseLabel": "Working capital"
       }
      }
     },
     "localname": "NetWorkingCapitalLiabilitiesRecognisedAsOfAcquisitionDate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NonCashAndFairValueChangesExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": 2.0,
       "parentTag": "cnq_NonCashAndFairValueChangesExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Cash And Fair Value Changes, Exploration For And Evaluation Of Mineral Resources",
        "label": "Non-Cash And Fair Value Changes, Exploration For And Evaluation Of Mineral Resources",
        "terseLabel": "Non-cash and fair value changes"
       }
      }
     },
     "localname": "NonCashAndFairValueChangesExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NonCashAndFairValueChangesExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Cash And Fair Value Changes, Exploration For And Evaluation Of Mineral Resources And Property, Plant and Equipment",
        "label": "Non-Cash And Fair Value Changes, Exploration For And Evaluation Of Mineral Resources And Property, Plant and Equipment",
        "totalLabel": "Total non-cash and fair value changes"
       }
      }
     },
     "localname": "NonCashAndFairValueChangesExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NonCashAndFairValueChangesPropertyPlantAndEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails": {
       "order": 1.0,
       "parentTag": "cnq_NonCashAndFairValueChangesExplorationForAndEvaluationOfMineralResourcesAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Cash And Fair Value Changes, Property, Plant And Equipment",
        "label": "Non-Cash And Fair Value Changes, Property, Plant And Equipment",
        "terseLabel": "Non-cash and fair value changes"
       }
      }
     },
     "localname": "NonCashAndFairValueChangesPropertyPlantAndEquipment",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NonCashChangesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Cash Changes",
        "label": "Non-Cash Changes [Abstract]",
        "terseLabel": "Non-cash changes:"
       }
      }
     },
     "localname": "NonCashChangesAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_NonCurrentDerivativeFinancialAssetsLiabilities": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Current Derivative Financial Assets (Liabilities)",
        "label": "Non-Current Derivative Financial Assets (Liabilities)",
        "verboseLabel": "Asset (liability), included in other long-term assets"
       }
      }
     },
     "localname": "NonCurrentDerivativeFinancialAssetsLiabilities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NonCurrentInventory": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails_1": {
       "order": 6.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Current Inventory",
        "label": "Non-Current Inventory",
        "terseLabel": "Long-term inventory"
       }
      }
     },
     "localname": "NonCurrentInventory",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NonCurrentLiabilitiesFromShareBasedPaymentTransactions": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_LiabilitiesFromSharebasedPaymentTransactions2011",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Current Liabilities From Share-Based Payment Transactions",
        "label": "Non-Current Liabilities From Share-Based Payment Transactions",
        "terseLabel": "Non-current liabilities from share-based payment arrangements"
       }
      }
     },
     "localname": "NonCurrentLiabilitiesFromShareBasedPaymentTransactions",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_NonRevolvingCreditFacilityMaturingJune2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non Revolving Credit Facility Maturing June 2023",
        "label": "Non Revolving Credit Facility Maturing June 2023 [Member]",
        "terseLabel": "Non Revolving Credit Facility Maturing June 2023"
       }
      }
     },
     "localname": "NonRevolvingCreditFacilityMaturingJune2023Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NonRevolvingTermCreditFacilityMaturingFebruary2021Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Revolving Term Credit Facility Maturing February 2021 [Member]",
        "label": "Non-Revolving Term Credit Facility Maturing February 2021 [Member]",
        "terseLabel": "Non-revolving term credit facility maturing February 2021"
       }
      }
     },
     "localname": "NonRevolvingTermCreditFacilityMaturingFebruary2021Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NonRevolvingTermCreditFacilityMaturingFebruary2022Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Revolving Term Credit Facility Maturing February 2022",
        "label": "Non-Revolving Term Credit Facility Maturing February 2022 [Member]",
        "terseLabel": "Non-revolving term credit facility maturing February 2022"
       }
      }
     },
     "localname": "NonRevolvingTermCreditFacilityMaturingFebruary2022Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NonRevolvingTermCreditFacilityMaturingFebruary2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Revolving Term Credit Facility Maturing February 2023 [Member]",
        "label": "Non-Revolving Term Credit Facility Maturing February 2023 [Member]",
        "terseLabel": "Non-revolving term credit facility maturing February 2023"
       }
      }
     },
     "localname": "NonRevolvingTermCreditFacilityMaturingFebruary2023Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NonRevolvingTermCreditFacilityMaturingJune2022Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Revolving Term Credit Facility Maturing June 2022 [Member]",
        "label": "Non-Revolving Term Credit Facility Maturing June 2022 [Member]",
        "terseLabel": "Non-revolving term credit facility maturing June 2022"
       }
      }
     },
     "localname": "NonRevolvingTermCreditFacilityMaturingJune2022Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NonRevolvingTermCreditFacilityMaturingMarch2022Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Revolving Term Credit Facility Maturing March 2022",
        "label": "Non-Revolving Term Credit Facility Maturing March 2022 [Member]",
        "terseLabel": "Non-Revolving Term Credit Facility Maturing March 2022"
       }
      }
     },
     "localname": "NonRevolvingTermCreditFacilityMaturingMarch2022Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NormalCourseIssuerBidPercentOfIssuedAndOutstandingShares": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Normal Course Issuer Bid, Percent Of Issued And Outstanding Shares",
        "label": "Normal Course Issuer Bid, Percent Of Issued And Outstanding Shares",
        "terseLabel": "Normal course issuer bid, percent of issued and outstanding shares"
       }
      }
     },
     "localname": "NormalCourseIssuerBidPercentOfIssuedAndOutstandingShares",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_NorthAmericaExplorationAndProductionSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "North America - Exploration And Production Segment [Member]",
        "label": "North America - Exploration And Production Segment [Member]",
        "terseLabel": "North America"
       }
      }
     },
     "localname": "NorthAmericaExplorationAndProductionSegmentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NorthSeaBrentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "North Sea Brent [Member]",
        "label": "North Sea Brent [Member]",
        "terseLabel": "North Sea Brent"
       }
      }
     },
     "localname": "NorthSeaBrentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NorthSeaExplorationAndProductionSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "North Sea - Exploration And Production Segment [Member]",
        "label": "North Sea - Exploration And Production Segment [Member]",
        "terseLabel": "North Sea"
       }
      }
     },
     "localname": "NorthSeaExplorationAndProductionSegmentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NorthSeaMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "North Sea [Member]",
        "label": "North Sea [Member]",
        "terseLabel": "North Sea"
       }
      }
     },
     "localname": "NorthSeaMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NorthWestRedwaterPartnershipMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "North West Redwater Partnership [Member]",
        "label": "North West Redwater Partnership [Member]",
        "terseLabel": "North West Redwater Partnership"
       }
      }
     },
     "localname": "NorthWestRedwaterPartnershipMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_NumberOfAcquisitions": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number Of Acquisitions",
        "label": "Number Of Acquisitions",
        "terseLabel": "Number of acquisitions"
       }
      }
     },
     "localname": "NumberOfAcquisitions",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "cnq_NumberOfGeographicSegments": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number Of Geographic Segments",
        "label": "Number Of Geographic Segments",
        "terseLabel": "Number of geographic segments"
       }
      }
     },
     "localname": "NumberOfGeographicSegments",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "cnq_NumberOfShareOptionsSurrenderedForCashInSharebasedPaymentArrangement": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number Of Share Options Surrendered For Cash In Share-based Payment Arrangement",
        "label": "Number Of Share Options Surrendered For Cash In Share-based Payment Arrangement",
        "negatedTerseLabel": "Stock options surrendered for cash settlement (in shares)"
       }
      }
     },
     "localname": "NumberOfShareOptionsSurrenderedForCashInSharebasedPaymentArrangement",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "cnq_NumberOfSharesAuthorisedInShareBasedPaymentArrangementAsAPercentageOfCommonSharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number Of Shares Authorised In Share Based Payment Arrangement As A Percentage Of Common Shares Outstanding",
        "label": "Number Of Shares Authorised In Share Based Payment Arrangement As A Percentage Of Common Shares Outstanding",
        "terseLabel": "Shares that may be reserved for issuance as a percentage of common shares outstanding"
       }
      }
     },
     "localname": "NumberOfSharesAuthorisedInShareBasedPaymentArrangementAsAPercentageOfCommonSharesOutstanding",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_OfficeLeasesAndOtherMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Office Leases And Other [Member]",
        "label": "Office Leases And Other [Member]",
        "terseLabel": "Office leases and other"
       }
      }
     },
     "localname": "OfficeLeasesAndOtherMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OffshoreAfricaExplorationAndProductionSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Offshore Africa - Exploration And Production Segment [Member]",
        "label": "Offshore Africa - Exploration And Production Segment [Member]",
        "terseLabel": "Offshore Africa"
       }
      }
     },
     "localname": "OffshoreAfricaExplorationAndProductionSegmentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OffshoreAfricaMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Offshore Africa [Member]",
        "label": "Offshore Africa [Member]",
        "terseLabel": "Offshore Africa"
       }
      }
     },
     "localname": "OffshoreAfricaMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OffshoreVesselsAndEquipmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Offshore Vessels And Equipment [Member]",
        "label": "Offshore Vessels And Equipment [Member]",
        "terseLabel": "Offshore vessels and equipment"
       }
      }
     },
     "localname": "OffshoreVesselsAndEquipmentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OilAndGas1Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Oil And Gas1 [Member]",
        "label": "Oil And Gas1 [Member]",
        "terseLabel": "Oil And Gas"
       }
      }
     },
     "localname": "OilAndGas1Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OilAndGasAverageSalePriceAndProductionCostPerUnit1LineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Table]",
        "label": "Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]",
        "terseLabel": "Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]"
       }
      }
     },
     "localname": "OilAndGasAverageSalePriceAndProductionCostPerUnit1LineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_OilAndGasAverageSalePriceAndProductionCostPerUnit1Table": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Table]",
        "label": "Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Table]",
        "terseLabel": "Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Table]"
       }
      }
     },
     "localname": "OilAndGasAverageSalePriceAndProductionCostPerUnit1Table",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_OilSandsMiningAndUpgradingSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Oil Sands Mining And Upgrading Segment [Member]",
        "label": "Oil Sands Mining And Upgrading Segment [Member]",
        "terseLabel": "Oil Sands Mining and Upgrading"
       }
      }
     },
     "localname": "OilSandsMiningAndUpgradingSegmentMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OilandNaturalGasLiquidsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Oil and Natural Gas Liquids [Member]",
        "label": "Oil and Natural Gas Liquids [Member]",
        "terseLabel": "Crude Oil, Synthetic Crude Oil, Bitumen, Natural Gas, Natural Gas Liquids"
       }
      }
     },
     "localname": "OilandNaturalGasLiquidsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OperatingSegmentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Operating Segments [Abstract]",
        "label": "Operating Segments [Abstract]",
        "terseLabel": "Operating Segments [Abstract]"
       }
      }
     },
     "localname": "OperatingSegmentsAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_OptimizationTransactionExtendedPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Optimization Transaction Extended Period",
        "label": "Optimization Transaction Extended Period",
        "terseLabel": "Optimization transaction extended period"
       }
      }
     },
     "localname": "OptimizationTransactionExtendedPeriod",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_OriginalIssuePremiumsDiscountsNetMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Original Issue Premiums (Discounts), Net [Member]",
        "label": "Original Issue Premiums (Discounts), Net [Member]",
        "terseLabel": "Original issue discounts, net"
       }
      }
     },
     "localname": "OriginalIssuePremiumsDiscountsNetMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OtherCommitments": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Commitments",
        "label": "Other Commitments",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherCommitments",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_OtherExplorationAndProductionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other - Exploration And Production [Member]",
        "label": "Other - Exploration And Production [Member]",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherExplorationAndProductionMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OtherIncomeAndRevenueMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Income And Revenue",
        "label": "Other Income And Revenue [Member]",
        "terseLabel": "Other Income And Revenue"
       }
      }
     },
     "localname": "OtherIncomeAndRevenueMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OtherLiabilitiesFromShareBasedPaymentTransactions": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Liabilities From Share-Based Payment Transactions",
        "label": "Other Liabilities From Share-Based Payment Transactions",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherLiabilitiesFromShareBasedPaymentTransactions",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_OtherNonCurrentAssetsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Non-Current Assets [Member]",
        "label": "Other Non-Current Assets [Member]",
        "terseLabel": "Other long-term assets"
       }
      }
     },
     "localname": "OtherNonCurrentAssetsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OtherNonCurrentLiabilitiesIncludingLiabilitiesIncurredMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Non-Current Liabilities, Including Liabilities Incurred [Member]",
        "label": "Other Non-Current Liabilities, Including Liabilities Incurred [Member]",
        "terseLabel": "Other long-term liabilities"
       }
      }
     },
     "localname": "OtherNonCurrentLiabilitiesIncludingLiabilitiesIncurredMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OtherNonCurrentLiabilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Non-Current Liabilities [Member]",
        "label": "Other Non-Current Liabilities [Member]",
        "terseLabel": "Other long-term liabilities"
       }
      }
     },
     "localname": "OtherNonCurrentLiabilitiesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_OtherProvisionsContingentLiabilitiesAndContingentAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]",
        "label": "Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]",
        "terseLabel": "Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]"
       }
      }
     },
     "localname": "OtherProvisionsContingentLiabilitiesAndContingentAssetsAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_PaintedPonyEnergyLtdMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Painted Pony Energy Ltd",
        "label": "Painted Pony Energy Ltd [Member]",
        "terseLabel": "Painted Pony Energy Ltd"
       }
      }
     },
     "localname": "PaintedPonyEnergyLtdMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_PartnershipDistributions": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Partnership Distributions",
        "label": "Partnership Distributions",
        "terseLabel": "Partnership distributions"
       }
      }
     },
     "localname": "PartnershipDistributions",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_PartnershipInterestTransferred": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Partnership Interest Transferred",
        "label": "Partnership Interest Transferred",
        "terseLabel": "Partnership interest transferred"
       }
      }
     },
     "localname": "PartnershipInterestTransferred",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_PercentageOfDividendIncreasedFromPreviousQuarterlyDividend": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage Of Dividend Increased From Previous Quarterly Dividend",
        "label": "Percentage Of Dividend Increased From Previous Quarterly Dividend",
        "terseLabel": "Dividend increase percentage"
       }
      }
     },
     "localname": "PercentageOfDividendIncreasedFromPreviousQuarterlyDividend",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_PercentageOfNetCarriedInterestAcquiredOnExistingLeasedAsset": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage Of Net Carried Interest Acquired On Existing Leased Asset",
        "label": "Percentage Of Net Carried Interest Acquired On Existing Leased Asset",
        "terseLabel": "Percentage of net carried interest"
       }
      }
     },
     "localname": "PercentageOfNetCarriedInterestAcquiredOnExistingLeasedAsset",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_PerformanceShareUnitsPSUMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Performance Share Units (PSU) [Member]",
        "label": "Performance Share Units (PSU) [Member]",
        "terseLabel": "Performance Share Units"
       }
      }
     },
     "localname": "PerformanceShareUnitsPSUMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_PrairieSkyRoyaltyLtd.Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "PrairieSky Royalty Ltd. [Member]",
        "label": "PrairieSky Royalty Ltd. [Member]",
        "terseLabel": "Investment in PrairieSky Royalty Ltd."
       }
      }
     },
     "localname": "PrairieSkyRoyaltyLtd.Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails",
      "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_PrepaidServiceTolls": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails_1": {
       "order": 5.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Prepaid Service Tolls",
        "label": "Prepaid Service Tolls",
        "terseLabel": "Prepaid cost of service toll"
       }
      }
     },
     "localname": "PrepaidServiceTolls",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ProceedsFromSaleOfInvestments": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 7.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proceeds From Sale Of Investments",
        "label": "Proceeds From Sale Of Investments",
        "terseLabel": "Proceeds from investment"
       }
      }
     },
     "localname": "ProceedsFromSaleOfInvestments",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ProceedsFromSaleOfInvestmentsCurrent": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proceeds From Sale Of Investments, Current",
        "label": "Proceeds From Sale Of Investments, Current",
        "terseLabel": "Cash proceeds"
       }
      }
     },
     "localname": "ProceedsFromSaleOfInvestmentsCurrent",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ProceedsFromSaleOfInvestmentsCurrentPerShare": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proceeds From Sale of Investments, Current, Per Share",
        "label": "Proceeds From Sale of Investments, Current, Per Share",
        "terseLabel": "Cash proceeds per common share (CAD per share)"
       }
      }
     },
     "localname": "ProceedsFromSaleOfInvestmentsCurrentPerShare",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "cnq_ProceedsFromSettlementOfCrossCurrencySwapsClassifiedAsFinancingActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 4.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proceeds From Settlement Of Cross Currency Swaps, Classified As Financing Activities",
        "label": "Proceeds From Settlement Of Cross Currency Swaps, Classified As Financing Activities",
        "terseLabel": "Proceeds on settlement of cross currency swaps"
       }
      }
     },
     "localname": "ProceedsFromSettlementOfCrossCurrencySwapsClassifiedAsFinancingActivities",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ProductTransportationAndProcessingObligation": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails_1": {
       "order": 4.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Product Transportation And Processing Obligation",
        "label": "Product Transportation And Processing Obligation",
        "terseLabel": "Transportation and processing contracts"
       }
      }
     },
     "localname": "ProductTransportationAndProcessingObligation",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ProductTransportationAndProcessingObligationUnrecorded": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Product Transportation And Processing Obligation, Unrecorded",
        "label": "Product Transportation And Processing Obligation, Unrecorded",
        "terseLabel": "Product transportation and processing obligation, unrecorded"
       }
      }
     },
     "localname": "ProductTransportationAndProcessingObligationUnrecorded",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ProductTransportationAndStorageMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Product Transportation And Storage [Member]",
        "label": "Product Transportation And Storage [Member]",
        "terseLabel": "Product transportation and storage"
       }
      }
     },
     "localname": "ProductTransportationAndStorageMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_PropertyPlantAndEquipmentAndExplorationAndEvaluationAssetsRelatedTemporaryDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Property, Plant And Equipment And Exploration And Evaluation Assets Related Temporary Differences [Member]",
        "label": "Property, Plant And Equipment And Exploration And Evaluation Assets Related Temporary Differences [Member]",
        "terseLabel": "Property, plant and equipment and exploration and evaluation assets"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentAndExplorationAndEvaluationAssetsRelatedTemporaryDifferencesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ProvedDevelopedAndUndevelopedReserves1RollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proved Developed And Undeveloped Reserves1 [Roll Forward]",
        "label": "Proved Developed And Undeveloped Reserves1 [Roll Forward]",
        "terseLabel": "Proved Developed And Undeveloped Reserves [Roll Forward]"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReserves1RollForward",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_ProvedDevelopedAndUndevelopedReservesEconomicRevisionsDueToPrices": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proved Developed And Undeveloped Reserves, Economic Revisions Due To Prices",
        "label": "Proved Developed And Undeveloped Reserves, Economic Revisions Due To Prices",
        "terseLabel": "Economic revisions due to prices (in MMbbl)",
        "verboseLabel": "Economic revisions due to prices (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesEconomicRevisionsDueToPrices",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "cnq_ProvincialCorporateIncomeTaxRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Provincial Corporate Income Tax Rate",
        "label": "Provincial Corporate Income Tax Rate",
        "terseLabel": "Provincial corporate income tax rate"
       }
      }
     },
     "localname": "ProvincialCorporateIncomeTaxRate",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_ProvincialCorporateIncomeTaxRateAnnualRateReduction": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Provincial Corporate Income Tax Rate, Annual Rate Reduction",
        "label": "Provincial Corporate Income Tax Rate, Annual Rate Reduction",
        "terseLabel": "Provincial corporate income tax rate, annual rate reduction"
       }
      }
     },
     "localname": "ProvincialCorporateIncomeTaxRateAnnualRateReduction",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_PurchaseOfCommonSharesForRetirementMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Purchase Of Common Shares For Retirement [Member]",
        "label": "Purchase Of Common Shares For Retirement [Member]",
        "terseLabel": "Purchase Of Common Shares For Retirement"
       }
      }
     },
     "localname": "PurchaseOfCommonSharesForRetirementMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_RecognizedShareOfLossesOfJointVentures": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Recognized Share Of Losses Of Joint Ventures",
        "label": "Recognized Share Of Losses Of Joint Ventures",
        "terseLabel": "Recognized share of losses of joint ventures"
       }
      }
     },
     "localname": "RecognizedShareOfLossesOfJointVentures",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_ReconciliationOfChangesInDerivativeFinancialAssetsLiabilitiesNetRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Reconciliation Of Changes In Derivative Financial Assets (Liabilities), Net [Roll Forward]",
        "label": "Reconciliation Of Changes In Derivative Financial Assets (Liabilities), Net [Roll Forward]",
        "terseLabel": "Reconciliation Of Changes In Derivative Financial Assets (Liabilities), Net [Roll Forward]"
       }
      }
     },
     "localname": "ReconciliationOfChangesInDerivativeFinancialAssetsLiabilitiesNetRollForward",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_ReconciliationOfChangesInLiabilitiesFromShareBasedPaymentTransactionsRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Reconciliation Of Changes In Liabilities From Share-Based Payment Transactions [Roll Forward]",
        "label": "Reconciliation Of Changes In Liabilities From Share-Based Payment Transactions [Roll Forward]",
        "terseLabel": "Reconciliation Of Changes In Liabilities From Share-Based Payment Transactions [Roll Forward]"
       }
      }
     },
     "localname": "ReconciliationOfChangesInLiabilitiesFromShareBasedPaymentTransactionsRollForward",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_ReconciliationOfChangesInProvisionForDecommissioningRestorationAndRehabilitationCostsRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Reconciliation Of Changes In Provision For Decommissioning Restoration And Rehabilitation Costs [Roll Forward]",
        "label": "Reconciliation Of Changes In Provision For Decommissioning Restoration And Rehabilitation Costs [Roll Forward]",
        "terseLabel": "Reconciliation Of Changes In Provision For Decommissioning Restoration And Rehabilitation Costs [Roll Forward]"
       }
      }
     },
     "localname": "ReconciliationOfChangesInProvisionForDecommissioningRestorationAndRehabilitationCostsRollForward",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_RelatedPartyAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Related Party [Abstract]",
        "label": "Related Party [Abstract]",
        "terseLabel": "Related Party [Abstract]"
       }
      }
     },
     "localname": "RelatedPartyAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_RevenueNetOfBlendingProductionTransportationAndFeedstockExpense": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revenue Net Of Blending, Production, Transportation, And Feedstock Expense",
        "label": "Revenue Net Of Blending, Production, Transportation, And Feedstock Expense",
        "terseLabel": "Revenue net of blending, production, transportation, and feedstock expense"
       }
      }
     },
     "localname": "RevenueNetOfBlendingProductionTransportationAndFeedstockExpense",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_RevolvingCreditFacilityMaturingJune2024Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving Credit Facility Maturing June 2024",
        "label": "Revolving Credit Facility Maturing June 2024 [Member]",
        "terseLabel": "Revolving Credit Facility Maturing June 2024"
       }
      }
     },
     "localname": "RevolvingCreditFacilityMaturingJune2024Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_RevolvingSyndicatedCreditFacilityMaturingJune2022AndJune2024Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving Syndicated Credit Facility Maturing June 2022 And June 2024",
        "label": "Revolving Syndicated Credit Facility Maturing June 2022 And June 2024 [Member]",
        "terseLabel": "Revolving Syndicated Credit Facility Maturing June 2022 And June 2024"
       }
      }
     },
     "localname": "RevolvingSyndicatedCreditFacilityMaturingJune2022AndJune2024Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_RevolvingSyndicatedCreditFacilityMaturingJune2022Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving Syndicated Credit Facility Maturing June 2022 [Member]",
        "label": "Revolving Syndicated Credit Facility Maturing June 2022 [Member]",
        "terseLabel": "Revolving syndicated credit facility maturing June 2022"
       }
      }
     },
     "localname": "RevolvingSyndicatedCreditFacilityMaturingJune2022Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_RevolvingSyndicatedCreditFacilityMaturingJune2023AndJune2025Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving Syndicated Credit Facility Maturing June 2023 And June 2025",
        "label": "Revolving Syndicated Credit Facility Maturing June 2023 And June 2025 [Member]",
        "terseLabel": "Revolving Syndicated Credit Facility Maturing June 2023 And June 2025"
       }
      }
     },
     "localname": "RevolvingSyndicatedCreditFacilityMaturingJune2023AndJune2025Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_RevolvingSyndicatedCreditFacilityMaturingJune2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving Syndicated Credit Facility Maturing June 2023 [Member]",
        "label": "Revolving Syndicated Credit Facility Maturing June 2023 [Member]",
        "terseLabel": "Revolving syndicated credit facility maturing June 2023"
       }
      }
     },
     "localname": "RevolvingSyndicatedCreditFacilityMaturingJune2023Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_RevolvingSyndicatedCreditFacilityMaturingJune2024Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving Syndicated Credit Facility Maturing June 2024",
        "label": "Revolving Syndicated Credit Facility Maturing June 2024 [Member]",
        "terseLabel": "Revolving syndicated credit facility maturing June 2024"
       }
      }
     },
     "localname": "RevolvingSyndicatedCreditFacilityMaturingJune2024Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_RevolvingSyndicatedCreditFacilityMaturingJune2025Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving Syndicated Credit Facility Maturing June 2025",
        "label": "Revolving Syndicated Credit Facility Maturing June 2025 [Member]",
        "terseLabel": "Revolving syndicated credit facility maturing June 2025"
       }
      }
     },
     "localname": "RevolvingSyndicatedCreditFacilityMaturingJune2025Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_STORMResourcesLtdMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "STORM Resources Ltd",
        "label": "STORM Resources Ltd [Member]",
        "terseLabel": "STORM Resources Ltd"
       }
      }
     },
     "localname": "STORMResourcesLtdMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ScheduleofTwelveMonthAverageBenchmarkPricesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule Of Twelve Month Average Benchmark Prices [Table Text Block]",
        "label": "Schedule of Twelve Month Average Benchmark Prices [Table Text Block]",
        "terseLabel": "Schedule of Twelve Month Average Benchmark Prices"
       }
      }
     },
     "localname": "ScheduleofTwelveMonthAverageBenchmarkPricesTableTextBlock",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "cnq_SeniorSecuredBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Senior Secured Bonds",
        "label": "Senior Secured Bonds [Member]",
        "terseLabel": "Senior Secured Bonds"
       }
      }
     },
     "localname": "SeniorSecuredBondsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableDollarAmount": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Dollar Amount. Positive value indicates an increase; negative value indicates a decrease.",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Dollar Amount",
        "terseLabel": "Strengthening of the Canadian dollar by US$0.01"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableDollarAmount",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableImpactOnNetProfitLoss": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Impact On Net Profit (Loss)",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Impact On Net Profit (Loss)",
        "terseLabel": "Increase (decrease) to net earnings"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableImpactOnNetProfitLoss",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableImpactOnOtherComprehensiveIncomeLoss": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Impact On Other Comprehensive Income (Loss)",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Impact On Other Comprehensive Income (Loss)",
        "terseLabel": "Increase (decrease) to other comprehensive income"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariableImpactOnOtherComprehensiveIncomeLoss",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariablePercent": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Percent",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Decrease In Risk Variable, Percent",
        "terseLabel": "Decrease interest rate 1%"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleDecreaseInRiskVariablePercent",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableDollarAmount": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Dollar Amount. Positive value indicates an increase; negative value indicates a decrease.",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Dollar Amount",
        "terseLabel": "Weakening of the Canadian dollar by US$0.01"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableDollarAmount",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnNetProfitLoss": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Impact On Net Profit (Loss)",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Impact On Net Profit (Loss)",
        "terseLabel": "Increase (decrease) to net earnings"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnNetProfitLoss",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnOtherComprehensiveIncomeLoss": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Impact On Other Comprehensive Income (Loss)",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Impact On Other Comprehensive Income (Loss)",
        "terseLabel": "Increase (decrease) to other comprehensive income"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariableImpactOnOtherComprehensiveIncomeLoss",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariablePercent": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Percent",
        "label": "Sensitivity Analysis For Types Of Market Risk, Reasonably Possible Increase In Risk Variable, Percent",
        "terseLabel": "Increase interest rate 1%"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRiskReasonablyPossibleIncreaseInRiskVariablePercent",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_SensitivityAnalysisForTypesOfMarketRisksReasonablyPossibleMovementOfNaturalGasAndCrudeOilBasisSwapCurrencyPerVolume": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity Analysis For Types Of Market Risks, Reasonably Possible Movement Of Natural Gas And Crude Oil Basis Swap, Currency Per Volume",
        "label": "Sensitivity Analysis For Types Of Market Risks, Reasonably Possible Movement Of Natural Gas And Crude Oil Basis Swap, Currency Per Volume",
        "terseLabel": "Movement of natural gas and crude oil basis swap"
       }
      }
     },
     "localname": "SensitivityAnalysisForTypesOfMarketRisksReasonablyPossibleMovementOfNaturalGasAndCrudeOilBasisSwapCurrencyPerVolume",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "cnq_SeriesLSeniorSecuredBondsDueDecember2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series L Senior Secured Bonds Due December 2023",
        "label": "Series L Senior Secured Bonds Due December 2023 [Member]",
        "terseLabel": "Series L Senior Secured Bonds Due December 2023"
       }
      }
     },
     "localname": "SeriesLSeniorSecuredBondsDueDecember2023Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_SeriesMSeniorSecuredBondsDueDecember2026Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series M Senior Secured Bonds Due December 2026",
        "label": "Series M Senior Secured Bonds Due December 2026 [Member]",
        "terseLabel": "Series M Senior Secured Bonds Due December 2026"
       }
      }
     },
     "localname": "SeriesMSeniorSecuredBondsDueDecember2026Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_SeriesNSeniorSecuredBondsDueJune2031Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series N Senior Secured Bonds Due June 2031",
        "label": "Series N Senior Secured Bonds Due June 2031 [Member]",
        "terseLabel": "Series N Senior Secured Bonds Due June 2031"
       }
      }
     },
     "localname": "SeriesNSeniorSecuredBondsDueJune2031Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_SeriesOSeniorSecuredBondsDueJune2051Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series O Senior Secured Bonds Due June 2051",
        "label": "Series O Senior Secured Bonds Due June 2051 [Member]",
        "terseLabel": "Series O Senior Secured Bonds Due June 2051"
       }
      }
     },
     "localname": "SeriesOSeniorSecuredBondsDueJune2051Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationPeriod1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based Compensation Arrangement By Share-based Payment Award Expiration Period1",
        "label": "Share-Based Compensation Arrangement By Share-Based Payment Award, Expiration Period1",
        "terseLabel": "Expiration term"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationPeriod1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_ShareBasedCompensationArrangementbySharebasedPaymentAwardAwardVestingPeriod2": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-Based Compensation Arrangement by Share-based Payment Award, Award Vesting Period2",
        "label": "Share-Based Compensation Arrangement by Share-based Payment Award, Award Vesting Period2",
        "terseLabel": "Vesting term"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementbySharebasedPaymentAwardAwardVestingPeriod2",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_ShareCapitalReservesAndOtherEquityInterestAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share Capital, Reserves And Other Equity Interest [Abstract]",
        "label": "Share Capital, Reserves And Other Equity Interest [Abstract]",
        "terseLabel": "Share Capital, Reserves And Other Equity Interest [Abstract]"
       }
      }
     },
     "localname": "ShareCapitalReservesAndOtherEquityInterestAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_SharePrice": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share Price",
        "label": "Share Price",
        "terseLabel": "Market price per common share (CAD per share)"
       }
      }
     },
     "localname": "SharePrice",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "cnq_SharebasedCompensationMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based Compensation [Member]",
        "label": "Share-based Compensation [Member]",
        "terseLabel": "Share-based compensation"
       }
      }
     },
     "localname": "SharebasedCompensationMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_StatementOfCashFlowsAdditionalDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Statement Of Cash Flows, Additional Disclosures [Abstract]",
        "label": "Statement Of Cash Flows, Additional Disclosures [Abstract]",
        "terseLabel": "Statement Of Cash Flows, Additional Disclosures [Abstract]"
       }
      }
     },
     "localname": "StatementOfCashFlowsAdditionalDisclosuresAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "xbrltype": "stringItemType"
    },
    "cnq_StockPurchaseProgramTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock Purchase Program, Term",
        "label": "Stock Purchase Program, Term",
        "terseLabel": "Share repurchase term"
       }
      }
     },
     "localname": "StockPurchaseProgramTerm",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock Repurchase Program, Number Of Shares Authorized To Be Repurchased1",
        "label": "Stock Repurchase Program, Number Of Shares Authorized To Be Repurchased1",
        "terseLabel": "Shares authorized to be repurchased through Normal Course Issuer Bid (in shares)"
       }
      }
     },
     "localname": "StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "cnq_StockRepurchasedAndRetiredDuringPeriodShares1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock Repurchased And Retired During Period, Shares 1",
        "label": "Stock Repurchased And Retired During Period, Shares 1",
        "negatedTerseLabel": "Purchase of common shares under Normal Course Issuer Bid (In shares)",
        "verboseLabel": "Shares repurchased and retired (in shares)"
       }
      }
     },
     "localname": "StockRepurchasedAndRetiredDuringPeriodShares1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "cnq_StockRepurchasedAndRetiredDuringPeriodValue1": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock Repurchased And Retired During Period, Value 1",
        "label": "Stock Repurchased And Retired During Period, Value 1",
        "negatedTerseLabel": "Purchase of common shares under Normal Course Issuer Bid",
        "terseLabel": "Purchase of common shares under Normal Course Issuer Bid"
       }
      }
     },
     "localname": "StockRepurchasedAndRetiredDuringPeriodValue1",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_StockRepurchasedDuringPeriodWeightedAveragePricePerShare": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock Repurchased During Period, Weighted Average Price Per Share",
        "label": "Stock Repurchased During Period, Weighted Average Price Per Share",
        "terseLabel": "Weighted average price per share of shares repurchased and retired (in CAD per share)"
       }
      }
     },
     "localname": "StockRepurchasedDuringPeriodWeightedAveragePricePerShare",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "cnq_SubordinateDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Subordinate Debt",
        "label": "Subordinate Debt [Member]",
        "terseLabel": "Subordinate Debt"
       }
      }
     },
     "localname": "SubordinateDebtMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Supplemental\u200b Cash\u200b Flow\u200b Information\u200b",
        "label": "Supplemental\u200b Cash\u200b Flow\u200b Information\u200b [Abstract]",
        "terseLabel": "Supplemental\u200b Cash\u200b Flow\u200b Information\u200b [Abstract]"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_SupplementaryOilGasInformationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Supplementary Oil &amp; Gas Information [Table]",
        "label": "Supplementary Oil &amp; Gas Information [Line Items]",
        "terseLabel": "Supplementary Oil &amp; Gas Information [Line Items]"
       }
      }
     },
     "localname": "SupplementaryOilGasInformationLineItems",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_SupplementaryOilGasInformationTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Supplementary Oil &amp; Gas Information [Table]",
        "label": "Supplementary Oil &amp; Gas Information [Table]",
        "terseLabel": "Supplementary Oil &amp; Gas Information [Table]"
       }
      }
     },
     "localname": "SupplementaryOilGasInformationTable",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "cnq_SyndicatedCreditFacilityMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Syndicated Credit Facility [Member]",
        "label": "Syndicated Credit Facility [Member]",
        "terseLabel": "Syndicated credit facility"
       }
      }
     },
     "localname": "SyndicatedCreditFacilityMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_TaxEffectFromDeferredTaxNotRecognized": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 8.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tax Effect From Deferred Tax Not Recognized",
        "label": "Tax Effect From Deferred Tax Not Recognized",
        "terseLabel": "Change in unrecognized capital loss carryforward asset"
       }
      }
     },
     "localname": "TaxEffectFromDeferredTaxNotRecognized",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_TaxEffectOfDeductiblePetroleumRevenueAndOtherTaxesOnCorporateIncomeTax": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tax Effect Of Deductible Petroleum Revenue And Other Taxes On Corporate Income Tax",
        "label": "Tax Effect Of Deductible Petroleum Revenue And Other Taxes On Corporate Income Tax",
        "negatedTerseLabel": "Impact of deductible UK PRT and other taxes on corporate income tax"
       }
      }
     },
     "localname": "TaxEffectOfDeductiblePetroleumRevenueAndOtherTaxesOnCorporateIncomeTax",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_TaxEffectOfExerciseOfOptions": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 5.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tax Effect Of Exercise Of Options",
        "label": "Tax Effect Of Exercise Of Options",
        "negatedTerseLabel": "Stock options exercised for common shares"
       }
      }
     },
     "localname": "TaxEffectOfExerciseOfOptions",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_TaxEffectOfGainsFromBusinessCombinationExemptFromTaxation": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 11.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tax Effect Of Gains From Business Combination Exempt From Taxation",
        "label": "Tax Effect Of Gains From Business Combination Exempt From Taxation",
        "negatedTerseLabel": "Non-taxable gain on corporate acquisitions"
       }
      }
     },
     "localname": "TaxEffectOfGainsFromBusinessCombinationExemptFromTaxation",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_TaxEffectOfPetroleumRevenueAndOtherTaxes": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tax Effect Of Petroleum Revenue And Other Taxes",
        "label": "Tax Effect Of Petroleum Revenue And Other Taxes",
        "terseLabel": "UK PRT and other taxes"
       }
      }
     },
     "localname": "TaxEffectOfPetroleumRevenueAndOtherTaxes",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_TaxEffectOfPriorYearIncomeTaxes": {
     "auth_ref": [],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 7.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tax Effect Of Prior Year Income Taxes",
        "label": "Tax Effect Of Prior Year Income Taxes",
        "terseLabel": "Revisions arising from prior year tax filings"
       }
      }
     },
     "localname": "TaxEffectOfPriorYearIncomeTaxes",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "cnq_TermCreditFacilityMaturingFebruary2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Term Credit Facility Maturing February 2023",
        "label": "Term Credit Facility Maturing February 2023 [Member]",
        "terseLabel": "Term Credit Facility Maturing February 2023"
       }
      }
     },
     "localname": "TermCreditFacilityMaturingFebruary2023Member",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_TermCreditFacilityMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Term Credit Facility [Member]",
        "label": "Term Credit Facility [Member]",
        "terseLabel": "Term Credit Facility"
       }
      }
     },
     "localname": "TermCreditFacilityMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_TollPayerPercentForOthers": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Toll Payer Percent For Others",
        "label": "Toll Payer Percent For Others",
        "terseLabel": "Toll payer percent for others"
       }
      }
     },
     "localname": "TollPayerPercentForOthers",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_TotalSegmentsAfterIntersegmentEliminationsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total Segments, After Intersegment Eliminations [Member]",
        "label": "Total Segments, After Intersegment Eliminations [Member]",
        "terseLabel": "Total Segments"
       }
      }
     },
     "localname": "TotalSegmentsAfterIntersegmentEliminationsMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_TwelveMonthAverageBenchmarkPriceDollarsPerBbl": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Twelve Month Average Benchmark Price (Dollars Per Bbl)",
        "label": "Twelve Month Average Benchmark Price (Dollars Per Bbl)",
        "terseLabel": "Twelve month average benchmark price dollars per bbl"
       }
      }
     },
     "localname": "TwelveMonthAverageBenchmarkPriceDollarsPerBbl",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "cnq_TwelveMonthAverageBenchmarkPriceDollarsPerMMBtu": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Twelve Month Average Benchmark Price (Dollars Per MMBtu)",
        "label": "Twelve Month Average Benchmark Price (Dollars Per MMBtu)",
        "terseLabel": "Twelve month average benchmark price dollars per MMBtu"
       }
      }
     },
     "localname": "TwelveMonthAverageBenchmarkPriceDollarsPerMMBtu",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "cnq_USCreditFacilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "US Credit Facilities [Member]",
        "label": "US Credit Facilities [Member]",
        "terseLabel": "Bank credit facilities (December 31, 2021 \u2013 US$901 million;\u2028December 31, 2020 \u2013 US$3,953 million)"
       }
      }
     },
     "localname": "USCreditFacilitiesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_UnrealisedRiskManagementActivitiesRelatedTemporaryDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unrealised Risk Management Activities Related Temporary Differences [Member]",
        "label": "Unrealised Risk Management Activities Related Temporary Differences [Member]",
        "terseLabel": "Unrealized risk management activities"
       }
      }
     },
     "localname": "UnrealisedRiskManagementActivitiesRelatedTemporaryDifferencesMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_UsefulLivesOrDepreciationRatesPropertyPlantAndEquipmentPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Useful Lives Or Depreciation Rates, Property, Plant And Equipment, Period",
        "label": "Useful Lives Or Depreciation Rates, Property, Plant And Equipment, Period",
        "terseLabel": "Estimated useful life"
       }
      }
     },
     "localname": "UsefulLivesOrDepreciationRatesPropertyPlantAndEquipmentPeriod",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "cnq_WeightedAverageDiscountRateUsedInCurrentMeasurementOfProvisionForDecommissioningRestorationAndRehabilitationCosts": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted Average Discount Rate Used In Current Measurement Of Provision For Decommissioning, Restoration And Rehabilitation Costs",
        "label": "Weighted Average Discount Rate Used In Current Measurement Of Provision For Decommissioning, Restoration And Rehabilitation Costs",
        "verboseLabel": "Weighted average discount rate"
       }
      }
     },
     "localname": "WeightedAverageDiscountRateUsedInCurrentMeasurementOfProvisionForDecommissioningRestorationAndRehabilitationCosts",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "cnq_WeightedAverageExercisePriceOfShareOptionsSurrenderedForCashInSharebasedPaymentArrangement": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted Average Exercise Price Of Share Options Surrendered (decrease) For Cash In Share-based Payment Arrangement",
        "label": "Weighted Average Exercise Price Of Share Options Surrendered For Cash In Share-based Payment Arrangement",
        "terseLabel": "Weighted average exercise price, options surrendered for cash settlement (in CAD per share)"
       }
      }
     },
     "localname": "WeightedAverageExercisePriceOfShareOptionsSurrenderedForCashInSharebasedPaymentArrangement",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "cnq_WestTexasIntermediateCushingOklahomaMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "West Texas Intermediate, Cushing Oklahoma [Member]",
        "label": "West Texas Intermediate, Cushing Oklahoma [Member]",
        "terseLabel": "WTI Cushing Oklahoma"
       }
      }
     },
     "localname": "WestTexasIntermediateCushingOklahomaMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "cnq_WesternCanadianSelectMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Western Canadian Select [Member]",
        "label": "Western Canadian Select [Member]",
        "terseLabel": "WCS"
       }
      }
     },
     "localname": "WesternCanadianSelectMember",
     "nsuri": "http://www.cnrl.com/20211231",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "currency_AllCurrenciesDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "All Currencies [Domain]",
        "terseLabel": "All Currencies [Domain]"
       }
      }
     },
     "localname": "AllCurrenciesDomain",
     "nsuri": "http://xbrl.sec.gov/currency/2021",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "currency_CAD": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Canada, Dollars",
        "terseLabel": "CAD"
       }
      }
     },
     "localname": "CAD",
     "nsuri": "http://xbrl.sec.gov/currency/2021",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "currency_USD": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "United States of America, Dollars",
        "terseLabel": "USD"
       }
      }
     },
     "localname": "USD",
     "nsuri": "http://xbrl.sec.gov/currency/2021",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "dei_AddressTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An entity may have several addresses for different purposes and this domain represents all such types.",
        "label": "Address Type [Domain]",
        "terseLabel": "Address Type [Domain]"
       }
      }
     },
     "localname": "AddressTypeDomain",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "domainItemType"
    },
    "dei_AmendmentFlag": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.",
        "label": "Amendment Flag",
        "terseLabel": "Amendment Flag"
       }
      }
     },
     "localname": "AmendmentFlag",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_AnnualInformationForm": {
     "auth_ref": [
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag with value true on a form if it is an annual report containing an annual information form.",
        "label": "Annual Information Form",
        "terseLabel": "Annual Information Form"
       }
      }
     },
     "localname": "AnnualInformationForm",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_AuditedAnnualFinancialStatements": {
     "auth_ref": [
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag with value true on a form if it is an annual report containing audited financial statements.",
        "label": "Audited Annual Financial Statements",
        "terseLabel": "Audited Annual Financial Statements"
       }
      }
     },
     "localname": "AuditedAnnualFinancialStatements",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_AuditorFirmId": {
     "auth_ref": [
      "r316",
      "r317",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "PCAOB issued Audit Firm Identifier",
        "label": "Auditor Firm ID",
        "terseLabel": "Auditor Firm ID"
       }
      }
     },
     "localname": "AuditorFirmId",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/AuditInformation"
     ],
     "xbrltype": "nonemptySequenceNumberItemType"
    },
    "dei_AuditorLocation": {
     "auth_ref": [
      "r316",
      "r317",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Auditor Location",
        "terseLabel": "Auditor Location"
       }
      }
     },
     "localname": "AuditorLocation",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/AuditInformation"
     ],
     "xbrltype": "internationalNameItemType"
    },
    "dei_AuditorName": {
     "auth_ref": [
      "r316",
      "r317",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Auditor Name",
        "terseLabel": "Auditor Name"
       }
      }
     },
     "localname": "AuditorName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/AuditInformation"
     ],
     "xbrltype": "internationalNameItemType"
    },
    "dei_BusinessContactMember": {
     "auth_ref": [
      "r317",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business contact for the entity",
        "label": "Business Contact [Member]",
        "terseLabel": "Business Contact"
       }
      }
     },
     "localname": "BusinessContactMember",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "domainItemType"
    },
    "dei_CityAreaCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Area code of city",
        "label": "City Area Code",
        "terseLabel": "City Area Code"
       }
      }
     },
     "localname": "CityAreaCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_ContactPersonnelName": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of contact personnel",
        "label": "Contact Personnel Name",
        "terseLabel": "Contact Personnel Name"
       }
      }
     },
     "localname": "ContactPersonnelName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cover page.",
        "label": "Cover [Abstract]"
       }
      }
     },
     "localname": "CoverAbstract",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "xbrltype": "stringItemType"
    },
    "dei_CurrentFiscalYearEndDate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "End date of current fiscal year in the format --MM-DD.",
        "label": "Current Fiscal Year End Date",
        "terseLabel": "Current Fiscal Year End Date"
       }
      }
     },
     "localname": "CurrentFiscalYearEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "gMonthDayItemType"
    },
    "dei_DocumentAnnualReport": {
     "auth_ref": [
      "r316",
      "r317",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as an annual report.",
        "label": "Document Annual Report",
        "terseLabel": "Document Annual Report"
       }
      }
     },
     "localname": "DocumentAnnualReport",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentFiscalPeriodFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fiscal period values are FY, Q1, Q2, and Q3.  1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY.",
        "label": "Document Fiscal Period Focus",
        "terseLabel": "Document Fiscal Period Focus"
       }
      }
     },
     "localname": "DocumentFiscalPeriodFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "fiscalPeriodItemType"
    },
    "dei_DocumentFiscalYearFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This is focus fiscal year of the document report in YYYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006.",
        "label": "Document Fiscal Year Focus",
        "terseLabel": "Document Fiscal Year Focus"
       }
      }
     },
     "localname": "DocumentFiscalYearFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "gYearItemType"
    },
    "dei_DocumentInformationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Document Information [Line Items]",
        "terseLabel": "Document Information [Line Items]"
       }
      }
     },
     "localname": "DocumentInformationLineItems",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_DocumentInformationTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Container to support the formal attachment of each official or unofficial, public or private document as part of a submission package.",
        "label": "Document Information [Table]",
        "terseLabel": "Document Information [Table]"
       }
      }
     },
     "localname": "DocumentInformationTable",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_DocumentPeriodEndDate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period.  The format of the date is YYYY-MM-DD.",
        "label": "Document Period End Date",
        "terseLabel": "Document Period End Date"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentRegistrationStatement": {
     "auth_ref": [
      "r312"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as a registration statement.",
        "label": "Document Registration Statement",
        "terseLabel": "Document Registration Statement"
       }
      }
     },
     "localname": "DocumentRegistrationStatement",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentType": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.",
        "label": "Document Type",
        "terseLabel": "Document Type"
       }
      }
     },
     "localname": "DocumentType",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "submissionTypeItemType"
    },
    "dei_EntityAddressAddressLine1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Address Line 1 such as Attn, Building Name, Street Name",
        "label": "Entity Address, Address Line One",
        "terseLabel": "Entity Address, Address Line One"
       }
      }
     },
     "localname": "EntityAddressAddressLine1",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressAddressLine2": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Address Line 2 such as Street or Suite number",
        "label": "Entity Address, Address Line Two",
        "terseLabel": "Entity Address, Address Line Two"
       }
      }
     },
     "localname": "EntityAddressAddressLine2",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCityOrTown": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the City or Town",
        "label": "Entity Address, City or Town",
        "terseLabel": "Entity Address, City or Town"
       }
      }
     },
     "localname": "EntityAddressCityOrTown",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCountry": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "ISO 3166-1 alpha-2 country code.",
        "label": "Entity Address, Country",
        "terseLabel": "Entity Address, Country"
       }
      }
     },
     "localname": "EntityAddressCountry",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "countryCodeItemType"
    },
    "dei_EntityAddressPostalZipCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Code for the postal or zip code",
        "label": "Entity Address, Postal Zip Code",
        "terseLabel": "Entity Address, Postal Zip Code"
       }
      }
     },
     "localname": "EntityAddressPostalZipCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressStateOrProvince": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the state or province.",
        "label": "Entity Address, State or Province",
        "terseLabel": "Entity Address, State or Province"
       }
      }
     },
     "localname": "EntityAddressStateOrProvince",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "stateOrProvinceItemType"
    },
    "dei_EntityAddressesAddressTypeAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the domain members or categories in the table and the line items or concepts that complete the table.",
        "label": "Entity Addresses, Address Type [Axis]",
        "terseLabel": "Entity Addresses, Address Type [Axis]"
       }
      }
     },
     "localname": "EntityAddressesAddressTypeAxis",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r314"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.",
        "label": "Entity Central Index Key",
        "terseLabel": "Entity Central Index Key"
       }
      }
     },
     "localname": "EntityCentralIndexKey",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "centralIndexKeyItemType"
    },
    "dei_EntityCommonStockSharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.",
        "label": "Entity Common Stock, Shares Outstanding",
        "terseLabel": "Entity Common Stock, Shares Outstanding (in shares)"
       }
      }
     },
     "localname": "EntityCommonStockSharesOutstanding",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "sharesItemType"
    },
    "dei_EntityCurrentReportingStatus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure.",
        "label": "Entity Current Reporting Status",
        "terseLabel": "Entity Current Reporting Status"
       }
      }
     },
     "localname": "EntityCurrentReportingStatus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "All the names of the entities being reported upon in a document. Any legal structure used to conduct activities or to hold assets. Some examples of such structures are corporations, partnerships, limited liability companies, grantor trusts, and other trusts. This item does not include business and geographical segments which are included in the geographical or business segments domains.",
        "label": "Entity [Domain]",
        "terseLabel": "Entity [Domain]"
       }
      }
     },
     "localname": "EntityDomain",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r314"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate if registrant meets the emerging growth company criteria.",
        "label": "Entity Emerging Growth Company",
        "terseLabel": "Emerging Growth Company"
       }
      }
     },
     "localname": "EntityEmergingGrowthCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityFileNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.",
        "label": "Entity File Number",
        "terseLabel": "Entity File Number"
       }
      }
     },
     "localname": "EntityFileNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityIncorporationStateCountryCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Two-character EDGAR code representing the state or country of incorporation.",
        "label": "Entity Incorporation, State or Country Code",
        "terseLabel": "Entity Incorporation, State or Country Code"
       }
      }
     },
     "localname": "EntityIncorporationStateCountryCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r322"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).",
        "label": "Entity Interactive Data Current",
        "terseLabel": "Entity Interactive Data Current"
       }
      }
     },
     "localname": "EntityInteractiveDataCurrent",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r314"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.",
        "label": "Entity Registrant Name",
        "terseLabel": "Entity Registrant Name"
       }
      }
     },
     "localname": "EntityRegistrantName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_IcfrAuditorAttestationFlag": {
     "auth_ref": [
      "r316",
      "r317",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "ICFR Auditor Attestation Flag",
        "terseLabel": "ICFR Auditor Attestation Flag"
       }
      }
     },
     "localname": "IcfrAuditorAttestationFlag",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_LegalEntityAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The set of legal entities associated with a report.",
        "label": "Legal Entity [Axis]",
        "terseLabel": "Legal Entity [Axis]"
       }
      }
     },
     "localname": "LegalEntityAxis",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_LocalPhoneNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Local phone number for entity.",
        "label": "Local Phone Number",
        "terseLabel": "Local Phone Number"
       }
      }
     },
     "localname": "LocalPhoneNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r313"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Title of a 12(b) registered security.",
        "label": "Title of 12(b) Security",
        "terseLabel": "Title of 12(b) Security"
       }
      }
     },
     "localname": "Security12bTitle",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r315"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the Exchange on which a security is registered.",
        "label": "Security Exchange Name",
        "terseLabel": "Security Exchange Name"
       }
      }
     },
     "localname": "SecurityExchangeName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "edgarExchangeCodeItemType"
    },
    "dei_TradingSymbol": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Trading symbol of an instrument as listed on an exchange.",
        "label": "Trading Symbol",
        "terseLabel": "Trading Symbol"
       }
      }
     },
     "localname": "TradingSymbol",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.cnrl.com/role/CoverPage"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "ifrs-full_AccrualsClassifiedAsCurrent": {
     "auth_ref": [
      "r36"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "ifrs-full_CurrentLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of accruals classified as current. [Refer: Accruals]"
       }
      },
      "en-us": {
       "role": {
        "label": "Accruals classified as current",
        "terseLabel": "Accrued liabilities"
       }
      }
     },
     "localname": "AccrualsClassifiedAsCurrent",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AccumulatedDepreciationAndAmortisationMember": {
     "auth_ref": [
      "r66",
      "r73",
      "r111",
      "r115",
      "r118"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for accumulated depreciation and amortisation. [Refer: Depreciation and amortisation expense]"
       }
      },
      "en-us": {
       "role": {
        "label": "Accumulated depreciation and amortisation [member]",
        "terseLabel": "Accumulated depletion and depreciation"
       }
      }
     },
     "localname": "AccumulatedDepreciationAndAmortisationMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_AccumulatedOtherComprehensiveIncome": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "ifrs-full_Equity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of accumulated items of income and expense (including reclassification adjustments) that are not recognised in profit or loss as required or permitted by other IFRSs. [Refer: IFRSs [member]; Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Accumulated other comprehensive income",
        "terseLabel": "Accumulated other comprehensive (loss) income",
        "totalLabel": "Accumulated other comprehensive income (loss)"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncomeDetails",
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r10"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for accumulated other comprehensive income. [Refer: Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Accumulated other comprehensive income [member]",
        "terseLabel": "Accumulated other comprehensive (loss) income"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_AcquisitiondateFairValueOfTotalConsiderationTransferred": {
     "auth_ref": [
      "r209"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The fair value, at acquisition date, of the consideration transferred in a business combination. [Refer: Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Consideration transferred, acquisition-date fair value",
        "terseLabel": "Total purchase consideration"
       }
      }
     },
     "localname": "AcquisitiondateFairValueOfTotalConsiderationTransferred",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AcquisitionsThroughBusinessCombinationsOtherProvisions": {
     "auth_ref": [
      "r108"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase in other provisions resulting from acquisitions through business combinations. [Refer: Business combinations [member]; Other provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Acquisitions through business combinations, other provisions",
        "terseLabel": "Liabilities acquired, net"
       }
      }
     },
     "localname": "AcquisitionsThroughBusinessCombinationsOtherProvisions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdditionalInformationAboutSharebasedPaymentArrangements": {
     "auth_ref": [
      "r207"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Additional information about share-based payment arrangements necessary to satisfy the disclosure requirements of IFRS 2. [Refer: Share-based payment arrangements [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Additional information about share-based payment arrangements [text block]",
        "terseLabel": "Summary of share-based compensation liability"
       }
      }
     },
     "localname": "AdditionalInformationAboutSharebasedPaymentArrangements",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_AdditionsToRightofuseAssets": {
     "auth_ref": [
      "r186"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of additions to right-of-use assets. [Refer: Right-of-use assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Additions to right-of-use assets",
        "terseLabel": "Additions"
       }
      }
     },
     "localname": "AdditionsToRightofuseAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustedWeightedAverageShares": {
     "auth_ref": [
      "r101"
     ],
     "calculation": {
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average number of ordinary shares used in calculating diluted earnings per share",
        "totalLabel": "Weighted average common shares outstanding \u2013 diluted (thousands of shares)"
       }
      }
     },
     "localname": "AdjustedWeightedAverageShares",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "ifrs-full_AdjustmentsForDecreaseIncreaseInInventories": {
     "auth_ref": [
      "r130"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for decrease (increase) in inventories to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Inventories; Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for decrease (increase) in inventories",
        "terseLabel": "Inventory"
       }
      }
     },
     "localname": "AdjustmentsForDecreaseIncreaseInInventories",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForDecreaseIncreaseInTradeAccountReceivable": {
     "auth_ref": [
      "r130"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 6.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for decrease (increase) in trade accounts receivable to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for decrease (increase) in trade accounts receivable",
        "terseLabel": "Accounts receivable"
       }
      }
     },
     "localname": "AdjustmentsForDecreaseIncreaseInTradeAccountReceivable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForDeferredTaxExpense": {
     "auth_ref": [
      "r132"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 5.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for deferred tax expense to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Deferred tax expense (income); Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for deferred tax expense",
        "terseLabel": "Deferred income tax expense (recovery)"
       }
      }
     },
     "localname": "AdjustmentsForDeferredTaxExpense",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForDepreciationAndAmortisationExpense": {
     "auth_ref": [
      "r131"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 4.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for depreciation and amortisation expense to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Depreciation and amortisation expense; Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for depreciation and amortisation expense",
        "terseLabel": "Depletion, depreciation and amortization"
       }
      }
     },
     "localname": "AdjustmentsForDepreciationAndAmortisationExpense",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForGainsLossesOnChangeInFairValueOfDerivatives": {
     "auth_ref": [
      "r132"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 9.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for gains (losses) on changes in the fair value of derivatives to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: At fair value [member]; Derivatives [member]; Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for gains (losses) on change in fair value of derivatives",
        "negatedTerseLabel": "Unrealized risk management loss (gain)"
       }
      }
     },
     "localname": "AdjustmentsForGainsLossesOnChangeInFairValueOfDerivatives",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForIncreaseDecreaseInOtherLiabilities": {
     "auth_ref": [
      "r132"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 7.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for increase (decrease) in other liabilities to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Other liabilities; Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for increase (decrease) in other liabilities",
        "terseLabel": "Other long-term liabilities"
       }
      }
     },
     "localname": "AdjustmentsForIncreaseDecreaseInOtherLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForIncreaseDecreaseInTradeAndOtherPayables": {
     "auth_ref": [
      "r132"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 4.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInWorkingCapital",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for increase (decrease) in trade and other payables to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Trade and other payables; Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for increase (decrease) in trade and other payables",
        "terseLabel": "Accounts payable"
       }
      }
     },
     "localname": "AdjustmentsForIncreaseDecreaseInTradeAndOtherPayables",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForReconcileProfitLossAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Adjustments to reconcile profit (loss) [abstract]",
        "terseLabel": "Non-cash items"
       }
      }
     },
     "localname": "AdjustmentsForReconcileProfitLossAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_AdjustmentsForSharebasedPayments": {
     "auth_ref": [
      "r131"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 3.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for share-based payments to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for share-based payments",
        "terseLabel": "Share-based compensation"
       }
      }
     },
     "localname": "AdjustmentsForSharebasedPayments",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdjustmentsForUnrealisedForeignExchangeLossesGains": {
     "auth_ref": [
      "r131",
      "r144"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 12.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Adjustments for unrealised foreign exchange losses (gains) to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Adjustments for unrealised foreign exchange losses (gains)",
        "terseLabel": "Unrealized foreign exchange gain"
       }
      }
     },
     "localname": "AdjustmentsForUnrealisedForeignExchangeLossesGains",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AdministrativeExpense": {
     "auth_ref": [
      "r2",
      "r50",
      "r92"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 1.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of expenses that the entity classifies as being administrative."
       }
      },
      "en-us": {
       "role": {
        "label": "Administrative expenses",
        "terseLabel": "Administration"
       }
      }
     },
     "localname": "AdministrativeExpense",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AggregatedTimeBandsMember": {
     "auth_ref": [
      "r28",
      "r78",
      "r177",
      "r190",
      "r191",
      "r225",
      "r261",
      "r263",
      "r287",
      "r288",
      "r290",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for aggregated time bands. It also represents the standard value for the 'Maturity' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Aggregated time bands [member]",
        "terseLabel": "Aggregated time bands"
       }
      }
     },
     "localname": "AggregatedTimeBandsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_AllLevelsOfFairValueHierarchyMember": {
     "auth_ref": [
      "r77",
      "r170"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for all levels of the fair value hierarchy. It also represents the standard value for the 'Levels of fair value hierarchy' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "All levels of fair value hierarchy [member]",
        "terseLabel": "All levels of fair value hierarchy [member]"
       }
      }
     },
     "localname": "AllLevelsOfFairValueHierarchyMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ApplicableTaxRate": {
     "auth_ref": [
      "r58"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The applicable income tax rate."
       }
      },
      "en-us": {
       "role": {
        "label": "Applicable tax rate",
        "terseLabel": "Canadian statutory income tax rate"
       }
      }
     },
     "localname": "ApplicableTaxRate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_Assets": {
     "auth_ref": [
      "r25",
      "r169",
      "r170",
      "r171",
      "r272",
      "r276"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of a present economic resource controlled by the entity as a result of past events. Economic resource is a right that has the potential to produce economic benefits."
       }
      },
      "en-us": {
       "role": {
        "label": "Assets",
        "terseLabel": "Assets",
        "totalLabel": "Assets"
       }
      }
     },
     "localname": "Assets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets [abstract]",
        "terseLabel": "ASSETS"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_AssetsArisingFromExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [
      "r220"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "ifrs-full_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "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."
       }
      },
      "en-us": {
       "role": {
        "label": "Assets arising from exploration for and evaluation of mineral resources",
        "periodEndLabel": "Ending balance",
        "periodStartLabel": "Beginning balance",
        "terseLabel": "Exploration and evaluation assets"
       }
      }
     },
     "localname": "AssetsArisingFromExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_AssetsHeldToHedgeLiabilitiesArisingFromFinancingActivitiesMember": {
     "auth_ref": [
      "r139",
      "r145"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for assets held to hedge liabilities arising from financing activities. [Refer: Assets; Liabilities arising from financing activities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Assets held to hedge liabilities arising from financing activities [member]",
        "terseLabel": "Cash flow hedges on US dollar debt securities"
       }
      }
     },
     "localname": "AssetsHeldToHedgeLiabilitiesArisingFromFinancingActivitiesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_AverageForeignExchangeRate": {
     "auth_ref": [
      "r11"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The average exchange rate used by the entity. Exchange rate is the ratio of exchange for two currencies."
       }
      },
      "en-us": {
       "role": {
        "label": "Average foreign exchange rate",
        "terseLabel": "Exchange rate (US$/C$)",
        "verboseLabel": "Average foreign exchange rate"
       }
      }
     },
     "localname": "AverageForeignExchangeRate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_AverageRateOfHedgingInstrument": {
     "auth_ref": [
      "r226"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The average rate of a hedging instrument. [Refer: Hedging instruments [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Average rate of hedging instrument",
        "terseLabel": "Interest rate"
       }
      }
     },
     "localname": "AverageRateOfHedgingInstrument",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_BasicEarningsLossPerShare": {
     "auth_ref": [
      "r99",
      "r100"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator) divided by the weighted average number of ordinary shares outstanding during the period (the denominator)."
       }
      },
      "en-us": {
       "role": {
        "label": "Basic earnings (loss) per share",
        "terseLabel": "Basic earnings per share (in CAD per share)",
        "verboseLabel": "Net earnings (loss) per common share - basic (in CAD per share)"
       }
      }
     },
     "localname": "BasicEarningsLossPerShare",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_BorrowingCostsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Borrowing costs [abstract]",
        "terseLabel": "Borrowing costs [abstract]"
       }
      }
     },
     "localname": "BorrowingCostsAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "stringItemType"
    },
    "ifrs-full_BorrowingCostsCapitalised": {
     "auth_ref": [
      "r85"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_FinanceCosts",
       "weight": -1.0
      }
     },
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of interest and other costs that an entity incurs in connection with the borrowing of funds that are directly attributable to the acquisition, construction or production of a qualifying asset and which form part of the cost of that asset."
       }
      },
      "en-us": {
       "role": {
        "label": "Borrowing costs capitalised",
        "negatedTerseLabel": "Less: amounts capitalized on qualifying assets",
        "verboseLabel": "Interest costs capitalized"
       }
      }
     },
     "localname": "BorrowingCostsCapitalised",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_Borrowings": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails": {
       "order": 2.0,
       "parentTag": "cnq_BorrowingsNetOfCashAndCashEquivalents",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of outstanding funds that the entity is obligated to repay."
       }
      },
      "en-us": {
       "role": {
        "label": "Borrowings",
        "terseLabel": "Borrowings",
        "totalLabel": "Borrowings",
        "verboseLabel": "Long-term debt"
       }
      }
     },
     "localname": "Borrowings",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_BorrowingsByNameAxis": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Borrowings by name [axis]",
        "terseLabel": "Borrowings by name [axis]"
       }
      }
     },
     "localname": "BorrowingsByNameAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_BorrowingsByNameMember": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for all borrowings when disaggregated by name. It also represents the standard value for the 'Borrowings by name' axis if no other member is used. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Borrowings by name [member]",
        "terseLabel": "Borrowings by name"
       }
      }
     },
     "localname": "BorrowingsByNameMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_BorrowingsInterestRate": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The interest rate on borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Borrowings, interest rate",
        "terseLabel": "Borrowings, interest rate"
       }
      }
     },
     "localname": "BorrowingsInterestRate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_BottomOfRangeMember": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r201",
      "r255",
      "r290"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the bottom of a range."
       }
      },
      "en-us": {
       "role": {
        "label": "Bottom of range [member]",
        "terseLabel": "Bottom of range"
       }
      }
     },
     "localname": "BottomOfRangeMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails",
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_BusinessCombinationsAxis": {
     "auth_ref": [
      "r212"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Business combinations [axis]",
        "terseLabel": "Business combinations [axis]"
       }
      }
     },
     "localname": "BusinessCombinationsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CapitalisationRateOfBorrowingCostsEligibleForCapitalisation": {
     "auth_ref": [
      "r86"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average of interest and other costs that an entity incurs in connection with the borrowing of funds applicable to the borrowings of the entity that are outstanding during the period, other than borrowings made specifically for the purpose of obtaining a qualifying asset. [Refer: Weighted average [member]; Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Capitalisation rate of borrowing costs eligible for capitalisation",
        "terseLabel": "Weighted average capitalization rate"
       }
      }
     },
     "localname": "CapitalisationRateOfBorrowingCostsEligibleForCapitalisation",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis": {
     "auth_ref": [
      "r66",
      "r70",
      "r111",
      "r112",
      "r114",
      "r115",
      "r116",
      "r117",
      "r118",
      "r213",
      "r242",
      "r243",
      "r308",
      "r311"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis]",
        "terseLabel": "Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis]"
       }
      }
     },
     "localname": "CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CarryingAmountMember": {
     "auth_ref": [
      "r70",
      "r112",
      "r114",
      "r116",
      "r117",
      "r213",
      "r242",
      "r243",
      "r308",
      "r310"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the amount at which an asset is recognised in the statement of financial position (after deducting any accumulated depreciation or amortisation and accumulated impairment losses). It also represents the standard value for the 'Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount' axis if no other member is used. [Refer: Depreciation and amortisation expense; Impairment loss]"
       }
      },
      "en-us": {
       "role": {
        "label": "Carrying amount [member]",
        "terseLabel": "Carrying amount"
       }
      }
     },
     "localname": "CarryingAmountMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_CashAndCashEquivalents": {
     "auth_ref": [
      "r22",
      "r141",
      "r164"
     ],
     "calculation": {
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails": {
       "order": 1.0,
       "parentTag": "cnq_BorrowingsNetOfCashAndCashEquivalents",
       "weight": -1.0
      },
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "ifrs-full_CurrentAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents]"
       }
      },
      "en-us": {
       "role": {
        "label": "Cash and cash equivalents",
        "periodEndLabel": "Cash and cash equivalents \u2013 end of year",
        "periodStartLabel": "Cash and cash equivalents \u2013 beginning of year",
        "terseLabel": "Cash and cash equivalents",
        "verboseLabel": "Less: cash and cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalents",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails",
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashFlowHedgesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cash flow hedges [abstract]",
        "terseLabel": "Net change in derivative financial instruments designated as cash flow hedges"
       }
      }
     },
     "localname": "CashFlowHedgesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CashFlowHedgesMember": {
     "auth_ref": [
      "r113",
      "r228",
      "r229",
      "r234"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for hedges of the exposure to variability in cash flows that (a) are attributable to a particular risk associated with a recognised asset or liability (such as all or some future interest payments on variable rate debt) or a highly probable forecast transaction; and (b) could affect profit or loss. [Refer: Hedges [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Cash flow hedges [member]",
        "terseLabel": "Cash flow hedges"
       }
      }
     },
     "localname": "CashFlowHedgesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_CashFlowsFromUsedInExplorationForAndEvaluationOfMineralResourcesClassifiedAsInvestingActivities": {
     "auth_ref": [
      "r220"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 1.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash flows from (used in) 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, classified as investing activities."
       }
      },
      "en-us": {
       "role": {
        "label": "Cash flows from (used in) exploration for and evaluation of mineral resources, classified as investing activities",
        "negatedTotalLabel": "Net expenditures on exploration and evaluation assets",
        "terseLabel": "Net expenditures on exploration and evaluation assets"
       }
      }
     },
     "localname": "CashFlowsFromUsedInExplorationForAndEvaluationOfMineralResourcesClassifiedAsInvestingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashFlowsFromUsedInFinancingActivities": {
     "auth_ref": [
      "r119",
      "r143"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 2.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInCashAndCashEquivalents",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash flows from (used in) financing activities, which are activities that result in changes in the size and composition of the contributed equity and borrowings of the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Cash flows from (used in) financing activities",
        "totalLabel": "Cash flows used in financing activities"
       }
      }
     },
     "localname": "CashFlowsFromUsedInFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashFlowsFromUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cash flows from (used in) financing activities [abstract]",
        "terseLabel": "Financing activities"
       }
      }
     },
     "localname": "CashFlowsFromUsedInFinancingActivitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CashFlowsFromUsedInInvestingActivities": {
     "auth_ref": [
      "r119",
      "r143"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 1.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInCashAndCashEquivalents",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash flows from (used in) investing activities, which are the acquisition and disposal of long-term assets and other investments not included in cash equivalents."
       }
      },
      "en-us": {
       "role": {
        "label": "Cash flows from (used in) investing activities",
        "totalLabel": "Cash flows used in investing activities"
       }
      }
     },
     "localname": "CashFlowsFromUsedInInvestingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashFlowsFromUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cash flows from (used in) investing activities [abstract]",
        "terseLabel": "Investing activities"
       }
      }
     },
     "localname": "CashFlowsFromUsedInInvestingActivitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CashFlowsFromUsedInOperatingActivities": {
     "auth_ref": [
      "r119",
      "r143"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 3.0,
       "parentTag": "ifrs-full_IncreaseDecreaseInCashAndCashEquivalents",
       "weight": 1.0
      }
     },
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash flows from (used in) operating activities, which are the principal revenue-producing activities of the entity and other activities that are not investing or financing activities. [Refer: Revenue]"
       }
      },
      "en-us": {
       "role": {
        "label": "Cash flows from (used in) operating activities",
        "totalLabel": "Cash flows from operating activities"
       }
      }
     },
     "localname": "CashFlowsFromUsedInOperatingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashFlowsFromUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cash flows from (used in) operating activities [abstract]",
        "terseLabel": "Operating activities"
       }
      }
     },
     "localname": "CashFlowsFromUsedInOperatingActivitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities": {
     "auth_ref": [
      "r135"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 3.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The aggregate cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities. [Refer: Subsidiaries [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities",
        "negatedTerseLabel": "Acquisition of Devon Canada Corporation assets"
       }
      }
     },
     "localname": "CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashOutflowForLeases": {
     "auth_ref": [
      "r185"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow for leases."
       }
      },
      "en-us": {
       "role": {
        "label": "Cash outflow for leases",
        "terseLabel": "Total cash outflows for leases"
       }
      }
     },
     "localname": "CashOutflowForLeases",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashReceiptsFromRepaymentOfAdvancesAndLoansMadeToOtherPartiesClassifiedAsInvestingActivities": {
     "auth_ref": [
      "r122"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 6.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash inflow from the repayment of advances and loans made to other parties (other than advances and loans of a financial institution), classified as investing activities."
       }
      },
      "en-us": {
       "role": {
        "label": "Cash receipts from repayment of advances and loans made to other parties, classified as investing activities",
        "terseLabel": "Repayment of North West Redwater Partnership subordinated debt advances"
       }
      }
     },
     "localname": "CashReceiptsFromRepaymentOfAdvancesAndLoansMadeToOtherPartiesClassifiedAsInvestingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CashTransferred": {
     "auth_ref": [
      "r208"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The fair value, at acquisition date, of cash transferred as consideration in a business combination. [Refer: Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Cash transferred",
        "terseLabel": "Less: cash consideration",
        "verboseLabel": "Cash consideration"
       }
      }
     },
     "localname": "CashTransferred",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CategoriesOfRelatedPartiesAxis": {
     "auth_ref": [
      "r90"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Categories of related parties [axis]",
        "terseLabel": "Categories of related parties [axis]"
       }
      }
     },
     "localname": "CategoriesOfRelatedPartiesAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ChangesInLiabilitiesArisingFromFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Changes in liabilities arising from financing activities [abstract]",
        "terseLabel": "Changes from financing cash flows:"
       }
      }
     },
     "localname": "ChangesInLiabilitiesArisingFromFinancingActivitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ChangesInTaxRatesOrTaxLawsEnactedOrAnnouncedMember": {
     "auth_ref": [
      "r53"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for changes in tax rates or tax laws enacted or announced."
       }
      },
      "en-us": {
       "role": {
        "label": "Changes in tax rates or tax laws enacted or announced [member]",
        "terseLabel": "Changes in tax rate"
       }
      }
     },
     "localname": "ChangesInTaxRatesOrTaxLawsEnactedOrAnnouncedMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ClassesOfFinancialAssetsAxis": {
     "auth_ref": [
      "r253",
      "r254",
      "r286",
      "r299",
      "r300",
      "r301"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Classes of financial assets [axis]",
        "terseLabel": "Classes of financial assets [axis]"
       }
      }
     },
     "localname": "ClassesOfFinancialAssetsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ClassesOfFinancialInstrumentsAxis": {
     "auth_ref": [
      "r242",
      "r244",
      "r246",
      "r248"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Classes of financial instruments [axis]",
        "terseLabel": "Classes of financial instruments [axis]"
       }
      }
     },
     "localname": "ClassesOfFinancialInstrumentsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ClassesOfFinancialInstrumentsMember": {
     "auth_ref": [
      "r242",
      "r244",
      "r246",
      "r248"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for aggregated classes of financial instruments. Financial instruments are contracts that give rise to a financial asset of one entity and a financial liability or equity instrument of another entity. It also represents the standard value for the 'Classes of financial instruments' axis if no other member is used. [Refer: Financial assets; Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial instruments, class [member]",
        "terseLabel": "Financial instruments, class [member]"
       }
      }
     },
     "localname": "ClassesOfFinancialInstrumentsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ClassesOfFinancialLiabilitiesAxis": {
     "auth_ref": [
      "r253",
      "r254",
      "r286",
      "r300"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Classes of financial liabilities [axis]",
        "terseLabel": "Classes of financial liabilities [axis]"
       }
      }
     },
     "localname": "ClassesOfFinancialLiabilitiesAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis": {
     "auth_ref": [
      "r71"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Classes of property, plant and equipment [axis]",
        "terseLabel": "Classes of property, plant and equipment [axis]"
       }
      }
     },
     "localname": "ClassesOfPropertyPlantAndEquipmentAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ClassesOfProvisionsAxis": {
     "auth_ref": [
      "r108"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Classes of other provisions [axis]",
        "terseLabel": "Classes of other provisions [axis]"
       }
      }
     },
     "localname": "ClassesOfProvisionsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ClassesOfShareCapitalAxis": {
     "auth_ref": [
      "r38"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Classes of share capital [axis]",
        "terseLabel": "Classes of share capital [axis]"
       }
      }
     },
     "localname": "ClassesOfShareCapitalAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ClassesOfShareCapitalMember": {
     "auth_ref": [
      "r38"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for share capital of the entity. It also represents the standard value for the 'Classes of share capital' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Share capital [member]",
        "terseLabel": "Share capital [member]"
       }
      }
     },
     "localname": "ClassesOfShareCapitalMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_CommodityPriceRiskMember": {
     "auth_ref": [
      "r251",
      "r266"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a component of other price risk that represents the type of risk that the fair value or future cash flows of a financial instrument will fluctuate because of changes in commodity prices. [Refer: Financial instruments, class [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Commodity price risk [member]",
        "terseLabel": "Commodity price risk"
       }
      }
     },
     "localname": "CommodityPriceRiskMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ComponentsOfEquityAxis": {
     "auth_ref": [
      "r7"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Components of equity [axis]",
        "terseLabel": "Components of equity [axis]"
       }
      }
     },
     "localname": "ComponentsOfEquityAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Components of other comprehensive income that will be reclassified to profit or loss, net of tax [abstract]",
        "terseLabel": "Items that may be reclassified subsequently to net earnings"
       }
      }
     },
     "localname": "ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ComprehensiveIncome": {
     "auth_ref": [
      "r4",
      "r41",
      "r150",
      "r152",
      "r156",
      "r161"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of change in equity resulting from transactions and other events, other than those changes resulting from transactions with owners in their capacity as owners."
       }
      },
      "en-us": {
       "role": {
        "label": "Comprehensive income",
        "totalLabel": "Comprehensive income (loss)"
       }
      }
     },
     "localname": "ComprehensiveIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ConstructionInProgress": {
     "auth_ref": [
      "r65"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of expenditure capitalised during the construction of non-current assets that are not yet available for use. [Refer: Non-current assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Construction in progress",
        "terseLabel": "Project costs not subject to depletion and depreciation"
       }
      }
     },
     "localname": "ConstructionInProgress",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CreditRiskMember": {
     "auth_ref": [
      "r238",
      "r291",
      "r292",
      "r293"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the risk that one party to a financial instrument will cause a financial loss for the other party by failing to discharge an obligation. [Refer: Financial instruments, class [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Credit risk [member]",
        "terseLabel": "Credit risk"
       }
      }
     },
     "localname": "CreditRiskMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_CumulativeUnrecognisedShareOfLossesOfJointVentures": {
     "auth_ref": [
      "r155"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cumulative amount of the unrecognised share of losses of joint ventures if the entity has stopped recognising its share of losses when applying the equity method. [Refer: Joint ventures [member]; Unrecognised share of losses of joint ventures]"
       }
      },
      "en-us": {
       "role": {
        "label": "Cumulative unrecognised share of losses of joint ventures",
        "terseLabel": "Cumulative unrecognised share of losses of joint ventures"
       }
      }
     },
     "localname": "CumulativeUnrecognisedShareOfLossesOfJointVentures",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrencyRiskMember": {
     "auth_ref": [
      "r267",
      "r291",
      "r292",
      "r293",
      "r294"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a type of market risk representing the risk that the fair value or future cash flows of a financial instrument will fluctuate because of changes in foreign exchange rates. [Refer: Financial instruments, class [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Currency risk [member]",
        "terseLabel": "Currency risk",
        "verboseLabel": "Foreign currency exchange rate risk"
       }
      }
     },
     "localname": "CurrencyRiskMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_CurrencySwapContractMember": {
     "auth_ref": [
      "r11"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a currency swap contract. [Refer: Swap contract [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Currency swap contract [member]",
        "terseLabel": "Cross currency swaps"
       }
      }
     },
     "localname": "CurrencySwapContractMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_CurrentAssets": {
     "auth_ref": [
      "r29",
      "r156",
      "r157"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "ifrs-full_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of assets that the entity (a) expects to realise or intends to sell or consume in its normal operating cycle; (b) holds primarily for the purpose of trading; (c) expects to realise within twelve months after the reporting period; or (d) classifies as cash or cash equivalents (as defined in IAS 7) unless the asset is restricted from being exchanged or used to settle a liability for at least twelve months after the reporting period. [Refer: Assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current assets",
        "terseLabel": "Current assets",
        "totalLabel": "Current assets"
       }
      }
     },
     "localname": "CurrentAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Current assets [abstract]",
        "terseLabel": "Current assets"
       }
      }
     },
     "localname": "CurrentAssetsAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CurrentBorrowingsAndCurrentPortionOfNoncurrentBorrowings": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "ifrs-full_CurrentLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current borrowings and current portion of non-current borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current borrowings and current portion of non-current borrowings",
        "terseLabel": "Current portion of long-term debt"
       }
      }
     },
     "localname": "CurrentBorrowingsAndCurrentPortionOfNoncurrentBorrowings",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentCrudeOil": {
     "auth_ref": [
      "r81"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InventoryScheduleofInventoryDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_Inventories",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "A classification of current inventory representing the amount of unrefined, unprocessed oil. [Refer: Inventories]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current crude oil",
        "terseLabel": "Product inventory"
       }
      }
     },
     "localname": "CurrentCrudeOil",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InventoryScheduleofInventoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentDerivativeFinancialAssets": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails": {
       "order": 1.0,
       "parentTag": "cnq_DerivativeFinancialAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current derivative financial assets. [Refer: Derivative financial assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current derivative financial assets",
        "terseLabel": "Current portion of other long-term assets"
       }
      }
     },
     "localname": "CurrentDerivativeFinancialAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentDerivativeFinancialLiabilities": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails": {
       "order": 3.0,
       "parentTag": "cnq_DerivativeFinancialAssetsLiabilitiesNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current derivative financial liabilities. [Refer: Derivative financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current derivative financial liabilities",
        "negatedTerseLabel": "Current portion of other long-term liabilities"
       }
      }
     },
     "localname": "CurrentDerivativeFinancialLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentInvestments": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "ifrs-full_CurrentAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current investments."
       }
      },
      "en-us": {
       "role": {
        "label": "Current investments",
        "terseLabel": "Investments"
       }
      }
     },
     "localname": "CurrentInvestments",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentLeaseLiabilities": {
     "auth_ref": [
      "r180"
     ],
     "calculation": {
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_LeaseLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current lease liabilities. [Refer: Lease liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current lease liabilities",
        "terseLabel": "Less: current portion"
       }
      }
     },
     "localname": "CurrentLeaseLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentLiabilities": {
     "auth_ref": [
      "r31",
      "r156",
      "r159"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "ifrs-full_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Expiry date 2023-01-01: The amount of liabilities that: (a) the entity expects to settle in its normal operating cycle; (b) the entity holds primarily for the purpose of trading; (c) are due to be settled within twelve months after the reporting period; or (d) the entity does not have an unconditional right to defer settlement for at least twelve months after the reporting period.\nEffective 2023-01-01: The amount of liabilities that: (a) the entity expects to settle in its normal operating cycle; (b) the entity holds primarily for the purpose of trading; (c) are due to be settled within twelve months after the reporting period; or (d) the entity does not have the right at the end of the reporting period to defer settlement for at least twelve months after the reporting period."
       }
      },
      "en-us": {
       "role": {
        "label": "Current liabilities",
        "terseLabel": "Current liabilities",
        "totalLabel": "Current liabilities"
       }
      }
     },
     "localname": "CurrentLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentLiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Current liabilities [abstract]",
        "terseLabel": "Current liabilities"
       }
      }
     },
     "localname": "CurrentLiabilitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CurrentPortionOfLongtermBorrowings": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_Borrowings",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The current portion of non-current borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current portion of non-current borrowings",
        "terseLabel": "current portion of other long term debt"
       }
      }
     },
     "localname": "CurrentPortionOfLongtermBorrowings",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentPrepaymentsAndOtherCurrentAssets": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "ifrs-full_CurrentAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current prepayments and other current assets. [Refer: Other current assets; Current prepayments]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current prepayments and other current assets",
        "terseLabel": "Prepaids and other"
       }
      }
     },
     "localname": "CurrentPrepaymentsAndOtherCurrentAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentTaxAssetsCurrent": {
     "auth_ref": [
      "r23"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "ifrs-full_CurrentAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The current amount of current tax assets. [Refer: Current tax assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current tax assets, current",
        "terseLabel": "Current income taxes receivable"
       }
      }
     },
     "localname": "CurrentTaxAssetsCurrent",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentTaxExpenseIncome": {
     "auth_ref": [
      "r55"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 2.0,
       "parentTag": "ifrs-full_ProfitLoss",
       "weight": -1.0
      },
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": 7.0,
       "parentTag": "ifrs-full_GrossProfit",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of income taxes payable (recoverable) in respect of the taxable profit (tax loss) for a period."
       }
      },
      "en-us": {
       "role": {
        "label": "Current tax expense (income)",
        "negatedTerseLabel": "Income tax",
        "terseLabel": "Current income tax expense (recovery)",
        "totalLabel": "Current income tax"
       }
      }
     },
     "localname": "CurrentTaxExpenseIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentTaxExpenseIncomeAndAdjustmentsForCurrentTaxOfPriorPeriodsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Current tax expense (income) and adjustments for current tax of prior periods [abstract]",
        "terseLabel": "Current"
       }
      }
     },
     "localname": "CurrentTaxExpenseIncomeAndAdjustmentsForCurrentTaxOfPriorPeriodsAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_CurrentTaxLiabilitiesCurrent": {
     "auth_ref": [
      "r23"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "ifrs-full_CurrentLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The current amount of current tax liabilities. [Refer: Current tax liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current tax liabilities, current",
        "terseLabel": "Current income taxes payable"
       }
      }
     },
     "localname": "CurrentTaxLiabilitiesCurrent",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_CurrentTradeReceivables": {
     "auth_ref": [
      "r30",
      "r34"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "ifrs-full_CurrentAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current trade receivables. [Refer: Trade receivables]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current trade receivables",
        "terseLabel": "Accounts receivable"
       }
      }
     },
     "localname": "CurrentTradeReceivables",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DebtInstrumentsHeld": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails_1": {
       "order": 2.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of instruments representing indebtedness held by the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Debt instruments held",
        "terseLabel": "North West Redwater Partnership subordinated debt"
       }
      }
     },
     "localname": "DebtInstrumentsHeld",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeductibleTemporaryDifferencesForWhichNoDeferredTaxAssetIsRecognised": {
     "auth_ref": [
      "r59"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of deductible temporary differences for which no deferred tax asset is recognised in the statement of financial position. [Refer: Temporary differences [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deductible temporary differences for which no deferred tax asset is recognised",
        "terseLabel": "Deductible temporary differences for which no deferred tax asset is recognised"
       }
      }
     },
     "localname": "DeductibleTemporaryDifferencesForWhichNoDeferredTaxAssetIsRecognised",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeferredTaxAssets": {
     "auth_ref": [
      "r24",
      "r26",
      "r60"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_DeferredTaxLiabilityAsset",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amounts of income taxes recoverable in future periods in respect of: (a) deductible temporary differences; (b) the carryforward of unused tax losses; and (c) the carryforward of unused tax credits. [Refer: Temporary differences [member]; Unused tax credits [member]; Unused tax losses [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deferred tax assets",
        "negatedTerseLabel": "Deferred income tax assets"
       }
      }
     },
     "localname": "DeferredTaxAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeferredTaxAssetsRecognisedAsOfAcquisitionDate": {
     "auth_ref": [
      "r210"
     ],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount recognised as of the acquisition date for deferred tax assets acquired in a business combination. [Refer: Deferred tax assets; Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deferred tax assets recognised as of acquisition date",
        "terseLabel": "Deferred tax asset"
       }
      }
     },
     "localname": "DeferredTaxAssetsRecognisedAsOfAcquisitionDate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeferredTaxExpenseIncome": {
     "auth_ref": [
      "r61"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 3.0,
       "parentTag": "ifrs-full_ProfitLoss",
       "weight": -1.0
      },
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of tax expense (income) relating to changes in deferred tax liabilities and deferred tax assets. [Refer: Deferred tax assets; Deferred tax liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deferred tax expense (income)",
        "terseLabel": "Deferred income tax expense (recovery)",
        "totalLabel": "Deferred income tax",
        "verboseLabel": "Deferred income tax expense (recovery)"
       }
      }
     },
     "localname": "DeferredTaxExpenseIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeferredTaxExpenseIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred tax expense (income) [abstract]",
        "terseLabel": "Deferred"
       }
      }
     },
     "localname": "DeferredTaxExpenseIncomeAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DeferredTaxExpenseIncomeRecognisedInProfitOrLoss": {
     "auth_ref": [
      "r61"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of tax expense or income relating to changes in deferred tax liabilities and deferred tax assets, recognised in profit or loss. [Refer: Deferred tax assets; Deferred tax expense (income); Deferred tax liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deferred tax expense (income) recognised in profit or loss",
        "terseLabel": "Deferred income tax expense (recovery)"
       }
      }
     },
     "localname": "DeferredTaxExpenseIncomeRecognisedInProfitOrLoss",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofNetDeferredIncomeTaxLiabilityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeferredTaxLiabilities": {
     "auth_ref": [
      "r24",
      "r26",
      "r60"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_DeferredTaxLiabilityAsset",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amounts of income taxes payable in future periods in respect of taxable temporary differences. [Refer: Temporary differences [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deferred tax liabilities",
        "terseLabel": "Deferred income tax liabilities"
       }
      }
     },
     "localname": "DeferredTaxLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeferredTaxLiabilitiesRecognisedAsOfAcquisitionDate": {
     "auth_ref": [
      "r210"
     ],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 9.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount recognised as of the acquisition date for deferred tax liabilities assumed in a business combination. [Refer: Deferred tax liabilities; Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deferred tax liabilities recognised as of acquisition date",
        "negatedTerseLabel": "Deferred tax liability",
        "terseLabel": "Deferred tax liability"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesRecognisedAsOfAcquisitionDate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DeferredTaxLiabilityAsset": {
     "auth_ref": [
      "r60"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "ifrs-full_Liabilities",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of deferred tax liabilities or assets. [Refer: Deferred tax liabilities; Deferred tax assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Deferred tax liability (asset)",
        "periodEndLabel": "Balance \u2013 end of year",
        "periodStartLabel": "Balance \u2013 beginning of year",
        "terseLabel": "Deferred income taxes",
        "totalLabel": "Net deferred income tax liability"
       }
      }
     },
     "localname": "DeferredTaxLiabilityAsset",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofNetDeferredIncomeTaxLiabilityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DepreciationAndAmortisationExpense": {
     "auth_ref": [
      "r1",
      "r3",
      "r50",
      "r165",
      "r270",
      "r278"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 9.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": 4.0,
       "parentTag": "ifrs-full_GrossProfit",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of depreciation and amortisation expense. Depreciation and amortisation are the systematic allocations of depreciable amounts of assets over their useful lives."
       }
      },
      "en-us": {
       "role": {
        "label": "Depreciation and amortisation expense",
        "negatedTerseLabel": "Depletion, depreciation and amortization",
        "terseLabel": "Depletion, depreciation and amortization"
       }
      }
     },
     "localname": "DepreciationAndAmortisationExpense",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DepreciationPropertyPlantAndEquipment": {
     "auth_ref": [
      "r68",
      "r72"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of depreciation of property, plant and equipment. [Refer: Depreciation and amortisation expense; Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Depreciation, property, plant and equipment",
        "terseLabel": "Expense"
       }
      }
     },
     "localname": "DepreciationPropertyPlantAndEquipment",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DepreciationRightofuseAssets": {
     "auth_ref": [
      "r181"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of depreciation of right-of-use assets. [Refer: Depreciation and amortisation expense; Right-of-use assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Depreciation, right-of-use assets",
        "negatedTerseLabel": "Depreciation"
       }
      }
     },
     "localname": "DepreciationRightofuseAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DerivativeFinancialAssets": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails_1": {
       "order": 3.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of financial assets classified as derivative instruments. [Refer: Financial assets; Derivatives [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Derivative financial assets",
        "terseLabel": "Risk management"
       }
      }
     },
     "localname": "DerivativeFinancialAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DerivativeFinancialLiabilities": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails_1": {
       "order": 3.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of financial liabilities classified as derivative instruments. [Refer: Financial assets; Derivatives [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Derivative financial liabilities",
        "terseLabel": "Risk management"
       }
      }
     },
     "localname": "DerivativeFinancialLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForBorrowingCostsExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for interest and other costs that the entity incurs in connection with the borrowing of funds."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for borrowing costs [text block]",
        "terseLabel": "CAPITALIZED BORROWING COSTS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForBorrowingCostsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForBusinessCombinationsAndGoodwillExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for business combinations and goodwill. [Refer: Business combinations [member]; Goodwill]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for business combinations and goodwill [text block]",
        "terseLabel": "BUSINESS COMBINATIONS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForBusinessCombinationsAndGoodwillExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForDecommissioningRestorationAndRehabilitationProvisionsExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for decommissioning, restoration and rehabilitation provisions. [Refer: Provision for decommissioning, restoration and rehabilitation costs]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for decommissioning, restoration and rehabilitation provisions [text block]",
        "terseLabel": "ASSET RETIREMENT OBLIGATIONS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForDecommissioningRestorationAndRehabilitationProvisionsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForDividendsExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for dividends. Dividends are distributions of profits to holders of equity investments in proportion to their holdings of a particular class of capital."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for dividends [text block]",
        "terseLabel": "DIVIDENDS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForDividendsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForEarningsPerShareExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for earnings per share."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for earnings per share [text block]",
        "terseLabel": "PER COMMON SHARE AMOUNTS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForEarningsPerShareExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForExplorationAndEvaluationExpenditures": {
     "auth_ref": [
      "r219"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for exploration and evaluation assets. [Refer: Exploration and evaluation assets [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for exploration and evaluation expenditures [text block]",
        "terseLabel": "EXPLORATION AND EVALUATION ASSETS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForExplorationAndEvaluationExpenditures",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForFinancialInstrumentsExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for financial instruments. [Refer: Financial instruments, class [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for financial instruments [text block]",
        "terseLabel": "FINANCIAL INSTRUMENTS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForFinancialInstrumentsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForForeignCurrencyTranslationExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for foreign currency translation."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for foreign currency translation [text block]",
        "terseLabel": "FOREIGN CURRENCY TRANSLATION"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForForeignCurrencyTranslationExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForGovernmentGrants": {
     "auth_ref": [
      "r83"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for government grants, including the methods of presentation adopted in the financial statements. [Refer: Government [member]; Government grants]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for government grants [text block]",
        "terseLabel": "GOVERNMENT GRANTS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForGovernmentGrants",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForIncomeTaxExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for income tax."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for income tax [text block]",
        "terseLabel": "INCOME TAX"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForIncomeTaxExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForInvestmentInAssociatesAndJointVenturesExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for investment in associates and joint ventures. [Refer: Associates [member]; Joint ventures [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for investment in associates and joint ventures [text block]",
        "terseLabel": "PRODUCTION SHARING CONTRACTS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForInvestmentInAssociatesAndJointVenturesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForIssuedCapitalExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for issued capital. [Refer: Issued capital]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for issued capital [text block]",
        "terseLabel": "SHARE CAPITAL"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForIssuedCapitalExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForLeasesExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for leases. A lease is an agreement whereby the lessor conveys to the lessee in return for a payment or series of payments the right to use an asset for an agreed period of time."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for leases [text block]",
        "terseLabel": "LEASES"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForLeasesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForMeasuringInventories": {
     "auth_ref": [
      "r79"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for measuring inventories. [Refer: Inventories]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for measuring inventories [text block]",
        "terseLabel": "INVENTORY"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForMeasuringInventories",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForPropertyPlantAndEquipmentExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for property, plant and equipment. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for property, plant and equipment [text block]",
        "terseLabel": "PROPERTY, PLANT AND EQUIPMENT"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForPropertyPlantAndEquipmentExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForRecognitionOfRevenue": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for recognising revenue. [Refer: Revenue]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for recognition of revenue [text block]",
        "terseLabel": "REVENUE RECOGNITION"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForRecognitionOfRevenue",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForSegmentReportingExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for segment reporting."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for segment reporting [text block]",
        "terseLabel": "SEGMENTED INFORMATION"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForSegmentReportingExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForSharebasedPaymentTransactionsExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for transactions in which the entity: (a) receives goods or services from the supplier of those goods or services (including an employee) in a share-based payment arrangement; or (b) incurs an obligation to settle the transaction with the supplier in a share-based payment arrangement when another group entity receives those goods or services. [Refer: Share-based payment arrangements [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for share-based payment transactions [text block]",
        "terseLabel": "SHARE-BASED COMPENSATION"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForSharebasedPaymentTransactionsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyForStrippingCostsExplanatory": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy for waste removal costs that are incurred in mining activity."
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for stripping costs [text block]",
        "terseLabel": "OVERBURDEN REMOVAL COSTS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyForStrippingCostsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfAccountingPolicyToDetermineComponentsOfCashAndCashEquivalents": {
     "auth_ref": [
      "r142"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The description of the entity's accounting policy used to determine the components of cash and cash equivalents. [Refer: Cash and cash equivalents]"
       }
      },
      "en-us": {
       "role": {
        "label": "Description of accounting policy for determining components of cash and cash equivalents [text block]",
        "terseLabel": "CASH AND CASH EQUIVALENTS"
       }
      }
     },
     "localname": "DescriptionOfAccountingPolicyToDetermineComponentsOfCashAndCashEquivalents",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfExpectedImpactOfInitialApplicationOfNewStandardsOrInterpretations": {
     "auth_ref": [
      "r148"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of the known or reasonably estimable information relevant to assessing the possible impact that the application of a new IFRS, that has been issued but is not yet effective, will have."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of expected impact of initial application of new standards or interpretations [text block]",
        "terseLabel": "Accounting Standards Issued But Not Yet Applied"
       }
      }
     },
     "localname": "DescriptionOfExpectedImpactOfInitialApplicationOfNewStandardsOrInterpretations",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfExpectedVolatilityShareOptionsGranted": {
     "auth_ref": [
      "r203"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time."
       }
      },
      "en-us": {
       "role": {
        "label": "Expected volatility, share options granted",
        "terseLabel": "Expected volatility"
       }
      }
     },
     "localname": "DescriptionOfExpectedVolatilityShareOptionsGranted",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_DescriptionOfInitialApplicationOfStandardsOrInterpretations": {
     "auth_ref": [
      "r147"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of the initial application of an IFRS. [Refer: IFRSs [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of initial application of standards or interpretations [text block]",
        "terseLabel": "Changes in Accounting Policies"
       }
      }
     },
     "localname": "DescriptionOfInitialApplicationOfStandardsOrInterpretations",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DescriptionOfOptionLifeShareOptionsGranted": {
     "auth_ref": [
      "r203"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The option life of share options granted."
       }
      },
      "en-us": {
       "role": {
        "label": "Option life, share options granted",
        "terseLabel": "Expected stock option life"
       }
      }
     },
     "localname": "DescriptionOfOptionLifeShareOptionsGranted",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_DescriptionOfRiskFreeInterestRateShareOptionsGranted": {
     "auth_ref": [
      "r203"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Risk free interest rate, share options granted",
        "terseLabel": "Risk free interest rate"
       }
      }
     },
     "localname": "DescriptionOfRiskFreeInterestRateShareOptionsGranted",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_DilutedEarningsLossPerShare": {
     "auth_ref": [
      "r99",
      "r100"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Diluted earnings (loss) per share",
        "terseLabel": "Diluted earnings per share (in CAD per share)",
        "verboseLabel": "Net earnings (loss) per common share - diluted (in CAD per share)"
       }
      }
     },
     "localname": "DilutedEarningsLossPerShare",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_DilutiveEffectOfShareOptionsOnNumberOfOrdinaryShares": {
     "auth_ref": [
      "r101"
     ],
     "calculation": {
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_AdjustedWeightedAverageShares",
       "weight": 1.0
      }
     },
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of dilutive potential ordinary shares that relate to the assumed exercise of the entity's share options."
       }
      },
      "en-us": {
       "role": {
        "label": "Dilutive effect of share options on number of ordinary shares",
        "terseLabel": "Effect of dilutive stock options (thousands of shares)"
       }
      }
     },
     "localname": "DilutiveEffectOfShareOptionsOnNumberOfOrdinaryShares",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "ifrs-full_DisclosureOfAccountingJudgementsAndEstimatesExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of judgements that management has made in the process of applying the entity's accounting policies that have the most significant effect on amounts recognised in the financial statements along with information about the assumptions that the entity makes about the future, and other major sources of estimation uncertainty at the end of the reporting period, that have a significant risk of resulting in a material adjustment to the carrying amounts of assets and liabilities within the next year. [Refer: Carrying amount [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of accounting judgements and estimates [text block]",
        "terseLabel": "Critical Accounting Estimates and Judgements"
       }
      }
     },
     "localname": "DisclosureOfAccountingJudgementsAndEstimatesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfAdditionalInformationAboutLeasingActivitiesForLesseeExplanatory": {
     "auth_ref": [
      "r189"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of additional information about leasing activities of a lessee."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of additional information about leasing activities for lessee [text block]",
        "terseLabel": "Schedule of Leases Impact on Net Earnings and Cash Flow"
       }
      }
     },
     "localname": "DisclosureOfAdditionalInformationAboutLeasingActivitiesForLesseeExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfAnalysisOfOtherComprehensiveIncomeByItemExplanatory": {
     "auth_ref": [
      "r8"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure of the analysis of other comprehensive income by item."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of analysis of other comprehensive income by item [text block]",
        "terseLabel": "Accumulated Other Comprehensive (Loss) Income"
       }
      }
     },
     "localname": "DisclosureOfAnalysisOfOtherComprehensiveIncomeByItemExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccumulatedOtherComprehensiveLossIncome"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfBorrowingsExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of borrowings [text block]",
        "terseLabel": "Long-Term Debt"
       }
      }
     },
     "localname": "DisclosureOfBorrowingsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebt"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfBusinessCombinationsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about business combination [line items]",
        "terseLabel": "Disclosure of detailed information about business combination [line items]"
       }
      }
     },
     "localname": "DisclosureOfBusinessCombinationsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfBusinessCombinationsTable": {
     "auth_ref": [
      "r212"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to details of business combinations."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about business combination [table]",
        "terseLabel": "Disclosure of detailed information about business combination [table]"
       }
      }
     },
     "localname": "DisclosureOfBusinessCombinationsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfCashFlowStatementExplanatory": {
     "auth_ref": [
      "r146"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for a statement of cash flows."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of cash flow statement [text block]",
        "terseLabel": "Supplemental Disclosure of Cash Flow Information"
       }
      }
     },
     "localname": "DisclosureOfCashFlowStatementExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformation"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfChangesInAccountingPoliciesExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of changes made to accounting policies by the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of changes in accounting policies [text block]",
        "terseLabel": "Changes in Accounting Policies",
        "verboseLabel": "Accounting Standards Issued But Not Yet Applied"
       }
      }
     },
     "localname": "DisclosureOfChangesInAccountingPoliciesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingStandardsIssuedButNotYetApplied",
      "http://www.cnrl.com/role/ChangesinAccountingPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfClassesOfShareCapitalExplanatory": {
     "auth_ref": [
      "r38"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of classes of share capital. [Refer: Share capital [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of classes of share capital [text block]",
        "terseLabel": "Summary of outstanding common stock"
       }
      }
     },
     "localname": "DisclosureOfClassesOfShareCapitalExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfClassesOfShareCapitalLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of classes of share capital [line items]",
        "terseLabel": "Disclosure of classes of share capital [line items]"
       }
      }
     },
     "localname": "DisclosureOfClassesOfShareCapitalLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfClassesOfShareCapitalTable": {
     "auth_ref": [
      "r38"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to classes of share capital."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of classes of share capital [table]",
        "terseLabel": "Disclosure of classes of share capital [table]"
       }
      }
     },
     "localname": "DisclosureOfClassesOfShareCapitalTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of commitments and contingent liabilities. [Refer: Contingent liabilities [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of commitments and contingent liabilities [text block]",
        "terseLabel": "Commitments and Contingencies"
       }
      }
     },
     "localname": "DisclosureOfCommitmentsAndContingentLiabilitiesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingencies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutBorrowingsExplanatory": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of detailed information about borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about borrowings [text block]",
        "terseLabel": "Summary of long-term debt"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutBorrowingsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutBorrowingsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about borrowings [line items]",
        "terseLabel": "Disclosure of detailed information about borrowings [line items]"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutBorrowingsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutBorrowingsTable": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to details of borrowings."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about borrowings [table]",
        "terseLabel": "Disclosure of detailed information about borrowings [table]"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutBorrowingsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory": {
     "auth_ref": [
      "r217"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of detailed information about business combinations. [Refer: Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about business combination [text block]",
        "terseLabel": "Summary of net assets acquired and liabilities assumed"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutFinancialInstrumentsExplanatory": {
     "auth_ref": [
      "r237",
      "r244",
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of detailed information about financial instruments. [Refer: Financial instruments, class [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about financial instruments [text block]",
        "terseLabel": "Schedule of information about financial instruments"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutFinancialInstrumentsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutHedgingInstrumentsExplanatory": {
     "auth_ref": [
      "r228"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of detailed information about hedging instruments. [Refer: Hedging instruments [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about hedging instruments [text block]",
        "terseLabel": "Schedule of derivative financial instruments"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutHedgingInstrumentsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutHedgingInstrumentsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about hedging instruments [line items]",
        "terseLabel": "Disclosure of detailed information about hedging instruments [line items]"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutHedgingInstrumentsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutHedgingInstrumentsTable": {
     "auth_ref": [
      "r228"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to details of hedging instruments."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about hedging instruments [table]",
        "terseLabel": "Disclosure of detailed information about hedging instruments [table]"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutHedgingInstrumentsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory": {
     "auth_ref": [
      "r71"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of detailed information about property, plant and equipment. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about property, plant and equipment [text block]",
        "terseLabel": "Detailed information about property, plant and equipment"
       }
      }
     },
     "localname": "DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfEarningsPerShareExplanatory": {
     "auth_ref": [
      "r102"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for earnings per share."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of earnings per share [text block]",
        "terseLabel": "Net Earnings Per Common Share"
       }
      }
     },
     "localname": "DisclosureOfEarningsPerShareExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/NetEarningsPerCommonShare"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfEntitysReportableSegmentsExplanatory": {
     "auth_ref": [
      "r285"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for operating segments."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of entity's operating segments [text block]",
        "terseLabel": "Segmented Information"
       }
      }
     },
     "localname": "DisclosureOfEntitysReportableSegmentsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformation"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfExplorationAndEvaluationAssetsExplanatory": {
     "auth_ref": [
      "r221"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for exploration and evaluation assets."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of exploration and evaluation assets [text block]",
        "terseLabel": "Exploration and Evaluation Assets"
       }
      }
     },
     "localname": "DisclosureOfExplorationAndEvaluationAssetsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ExplorationandEvaluationAssets"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfFairValueMeasurementOfAssetsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of fair value measurement of assets [line items]",
        "terseLabel": "Disclosure of fair value measurement of assets [line items]"
       }
      }
     },
     "localname": "DisclosureOfFairValueMeasurementOfAssetsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfFairValueMeasurementOfAssetsTable": {
     "auth_ref": [
      "r172"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to the fair value measurement of assets."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of fair value measurement of assets [table]",
        "terseLabel": "Disclosure of fair value measurement of assets [table]"
       }
      }
     },
     "localname": "DisclosureOfFairValueMeasurementOfAssetsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfFinanceIncomeExpenseExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of finance income (cost). [Refer: Finance income (cost)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of finance income (cost) [text block]",
        "terseLabel": "Interest and Other Financing Expense"
       }
      }
     },
     "localname": "DisclosureOfFinanceIncomeExpenseExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InterestandOtherFinancingExpense"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfFinancialAssetsExplanatory": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of financial assets. [Refer: Financial assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of financial assets [text block]",
        "terseLabel": "Schedule of financial assets"
       }
      }
     },
     "localname": "DisclosureOfFinancialAssetsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfFinancialAssetsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of financial assets [line items]",
        "terseLabel": "Disclosure of financial assets [line items]"
       }
      }
     },
     "localname": "DisclosureOfFinancialAssetsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfFinancialAssetsTable": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to financial assets."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of financial assets [table]",
        "terseLabel": "Disclosure of financial assets [table]"
       }
      }
     },
     "localname": "DisclosureOfFinancialAssetsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfFinancialInstrumentsExplanatory": {
     "auth_ref": [
      "r268"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for financial instruments."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of financial instruments [text block]",
        "terseLabel": "Financial Instruments"
       }
      }
     },
     "localname": "DisclosureOfFinancialInstrumentsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstruments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfFinancialInstrumentsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about financial instruments [line items]",
        "terseLabel": "Disclosure of detailed information about financial instruments [line items]"
       }
      }
     },
     "localname": "DisclosureOfFinancialInstrumentsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails",
      "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfFinancialInstrumentsTable": {
     "auth_ref": [
      "r237",
      "r244",
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to details of financial instruments."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about financial instruments [table]",
        "terseLabel": "Disclosure of detailed information about financial instruments [table]"
       }
      }
     },
     "localname": "DisclosureOfFinancialInstrumentsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/InvestmentsNarrativeDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails",
      "http://www.cnrl.com/role/InvestmentsSummaryofInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfFinancialLiabilitiesExplanatory": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of financial liabilities. [Refer: Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of financial liabilities [text block]",
        "terseLabel": "Schedule of financial liabilities"
       }
      }
     },
     "localname": "DisclosureOfFinancialLiabilitiesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfIncomeTaxExplanatory": {
     "auth_ref": [
      "r64"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for income taxes."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of income tax [text block]",
        "terseLabel": "Income Taxes"
       }
      }
     },
     "localname": "DisclosureOfIncomeTaxExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxes"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfIndirectMeasurementOfFairValueOfGoodsOrServicesReceivedShareOptionsGrantedDuringPeriodExplanatory": {
     "auth_ref": [
      "r204"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of information about indirect, by reference to the fair value of the equity instruments granted, measurement of the fair value of goods or services received as consideration for the entity's share options."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of indirect measurement of fair value of goods or services received, share options granted during period [text block]",
        "terseLabel": "Disclosure of weighted average assumptions used"
       }
      }
     },
     "localname": "DisclosureOfIndirectMeasurementOfFairValueOfGoodsOrServicesReceivedShareOptionsGrantedDuringPeriodExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfInformationAboutKeyManagementPersonnelExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of information about key management personnel. [Refer: Key management personnel of entity or parent [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of information about key management personnel [text block]",
        "terseLabel": "Remuneration of Directors and Senior Management"
       }
      }
     },
     "localname": "DisclosureOfInformationAboutKeyManagementPersonnelExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagement"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfInterestsInJointArrangementsExplanatory": {
     "auth_ref": [
      "r153"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of interests in joint arrangements. A joint arrangement is an arrangement of which two or more parties have joint control."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of interests in joint arrangements [text block]",
        "terseLabel": "Summary of assets, liabilities, partners' equity and equity (income) loss related to joint venture"
       }
      }
     },
     "localname": "DisclosureOfInterestsInJointArrangementsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfInventoriesExplanatory": {
     "auth_ref": [
      "r82"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for inventories."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of inventories [text block]",
        "terseLabel": "Inventory"
       }
      }
     },
     "localname": "DisclosureOfInventoriesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/Inventory"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of investments other than investments accounted for using the equity method. [Refer: Investments other than investments accounted for using equity method]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of investments other than investments accounted for using equity method [text block]",
        "terseLabel": "Investments"
       }
      }
     },
     "localname": "DisclosureOfInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/Investments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfIssuedCapitalExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of issued capital. [Refer: Issued capital]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of issued capital [text block]",
        "terseLabel": "Share Capital"
       }
      }
     },
     "localname": "DisclosureOfIssuedCapitalExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapital"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfJointVenturesLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of joint ventures [line items]",
        "terseLabel": "Disclosure of joint ventures [line items]"
       }
      }
     },
     "localname": "DisclosureOfJointVenturesLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfJointVenturesTable": {
     "auth_ref": [
      "r96",
      "r98",
      "r168"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to joint ventures."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of joint ventures [table]",
        "terseLabel": "Disclosure of joint ventures [table]"
       }
      }
     },
     "localname": "DisclosureOfJointVenturesTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfLeasesExplanatory": {
     "auth_ref": [
      "r192",
      "r193"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for leases."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of leases [text block]",
        "terseLabel": "Leases"
       }
      }
     },
     "localname": "DisclosureOfLeasesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/Leases"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfMaturityAnalysisForNonderivativeFinancialLiabilitiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of maturity analysis for non-derivative financial liabilities [line items]",
        "terseLabel": "Disclosure of maturity analysis for non-derivative financial liabilities [line items]"
       }
      }
     },
     "localname": "DisclosureOfMaturityAnalysisForNonderivativeFinancialLiabilitiesLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfMaturityAnalysisForNonderivativeFinancialLiabilitiesTable": {
     "auth_ref": [
      "r249"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to the maturity analysis for non-derivative financial liabilities."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of maturity analysis for non-derivative financial liabilities [table]",
        "terseLabel": "Disclosure of maturity analysis for non-derivative financial liabilities [table]"
       }
      }
     },
     "localname": "DisclosureOfMaturityAnalysisForNonderivativeFinancialLiabilitiesTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfNumberAndWeightedAverageExercisePricesOfShareOptionsExplanatory": {
     "auth_ref": [
      "r200"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of the number and weighted average exercise prices of share options. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of number and weighted average exercise prices of share options [text block]",
        "terseLabel": "Summary of stock option activity"
       }
      }
     },
     "localname": "DisclosureOfNumberAndWeightedAverageExercisePricesOfShareOptionsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalExplanatory": {
     "auth_ref": [
      "r15"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of information that enables users of financial statements to evaluate the entity's objectives, policies and processes for managing capital."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of objectives, policies and processes for managing capital [text block]",
        "terseLabel": "Capital Disclosures"
       }
      }
     },
     "localname": "DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosures"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of objectives, policies and processes for managing capital [line items]",
        "terseLabel": "Disclosure of objectives, policies and processes for managing capital [line items]"
       }
      }
     },
     "localname": "DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalTable": {
     "auth_ref": [
      "r16"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to the objectives, policies and processes for managing capital."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of objectives, policies and processes for managing capital [table]",
        "terseLabel": "Disclosure of objectives, policies and processes for managing capital [table]"
       }
      }
     },
     "localname": "DisclosureOfObjectivesPoliciesAndProcessesForManagingCapitalTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfOperatingSegmentsExplanatory": {
     "auth_ref": [
      "r272"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of operating segments. [Refer: Operating segments [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of operating segments [text block]",
        "terseLabel": "Disclosure of operating segments"
       }
      }
     },
     "localname": "DisclosureOfOperatingSegmentsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfOperatingSegmentsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of operating segments [line items]",
        "terseLabel": "Disclosure of operating segments [line items]"
       }
      }
     },
     "localname": "DisclosureOfOperatingSegmentsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfOperatingSegmentsTable": {
     "auth_ref": [
      "r272"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to operating segments."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of operating segments [table]",
        "terseLabel": "Disclosure of operating segments [table]"
       }
      }
     },
     "localname": "DisclosureOfOperatingSegmentsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfOtherNoncurrentAssetsExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of other non-current assets. [Refer: Other non-current assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of other non-current assets [text block]",
        "terseLabel": "Other Long-Term Assets"
       }
      }
     },
     "localname": "DisclosureOfOtherNoncurrentAssetsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssets"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfOtherNoncurrentLiabilitiesExplanatory": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of other non-current liabilities. [Refer: Other non-current liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of other non-current liabilities [text block]",
        "terseLabel": "Other Long-Term Liabilities"
       }
      }
     },
     "localname": "DisclosureOfOtherNoncurrentLiabilitiesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilities"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfOtherProvisionsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of other provisions [line items]",
        "terseLabel": "Disclosure of other provisions [line items]"
       }
      }
     },
     "localname": "DisclosureOfOtherProvisionsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfOtherProvisionsTable": {
     "auth_ref": [
      "r108"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to other provisions."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of other provisions [table]",
        "terseLabel": "Disclosure of other provisions [table]"
       }
      }
     },
     "localname": "DisclosureOfOtherProvisionsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfPropertyPlantAndEquipmentExplanatory": {
     "auth_ref": [
      "r74"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for property, plant and equipment."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of property, plant and equipment [text block]",
        "terseLabel": "Property, Plant and Equipment"
       }
      }
     },
     "localname": "DisclosureOfPropertyPlantAndEquipmentExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipment"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfPropertyPlantAndEquipmentLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about property, plant and equipment [line items]",
        "terseLabel": "Disclosure of detailed information about property, plant and equipment [line items]"
       }
      }
     },
     "localname": "DisclosureOfPropertyPlantAndEquipmentLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfPropertyPlantAndEquipmentTable": {
     "auth_ref": [
      "r71"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to details of property, plant and equipment."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of detailed information about property, plant and equipment [table]",
        "terseLabel": "Disclosure of detailed information about property, plant and equipment [table]"
       }
      }
     },
     "localname": "DisclosureOfPropertyPlantAndEquipmentTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfQuantitativeInformationAboutRightofuseAssetsExplanatory": {
     "auth_ref": [
      "r188"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of quantitative information about right-of-use assets. [Refer: Right-of-use assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of quantitative information about right-of-use assets [text block]",
        "terseLabel": "Schedule of Lease Assets"
       }
      }
     },
     "localname": "DisclosureOfQuantitativeInformationAboutRightofuseAssetsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsExplanatory": {
     "auth_ref": [
      "r201"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of the range of exercise prices for outstanding share options."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of range of exercise prices of outstanding share options [text block]",
        "terseLabel": "Summary of range of exercise prices of stock options outstanding"
       }
      }
     },
     "localname": "DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of range of exercise prices of outstanding share options [line items]",
        "terseLabel": "Disclosure of range of exercise prices of outstanding share options [line items]"
       }
      }
     },
     "localname": "DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsTable": {
     "auth_ref": [
      "r201"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to the range of exercise prices of outstanding share options."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of range of exercise prices of outstanding share options [table]",
        "terseLabel": "Disclosure of range of exercise prices of outstanding share options [table]"
       }
      }
     },
     "localname": "DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesExplanatory": {
     "auth_ref": [
      "r140"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of the reconciliation of liabilities arising from financing activities. [Refer: Liabilities arising from financing activities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of reconciliation of liabilities arising from financing activities [text block]",
        "terseLabel": "Reconciliation of liabilities arising from financing activities"
       }
      }
     },
     "localname": "DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of reconciliation of liabilities arising from financing activities [line items]",
        "terseLabel": "Disclosure of reconciliation of liabilities arising from financing activities [line items]"
       }
      }
     },
     "localname": "DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesTable": {
     "auth_ref": [
      "r140"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to the reconciliation of liabilities arising from financing activities."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of reconciliation of liabilities arising from financing activities [table]",
        "terseLabel": "Disclosure of reconciliation of liabilities arising from financing activities [table]"
       }
      }
     },
     "localname": "DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfSummaryOfSignificantAccountingPoliciesExplanatory": {
     "auth_ref": [
      "r14"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The entire disclosure for significant accounting policies applied by the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of significant accounting policies [text block]",
        "terseLabel": "Accounting Policies"
       }
      }
     },
     "localname": "DisclosureOfSummaryOfSignificantAccountingPoliciesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of types of temporary differences, unused tax losses and unused tax credits. [Refer: Unused tax credits [member]; Unused tax losses [member]; Temporary differences [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of temporary difference, unused tax losses and unused tax credits [text block]",
        "terseLabel": "Summary of major temporary differences, movements in deferred tax assets and liabilities, and net deferred income tax liability"
       }
      }
     },
     "localname": "DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of temporary difference, unused tax losses and unused tax credits [line items]",
        "terseLabel": "Disclosure of temporary difference, unused tax losses and unused tax credits [line items]"
       }
      }
     },
     "localname": "DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsTable": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to temporary differences, unused tax losses and unused tax credits."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of temporary difference, unused tax losses and unused tax credits [table]",
        "terseLabel": "Disclosure of temporary difference, unused tax losses and unused tax credits [table]"
       }
      }
     },
     "localname": "DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of terms and conditions of share-based payment arrangement [line items]",
        "terseLabel": "Disclosure of terms and conditions of share-based payment arrangement [line items]"
       }
      }
     },
     "localname": "DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementTable": {
     "auth_ref": [
      "r202"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to terms and conditions of share-based payment arrangements."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of terms and conditions of share-based payment arrangement [table]",
        "terseLabel": "Disclosure of terms and conditions of share-based payment arrangement [table]"
       }
      }
     },
     "localname": "DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesExplanatory": {
     "auth_ref": [
      "r89"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of transactions between the entity and its related parties. [Refer: Related parties [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of transactions between related parties [text block]",
        "terseLabel": "Remuneration of non-management directors and senior management"
       }
      }
     },
     "localname": "DisclosureOfTransactionsBetweenRelatedPartiesExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of transactions between related parties [line items]",
        "terseLabel": "Disclosure of transactions between related parties [line items]"
       }
      }
     },
     "localname": "DisclosureOfTransactionsBetweenRelatedPartiesLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesTable": {
     "auth_ref": [
      "r90"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to transactions between related parties."
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of transactions between related parties [table]",
        "terseLabel": "Disclosure of transactions between related parties [table]"
       }
      }
     },
     "localname": "DisclosureOfTransactionsBetweenRelatedPartiesTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_DisposalsPropertyPlantAndEquipment": {
     "auth_ref": [
      "r67"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The decrease in property, plant and equipment resulting from disposals. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disposals, property, plant and equipment",
        "negatedLabel": "Disposals"
       }
      }
     },
     "localname": "DisposalsPropertyPlantAndEquipment",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DividendsPaid": {
     "auth_ref": [
      "r9"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of dividends recognised as distributions to owners."
       }
      },
      "en-us": {
       "role": {
        "label": "Dividends recognised as distributions to owners",
        "negatedTerseLabel": "Dividends on common shares"
       }
      }
     },
     "localname": "DividendsPaid",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DividendsPaidClassifiedAsFinancingActivities": {
     "auth_ref": [
      "r133"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 9.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow for dividends paid by the entity, classified as financing activities."
       }
      },
      "en-us": {
       "role": {
        "label": "Dividends paid, classified as financing activities",
        "negatedTerseLabel": "Dividends on common shares"
       }
      }
     },
     "localname": "DividendsPaidClassifiedAsFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_DividendsRecognisedAsDistributionsToOwnersPerShare": {
     "auth_ref": [
      "r9"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount, per share, of dividends recognised as distributions to owners."
       }
      },
      "en-us": {
       "role": {
        "label": "Dividends recognised as distributions to owners per share",
        "terseLabel": "Quarterly dividend declared (in CAD per share)"
       }
      }
     },
     "localname": "DividendsRecognisedAsDistributionsToOwnersPerShare",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_EarningsPerShareAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Earnings per share [abstract]",
        "terseLabel": "Net earnings (loss) per common share"
       }
      }
     },
     "localname": "EarningsPerShareAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_EarningsPerShareExplanatory": {
     "auth_ref": [
      "r99"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of earnings per share."
       }
      },
      "en-us": {
       "role": {
        "label": "Earnings per share [text block]",
        "terseLabel": "Net earnings (loss) per common share"
       }
      }
     },
     "localname": "EarningsPerShareExplanatory",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/NetEarningsPerCommonShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_EliminationOfIntersegmentAmountsMember": {
     "auth_ref": [
      "r279",
      "r284"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the elimination of intersegment amounts in the reconciliations of total segment amounts to amounts recognised in the entity's financial statements."
       }
      },
      "en-us": {
       "role": {
        "label": "Elimination of intersegment amounts [member]",
        "terseLabel": "Inter\u2013segment elimination and other"
       }
      }
     },
     "localname": "EliminationOfIntersegmentAmountsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_EntitysTotalForBusinessCombinationsMember": {
     "auth_ref": [
      "r212",
      "r215"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the standard value for the 'Business combinations' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Entity's total for business combinations [member]",
        "terseLabel": "Entity's total for business combinations [member]"
       }
      }
     },
     "localname": "EntitysTotalForBusinessCombinationsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsNarrativeDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_EntitysTotalForJointVenturesMember": {
     "auth_ref": [
      "r96",
      "r98",
      "r168",
      "r303",
      "r304"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the standard value for the 'Joint ventures' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Entity's total for joint ventures [member]",
        "terseLabel": "Entity's total for joint ventures [member]"
       }
      }
     },
     "localname": "EntitysTotalForJointVenturesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_EntitysTotalForRelatedPartiesMember": {
     "auth_ref": [
      "r90"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the standard value for the 'Categories of related parties' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Entity's total for related parties [member]",
        "terseLabel": "Entity's total for related parties [member]"
       }
      }
     },
     "localname": "EntitysTotalForRelatedPartiesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_EntitysTotalForSegmentConsolidationItemsMember": {
     "auth_ref": [
      "r279"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the standard value for the 'Segment consolidation items' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Entity's total for segment consolidation items [member]",
        "terseLabel": "Entity's total for segment consolidation items [member]"
       }
      }
     },
     "localname": "EntitysTotalForSegmentConsolidationItemsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_Equity": {
     "auth_ref": [
      "r25",
      "r35",
      "r149",
      "r151",
      "r169",
      "r170",
      "r171"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "ifrs-full_EquityAndLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of residual interest in the assets of the entity after deducting all its liabilities."
       }
      },
      "en-us": {
       "role": {
        "label": "Equity",
        "periodEndLabel": "Balance \u2013 end of year",
        "periodStartLabel": "Balance \u2013 beginning of year",
        "terseLabel": "Partners' equity",
        "totalLabel": "Shareholders' equity",
        "verboseLabel": "Total shareholders\u2019 equity"
       }
      }
     },
     "localname": "Equity",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CapitalDisclosuresScheduleofDebttoBookCapitalizationRatioDetails",
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_EquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Equity [abstract]",
        "terseLabel": "SHAREHOLDERS\u2019 EQUITY"
       }
      }
     },
     "localname": "EquityAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_EquityAndLiabilities": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of the entity's equity and liabilities. [Refer: Equity; Liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Equity and liabilities",
        "totalLabel": "Liabilities and shareholders' equity"
       }
      }
     },
     "localname": "EquityAndLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_EquityMember": {
     "auth_ref": [
      "r7"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the residual interest in the assets of the entity after deducting all its liabilities. It also represents the standard value for the 'Components of equity' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Equity [member]",
        "terseLabel": "Equity [member]"
       }
      }
     },
     "localname": "EquityMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ExchangeDifferencesOnTranslationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Exchange differences on translation [abstract]",
        "terseLabel": "Foreign currency translation adjustment"
       }
      }
     },
     "localname": "ExchangeDifferencesOnTranslationAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ExercisePriceOfOutstandingShareOptions2019": {
     "auth_ref": [
      "r201"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The exercise price of outstanding share options."
       }
      },
      "en-us": {
       "role": {
        "label": "Exercise price of outstanding share options",
        "terseLabel": "Range of exercise prices"
       }
      }
     },
     "localname": "ExercisePriceOfOutstandingShareOptions2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_ExpectedCreditLossRate": {
     "auth_ref": [
      "r247",
      "r264"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The rate of expected credit losses, calculated as percentage of the gross carrying amount. Expected credit losses are the weighted average of credit losses with the respective risks of a default occurring as the weights."
       }
      },
      "en-us": {
       "role": {
        "label": "Expected credit loss rate",
        "terseLabel": "Expected credit loss rate"
       }
      }
     },
     "localname": "ExpectedCreditLossRate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_ExpectedDividendAsPercentageShareOptionsGranted": {
     "auth_ref": [
      "r203"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The percentage of an expected dividend used to calculate the fair value of share options granted."
       }
      },
      "en-us": {
       "role": {
        "label": "Expected dividend as percentage, share options granted",
        "terseLabel": "Expected dividend yield"
       }
      }
     },
     "localname": "ExpectedDividendAsPercentageShareOptionsGranted",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_ExpenseArisingFromExplorationForAndEvaluationOfMineralResources": {
     "auth_ref": [
      "r220"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails": {
       "order": 4.0,
       "parentTag": "cnq_CostsIncurredOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivities1",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of expense 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."
       }
      },
      "en-us": {
       "role": {
        "label": "Expense arising from exploration for and evaluation of mineral resources",
        "terseLabel": "Exploration"
       }
      }
     },
     "localname": "ExpenseArisingFromExplorationForAndEvaluationOfMineralResources",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ExpenseByNature": {
     "auth_ref": [
      "r50"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 1.0,
       "parentTag": "ifrs-full_ProfitLossBeforeTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of expenses aggregated according to their nature (for example, depreciation, purchases of materials, transport costs, employee benefits and advertising costs), and not reallocated among functions within the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Expenses, by nature",
        "totalLabel": "Total expenses"
       }
      }
     },
     "localname": "ExpenseByNature",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ExpenseByNatureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Expenses by nature [abstract]",
        "terseLabel": "Expenses"
       }
      }
     },
     "localname": "ExpenseByNatureAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ExpenseFromSharebasedPaymentTransactionsWithEmployees": {
     "auth_ref": [
      "r11"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 2.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of expense from share-based payment transactions with employees. [Refer: Expense from share-based payment transactions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Expense from share-based payment transactions with employees",
        "terseLabel": "Share-based compensation",
        "verboseLabel": "Share-based compensation expense (recovery)"
       }
      }
     },
     "localname": "ExpenseFromSharebasedPaymentTransactionsWithEmployees",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ExpenseRelatingToShorttermLeasesForWhichRecognitionExemptionHasBeenUsed": {
     "auth_ref": [
      "r183"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of the expense relating to short-term leases accounted for applying paragraph 6 of IFRS 16. This expense need not include the expense relating to leases with a lease term of one month or less. Short-term lease is a lease that, at the commencement date, has a lease term of 12 months or less. A lease that contains a purchase option is not a short-term lease."
       }
      },
      "en-us": {
       "role": {
        "label": "Expense relating to short-term leases for which recognition exemption has been used",
        "terseLabel": "Expenses relating to short-term leases"
       }
      }
     },
     "localname": "ExpenseRelatingToShorttermLeasesForWhichRecognitionExemptionHasBeenUsed",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ExpenseRelatingToVariableLeasePaymentsNotIncludedInMeasurementOfLeaseLiabilities": {
     "auth_ref": [
      "r184"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of the expense relating to variable lease payments not included in the measurement of lease liabilities. Variable lease payments are the portion of payments made by a lessee to a lessor for the right to use an underlying asset during the lease term that varies because of changes in facts or circumstances occurring after the commencement date, other than the passage of time. [Refer: Lease liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Expense relating to variable lease payments not included in measurement of lease liabilities",
        "terseLabel": "Variable lease payments not included in the measurement of lease liabilities"
       }
      }
     },
     "localname": "ExpenseRelatingToVariableLeasePaymentsNotIncludedInMeasurementOfLeaseLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ExplanationOfMeasurementBasesUsedInPreparingFinancialStatements": {
     "auth_ref": [
      "r12"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The explanation of the measurement basis (or bases) used in preparing the financial statements."
       }
      },
      "en-us": {
       "role": {
        "label": "Explanation of measurement bases used in preparing financial statements [text block]",
        "terseLabel": "PRINCIPLES OF CONSOLIDATION"
       }
      }
     },
     "localname": "ExplanationOfMeasurementBasesUsedInPreparingFinancialStatements",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_FinanceCosts": {
     "auth_ref": [
      "r43"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_FinanceIncomeCost",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of costs associated with financing activities of the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Finance costs",
        "terseLabel": "Interest and other financing expense",
        "totalLabel": "Total interest and other financing expense"
       }
      }
     },
     "localname": "FinanceCosts",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinanceIncome": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_FinanceIncomeCost",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of income associated with interest and other financing activities of the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Finance income",
        "negatedTerseLabel": "Total interest income and other"
       }
      }
     },
     "localname": "FinanceIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinanceIncomeCost": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 4.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": -1.0
      },
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of income or cost associated with interest and other financing activities of the entity."
       }
      },
      "en-us": {
       "role": {
        "label": "Finance income (cost)",
        "negatedTerseLabel": "Interest and other financing expense",
        "negatedTotalLabel": "Net interest and other financing expense"
       }
      }
     },
     "localname": "FinanceIncomeCost",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialAssets": {
     "auth_ref": [
      "r236",
      "r242",
      "r243",
      "r246",
      "r247"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 5.0,
       "parentTag": "cnq_FinancialAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of assets that are: (a) cash; (b) an equity instrument of another entity; (c) a contractual right: (i) to receive cash or another financial asset from another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially favourable to the entity; or (d) a contract that will, or may be, settled in the entity\u2019s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to receive a variable number of the entity\u2019s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity\u2019s own equity instruments. For this purpose the entity\u2019s own equity instruments do not include puttable financial instruments classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity\u2019s own equity instruments. [Refer: Financial instruments, class [member]; Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial assets",
        "totalLabel": "Financial assets",
        "verboseLabel": "Financial assets, carrying amount"
       }
      }
     },
     "localname": "FinancialAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialAssetsAtAmortisedCost": {
     "auth_ref": [
      "r258"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_FinancialAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of financial assets at amortised cost. The amortised cost is the amount at which financial assets are measured at initial recognition minus principal repayments, plus or minus the cumulative amortisation using the effective interest method of any difference between that initial amount and the maturity amount, and adjusted for any impairment. [Refer: Financial assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial assets at amortised cost",
        "terseLabel": "Financial assets at amortized cost"
       }
      }
     },
     "localname": "FinancialAssetsAtAmortisedCost",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialAssetsAtFairValue": {
     "auth_ref": [
      "r236"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The fair value of financial assets. [Refer: At fair value [member]; Financial assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial assets, at fair value",
        "verboseLabel": "Financial assets, at fair value"
       }
      }
     },
     "localname": "FinancialAssetsAtFairValue",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialAssetsAtFairValueThroughOtherComprehensiveIncome": {
     "auth_ref": [
      "r260"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_FinancialAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of financial assets at fair value through other comprehensive income. [Refer: At fair value [member]; Financial assets; Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial assets at fair value through other comprehensive income",
        "terseLabel": "Financial assets, derivatives used for hedging"
       }
      }
     },
     "localname": "FinancialAssetsAtFairValueThroughOtherComprehensiveIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLoss": {
     "auth_ref": [
      "r256"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_FinancialAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of financial assets that are measured at fair value and for which gains (losses) are recognised in profit or loss. A financial asset shall be measured at fair value through profit or loss unless it is measured at amortised cost or at fair value through other comprehensive income. A gain (loss) on a financial asset measured at fair value shall be recognised in profit or loss unless it is part of a hedging relationship, it is an investment in an equity instrument for which the entity has elected to present gains and losses in other comprehensive income or it is a financial asset measured at fair value through other comprehensive income. [Refer: At fair value [member]; Financial assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial assets at fair value through profit or loss",
        "terseLabel": "Financial assets, fair value through profit or loss"
       }
      }
     },
     "localname": "FinancialAssetsAtFairValueThroughProfitOrLoss",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialAssetsMember": {
     "auth_ref": [
      "r253",
      "r254",
      "r286",
      "r299",
      "r300",
      "r301"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for aggregated classes of financial assets. It also represents the standard value for the 'Classes of financial assets' axis if no other member is used. [Refer: Financial assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial assets, class [member]",
        "terseLabel": "Financial assets, class [member]"
       }
      }
     },
     "localname": "FinancialAssetsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_FinancialLiabilities": {
     "auth_ref": [
      "r236"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity\u2019s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity\u2019s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity\u2019s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity\u2019s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity\u2019s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity\u2019s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Financial instruments, class [member]; Financial assets; Derivatives [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial liabilities",
        "negatedLabel": "Financial liabilities, carrying amount",
        "negatedTotalLabel": "Financial liabilities"
       }
      }
     },
     "localname": "FinancialLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialLiabilitiesAtAmortisedCost": {
     "auth_ref": [
      "r259",
      "r309"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 4.0,
       "parentTag": "cnq_FinancialAssetsLiabilitiesNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of financial liabilities at amortised cost. The amortised cost is the amount at which financial liabilities are measured at initial recognition minus principal repayments, plus or minus the cumulative amortisation using the effective interest method of any difference between that initial amount and the maturity amount. [Refer: Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial liabilities at amortised cost",
        "negatedTerseLabel": "Financial liabilities at amortized cost"
       }
      }
     },
     "localname": "FinancialLiabilitiesAtAmortisedCost",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialLiabilitiesAtFairValue": {
     "auth_ref": [
      "r236"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The fair value of financial liabilities. [Refer: At fair value [member]; Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial liabilities, at fair value",
        "negatedTerseLabel": "Financial liabilities, at fair value"
       }
      }
     },
     "localname": "FinancialLiabilitiesAtFairValue",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialLiabilitiesAtFairValueThroughProfitOrLoss": {
     "auth_ref": [
      "r257"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails": {
       "order": 2.0,
       "parentTag": "cnq_FinancialAssetsLiabilitiesAtFairValueThroughProfitOrLossNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of financial liabilities that meet either of the following conditions: (a) they meet the definition of held for trading; or (b) upon initial recognition they are designated by the entity as at fair value through profit or loss. An entity may use this designation only when permitted by paragraph 4.3.5 of IFRS 9 (embedded derivatives) or when doing so results in more relevant information, because either: (a) it eliminates or significantly reduces a measurement or recognition inconsistency (sometimes referred to as \u2018an accounting mismatch\u2019) that would otherwise arise from measuring assets or liabilities or recognising the gains and losses on them on different bases; or (b) a group of financial liabilities or financial assets and financial liabilities is managed and its performance is evaluated on a fair value basis, in accordance with a documented risk management or investment strategy, and information about the group is provided internally on that basis to the entity\u2019s key management personnel (as defined in IAS 24). [Refer: At fair value [member]; Key management personnel of entity or parent [member]; Derivatives [member]; Financial assets; Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial liabilities at fair value through profit or loss",
        "negatedTerseLabel": "Financial liabilities, fair value through profit or loss"
       }
      }
     },
     "localname": "FinancialLiabilitiesAtFairValueThroughProfitOrLoss",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FinancialLiabilitiesMember": {
     "auth_ref": [
      "r253",
      "r254",
      "r286",
      "r300"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for aggregated classes financial liabilities. It also represents the standard value for the 'Classes of financial liabilities' axis if no other member is used. [Refer: Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial liabilities, class [member]",
        "terseLabel": "Financial liabilities, class [member]"
       }
      }
     },
     "localname": "FinancialLiabilitiesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_FinancialLiabilitiesRecognisedAsOfAcquisitionDate": {
     "auth_ref": [
      "r210",
      "r216"
     ],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 5.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount recognised as of the acquisition date for financial liabilities assumed in a business combination. [Refer: Financial liabilities; Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Financial liabilities recognised as of acquisition date",
        "negatedTerseLabel": "Long-term debt"
       }
      }
     },
     "localname": "FinancialLiabilitiesRecognisedAsOfAcquisitionDate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_FixedInterestRateMember": {
     "auth_ref": [
      "r250"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a fixed interest rate. [Refer: Interest rate risk [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Fixed interest rate [member]",
        "terseLabel": "Fixed interest rate"
       }
      }
     },
     "localname": "FixedInterestRateMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ForwardContractMember": {
     "auth_ref": [
      "r11"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a contract between two parties for the purchase or sale of an underlying asset at a specified future date for a settlement price determined in advance."
       }
      },
      "en-us": {
       "role": {
        "label": "Forward contract [member]",
        "terseLabel": "Foreign currency forward contracts"
       }
      }
     },
     "localname": "ForwardContractMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_GainLossOnHedgeIneffectivenessRecognisedInProfitOrLoss": {
     "auth_ref": [
      "r230",
      "r232"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The gain (loss) recognised in profit or loss on hedge ineffectiveness. [Refer: Gain (loss) on hedge ineffectiveness]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gain (loss) on hedge ineffectiveness recognised in profit or loss",
        "terseLabel": "Gain (loss) on hedge ineffectiveness"
       }
      }
     },
     "localname": "GainLossOnHedgeIneffectivenessRecognisedInProfitOrLoss",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_GainLossThatRelatesToIdentifiableAssetsAcquiredOrLiabilitiesAssumedInBusinessCombination": {
     "auth_ref": [
      "r214"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The gain (loss) that both: (a) relates to identifiable assets acquired or liabilities assumed in a business combination; and (b) is of such size, nature or incidence that disclosure is relevant to understanding the combined entity's financial statements. [Refer: Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gain (loss) that relates to identifiable assets acquired or liabilities assumed in business combination and is of such size, nature or incidence that disclosure is relevant to understanding combined entity's financial statements",
        "terseLabel": "Gain on acquisition"
       }
      }
     },
     "localname": "GainLossThatRelatesToIdentifiableAssetsAcquiredOrLiabilitiesAssumedInBusinessCombination",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_GainsLossesOnCashFlowHedgesBeforeTax": {
     "auth_ref": [
      "r48",
      "r306"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The gains (losses) recognised in other comprehensive income on cash flow hedges, before tax, before reclassification adjustments. [Refer: Cash flow hedges [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gains (losses) on cash flow hedges, before tax",
        "terseLabel": "Net change in fair value of outstanding derivatives financial instruments recognized in: Other comprehensive income (loss)"
       }
      }
     },
     "localname": "GainsLossesOnCashFlowHedgesBeforeTax",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsEstimatedFairValuesofDerivativeFinancialInstrumentsIncludedinRiskManagementAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_GainsLossesOnCashFlowHedgesNetOfTax": {
     "auth_ref": [
      "r47",
      "r231",
      "r235",
      "r306"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxCashFlowHedges",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The gains (losses) recognised in other comprehensive income on cash flow hedges, net of tax, before reclassification adjustments. [Refer: Cash flow hedges [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gains (losses) on cash flow hedges, net of tax",
        "terseLabel": "Unrealized income, net of taxes of $2 million (2020 \u2013 $2 million, 2019 \u2013 $13\u00a0million)",
        "verboseLabel": "Cash proceeds from settlement of cash flow hedge"
       }
      }
     },
     "localname": "GainsLossesOnCashFlowHedgesNetOfTax",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_GainsLossesOnChangeInFairValueOfDerivatives": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 5.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": -1.0
      },
      "http://www.cnrl.com/role/FinancialInstrumentsNetGainsLossesfromRiskManagementActivitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The gains (losses) resulting from change in the fair value of derivatives recognised in profit or loss. [Refer: Derivatives [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gains (losses) on change in fair value of derivatives",
        "negatedLabel": "Risk management activities",
        "negatedTotalLabel": "Gains (losses) on change in fair value of derivatives"
       }
      }
     },
     "localname": "GainsLossesOnChangeInFairValueOfDerivatives",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/FinancialInstrumentsNetGainsLossesfromRiskManagementActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_GainsLossesOnExchangeDifferencesOnTranslationRecognisedInProfitOrLoss": {
     "auth_ref": [
      "r18",
      "r84"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 6.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of exchange differences recognised in profit or loss that arise from foreign currency transactions, excluding those arising on financial instruments measured at fair value through profit or loss in accordance with IFRS 9. [Refer: At fair value [member]; Financial instruments, class [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Foreign exchange gain (loss)",
        "negatedLabel": "Foreign exchange gain",
        "negatedTerseLabel": "Foreign exchange gain"
       }
      }
     },
     "localname": "GainsLossesOnExchangeDifferencesOnTranslationRecognisedInProfitOrLoss",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLoss": {
     "auth_ref": [
      "r222"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails": {
       "order": 1.0,
       "parentTag": "cnq_GainsLossesOnInvestments",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The gains (losses) on financial assets at fair value through profit or loss. [Refer: Financial assets at fair value through profit or loss]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gains (losses) on financial assets at fair value through profit or loss",
        "negatedLabel": "(Gain) loss from investment",
        "negatedTerseLabel": "(Gain) loss from investment"
       }
      }
     },
     "localname": "GainsLossesOnFinancialAssetsAtFairValueThroughProfitOrLoss",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_GeographicalAreasAxis": {
     "auth_ref": [
      "r75",
      "r179",
      "r282",
      "r297"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Geographical areas [axis]",
        "terseLabel": "Geographical areas [axis]"
       }
      }
     },
     "localname": "GeographicalAreasAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_GeographicalAreasMember": {
     "auth_ref": [
      "r75",
      "r179",
      "r282",
      "r297"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for aggregated geographical areas. It also represents the standard value for the 'Geographical areas' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Geographical areas [member]",
        "terseLabel": "Geographical areas"
       }
      }
     },
     "localname": "GeographicalAreasMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_GrossCarryingAmountMember": {
     "auth_ref": [
      "r66",
      "r111",
      "r115",
      "r118",
      "r213",
      "r243",
      "r246",
      "r247",
      "r308",
      "r311"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the amount at which an asset is recognised before deducting any accumulated depreciation (amortisation) and accumulated impairment losses thereon. [Refer: Depreciation and amortisation expense; Impairment loss]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gross carrying amount [member]",
        "terseLabel": "Gross carrying amount",
        "verboseLabel": "Cost"
       }
      }
     },
     "localname": "GrossCarryingAmountMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_GrossProfit": {
     "auth_ref": [
      "r2"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of revenue less cost of sales. [Refer: Cost of sales; Revenue]"
       }
      },
      "en-us": {
       "role": {
        "label": "Gross profit",
        "totalLabel": "Results of operations"
       }
      }
     },
     "localname": "GrossProfit",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_HedgingInstrumentsAxis": {
     "auth_ref": [
      "r224",
      "r228"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Hedging instruments [axis]",
        "terseLabel": "Hedging instruments [axis]"
       }
      }
     },
     "localname": "HedgingInstrumentsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_HedgingInstrumentsMember": {
     "auth_ref": [
      "r224",
      "r228"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for hedging instruments. A hedging instrument can be a designated: (a) derivative measured at fair value through profit or loss, except for some written options (see paragraph B6.2.4 of IFRS 9); (b) non-derivative financial asset or non-derivative financial liability measured at fair value through profit or loss, unless it is a financial liability designated as at fair value through profit or loss for which the amount of its change in fair value that is attributable to changes in the credit risk of that liability is presented in other comprehensive income in accordance with paragraph 5.7.7 of IFRS 9. For a hedge of foreign currency risk, the foreign currency risk component of a non-derivative financial asset or a non-derivative financial liability may be designated as a hedging instrument provided that it is not an investment in an equity instrument for which an entity has elected to present changes in fair value in other comprehensive income in accordance with paragraph 5.7.5 of IFRS 9. This member also represents the standard value for the 'Hedging instruments' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Hedging instruments [member]",
        "terseLabel": "Hedging instruments [member]"
       }
      }
     },
     "localname": "HedgingInstrumentsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed": {
     "auth_ref": [
      "r210",
      "r216"
     ],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount recognised as of the acquisition date for net identifiable assets acquired or liabilities assumed in a business combination. [Refer: Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Identifiable assets acquired (liabilities assumed)",
        "totalLabel": "Net assets acquired"
       }
      }
     },
     "localname": "IdentifiableAssetsAcquiredLiabilitiesAssumed",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Profit or loss [abstract]",
        "terseLabel": "Profit or loss [abstract]"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "stringItemType"
    },
    "ifrs-full_IncomeTaxExpenseContinuingOperations": {
     "auth_ref": [
      "r44",
      "r54",
      "r57",
      "r58",
      "r93",
      "r166",
      "r271"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax. [Refer: Current tax expense (income); Deferred tax expense (income)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Tax expense (income)",
        "totalLabel": "Income tax"
       }
      }
     },
     "localname": "IncomeTaxExpenseContinuingOperations",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome": {
     "auth_ref": [
      "r46",
      "r56"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of income tax relating to amounts recognised in other comprehensive income. [Refer: Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Income tax relating to components of other comprehensive income",
        "terseLabel": "Deferred income tax expense included in other \u00a0\u00a0 comprehensive loss"
       }
      }
     },
     "localname": "IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofNetDeferredIncomeTaxLiabilityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncomeTaxesPaidRefund": {
     "auth_ref": [
      "r134"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash flows from income taxes paid or refunded."
       }
      },
      "en-us": {
       "role": {
        "label": "Income taxes paid (refund)",
        "terseLabel": "Income taxes (received) paid"
       }
      }
     },
     "localname": "IncomeTaxesPaidRefund",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseInCashAndCashEquivalents": {
     "auth_ref": [
      "r141"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in cash and cash equivalents after the effect of exchange rate changes on cash and cash equivalents held in foreign currencies. [Refer: Cash and cash equivalents; Effect of exchange rate changes on cash and cash equivalents]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) in cash and cash equivalents after effect of exchange rate changes",
        "totalLabel": "Increase in cash and cash equivalents"
       }
      }
     },
     "localname": "IncreaseDecreaseInCashAndCashEquivalents",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseInWorkingCapital": {
     "auth_ref": [
      "r132"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in working capital."
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) in working capital",
        "negatedTotalLabel": "Net changes in non-cash working capital"
       }
      }
     },
     "localname": "IncreaseDecreaseInWorkingCapital",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughBusinessCombinationsDeferredTaxLiabilityAsset": {
     "auth_ref": [
      "r63"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in deferred tax liability (asset) resulting from business combinations. [Refer: Deferred tax liability (asset)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through business combinations, deferred tax liability (asset)",
        "terseLabel": "Business combinations"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughBusinessCombinationsDeferredTaxLiabilityAsset",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofNetDeferredIncomeTaxLiabilityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughChangeInDiscountRateOtherProvisions": {
     "auth_ref": [
      "r107"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in other provisions resulting from a change in discount rate. [Refer: Other provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through change in discount rate, other provisions",
        "terseLabel": "Change in discount rates"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughChangeInDiscountRateOtherProvisions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughNetExchangeDifferencesDeferredTaxLiabilityAsset": {
     "auth_ref": [
      "r63"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in deferred tax liability (asset) resulting from the net exchange differences arising when the financial statements are translated from the functional currency into a different presentation currency, including the translation of a foreign operation into the presentation currency of the reporting entity. [Refer: Deferred tax liability (asset)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through net exchange differences, deferred tax liability (asset)",
        "terseLabel": "Foreign exchange adjustments"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughNetExchangeDifferencesDeferredTaxLiabilityAsset",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofNetDeferredIncomeTaxLiabilityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughNetExchangeDifferencesOtherProvisions": {
     "auth_ref": [
      "r108"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in other provisions resulting from foreign currency exchange rate changes on provisions measured in a currency different from the entity's presentation currency. [Refer: Other provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through net exchange differences, other provisions",
        "terseLabel": "Foreign exchange adjustments"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughNetExchangeDifferencesOtherProvisions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughNetExchangeDifferencesPropertyPlantAndEquipment": {
     "auth_ref": [
      "r69"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in property, plant and equipment resulting from net exchange differences arising on the translation of the financial statements from the functional currency into a different presentation currency, including the translation of a foreign operation into the presentation currency of the reporting entity. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through net exchange differences, property, plant and equipment",
        "negatedTerseLabel": "Foreign exchange adjustments and other"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughNetExchangeDifferencesPropertyPlantAndEquipment",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughObtainingOrLosingControlOfSubsidiariesOrOtherBusinessesLiabilitiesArisingFromFinancingActivities": {
     "auth_ref": [
      "r136"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in liabilities arising from financing activities resulting from obtaining or losing control of subsidiaries or other businesses. [Refer: Liabilities arising from financing activities; Subsidiaries [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through obtaining or losing control of subsidiaries or other businesses, liabilities arising from financing activities",
        "terseLabel": "Assumption of long-term debt"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughObtainingOrLosingControlOfSubsidiariesOrOtherBusinessesLiabilitiesArisingFromFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughOtherChangesLiabilitiesArisingFromFinancingActivities": {
     "auth_ref": [
      "r137"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in liabilities arising from financing activities resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Liabilities arising from financing activities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through other changes, liabilities arising from financing activities",
        "terseLabel": "Changes in foreign exchange and fair value"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughOtherChangesLiabilitiesArisingFromFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughTimeValueOfMoneyAdjustmentOtherProvisions": {
     "auth_ref": [
      "r107"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase in other provisions through adjustments arising from the passage of time. [Refer: Other provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase through adjustments arising from passage of time, other provisions",
        "terseLabel": "Asset retirement obligation accretion"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughTimeValueOfMoneyAdjustmentOtherProvisions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseDecreaseThroughTransfersPropertyPlantAndEquipment": {
     "auth_ref": [
      "r70"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase (decrease) in property, plant and equipment resulting from transfers. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase (decrease) through transfers, property, plant and equipment",
        "terseLabel": "Transfers from E&amp;E assets"
       }
      }
     },
     "localname": "IncreaseDecreaseThroughTransfersPropertyPlantAndEquipment",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IncreaseThroughNewLeasesLiabilitiesArisingFromFinancingActivities": {
     "auth_ref": [
      "r138",
      "r144"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The increase in liabilities arising from financing activities resulting from new leases. [Refer: Liabilities arising from financing activities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Increase through new leases, liabilities arising from financing activities",
        "terseLabel": "Lease additions"
       }
      }
     },
     "localname": "IncreaseThroughNewLeasesLiabilitiesArisingFromFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_InterestExpenseOnBorrowings": {
     "auth_ref": [
      "r11"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_FinanceCosts",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of interest expense on borrowings. [Refer: Interest expense; Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Interest expense on borrowings",
        "terseLabel": "Long-term debt"
       }
      }
     },
     "localname": "InterestExpenseOnBorrowings",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_InterestExpenseOnLeaseLiabilities": {
     "auth_ref": [
      "r182"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_FinanceCosts",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of interest expense on lease liabilities. [Refer: Lease liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Interest expense on lease liabilities",
        "terseLabel": "Interest expense on lease liabilities",
        "verboseLabel": "Lease liabilities"
       }
      }
     },
     "localname": "InterestExpenseOnLeaseLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InterestandOtherFinancingExpenseDetails",
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_InterestRateRiskMember": {
     "auth_ref": [
      "r267",
      "r291",
      "r292",
      "r293",
      "r294"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the type of risk that the fair value or future cash flows of a financial instrument will fluctuate because of changes in market interest rates. [Refer: Financial instruments, class [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Interest rate risk [member]",
        "terseLabel": "Interest rate risk"
       }
      }
     },
     "localname": "InterestRateRiskMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_InterestRateTypesMember": {
     "auth_ref": [
      "r250"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for all types of interest rates. It also represents the standard value for the 'Types of interest rates' axis if no other member is used. [Refer: Interest rate risk [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Interest rate types [member]",
        "terseLabel": "Interest rate types [member]"
       }
      }
     },
     "localname": "InterestRateTypesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_IntrinsicValueOfLiabilitiesFromSharebasedPaymentTransactionsForWhichCounterpartysRightToCashOrOtherAssetsVested2011": {
     "auth_ref": [
      "r206"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The intrinsic value of liabilities arising from share-based transactions for which the counterparty's right to cash or other assets had vested by the end of the period (for example, vested share appreciation rights). The intrinsic value is the difference between the fair value of the shares to which the counterparty has the (conditional or unconditional) right to subscribe, or which it has the right to receive, and the price (if any) that the counterparty is (or will be) required to pay for those shares. Share-based payment transactions are transactions in which the entity: (a) receives goods or services from the supplier of those goods or services (including an employee) in a share-based payment arrangement; or (b) incurs an obligation to settle the transaction with the supplier in a share-based payment arrangement when another group entity receives those goods or services, for which the counterparty's right to cash or other assets had vested by the end of the period (for example, vested share appreciation rights)."
       }
      },
      "en-us": {
       "role": {
        "label": "Intrinsic value of liabilities from share-based payment transactions for which counterparty's right to cash or other assets vested",
        "terseLabel": "Intrinsic value of vested stock options"
       }
      }
     },
     "localname": "IntrinsicValueOfLiabilitiesFromSharebasedPaymentTransactionsForWhichCounterpartysRightToCashOrOtherAssetsVested2011",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_Inventories": {
     "auth_ref": [
      "r21",
      "r30",
      "r80"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "ifrs-full_CurrentAssets",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/InventoryScheduleofInventoryDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current inventories. [Refer: Inventories]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current inventories",
        "terseLabel": "Inventory",
        "totalLabel": "Total inventory"
       }
      }
     },
     "localname": "Inventories",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/InventoryScheduleofInventoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_InvestmentAccountedForUsingEquityMethod": {
     "auth_ref": [
      "r20",
      "r167",
      "r273"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails_1": {
       "order": 1.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]]"
       }
      }
     },
     "localname": "InvestmentAccountedForUsingEquityMethod",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_InvestmentIncome": {
     "auth_ref": [
      "r45",
      "r91"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 12.0,
       "parentTag": "ifrs-full_ExpenseByNature",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of investment income, such as interest and dividends."
       }
      },
      "en-us": {
       "role": {
        "label": "Investment income",
        "negatedTerseLabel": "Income from North West Redwater Partnership"
       }
      }
     },
     "localname": "InvestmentIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_InvestmentsInJointVentures": {
     "auth_ref": [
      "r94"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of investments in joint ventures in an entity's separate financial statements. [Refer: Joint ventures [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Investments in joint ventures reported in separate financial statements",
        "terseLabel": "Investments in joint ventures"
       }
      }
     },
     "localname": "InvestmentsInJointVentures",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IssuedCapital": {
     "auth_ref": [
      "r35"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "ifrs-full_Equity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The nominal value of capital issued."
       }
      },
      "en-us": {
       "role": {
        "label": "Issued capital",
        "terseLabel": "Share capital"
       }
      }
     },
     "localname": "IssuedCapital",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_IssuedCapitalMember": {
     "auth_ref": [
      "r7"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a component of equity representing issued capital."
       }
      },
      "en-us": {
       "role": {
        "label": "Issued capital [member]",
        "terseLabel": "Share capital"
       }
      }
     },
     "localname": "IssuedCapitalMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_JointVenturesAxis": {
     "auth_ref": [
      "r96",
      "r98",
      "r168",
      "r303",
      "r304"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Joint ventures [axis]",
        "terseLabel": "Joint ventures [axis]"
       }
      }
     },
     "localname": "JointVenturesAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_KeyManagementPersonnelCompensation": {
     "auth_ref": [
      "r88"
     ],
     "calculation": {
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of compensation to key management personnel. [Refer: Key management personnel of entity or parent [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Key management personnel compensation",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "KeyManagementPersonnelCompensation",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_KeyManagementPersonnelCompensationShorttermEmployeeBenefits": {
     "auth_ref": [
      "r87"
     ],
     "calculation": {
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_KeyManagementPersonnelCompensation",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of compensation to key management personnel in the form of short-term employee benefits. [Refer: Key management personnel of entity or parent [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Key management personnel compensation, short-term employee benefits",
        "terseLabel": "Fees earned and salary"
       }
      }
     },
     "localname": "KeyManagementPersonnelCompensationShorttermEmployeeBenefits",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/RemunerationofDirectorsandSeniorManagementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_LaterThanFiveYearsMember": {
     "auth_ref": [
      "r190",
      "r191",
      "r261",
      "r262",
      "r265",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a time band of later than five years."
       }
      },
      "en-us": {
       "role": {
        "label": "Later than five years [member]",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "LaterThanFiveYearsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LaterThanFourYearsAndNotLaterThanFiveYearsMember": {
     "auth_ref": [
      "r11",
      "r190",
      "r191",
      "r261",
      "r265",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a time band of later than four years and not later than five years."
       }
      },
      "en-us": {
       "role": {
        "label": "Later than four years and not later than five years [member]",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "LaterThanFourYearsAndNotLaterThanFiveYearsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LaterThanOneYearAndNotLaterThanTwoYearsMember": {
     "auth_ref": [
      "r11",
      "r190",
      "r191",
      "r261",
      "r265",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a time band of later than one year and not later than two years."
       }
      },
      "en-us": {
       "role": {
        "label": "Later than one year and not later than two years [member]",
        "terseLabel": "1 to less than 2 years",
        "verboseLabel": "2023"
       }
      }
     },
     "localname": "LaterThanOneYearAndNotLaterThanTwoYearsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LaterThanThreeYearsAndNotLaterThanFourYearsMember": {
     "auth_ref": [
      "r11",
      "r190",
      "r191",
      "r261",
      "r265",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a time band of later than three years and not later than four years."
       }
      },
      "en-us": {
       "role": {
        "label": "Later than three years and not later than four years [member]",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "LaterThanThreeYearsAndNotLaterThanFourYearsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LaterThanTwoYearsAndNotLaterThanFiveYearsMember": {
     "auth_ref": [
      "r11"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a time band of later than two years and not later than five years."
       }
      },
      "en-us": {
       "role": {
        "label": "Later than two years and not later than five years [member]",
        "terseLabel": "2 to less than 5 years"
       }
      }
     },
     "localname": "LaterThanTwoYearsAndNotLaterThanFiveYearsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LaterThanTwoYearsAndNotLaterThanThreeYearsMember": {
     "auth_ref": [
      "r11",
      "r190",
      "r191",
      "r261",
      "r265",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a time band of later than two years and not later than three years."
       }
      },
      "en-us": {
       "role": {
        "label": "Later than two years and not later than three years [member]",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "LaterThanTwoYearsAndNotLaterThanThreeYearsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LeaseLiabilities": {
     "auth_ref": [
      "r180"
     ],
     "calculation": {
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails_1": {
       "order": 6.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of liabilities related to the entity's leases. Lease is a contract, or part of a contract, that conveys the right to use an underlying asset for a period of time in exchange for consideration."
       }
      },
      "en-us": {
       "role": {
        "label": "Lease liabilities",
        "terseLabel": "Lease liabilities",
        "totalLabel": "Lease liabilities"
       }
      }
     },
     "localname": "LeaseLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails",
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_LeaseLiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Lease liabilities [abstract]",
        "terseLabel": "Lease liabilities [abstract]"
       }
      }
     },
     "localname": "LeaseLiabilitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_LeaseLiabilitiesMember": {
     "auth_ref": [
      "r139",
      "r145"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for lease liabilities. [Refer: Lease liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Lease liabilities [member]",
        "terseLabel": "Lease liabilities"
       }
      }
     },
     "localname": "LeaseLiabilitiesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_Level1OfFairValueHierarchyMember": {
     "auth_ref": [
      "r77",
      "r170"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a category of the fair value hierarchy where inputs to the valuation techniques are quoted prices (unadjusted) in active markets for identical assets or liabilities that the entity can access at the measurement date."
       }
      },
      "en-us": {
       "role": {
        "label": "Level 1 of fair value hierarchy [member]",
        "terseLabel": "Level 1"
       }
      }
     },
     "localname": "Level1OfFairValueHierarchyMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_Level2OfFairValueHierarchyMember": {
     "auth_ref": [
      "r170"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a category of the fair value hierarchy where inputs to the valuation techniques are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly."
       }
      },
      "en-us": {
       "role": {
        "label": "Level 2 of fair value hierarchy [member]",
        "terseLabel": "Level 2"
       }
      }
     },
     "localname": "Level2OfFairValueHierarchyMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_Level3OfFairValueHierarchyMember": {
     "auth_ref": [
      "r170"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a category of the fair value hierarchy where inputs to the valuation techniques are unobservable inputs for the asset or liability. Unobservable inputs are inputs for which market data are not available and that are developed using the best information available about the assumptions that the market participants would use when pricing the asset or liability."
       }
      },
      "en-us": {
       "role": {
        "label": "Level 3 of fair value hierarchy [member]",
        "terseLabel": "Level 3"
       }
      }
     },
     "localname": "Level3OfFairValueHierarchyMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LevelsOfFairValueHierarchyAxis": {
     "auth_ref": [
      "r77",
      "r170"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Levels of fair value hierarchy [axis]",
        "terseLabel": "Levels of fair value hierarchy [axis]"
       }
      }
     },
     "localname": "LevelsOfFairValueHierarchyAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_Liabilities": {
     "auth_ref": [
      "r25",
      "r169",
      "r170",
      "r171",
      "r272",
      "r277"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "ifrs-full_EquityAndLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of a present obligation of the entity to transfer an economic resource as a result of past events. Economic resource is a right that has the potential to produce economic benefits."
       }
      },
      "en-us": {
       "role": {
        "label": "Liabilities",
        "totalLabel": "Liabilities"
       }
      }
     },
     "localname": "Liabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_LiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities [abstract]",
        "terseLabel": "LIABILITIES"
       }
      }
     },
     "localname": "LiabilitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_LiabilitiesArisingFromFinancingActivities": {
     "auth_ref": [
      "r140"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of liabilities for which cash flows were, or future cash flows will be, classified in the statement of cash flows as cash flows from financing activities. [Refer: Cash flows from (used in) financing activities; Liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Liabilities arising from financing activities",
        "periodEndLabel": "Liabilities arising from financing activities, ending balance",
        "periodStartLabel": "Liabilities arising from financing activities, beginning balance"
       }
      }
     },
     "localname": "LiabilitiesArisingFromFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_LiabilitiesArisingFromFinancingActivitiesAxis": {
     "auth_ref": [
      "r140"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Liabilities arising from financing activities [axis]",
        "terseLabel": "Liabilities arising from financing activities [axis]"
       }
      }
     },
     "localname": "LiabilitiesArisingFromFinancingActivitiesAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_LiabilitiesArisingFromFinancingActivitiesMember": {
     "auth_ref": [
      "r140"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for liabilities arising from financing activities. It also represents the standard value for the 'Liabilities arising from financing activities' axis if no other member is used. [Refer: Liabilities arising from financing activities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Liabilities arising from financing activities [member]",
        "terseLabel": "Liabilities arising from financing activities [member]"
       }
      }
     },
     "localname": "LiabilitiesArisingFromFinancingActivitiesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LiabilitiesFromSharebasedPaymentTransactions2011": {
     "auth_ref": [
      "r205"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails_1": {
       "order": 2.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of liabilities arising from share-based payment transactions. Share-based payment transactions are transactions in which the entity: (a) receives goods or services from the supplier of those goods or services (including an employee) in a share-based payment arrangement; or (b) incurs an obligation to settle the transaction with the supplier in a share-based payment arrangement when another group entity receives those goods or services. [Refer: Share-based payment arrangements [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Liabilities from share-based payment transactions",
        "periodEndLabel": "Balance \u2013 end of year",
        "periodStartLabel": "Balance \u2013 beginning of year",
        "terseLabel": "Share-based compensation"
       }
      }
     },
     "localname": "LiabilitiesFromSharebasedPaymentTransactions2011",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_LiquidityRiskMember": {
     "auth_ref": [
      "r238",
      "r291",
      "r292",
      "r293"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the risk that an entity will encounter difficulty in meeting obligations associated with financial liabilities that are settled by delivering cash or another financial asset. [Refer: Financial assets; Financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Liquidity risk [member]",
        "terseLabel": "Liquidity risk"
       }
      }
     },
     "localname": "LiquidityRiskMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LongtermBorrowings": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "ifrs-full_Liabilities",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_Borrowings",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The non-current portion of non-current borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current portion of non-current borrowings",
        "terseLabel": "Long-term debt",
        "verboseLabel": "Long-term debt"
       }
      }
     },
     "localname": "LongtermBorrowings",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_LongtermBorrowingsMember": {
     "auth_ref": [
      "r139",
      "r145"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for long-term borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Long-term borrowings [member]",
        "terseLabel": "Long-term debt"
       }
      }
     },
     "localname": "LongtermBorrowingsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_LongtermProvisionForDecommissioningRestorationAndRehabilitationCosts": {
     "auth_ref": [
      "r109",
      "r110"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_ProvisionForDecommissioningRestorationAndRehabilitationCosts",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of non-current provision for decommissioning, restoration and rehabilitation costs. [Refer: Provision for decommissioning, restoration and rehabilitation costs]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current provision for decommissioning, restoration and rehabilitation costs",
        "terseLabel": "Non-current asset retirement obligation"
       }
      }
     },
     "localname": "LongtermProvisionForDecommissioningRestorationAndRehabilitationCosts",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_MaturityAnalysisForNonderivativeFinancialLiabilities": {
     "auth_ref": [
      "r249"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of a maturity analysis for non-derivative financial liabilities (including issued financial guarantee contracts) that shows the remaining contractual maturities. [Refer: Derivative financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Disclosure of maturity analysis for non-derivative financial liabilities [text block]",
        "terseLabel": "Schedule of maturity dates for financial liabilities",
        "verboseLabel": "Schedule of debt repayments"
       }
      }
     },
     "localname": "MaturityAnalysisForNonderivativeFinancialLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsTables",
      "http://www.cnrl.com/role/LongTermDebtTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_MaturityAxis": {
     "auth_ref": [
      "r28",
      "r78",
      "r177",
      "r190",
      "r191",
      "r225",
      "r252",
      "r261",
      "r287",
      "r288",
      "r290",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Maturity [axis]",
        "terseLabel": "Maturity [axis]"
       }
      }
     },
     "localname": "MaturityAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_NewProvisionsOtherProvisions": {
     "auth_ref": [
      "r105"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount recognised for new other provisions. [Refer: Other provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "New provisions, other provisions",
        "terseLabel": "Liabilities incurred"
       }
      }
     },
     "localname": "NewProvisionsOtherProvisions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NominalAmountOfHedgingInstrument": {
     "auth_ref": [
      "r225",
      "r227"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The nominal amount of a hedging instrument. [Refer: Hedging instruments [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Nominal amount of hedging instrument",
        "terseLabel": "Amount"
       }
      }
     },
     "localname": "NominalAmountOfHedgingInstrument",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_NonadjustingEventsAfterReportingPeriodAxis": {
     "auth_ref": [
      "r52"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Non-adjusting events after reporting period [axis]",
        "terseLabel": "Non-adjusting events after reporting period [axis]"
       }
      }
     },
     "localname": "NonadjustingEventsAfterReportingPeriodAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_NonadjustingEventsMember": {
     "auth_ref": [
      "r52"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for events that occur between the end of the reporting period and the date when the financial statements are authorised for issue and are indicative of conditions that arose after the reporting period. It also represents the standard value for the 'Non-adjusting events after reporting period' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Non-adjusting events after reporting period [member]",
        "terseLabel": "Non-adjusting events after reporting period [member]"
       }
      }
     },
     "localname": "NonadjustingEventsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_NoncurrentAssets": {
     "auth_ref": [
      "r29",
      "r156",
      "r158"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of assets that do not meet the definition of current assets. [Refer: Current assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current assets",
        "terseLabel": "Non-current assets"
       }
      }
     },
     "localname": "NoncurrentAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NoncurrentAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Non-current assets [abstract]",
        "terseLabel": "Non-current assets"
       }
      }
     },
     "localname": "NoncurrentAssetsAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_NoncurrentAssetsRecognisedAsOfAcquisitionDate": {
     "auth_ref": [
      "r210"
     ],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 6.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Expiry date 2022-01-01: The amount recognised as of the acquisition date for non-current assets acquired in a business combination. [Refer: Business combinations [member]]\nEffective 2022-01-01: The amount recognised as of the acquisition date for non-current assets acquired in a business combination. [Refer: Non-current assets; Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current assets recognised as of acquisition date",
        "terseLabel": "Other long-term assets"
       }
      }
     },
     "localname": "NoncurrentAssetsRecognisedAsOfAcquisitionDate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NoncurrentDerivativeFinancialAssets": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails": {
       "order": 4.0,
       "parentTag": "cnq_DerivativeFinancialAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of non-current derivative financial assets. [Refer: Derivative financial assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current derivative financial assets",
        "terseLabel": "Other long-term assets"
       }
      }
     },
     "localname": "NoncurrentDerivativeFinancialAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NoncurrentDerivativeFinancialLiabilities": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails": {
       "order": 2.0,
       "parentTag": "cnq_DerivativeFinancialAssetsLiabilitiesNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of non-current derivative financial liabilities. [Refer: Derivative financial liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current derivative financial liabilities",
        "negatedTerseLabel": "Other long-term liabilities"
       }
      }
     },
     "localname": "NoncurrentDerivativeFinancialLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NoncurrentLeaseLiabilities": {
     "auth_ref": [
      "r180"
     ],
     "calculation": {
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_LeaseLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of non-current lease liabilities. [Refer: Lease liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current lease liabilities",
        "verboseLabel": "Non-current lease liabilities"
       }
      }
     },
     "localname": "NoncurrentLeaseLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseLiabilitiesandExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NoncurrentLiabilities": {
     "auth_ref": [
      "r31",
      "r156",
      "r160"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of liabilities that do not meet the definition of current liabilities. [Refer: Current liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current liabilities",
        "terseLabel": "Non-current liabilities"
       }
      }
     },
     "localname": "NoncurrentLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NoncurrentLiabilitiesRecognisedAsOfAcquisitionDate": {
     "auth_ref": [
      "r210"
     ],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Expiry date 2022-01-01: The amount recognised as of the acquisition date for non-current liabilities assumed in a business combination. [Refer: Business combinations [member]]\nEffective 2022-01-01: The amount recognised as of the acquisition date for non-current liabilities assumed in a business combination. [Refer: Non-current liabilities; Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Non-current liabilities recognised as of acquisition date",
        "negatedTerseLabel": "Other long-term liabilities",
        "terseLabel": "Non-current liabilities recognised as of acquisition date"
       }
      }
     },
     "localname": "NoncurrentLiabilitiesRecognisedAsOfAcquisitionDate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NotLaterThanOneYearMember": {
     "auth_ref": [
      "r27",
      "r190",
      "r191",
      "r261",
      "r265",
      "r296"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a time band of not later than one year."
       }
      },
      "en-us": {
       "role": {
        "label": "Not later than one year [member]",
        "terseLabel": "Less than 1 year",
        "verboseLabel": "2022"
       }
      }
     },
     "localname": "NotLaterThanOneYearMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/LongTermDebtScheduleofDebtRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_NotionalAmount": {
     "auth_ref": [
      "r11"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The nominal or face amount of a financial instrument, used to calculate payments made on that instrument."
       }
      },
      "en-us": {
       "role": {
        "label": "Notional amount",
        "terseLabel": "Notional amount"
       }
      }
     },
     "localname": "NotionalAmount",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_NumberOfOutstandingShareOptions": {
     "auth_ref": [
      "r194",
      "r198",
      "r201"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of share options outstanding in a share-based payment arrangement."
       }
      },
      "en-us": {
       "role": {
        "label": "Number of share options outstanding in share-based payment arrangement",
        "periodEndLabel": "Stock options outstanding - end of year (in shares)",
        "periodStartLabel": "Stock options outstanding - beginning of year (in shares)",
        "terseLabel": "Stock options outstanding (in shares)"
       }
      }
     },
     "localname": "NumberOfOutstandingShareOptions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails",
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_NumberOfShareOptionsExercisableInSharebasedPaymentArrangement": {
     "auth_ref": [
      "r199"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of share options exercisable in a share-based payment arrangement."
       }
      },
      "en-us": {
       "role": {
        "label": "Number of share options exercisable in share-based payment arrangement",
        "terseLabel": "Stock options exercisable (in shares)"
       }
      }
     },
     "localname": "NumberOfShareOptionsExercisableInSharebasedPaymentArrangement",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails",
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_NumberOfShareOptionsExercisedInSharebasedPaymentArrangement": {
     "auth_ref": [
      "r197"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of share options exercised in a share-based payment arrangement."
       }
      },
      "en-us": {
       "role": {
        "label": "Number of share options exercised in share-based payment arrangement",
        "negatedTerseLabel": "Stock options exercised for common shares (in shares)",
        "verboseLabel": "Issued upon exercise of stock options (in shares)"
       }
      }
     },
     "localname": "NumberOfShareOptionsExercisedInSharebasedPaymentArrangement",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails",
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_NumberOfShareOptionsForfeitedInSharebasedPaymentArrangement": {
     "auth_ref": [
      "r196"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of share options forfeited in a share-based payment arrangement."
       }
      },
      "en-us": {
       "role": {
        "label": "Number of share options forfeited in share-based payment arrangement",
        "negatedTerseLabel": "Stock options forfeited (in shares)"
       }
      }
     },
     "localname": "NumberOfShareOptionsForfeitedInSharebasedPaymentArrangement",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_NumberOfShareOptionsGrantedInSharebasedPaymentArrangement": {
     "auth_ref": [
      "r195"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of share options granted in a share-based payment arrangement."
       }
      },
      "en-us": {
       "role": {
        "label": "Number of share options granted in share-based payment arrangement",
        "terseLabel": "Stock options granted (in shares)"
       }
      }
     },
     "localname": "NumberOfShareOptionsGrantedInSharebasedPaymentArrangement",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "ifrs-full_NumberOfSharesOutstanding": {
     "auth_ref": [
      "r37"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of shares that have been authorised and issued, reduced by treasury shares held. [Refer: Treasury shares]"
       }
      },
      "en-us": {
       "role": {
        "label": "Number of shares outstanding",
        "periodEndLabel": "Balance - end of year (in shares)",
        "periodStartLabel": "Balance - beginning of year (in shares)"
       }
      }
     },
     "localname": "NumberOfSharesOutstanding",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "ifrs-full_OilAndGasAssetsMember": {
     "auth_ref": [
      "r65"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for oil and gas assets. [Refer: Oil and gas assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Oil and gas assets [member]",
        "terseLabel": "Oil and gas assets"
       }
      }
     },
     "localname": "OilAndGasAssetsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_OperatingSegmentsMember": {
     "auth_ref": [
      "r279"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for operating segments. An operating segment is a component of an entity: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same entity); (b) whose operating results are regularly reviewed by the entity\u2019s chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance; and (c) for which discrete financial information is available. [Refer: Revenue]"
       }
      },
      "en-us": {
       "role": {
        "label": "Operating segments [member]",
        "terseLabel": "Operating segments"
       }
      }
     },
     "localname": "OperatingSegmentsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_OrdinarySharesMember": {
     "auth_ref": [
      "r38",
      "r99"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for equity instruments that are subordinate to all other classes of equity instruments. It also represents the standard value for the 'Classes of ordinary shares' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Ordinary shares [member]",
        "terseLabel": "Ordinary shares"
       }
      }
     },
     "localname": "OrdinarySharesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_OtherAssets": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails_1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of assets that the entity does not separately disclose in the same statement or note."
       }
      },
      "en-us": {
       "role": {
        "label": "Other assets",
        "totalLabel": "Other assets"
       }
      }
     },
     "localname": "OtherAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherComprehensiveIncome": {
     "auth_ref": [
      "r6",
      "r40",
      "r47",
      "r163"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "ifrs-full_ComprehensiveIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of income and expense (including reclassification adjustments) that is not recognised in profit or loss as required or permitted by IFRSs. [Refer: IFRSs [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other comprehensive income",
        "terseLabel": "Other comprehensive loss, net of taxes",
        "totalLabel": "Other comprehensive loss, net of taxes"
       }
      }
     },
     "localname": "OtherComprehensiveIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherComprehensiveIncomeNetOfTaxCashFlowHedges": {
     "auth_ref": [
      "r32",
      "r47"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "ifrs-full_OtherComprehensiveIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of other comprehensive income, net of tax, after reclassification adjustments, related to cash flow hedges. [Refer: Cash flow hedges [member]; Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other comprehensive income, net of tax, cash flow hedges",
        "totalLabel": "Net change in derivative financial instruments designated as cash flow hedges"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeNetOfTaxCashFlowHedges",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherComprehensiveIncomeNetOfTaxExchangeDifferencesOnTranslation": {
     "auth_ref": [
      "r32",
      "r47"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "ifrs-full_OtherComprehensiveIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of other comprehensive income, net of tax, after reclassification adjustments, related to exchange differences when financial statements of foreign operations are translated. [Refer: Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other comprehensive income, net of tax, exchange differences on translation of foreign operations",
        "terseLabel": "Translation of net investment"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeNetOfTaxExchangeDifferencesOnTranslation",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherCurrentAssets": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 7.0,
       "parentTag": "ifrs-full_CurrentAssets",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current assets that the entity does not separately disclose in the same statement or note. [Refer: Current assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other current assets",
        "terseLabel": "Current portion of other long-term assets",
        "verboseLabel": "Less: current portion"
       }
      }
     },
     "localname": "OtherCurrentAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherCurrentLiabilities": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "ifrs-full_CurrentLiabilities",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current liabilities that the entity does not separately disclose in the same statement or note. [Refer: Current liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other current liabilities",
        "terseLabel": "Current portion of other long-term liabilities",
        "verboseLabel": "Less: current portion"
       }
      }
     },
     "localname": "OtherCurrentLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherInflowsOutflowsOfCashClassifiedAsOperatingActivities": {
     "auth_ref": [
      "r120"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 1.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "Inflows (outflows) of cash, classified as operating activities, that the entity does not separately disclose in the same statement or note."
       }
      },
      "en-us": {
       "role": {
        "label": "Other inflows (outflows) of cash, classified as operating activities",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherInflowsOutflowsOfCashClassifiedAsOperatingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherLiabilities": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails_1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of liabilities that the entity does not separately disclose in the same statement or note."
       }
      },
      "en-us": {
       "role": {
        "label": "Other liabilities",
        "totalLabel": "Other liabilities"
       }
      }
     },
     "localname": "OtherLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherNoncurrentAssets": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "ifrs-full_Assets",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_OtherAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of non-current assets that the entity does not separately disclose in the same statement or note. [Refer: Non-current assets]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other non-current assets",
        "terseLabel": "Other long-term assets"
       }
      }
     },
     "localname": "OtherNoncurrentAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/OtherLongTermAssetsScheduleofotherlongtermassetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherNoncurrentLiabilities": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "ifrs-full_Liabilities",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of non-current liabilities that the entity does not separately disclose in the same statement or note. [Refer: Non-current liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other non-current liabilities",
        "terseLabel": "Other long-term liabilities"
       }
      }
     },
     "localname": "OtherNoncurrentLiabilities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherPropertyPlantAndEquipmentMember": {
     "auth_ref": [
      "r65"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a class of property, plant and equipment representing property, plant and equipment that the entity does not separately disclose in the same statement or note. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other property, plant and equipment [member]",
        "terseLabel": "Other equipment"
       }
      }
     },
     "localname": "OtherPropertyPlantAndEquipmentMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_OtherProvisionsMember": {
     "auth_ref": [
      "r108"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for provisions other than provisions for employee benefits. It also represents the standard value for the 'Classes of other provisions' axis if no other member is used. [Refer: Provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other provisions [member]",
        "terseLabel": "Other provisions [member]"
       }
      }
     },
     "localname": "OtherProvisionsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome": {
     "auth_ref": [
      "r57"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 9.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that the entity does not separately disclose in the same statement or note. [Refer: Accounting profit; Applicable tax rate]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other tax effects for reconciliation between accounting profit and tax expense (income)",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_OtherTemporaryDifferencesMember": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for temporary differences that the entity does not separately disclose in the same statement or note. [Refer: Temporary differences [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Other temporary differences [member]",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherTemporaryDifferencesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities": {
     "auth_ref": [
      "r127"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 6.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow for payment of lease liabilities, classified as financing activities. [Refer: Lease liabilities]"
       }
      },
      "en-us": {
       "role": {
        "label": "Payments of lease liabilities, classified as financing activities",
        "negatedTerseLabel": "Payment of lease liabilities"
       }
      }
     },
     "localname": "PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_PaymentsOfOtherEquityInstruments": {
     "auth_ref": [
      "r128"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow for payments for equity instruments that the entity does not separately disclose in the same statement or note."
       }
      },
      "en-us": {
       "role": {
        "label": "Payments of other equity instruments",
        "negatedTerseLabel": "Cash payment for stock options surrendered and PSUs vested"
       }
      }
     },
     "localname": "PaymentsOfOtherEquityInstruments",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_PaymentsToAcquireOrRedeemEntitysShares": {
     "auth_ref": [
      "r124"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 1.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow to acquire or redeem entity's shares."
       }
      },
      "en-us": {
       "role": {
        "label": "Payments to acquire or redeem entity's shares",
        "negatedTerseLabel": "Purchase of common shares under Normal Course Issuer Bid"
       }
      }
     },
     "localname": "PaymentsToAcquireOrRedeemEntitysShares",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ProceedsFromBorrowingsClassifiedAsFinancingActivities": {
     "auth_ref": [
      "r125"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash inflow from borrowings obtained. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Proceeds from borrowings, classified as financing activities",
        "terseLabel": "Proceeds from borrowings"
       }
      }
     },
     "localname": "ProceedsFromBorrowingsClassifiedAsFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ProceedsFromDisposalOfExplorationAndEvaluationAssets": {
     "auth_ref": [
      "r123"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 2.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInExplorationForAndEvaluationOfMineralResourcesClassifiedAsInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash inflow from the disposal of exploration and evaluation assets. [Refer: Exploration and evaluation assets [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Proceeds from disposal of exploration and evaluation assets",
        "negatedLabel": "Net proceeds on sale of exploration and evaluation assets"
       }
      }
     },
     "localname": "ProceedsFromDisposalOfExplorationAndEvaluationAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ProceedsFromExerciseOfOptions": {
     "auth_ref": [
      "r128"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 8.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash inflow from the exercise of options."
       }
      },
      "en-us": {
       "role": {
        "label": "Proceeds from exercise of options",
        "terseLabel": "Issue of common shares on exercise of stock options"
       }
      }
     },
     "localname": "ProceedsFromExerciseOfOptions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ProductsAndServicesAxis": {
     "auth_ref": [
      "r178",
      "r280"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Products and services [axis]",
        "terseLabel": "Products and services [axis]"
       }
      }
     },
     "localname": "ProductsAndServicesAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ProductsAndServicesMember": {
     "auth_ref": [
      "r178",
      "r280"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for the entity's products and services. It also represents the standard value for the 'Products and services' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Products and services [member]",
        "terseLabel": "Products and services"
       }
      }
     },
     "localname": "ProductsAndServicesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ProfitLoss": {
     "auth_ref": [
      "r5",
      "r39",
      "r129",
      "r150",
      "r152",
      "r156",
      "r272",
      "r275",
      "r289",
      "r302"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 2.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "ifrs-full_ComprehensiveIncome",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The total of income less expenses from continuing and discontinued operations, excluding the components of other comprehensive income. [Refer: Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Profit (loss)",
        "negatedLabel": "Net loss",
        "netLabel": "Net earnings (loss)",
        "terseLabel": "Net earnings (loss)",
        "totalLabel": "Net earnings (loss)",
        "verboseLabel": "Net earnings (loss)"
       }
      }
     },
     "localname": "ProfitLoss",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss",
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ProfitLossBeforeTax": {
     "auth_ref": [
      "r1",
      "r2",
      "r218",
      "r272",
      "r275"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 1.0,
       "parentTag": "ifrs-full_ProfitLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The profit (loss) before tax expense or income. [Refer: Profit (loss)]"
       }
      },
      "en-us": {
       "role": {
        "label": "Profit (loss) before tax",
        "totalLabel": "Earnings (loss) before taxes"
       }
      }
     },
     "localname": "ProfitLossBeforeTax",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_PropertyPlantAndEquipment": {
     "auth_ref": [
      "r19",
      "r70"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "ifrs-full_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period."
       }
      },
      "en-us": {
       "role": {
        "label": "Property, plant and equipment",
        "periodEndLabel": "Property, plant and equipment at end of period",
        "periodStartLabel": "Property, plant and equipment at beginning of period",
        "terseLabel": "Property, plant and equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipment",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_PropertyPlantAndEquipmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Property, plant and equipment [abstract]",
        "terseLabel": "Property, plant and \u00a0\u00a0 equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_PropertyPlantAndEquipmentMember": {
     "auth_ref": [
      "r71",
      "r103",
      "r188"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for property, plant and equipment. It also represents the standard value for the 'Classes of property, plant and equipment' axis if no other member is used. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Property, plant and equipment [member]",
        "terseLabel": "Property, plant and equipment [member]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/CommitmentsandContingenciesDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_PropertyPlantAndEquipmentRecognisedAsOfAcquisitionDate": {
     "auth_ref": [
      "r210",
      "r216"
     ],
     "calculation": {
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails": {
       "order": 4.0,
       "parentTag": "ifrs-full_IdentifiableAssetsAcquiredLiabilitiesAssumed",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount recognised as of the acquisition date for plant, property and equipment acquired in a business combination. [Refer: Property, plant and equipment; Business combinations [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Property, plant and equipment recognised as of acquisition date",
        "terseLabel": "Property, plant and equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentRecognisedAsOfAcquisitionDate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentSummaryofNetAssetsAcquiredandLiablitiesAssumedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ProportionOfVotingRightsHeldInJointVenture": {
     "auth_ref": [
      "r95",
      "r97",
      "r154"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The proportion of the voting rights in a joint venture held by the entity. [Refer: Joint ventures [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Proportion of voting rights held in joint venture",
        "terseLabel": "Company's voting percent interest in joint venture"
       }
      }
     },
     "localname": "ProportionOfVotingRightsHeldInJointVenture",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ifrs-full_ProvisionForDecommissioningRestorationAndRehabilitationCosts": {
     "auth_ref": [
      "r109",
      "r110"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails_1": {
       "order": 1.0,
       "parentTag": "ifrs-full_OtherLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of provision for costs related to decommissioning, restoration and rehabilitation. [Refer: Other provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Provision for decommissioning, restoration and rehabilitation costs",
        "periodEndLabel": "Balance \u2013 end of year",
        "periodStartLabel": "Balance \u2013 beginning of year",
        "terseLabel": "Asset retirement obligations"
       }
      }
     },
     "localname": "ProvisionForDecommissioningRestorationAndRehabilitationCosts",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesScheduleofOtherLongTermLiabilitiesDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ProvisionForDecommissioningRestorationAndRehabilitationCostsMember": {
     "auth_ref": [
      "r109",
      "r110"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a provision relating to decommissioning, restoration and rehabilitation costs. [Refer: Other provisions [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Provision for decommissioning, restoration and rehabilitation costs [member]",
        "terseLabel": "Provision for decommissioning, restoration and rehabilitation costs"
       }
      }
     },
     "localname": "ProvisionForDecommissioningRestorationAndRehabilitationCostsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ProvisionUsedOtherProvisions": {
     "auth_ref": [
      "r106"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount used (ie incurred and charged against the provision) for other provisions. [Refer: Other provisions]"
       }
      },
      "en-us": {
       "role": {
        "label": "Provision used, other provisions",
        "negatedTerseLabel": "Liabilities settled"
       }
      }
     },
     "localname": "ProvisionUsedOtherProvisions",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_PurchaseOfExplorationAndEvaluationAssets": {
     "auth_ref": [
      "r123"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInExplorationForAndEvaluationOfMineralResourcesClassifiedAsInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow for the purchase of exploration and evaluation assets. [Refer: Exploration and evaluation assets [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Purchase of exploration and evaluation assets",
        "terseLabel": "Expenditures on exploration and evaluation assets"
       }
      }
     },
     "localname": "PurchaseOfExplorationAndEvaluationAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationSupplementalScheduleOfCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_PurchaseOfOtherLongtermAssetsClassifiedAsInvestingActivities": {
     "auth_ref": [
      "r121"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 4.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow for the purchases of long-term assets that the entity does not separately disclose in the same statement or note, classified as investing activities. [Refer: Assets]"
       }
      }
     },
     "localname": "PurchaseOfOtherLongtermAssetsClassifiedAsInvestingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RangeAxis": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r201",
      "r255",
      "r290"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Range [axis]",
        "terseLabel": "Range [axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails",
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_RangesMember": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r201",
      "r255",
      "r290"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for aggregate ranges. It also represents the standard value for the 'Range' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Ranges [member]",
        "terseLabel": "Ranges"
       }
      }
     },
     "localname": "RangesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails",
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_RangesOfExercisePricesForOutstandingShareOptionsAxis": {
     "auth_ref": [
      "r201"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Ranges of exercise prices for outstanding share options [axis]",
        "terseLabel": "Ranges of exercise prices for outstanding share options [axis]"
       }
      }
     },
     "localname": "RangesOfExercisePricesForOutstandingShareOptionsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_RangesOfExercisePricesForOutstandingShareOptionsMember": {
     "auth_ref": [
      "r201"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for aggregated ranges of exercise prices for outstanding share options that are meaningful for assessing the number and timing of additional shares that may be issued and the cash that may be received upon exercise of those options. It also represents the standard value for the 'Ranges of exercise prices for outstanding share options' axis if no other member is used. [Refer: Ranges [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Ranges of exercise prices for outstanding share options [member]",
        "terseLabel": "Ranges of exercise prices for outstanding share options [member]"
       }
      }
     },
     "localname": "RangesOfExercisePricesForOutstandingShareOptionsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ReclassificationAdjustmentsOnCashFlowHedgesNetOfTax": {
     "auth_ref": [
      "r49",
      "r233",
      "r235",
      "r307"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "ifrs-full_OtherComprehensiveIncomeNetOfTaxCashFlowHedges",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of reclassification adjustments related to cash flow hedges, net of tax. Reclassification adjustments are amounts reclassified to profit (loss) in the current period that were recognised in other comprehensive income in the current or previous periods. [Refer: Cash flow hedges [member]; Other comprehensive income]"
       }
      },
      "en-us": {
       "role": {
        "label": "Reclassification adjustments on cash flow hedges, net of tax",
        "negatedTerseLabel": "Reclassification to net earnings (loss), net of taxes of $1 million (2020 \u2013 $2 million, 2019 \u2013 $5\u00a0million)"
       }
      }
     },
     "localname": "ReclassificationAdjustmentsOnCashFlowHedgesNetOfTax",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Reconciliation of accounting profit multiplied by applicable tax rates [abstract]",
        "terseLabel": "Reconciliation of accounting profit multiplied by applicable tax rates [abstract]"
       }
      }
     },
     "localname": "ReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ReconciliationOfChangesInDeferredTaxLiabilityAssetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Reconciliation of changes in deferred tax liability (asset) [abstract]",
        "terseLabel": "Reconciliation of changes in deferred tax liability (asset) [abstract]"
       }
      }
     },
     "localname": "ReconciliationOfChangesInDeferredTaxLiabilityAssetAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofNetDeferredIncomeTaxLiabilityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ReconciliationOfChangesInPropertyPlantAndEquipmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Reconciliation of changes in property, plant and equipment [abstract]",
        "terseLabel": "Reconciliation of changes in property, plant and equipment [abstract]"
       }
      }
     },
     "localname": "ReconciliationOfChangesInPropertyPlantAndEquipmentAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_ReconciliationOfNumberOfSharesOutstandingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Reconciliation of number of shares outstanding [abstract]",
        "terseLabel": "Reconciliation of number of shares outstanding [abstract]"
       }
      }
     },
     "localname": "ReconciliationOfNumberOfSharesOutstandingAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalOutstandingCommonSharesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_RepaymentsOfBorrowingsClassifiedAsFinancingActivities": {
     "auth_ref": [
      "r126"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows": {
       "order": 2.0,
       "parentTag": "ifrs-full_CashFlowsFromUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The cash outflow to settle borrowings, classified as financing activities. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Repayments of borrowings, classified as financing activities",
        "negatedTerseLabel": "Settlement of long-term debt acquired",
        "verboseLabel": "Repayments of borrowings"
       }
      }
     },
     "localname": "RepaymentsOfBorrowingsClassifiedAsFinancingActivities",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofCashFlows",
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails",
      "http://www.cnrl.com/role/SupplementalDisclosureofCashFlowInformationLiabilitiesArisingFromFinancingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RetainedEarnings": {
     "auth_ref": [
      "r35",
      "r51"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "ifrs-full_Equity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "A component of equity representing the entity's cumulative undistributed earnings or deficit."
       }
      },
      "en-us": {
       "role": {
        "label": "Retained earnings",
        "terseLabel": "Retained earnings"
       }
      }
     },
     "localname": "RetainedEarnings",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RetainedEarningsMember": {
     "auth_ref": [
      "r7",
      "r10"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for a component of equity representing an entity's cumulative undistributed earnings or deficit."
       }
      },
      "en-us": {
       "role": {
        "label": "Retained earnings [member]",
        "terseLabel": "Retained earnings"
       }
      }
     },
     "localname": "RetainedEarningsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_RetirementsPropertyPlantAndEquipment": {
     "auth_ref": [
      "r70"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The decrease in property, plant and equipment resulting from retirements. [Refer: Property, plant and equipment]"
       }
      },
      "en-us": {
       "role": {
        "label": "Retirements, property, plant and equipment",
        "negatedLabel": "Derecognitions and other"
       }
      }
     },
     "localname": "RetirementsPropertyPlantAndEquipment",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_Revenue": {
     "auth_ref": [
      "r1",
      "r2",
      "r42",
      "r156",
      "r162",
      "r218",
      "r269",
      "r274",
      "r280",
      "r281",
      "r283"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 2.0,
       "parentTag": "ifrs-full_ProfitLossBeforeTax",
       "weight": 1.0
      },
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_GrossProfit",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims."
       }
      },
      "en-us": {
       "role": {
        "label": "Revenue",
        "totalLabel": "Revenue",
        "verboseLabel": "Crude oil and natural gas revenue, net of royalties, blending and feedstock costs"
       }
      }
     },
     "localname": "Revenue",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RevenueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Revenue [abstract]",
        "terseLabel": "Revenue [abstract]"
       }
      }
     },
     "localname": "RevenueAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_RevenueFromDividends": {
     "auth_ref": [
      "r11"
     ],
     "calculation": {
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails": {
       "order": 2.0,
       "parentTag": "cnq_GainsLossesOnInvestments",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of dividends recognised as income. Dividends are distributions of profits to holders of equity investments in proportion to their holdings of a particular class of capital."
       }
      },
      "en-us": {
       "role": {
        "label": "Dividend income",
        "negatedLabel": "Dividend income",
        "negatedTerseLabel": "Dividend income"
       }
      }
     },
     "localname": "RevenueFromDividends",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/InvestmentsInterPipelineDetails",
      "http://www.cnrl.com/role/InvestmentsPrairieSkyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RevenueFromSaleOfOilAndGasProducts": {
     "auth_ref": [
      "r11"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 1.0,
       "parentTag": "ifrs-full_Revenue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of revenue arising from the sale of oil and gas products. [Refer: Revenue]"
       }
      },
      "en-us": {
       "role": {
        "label": "Revenue from sale of oil and gas products",
        "terseLabel": "Revenue",
        "verboseLabel": "Product sales"
       }
      }
     },
     "localname": "RevenueFromSaleOfOilAndGasProducts",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/OtherLongTermAssetsSummaryofAssetsLiabilitiesPartnersEquityandEquityIncomeLossDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RevenueOfAcquiree": {
     "auth_ref": [
      "r211"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of revenue of the acquiree since the acquisition date included in the consolidated statement of comprehensive income. [Refer: Revenue]"
       }
      },
      "en-us": {
       "role": {
        "label": "Revenue of acquiree since acquisition date",
        "terseLabel": "Revenue of acquiree since acquisition date"
       }
      }
     },
     "localname": "RevenueOfAcquiree",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RightofuseAssets": {
     "auth_ref": [
      "r187"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "ifrs-full_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of assets that represent a lessee's right to use an underlying asset for the lease term. Underlying asset is an asset that is the subject of a lease, for which the right to use that asset has been provided by a lessor to a lessee."
       }
      },
      "en-us": {
       "role": {
        "label": "Right-of-use assets",
        "periodEndLabel": "Lease assets, ending balance",
        "periodStartLabel": "Lease assets, beginning balance",
        "terseLabel": "Lease assets"
       }
      }
     },
     "localname": "RightofuseAssets",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/LeasesLeaseAssetsDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_RoyaltyExpense": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss": {
       "order": 2.0,
       "parentTag": "ifrs-full_Revenue",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of expense arising from royalties."
       }
      },
      "en-us": {
       "role": {
        "label": "Royalty expense",
        "negatedTerseLabel": "Less: royalties"
       }
      }
     },
     "localname": "RoyaltyExpense",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofEarningsLoss",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_SegmentConsolidationItemsAxis": {
     "auth_ref": [
      "r272"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Segment consolidation items [axis]",
        "terseLabel": "Segment consolidation items [axis]"
       }
      }
     },
     "localname": "SegmentConsolidationItemsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_SegmentsAxis": {
     "auth_ref": [
      "r76",
      "r104",
      "r176",
      "r272",
      "r298"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Segments [axis]",
        "terseLabel": "Segments [axis]"
       }
      }
     },
     "localname": "SegmentsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_SegmentsMember": {
     "auth_ref": [
      "r76",
      "r104",
      "r176",
      "r279",
      "r298"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for all segments of an entity. It also represents the standard value for the 'Segments' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Segments [member]",
        "terseLabel": "Segments [member]"
       }
      }
     },
     "localname": "SegmentsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/ExplorationandEvaluationAssetsDetailedinformationaboutexplorationandevaluationassetsDetails",
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesSegmentedAssetRetirementObligationsDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentNarrativeDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_SensitivityAnalysisForEachTypeOfMarketRisk": {
     "auth_ref": [
      "r251"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The disclosure of the sensitivity analysis for types of market risk to which the entity is exposed, showing how profit or loss and equity would have been affected by changes in the relevant risk variable that were reasonably possible at that date. [Refer: Market risk [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Sensitivity analysis for types of market risk [text block]",
        "terseLabel": "Disclosure of financial instrument sensitivities"
       }
      }
     },
     "localname": "SensitivityAnalysisForEachTypeOfMarketRisk",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_SharebasedPaymentArrangementsMember": {
     "auth_ref": [
      "r202"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for an agreement between the entity or another group entity or any shareholder of the group entity and another party (including an employee) that entitles the other party to receive (a) cash or other assets of the entity for amounts that are based on the price (or value) of equity instruments (including shares or share options) of the entity or another group entity; or (b) equity instruments (including shares or share options) of the entity or another group entity, provided that the specified vesting conditions, if any, are met. It also represents the standard value for the 'Types of share-based payment arrangements' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Share-based payment arrangements [member]",
        "terseLabel": "Share-based payment arrangements"
       }
      }
     },
     "localname": "SharebasedPaymentArrangementsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_ShorttermBorrowings": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_Borrowings",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current borrowings. [Refer: Borrowings]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current borrowings",
        "terseLabel": "Less: current portion of commercial paper"
       }
      }
     },
     "localname": "ShorttermBorrowings",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtSummaryofLongtermDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_ShorttermProvisionForDecommissioningRestorationAndRehabilitationCosts": {
     "auth_ref": [
      "r109",
      "r110"
     ],
     "calculation": {
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_ProvisionForDecommissioningRestorationAndRehabilitationCosts",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of current provision for decommissioning, restoration and rehabilitation costs. [Refer: Provision for decommissioning, restoration and rehabilitation costs]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current provision for decommissioning, restoration and rehabilitation costs",
        "terseLabel": "Less: current portion"
       }
      }
     },
     "localname": "ShorttermProvisionForDecommissioningRestorationAndRehabilitationCosts",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesAssetRetirementObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_StatementOfCashFlowsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of cash flows [abstract]",
        "terseLabel": "Statement of cash flows [abstract]"
       }
      }
     },
     "localname": "StatementOfCashFlowsAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "stringItemType"
    },
    "ifrs-full_StatementOfChangesInEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of changes in equity [abstract]",
        "terseLabel": "Statement of changes in equity [abstract]"
       }
      }
     },
     "localname": "StatementOfChangesInEquityAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "stringItemType"
    },
    "ifrs-full_StatementOfChangesInEquityLineItems": {
     "auth_ref": [],
     "lang": {
      "en": {
       "role": {
        "documentation": "Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Statement of changes in equity [line items]",
        "terseLabel": "Statement of changes in equity [line items]"
       }
      }
     },
     "localname": "StatementOfChangesInEquityLineItems",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_StatementOfChangesInEquityTable": {
     "auth_ref": [
      "r7"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "Schedule disclosing information related to changes in equity."
       }
      },
      "en-us": {
       "role": {
        "label": "Statement of changes in equity [table]",
        "terseLabel": "Statement of changes in equity [table]"
       }
      }
     },
     "localname": "StatementOfChangesInEquityTable",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedStatementsofChangesinEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_StatementOfComprehensiveIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of comprehensive income [abstract]",
        "terseLabel": "Statement of comprehensive income [abstract]"
       }
      }
     },
     "localname": "StatementOfComprehensiveIncomeAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "stringItemType"
    },
    "ifrs-full_StatementOfFinancialPositionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of financial position [abstract]",
        "terseLabel": "Statement of financial position [abstract]"
       }
      }
     },
     "localname": "StatementOfFinancialPositionAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "stringItemType"
    },
    "ifrs-full_StatementOfIFRSCompliance": {
     "auth_ref": [
      "r17"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "An explicit and unreserved statement of compliance with all the requirements of IFRSs."
       }
      },
      "en-us": {
       "role": {
        "label": "Statement of IFRS compliance [text block]",
        "terseLabel": "IFRS Compliance"
       }
      }
     },
     "localname": "StatementOfIFRSCompliance",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ifrs-full_SubclassificationsOfAssetsLiabilitiesAndEquitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Subclassifications of assets, liabilities and equities [abstract]",
        "terseLabel": "Subclassifications of assets, liabilities and equities [abstract]"
       }
      }
     },
     "localname": "SubclassificationsOfAssetsLiabilitiesAndEquitiesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "xbrltype": "stringItemType"
    },
    "ifrs-full_TaxEffectFromChangeInTaxRate": {
     "auth_ref": [
      "r57"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 6.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to changes in the tax rate. [Refer: Accounting profit]"
       }
      },
      "en-us": {
       "role": {
        "label": "Tax effect from change in tax rate",
        "terseLabel": "Income tax rate and other legislative changes"
       }
      }
     },
     "localname": "TaxEffectFromChangeInTaxRate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_TaxEffectOfForeignTaxRates": {
     "auth_ref": [
      "r57"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 3.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to foreign tax rates. [Refer: Accounting profit]"
       }
      },
      "en-us": {
       "role": {
        "label": "Tax effect of foreign tax rates",
        "terseLabel": "Foreign and domestic tax rate differentials"
       }
      }
     },
     "localname": "TaxEffectOfForeignTaxRates",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_TaxEffectOfRevenuesExemptFromTaxation2011": {
     "auth_ref": [
      "r57"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 4.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to revenues that are exempt from taxation. [Refer: Accounting profit]"
       }
      },
      "en-us": {
       "role": {
        "label": "Tax effect of revenues exempt from taxation",
        "negatedTerseLabel": "Non-taxable portion of capital gains"
       }
      }
     },
     "localname": "TaxEffectOfRevenuesExemptFromTaxation2011",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_TaxExpenseIncomeAtApplicableTaxRate": {
     "auth_ref": [
      "r57"
     ],
     "calculation": {
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails": {
       "order": 10.0,
       "parentTag": "ifrs-full_IncomeTaxExpenseContinuingOperations",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The product of the accounting profit multiplied by the applicable tax rate(s). [Refer: Accounting profit; Applicable tax rate]"
       }
      },
      "en-us": {
       "role": {
        "label": "Tax expense (income) at applicable tax rate",
        "terseLabel": "Income tax provision at statutory rate"
       }
      }
     },
     "localname": "TaxExpenseIncomeAtApplicableTaxRate",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleofProvisionForIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_TaxExpenseOtherThanIncomeTaxExpense": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails": {
       "order": 6.0,
       "parentTag": "ifrs-full_GrossProfit",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of tax expense exclusive of income tax expense."
       }
      },
      "en-us": {
       "role": {
        "label": "Tax expense other than income tax expense",
        "terseLabel": "Petroleum revenue tax"
       }
      }
     },
     "localname": "TaxExpenseOtherThanIncomeTaxExpense",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Temporary difference, unused tax losses and unused tax credits [axis]",
        "terseLabel": "Temporary difference, unused tax losses and unused tax credits [axis]"
       }
      }
     },
     "localname": "TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsMember": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for temporary differences, unused tax losses and unused tax credits. It also represents the standard value for the 'Temporary difference, unused tax losses and unused tax credits' axis if no other member is used. [Refer: Temporary differences [member]; Unused tax credits [member]; Unused tax losses [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Temporary difference, unused tax losses and unused tax credits [member]",
        "terseLabel": "Temporary difference, unused tax losses and unused tax credits [member]"
       }
      }
     },
     "localname": "TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_TopOfRangeMember": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r201",
      "r255",
      "r290"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for top of a range."
       }
      },
      "en-us": {
       "role": {
        "label": "Top of range [member]",
        "terseLabel": "Top of range"
       }
      }
     },
     "localname": "TopOfRangeMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/CapitalDisclosuresNarrativeDetails",
      "http://www.cnrl.com/role/CriticalAccountingEstimatesandJudgementsNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails",
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_TradeAndOtherCurrentPayablesToTradeSuppliers": {
     "auth_ref": [
      "r33",
      "r36"
     ],
     "calculation": {
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "ifrs-full_CurrentLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The current amount of payment due to suppliers for goods and services used in entity's business. [Refer: Current liabilities; Trade payables]"
       }
      },
      "en-us": {
       "role": {
        "label": "Current trade payables",
        "terseLabel": "Accounts payable"
       }
      }
     },
     "localname": "TradeAndOtherCurrentPayablesToTradeSuppliers",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ConsolidatedBalanceSheets",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_TradeReceivablesMember": {
     "auth_ref": [
      "r11",
      "r241",
      "r245",
      "r247"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for trade receivables. [Refer: Trade receivables]"
       }
      },
      "en-us": {
       "role": {
        "label": "Trade receivables [member]",
        "terseLabel": "Accounts receivable"
       }
      }
     },
     "localname": "TradeReceivablesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsofFinancialInstrumentsbyCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_TypesOfHedgesAxis": {
     "auth_ref": [
      "r228",
      "r229",
      "r234",
      "r305"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Types of hedges [axis]",
        "terseLabel": "Types of hedges [axis]"
       }
      }
     },
     "localname": "TypesOfHedgesAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_TypesOfHedgesMember": {
     "auth_ref": [
      "r228",
      "r229",
      "r234",
      "r305"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for all types of hedges. It also represents the standard value for the 'Types of hedges' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Hedges [member]",
        "terseLabel": "Hedges [member]"
       }
      }
     },
     "localname": "TypesOfHedgesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_TypesOfInterestRatesAxis": {
     "auth_ref": [
      "r250"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Types of interest rates [axis]",
        "terseLabel": "Types of interest rates [axis]"
       }
      }
     },
     "localname": "TypesOfInterestRatesAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandFairValuesofFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_TypesOfRisksAxis": {
     "auth_ref": [
      "r223",
      "r239",
      "r240",
      "r291",
      "r292",
      "r293",
      "r295"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Types of risks [axis]",
        "terseLabel": "Types of risks [axis]"
       }
      }
     },
     "localname": "TypesOfRisksAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_TypesOfRisksMember": {
     "auth_ref": [
      "r223",
      "r239",
      "r240",
      "r291",
      "r292",
      "r293",
      "r295"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for all types of risks. It also represents the standard value for the 'Types of risks' axis if no other member is used."
       }
      },
      "en-us": {
       "role": {
        "label": "Risks [member]",
        "terseLabel": "Risks [member]"
       }
      }
     },
     "localname": "TypesOfRisksMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCounterpartyCreditRiskManagementDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsFinancialInstrumentSensitivitiesDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/FinancialInstrumentsMaturityDatesforFinancialLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_TypesOfSharebasedPaymentArrangementsAxis": {
     "auth_ref": [
      "r202"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The axis of a table defines the relationship between the members in the table and the line items or concepts that complete the table."
       }
      },
      "en-us": {
       "role": {
        "label": "Types of share-based payment arrangements [axis]",
        "terseLabel": "Types of share-based payment arrangements [axis]"
       }
      }
     },
     "localname": "TypesOfSharebasedPaymentArrangementsAxis",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/AccountingPoliciesNarrativeDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails",
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails",
      "http://www.cnrl.com/role/ShareCapitalNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ifrs-full_UnallocatedAmountsMember": {
     "auth_ref": [
      "r279",
      "r284"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for items that have not been allocated to operating segments."
       }
      },
      "en-us": {
       "role": {
        "label": "Unallocated amounts [member]",
        "terseLabel": "Head office",
        "verboseLabel": "Non-segmented"
       }
      }
     },
     "localname": "UnallocatedAmountsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LeasesLeaseAssetsbySegmentDetails",
      "http://www.cnrl.com/role/PropertyPlantandEquipmentDetailedinformationaboutpropertyplantandequipmentDetails",
      "http://www.cnrl.com/role/SegmentedInformationCapitalExpendituresDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SegmentedInformationSegmentedAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_UnrealisedForeignExchangeGainsLossesMember": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for gains (losses) resulting from changes in foreign exchange rates which have not yet been realised."
       }
      },
      "en-us": {
       "role": {
        "label": "Unrealised foreign exchange gains (losses) [member]",
        "terseLabel": "Unrealized foreign exchange on long-term debt"
       }
      }
     },
     "localname": "UnrealisedForeignExchangeGainsLossesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_UnrecognisedShareOfLossesOfJointVentures": {
     "auth_ref": [
      "r155"
     ],
     "crdr": "debit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The amount of the unrecognised share of joint ventures' losses if the entity has stopped recognising its share of losses when applying the equity method. [Refer: Joint ventures [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Unrecognised share of losses of joint ventures",
        "terseLabel": "Unrecognised share of losses of joint ventures"
       }
      }
     },
     "localname": "UnrecognisedShareOfLossesOfJointVentures",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_UnusedTaxCreditsMember": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for tax credits that have been received and are carried forward for use against future taxable profit."
       }
      },
      "en-us": {
       "role": {
        "label": "Unused tax credits [member]",
        "terseLabel": "Unused tax credits"
       }
      }
     },
     "localname": "UnusedTaxCreditsMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_UnusedTaxLossesMember": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for tax losses that have been incurred and are carried forward for use against future taxable profit."
       }
      },
      "en-us": {
       "role": {
        "label": "Unused tax losses [member]",
        "terseLabel": "Loss carryforwards",
        "verboseLabel": "Unused tax losses"
       }
      }
     },
     "localname": "UnusedTaxLossesMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesNarrativeDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMajorTemporaryDifferencesDetails",
      "http://www.cnrl.com/role/IncomeTaxesSummaryofMovementsinDeferredTaxAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement2019": {
     "auth_ref": [
      "r199"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average exercise price of share options exercisable in a share-based payment arrangement. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average exercise price of share options exercisable in share-based payment arrangement",
        "terseLabel": "Weighted average exercise price, options exercisable (in CAD per share)"
       }
      }
     },
     "localname": "WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails",
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_WeightedAverageExercisePriceOfShareOptionsExercisedInSharebasedPaymentArrangement2019": {
     "auth_ref": [
      "r197"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average exercise price of share options exercised in a share-based payment arrangement. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average exercise price of share options exercised in share-based payment arrangement",
        "terseLabel": "Weighted average exercise price, options exercised (in CAD per share)"
       }
      }
     },
     "localname": "WeightedAverageExercisePriceOfShareOptionsExercisedInSharebasedPaymentArrangement2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_WeightedAverageExercisePriceOfShareOptionsForfeitedInSharebasedPaymentArrangement2019": {
     "auth_ref": [
      "r196"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average exercise price of share options forfeited in a share-based payment arrangement. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average exercise price of share options forfeited in share-based payment arrangement",
        "terseLabel": "Weighted average exercise price, options forfeited (in CAD per share)"
       }
      }
     },
     "localname": "WeightedAverageExercisePriceOfShareOptionsForfeitedInSharebasedPaymentArrangement2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_WeightedAverageExercisePriceOfShareOptionsGrantedInSharebasedPaymentArrangement2019": {
     "auth_ref": [
      "r195"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average exercise price of share options granted in a share-based payment arrangement. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average exercise price of share options granted in share-based payment arrangement",
        "terseLabel": "Weighted average exercise price, options granted (in CAD per share)"
       }
      }
     },
     "localname": "WeightedAverageExercisePriceOfShareOptionsGrantedInSharebasedPaymentArrangement2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement2019": {
     "auth_ref": [
      "r194",
      "r198"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average exercise price of share options outstanding in a share-based payment arrangement. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average exercise price of share options outstanding in share-based payment arrangement",
        "periodEndLabel": "Weighted average exercise price, options outstanding - beginning of year (in CAD per share)",
        "periodStartLabel": "Weighted average exercise price, options outstanding - beginning of year (in CAD per share)",
        "terseLabel": "Weighted average exercise price, options outstanding (in CAD per share)"
       }
      }
     },
     "localname": "WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails",
      "http://www.cnrl.com/role/ShareCapitalStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_WeightedAverageFairValueAtMeasurementDateShareOptionsGranted": {
     "auth_ref": [
      "r204"
     ],
     "crdr": "credit",
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average fair value of share options granted during the period at the measurement date. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average fair value at measurement date, share options granted",
        "terseLabel": "Fair value"
       }
      }
     },
     "localname": "WeightedAverageFairValueAtMeasurementDateShareOptionsGranted",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ifrs-full_WeightedAverageMember": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r255",
      "r290"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "This member stands for an average in which each quantity to be averaged is assigned a weight that determines the relative effect of each quantity on the average."
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average [member]",
        "terseLabel": "Weighted average"
       }
      }
     },
     "localname": "WeightedAverageMember",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/LongTermDebtNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ifrs-full_WeightedAverageRemainingContractualLifeOfOutstandingShareOptions2019": {
     "auth_ref": [
      "r201"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average remaining contractual life of outstanding share options. [Refer: Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average remaining contractual life of outstanding share options",
        "terseLabel": "Weighted \u00a0average \u00a0remaining \u00a0term (years)"
       }
      }
     },
     "localname": "WeightedAverageRemainingContractualLifeOfOutstandingShareOptions2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/ShareCapitalRangeofExercisePricesofStockOptionsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "ifrs-full_WeightedAverageSharePriceShareOptionsGranted2019": {
     "auth_ref": [
      "r203"
     ],
     "lang": {
      "en": {
       "role": {
        "documentation": "The weighted average share price used as input to the option pricing model to calculate the fair value of share options granted. [Refer: Option pricing model [member]; Weighted average [member]]"
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average share price, share options granted",
        "terseLabel": "Share price"
       }
      }
     },
     "localname": "WeightedAverageSharePriceShareOptionsGranted2019",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesWeightedAverageAssumptionsUsedtoCalculateShareBasedCompensationLiabilityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ifrs-full_WeightedAverageShares": {
     "auth_ref": [
      "r101"
     ],
     "calculation": {
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails": {
       "order": 1.0,
       "parentTag": "ifrs-full_AdjustedWeightedAverageShares",
       "weight": 1.0
      }
     },
     "lang": {
      "en": {
       "role": {
        "documentation": "The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor."
       }
      },
      "en-us": {
       "role": {
        "label": "Weighted average number of ordinary shares used in calculating basic earnings per share",
        "terseLabel": "Weighted average common shares outstanding \u2013 basic (thousands of shares)"
       }
      }
     },
     "localname": "WeightedAverageShares",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "ifrs-full_WeightedAverageSharesAndAdjustedWeightedAverageSharesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Weighted average ordinary shares used in calculating basic and diluted earnings per share [abstract]",
        "terseLabel": "Weighted average ordinary shares and adjusted weighted average ordinary shares [abstract]"
       }
      }
     },
     "localname": "WeightedAverageSharesAndAdjustedWeightedAverageSharesAbstract",
     "nsuri": "http://xbrl.ifrs.org/taxonomy/2021-03-24/ifrs-full",
     "presentation": [
      "http://www.cnrl.com/role/NetEarningsPerCommonShareScheduleofBasicandDilutedNetEarningsLossperCommonShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CommonDomainMembersAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Common Domain Members [Abstract]"
       }
      }
     },
     "localname": "CommonDomainMembersAbstract",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "srt_CounterpartyNameAxis": {
     "auth_ref": [
      "r323"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by name of counterparty. A counterparty is the other party that participates in a financial transaction. Examples include, but not limited to, the name of the financial institution.",
        "label": "Counterparty Name [Axis]",
        "terseLabel": "Counterparty Name [Axis]"
       }
      }
     },
     "localname": "CounterpartyNameAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CrudeOilMember": {
     "auth_ref": [
      "r320",
      "r321"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unrefined, unprocessed oil, which may be used in a variety of applications, and from which, petroleum-based products are produced.",
        "label": "Crude Oil [Member]",
        "terseLabel": "Crude oil"
       }
      }
     },
     "localname": "CrudeOilMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CurrencyAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by currency.",
        "label": "Currency [Axis]",
        "terseLabel": "Currency [Axis]"
       }
      }
     },
     "localname": "CurrencyAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsForeignCurrencyExchangeRateRiskManagementDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_DecreaseDueToSalesOfMineralsInPlace": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 6.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of decrease in standardized measure of discounted future net cash flow as a result of sales of minerals in place.",
        "label": "Decrease Due to Sales of Minerals in Place",
        "negatedTerseLabel": "Sales of proved reserves in place"
       }
      }
     },
     "localname": "DecreaseDueToSalesOfMineralsInPlace",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]",
        "terseLabel": "Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]"
       }
      }
     },
     "localname": "DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesLineItems",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesTable": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "These elements contained detailed information about the future cash inflows and future development costs related to proved oil and gas reserves. This information is presented in aggregate and for each geographic area for which reserve quantities are disclosed. The estimated future net cash flows are discounted using a rate of 10 percent per year to reflect the estimated timing of the future cash flows. Note that future cash flows related to the settlement of an asset retirement obligation are included in the disclosure.",
        "label": "Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Table]",
        "terseLabel": "Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Table]"
       }
      }
     },
     "localname": "DiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReservesTable",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 3.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of extensions, discoveries and improved recovery of proved oil and gas reserves.",
        "label": "Extensions, Discoveries, Additions and Improved Recovery, Less Related Costs",
        "terseLabel": "Extensions, discoveries and improved recovery"
       }
      }
     },
     "localname": "ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_ExtractiveIndustriesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Extractive Industries [Abstract]",
        "terseLabel": "Extractive Industries [Abstract]"
       }
      }
     },
     "localname": "ExtractiveIndustriesAbstract",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails": {
       "order": 1.0,
       "parentTag": "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of estimated future accumulated cash inflow from the sale of proved oil and gas reserves.",
        "label": "Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Cash Inflows",
        "terseLabel": "Future cash inflows"
       }
      }
     },
     "localname": "FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails": {
       "order": 4.0,
       "parentTag": "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of estimated future accumulated cash outflow for income tax, based on the future income less future expense derived from production and sale of proved oil and gas reserves.",
        "label": "Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Income Tax Expense",
        "negatedTerseLabel": "Future income taxes"
       }
      }
     },
     "localname": "FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails": {
       "order": 1.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after future accumulated cash outflow for development and production costs and future income tax, of estimated future accumulated cash inflow from the sale of proved oil and gas reserves.",
        "label": "Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Net Cash Flows",
        "totalLabel": "Future net cash flows"
       }
      }
     },
     "localname": "FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails": {
       "order": 2.0,
       "parentTag": "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of estimated future accumulated cash outflow for costs to be incurred in producing proved oil and gas reserves.",
        "label": "Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Production Costs",
        "negatedTerseLabel": "Future production costs"
       }
      }
     },
     "localname": "FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails": {
       "order": 2.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of discount on future accumulated cash inflow, after deducting future accumulated cash outflow for development and production costs and future income tax, from sale of proved oil and gas reserves, using a discount rate of ten percent a year.",
        "label": "Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Ten Percent Annual Discount for Estimated Timing of Cash Flows",
        "negatedTerseLabel": "10% annual discount for timing of future cash flows"
       }
      }
     },
     "localname": "FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_IncreaseDecreaseInEstimatedFutureDevelopmentCosts": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 4.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of change in estimated future development costs.",
        "label": "Changes in Estimated Future Development Costs",
        "terseLabel": "Changes in estimated future development costs"
       }
      }
     },
     "localname": "IncreaseDecreaseInEstimatedFutureDevelopmentCosts",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 10.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of change in the estimated future income tax on future pretax net cash flows related to the entity's proved oil and gas reserves.",
        "label": "Changes in Future Income Tax Expense Estimates on Future Cash Flows Related to Proved Oil and Gas Reserves",
        "terseLabel": "Net change in income taxes"
       }
      }
     },
     "localname": "IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_IncreaseDecreaseInStandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward]",
        "terseLabel": "Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves 1 [Roll Forward]"
       }
      }
     },
     "localname": "IncreaseDecreaseInStandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesRollForward",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_IncreaseDueToPurchasesOfMineralsInPlace": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 5.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in standardized measure of discounted future net cash flow as a result of purchases of minerals in place.",
        "label": "Increase Due to Purchases of Minerals in Place",
        "terseLabel": "Purchases of proved reserves in place"
       }
      }
     },
     "localname": "IncreaseDueToPurchasesOfMineralsInPlace",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_NaturalGasReservesMember": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Natural gas composed primarily of methane gas, excluding liquid or condensate natural gas.",
        "label": "Natural Gas [Member]",
        "terseLabel": "Natural gas",
        "verboseLabel": "Natural gas"
       }
      }
     },
     "localname": "NaturalGasReservesMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/FinancialInstrumentsCarryingAmountsandReconciliationofDerivativeFinancialInstrumentsDetails",
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 2.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of change in sales and transfer prices and in production (lifting) costs related to future production.",
        "label": "Net Increase (Decrease) in Sales and Transfer Prices and Production Costs",
        "terseLabel": "Net changes in sales prices and production costs"
       }
      }
     },
     "localname": "NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_NorthAmericaMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Continent of North America.",
        "label": "North America [Member]",
        "terseLabel": "North America"
       }
      }
     },
     "localname": "NorthAmericaMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCapitalizedCostsRelatedtoCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedCostsIncurredinCrudeOilandNaturalGasActivitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedResultsofOperationsfromCrudeOilandNaturalGasProducingActivitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_OilReservesMember": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Crude oil, which may also include condensate and natural gas liquids.",
        "label": "Oil [Member]",
        "terseLabel": "Crude Oil and NGLs"
       }
      }
     },
     "localname": "OilReservesMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedOilAndGasReserveQuantitiesTable": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Detailed information on net quantities of proved reserves by geographic area.",
        "label": "Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table]",
        "terseLabel": "Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table]"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedOilAndGasReserveQuantitiesTable",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additions to proved reserves that result from (1) extension of the proved acreage of previously discovered (old) reservoirs through additional drilling in periods after discovery and (2) discovery of new fields with proved reserves or of new reservoirs of proved reserves in old fields.",
        "label": "Proved Developed and Undeveloped Reserves, Extensions, Discoveries, and Additions",
        "terseLabel": "Extensions and discoveries (in MMbbl)",
        "verboseLabel": "Extensions and discoveries (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesImprovedRecovery": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Changes in proved reserve estimates resulting from application of improved recovery techniques.",
        "label": "Proved Developed and Undeveloped Reserves, Improved Recovery",
        "terseLabel": "Improved recovery (in MMbbl)",
        "verboseLabel": "Improved recovery (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesImprovedRecovery",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesNet": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable.",
        "label": "Proved Developed and Undeveloped Reserves, Net",
        "periodEndLabel": "Proved reserves, net, ending balance",
        "periodStartLabel": "Proved reserves, net, beginning balance"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesNet",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesNetPeriodIncreaseDecrease": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Volume increase (decrease) of proved reserves of oil and gas.",
        "label": "Proved Developed and Undeveloped Reserves, Net, Period Increase (Decrease)",
        "terseLabel": "Change in proved developed and undeveloped reserves, net (in MMbbl)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesNetPeriodIncreaseDecrease",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesProduction": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Production of proved reserves.",
        "label": "Proved Developed and Undeveloped Reserves, Production",
        "negatedLabel": "Production (in Bcf)",
        "negatedTerseLabel": "Production (in MMbbl)",
        "terseLabel": "Production (in MMbbl)",
        "verboseLabel": "Production (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesProduction",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesPurchasesOfMineralsInPlace": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Purchase of minerals in place.",
        "label": "Proved Developed and Undeveloped Reserves, Purchases of Minerals in Place",
        "terseLabel": "Purchases of reserves in place (in MMbbl)",
        "verboseLabel": "Purchases of reserves in place (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesPurchasesOfMineralsInPlace",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revisions represent changes in previous estimates of proved reserves, either upward or downward, resulting from new information (except for an increase in proved acreage) normally obtained from development drilling and production history or resulting from change in economic factors.",
        "label": "Proved Developed and Undeveloped Reserves, Revisions of Previous Estimates",
        "terseLabel": "Revisions of prior estimates (in MMbbl)",
        "verboseLabel": "Revisions of prior estimates (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlace": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sales of minerals in place.",
        "label": "Proved Developed and Undeveloped Reserves, Sales of Minerals in Place",
        "negatedLabel": "Sales of reserves in place (in Bcf)",
        "negatedTerseLabel": "Sales of reserves in place (in MMbbl)",
        "terseLabel": "Sales of reserves in place (in MMbbl)",
        "verboseLabel": "Sales of reserves in place (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlace",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_ProvedDevelopedReservesVolume": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Net quantities of an enterprise's interests in proved developed reserves of either crude oil (including condensate and natural gas liquids), natural gas, synthetic oil and gas, or other nonrenewable natural resource that is intended to be upgraded into synthetic oil and gas as of the beginning and the end of the year. \"Net\" quantities of reserves include those relating to the enterprise's operating and nonoperating interests in properties. Quantities of reserves relating to royalty interests owned are included in \"net\" quantities if the necessary information is available to the enterprise. \"Net\" quantities does not include reserves relating to interests of others in properties owned by the enterprise. The unit of measure for reserve quantities is defined as \"barrels\" for oil and synthetic oil reserves or \"cubic feet\" or \"cubic meters\" for natural gas and synthetic gas reserves.",
        "label": "Proved Developed Reserves (Volume)",
        "terseLabel": "Net proved developed reserves (in MMbbl)",
        "verboseLabel": "Net proved developed reserves (in Bcf)"
       }
      }
     },
     "localname": "ProvedDevelopedReservesVolume",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "volumeItemType"
    },
    "srt_RepurchaseAgreementCounterpartyNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Named other party that participates in a financial transaction. Examples include, but not limited to, the name of the financial institution.",
        "label": "Counterparty Name [Domain]",
        "terseLabel": "Counterparty Name [Domain]"
       }
      }
     },
     "localname": "RepurchaseAgreementCounterpartyNameDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermAssetsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ReserveQuantitiesByTypeOfReserveAxis": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by types of proved developed and undeveloped petroleum reserves.",
        "label": "Petroleum Reserves [Axis]",
        "terseLabel": "Petroleum Reserves [Axis]"
       }
      }
     },
     "localname": "ReserveQuantitiesByTypeOfReserveAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ReserveQuantitiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Reserve Quantities [Line Items]",
        "terseLabel": "Reserve Quantities [Line Items]"
       }
      }
     },
     "localname": "ReserveQuantitiesLineItems",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RevisionsOfPreviousQuantityEstimates": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 7.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of revisions of estimated quantity of oil and gas in proved reserves.",
        "label": "Revisions of Previous Quantity Estimates",
        "terseLabel": "Revisions of previous reserve estimates"
       }
      }
     },
     "localname": "RevisionsOfPreviousQuantityEstimates",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 1.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of (increase) decrease in standardized measure of discounted future net cash flow as a result of sales and transfers of oil and gas produced.",
        "label": "Sales and Transfers of Oil and Gas Produced, Net of Production Costs",
        "negatedTerseLabel": "Sales of crude oil and natural gas produced, net of production costs"
       }
      }
     },
     "localname": "SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_ScheduleOfChangesInStandardizedMeasureOfDiscountedFutureNetCashFlowsTableTextBlock": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the aggregate change in the standardized measure of discounted future net cash flows relating to proved oil and gas reserves and oil and gas subject to purchases under long-term agreements in which the enterprise participates in the operation of the properties on which oil and gas is located or otherwise serves as the producer.",
        "label": "Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows [Table Text Block]",
        "terseLabel": "Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows"
       }
      }
     },
     "localname": "ScheduleOfChangesInStandardizedMeasureOfDiscountedFutureNetCashFlowsTableTextBlock",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "srt_ScheduleOfProvedDevelopedAndUndevelopedOilAndGasReserveQuantitiesTextBlock": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the net quantities of an enterprise's interests in proved developed and undeveloped reserves of (a) crude oil (including condensate and natural gas liquids), (b) natural gas (including coal bed methane), (c) synthetic oil, (d) synthetic gas, and (e) other nonrenewable natural resources that are intended to be upgraded during the period as of the beginning of the period, changes in quantities during the period, and as of the end of the period.",
        "label": "Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table Text Block]",
        "terseLabel": "Schedule of Crude Oil, NGL's and Natural Gas Net Proved Reserve Quantities"
       }
      }
     },
     "localname": "ScheduleOfProvedDevelopedAndUndevelopedOilAndGasReserveQuantitiesTextBlock",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "srt_StandardizedMeasureOfDiscountedFutureCashFlowsRelatingToProvedReservesDisclosureTextBlock": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the future net cash flows relating to proved oil and gas reserves and oil and gas subject to purchase under long-term agreements in which the enterprise participates in the operation of the properties on which the oil and gas is located or otherwise serves as the producer. This information is presented in aggregate and for each geographic area for which reserve quantities are disclosed.",
        "label": "Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure [Table Text Block]",
        "terseLabel": "Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure"
       }
      }
     },
     "localname": "StandardizedMeasureOfDiscountedFutureCashFlowsRelatingToProvedReservesDisclosureTextBlock",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesOther": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 9.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of changes from other sources.",
        "label": "Standardized Measure of Discounted Future Net Cash Flow of Proved Oil and Gas Reserves, Other",
        "terseLabel": "Changes in production timing and other"
       }
      }
     },
     "localname": "StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesOther",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in standardized measure of discounted future net cash flow relating to proved oil and gas reserves.",
        "label": "Standardized Measure of Discounted Future Net Cash Flow of Proved Oil and Gas Reserves, Period Increase (Decrease)",
        "totalLabel": "Net change"
       }
      }
     },
     "localname": "StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesAccretionOfDiscount": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails": {
       "order": 8.0,
       "parentTag": "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowOfProvedOilAndGasReservesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accretion of discount for the standardized measure of discounted future net cash flow related to proved oil and gas reserves.",
        "label": "Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves, Accretion of Discount",
        "terseLabel": "Accretion of discount"
       }
      }
     },
     "localname": "StandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesAccretionOfDiscount",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves": {
     "auth_ref": [
      "r318"
     ],
     "calculation": {
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of discounted future accumulated cash inflow relating to proved oil and gas reserves.",
        "label": "Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves",
        "periodEndLabel": "Balance - end of year",
        "periodStartLabel": "Balance - beginning of year",
        "totalLabel": "Standardized measure of future net cash flows"
       }
      }
     },
     "localname": "StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedFutureNetCashFlowsRelatingtoProvedCrudeOilandNaturalGasReservesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedSourcesofChangeintheStandardizedMeasureofDiscountedFutureNetCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "srt_SyntheticOilMember": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lubricant consisting of chemical compounds that are synthetically made.",
        "label": "Synthetic Oil [Member]",
        "terseLabel": "Synthetic Crude Oil"
       }
      }
     },
     "localname": "SyntheticOilMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_TitleOfIndividualAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by title of individual or nature of relationship to individual or group of individuals.",
        "label": "Title of Individual [Axis]",
        "terseLabel": "Title of Individual [Axis]"
       }
      }
     },
     "localname": "TitleOfIndividualAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_TitleOfIndividualWithRelationshipToEntityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Title of individual, or nature of relationship to individual or group of individuals.",
        "label": "Title of Individual [Domain]",
        "terseLabel": "Title of Individual [Domain]"
       }
      }
     },
     "localname": "TitleOfIndividualWithRelationshipToEntityDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/OtherLongTermLiabilitiesShareBasedCompensationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_TypeOfReserveDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The type of petroleum reserve being disclosed: oil, natural gas, natural gas liquids, synthetic oil, synthetic gas, or other nonrenewable natural resource that is intended to be upgraded into synthetic oil and gas with separate disclosures for consolidated entities and equity method investments.",
        "label": "Type of Reserve [Domain]",
        "terseLabel": "Type of Reserve [Domain]"
       }
      }
     },
     "localname": "TypeOfReserveDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.cnrl.com/role/SegmentedInformationOperatingSegmentsEarningsDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedNaturalGasNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedOilandNaturalGasLiquidsNarrativeDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedNaturalGasReserveQuantitiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedProvedandProvedDevelopedOilandNaturalGasLiquidsNetofRoyaltiesDetails",
      "http://www.cnrl.com/role/SupplementaryOilAndGasInformationUnauditedTwelveMonthAverageBenchmarkPricesDetails"
     ],
     "xbrltype": "domainItemType"
    }
   },
   "unitCount": 18
  }
 },
 "std_ref": {
  "r0": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "10",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_10_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r1": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "102",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_102&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r10": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "108",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_108&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r100": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "33",
   "Paragraph": "67",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2021-en-r&anchor=para_67&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r101": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "33",
   "Paragraph": "70",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2021-en-r&anchor=para_70_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r102": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "33",
   "Section": "Disclosure",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IAS33_g70-73A_TI",
   "URIDate": "2021-03-24"
  },
  "r103": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "36",
   "Paragraph": "127",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_127&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r104": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "36",
   "Paragraph": "130",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_130_d_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r105": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "37",
   "Paragraph": "84",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=37&code=ifrs-tx-2021-en-r&anchor=para_84_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r106": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "37",
   "Paragraph": "84",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=37&code=ifrs-tx-2021-en-r&anchor=para_84_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r107": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "37",
   "Paragraph": "84",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=37&code=ifrs-tx-2021-en-r&anchor=para_84_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r108": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "37",
   "Paragraph": "84",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=37&code=ifrs-tx-2021-en-r&anchor=para_84&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r109": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "37",
   "Paragraph": "87",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=37&code=ifrs-tx-2021-en-r&anchor=para_87&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r11": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "112",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_112_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r110": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "37",
   "Section": "D Examples: disclosures",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=37&code=ifrs-tx-2021-en-r&doctype=Illustrative%20Examples&dita_xref=IAS37_IE_D__IAS37_IE_D_TI",
   "URIDate": "2021-03-24"
  },
  "r111": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "38",
   "Paragraph": "118",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=38&code=ifrs-tx-2021-en-r&anchor=para_118_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r112": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "38",
   "Paragraph": "118",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=38&code=ifrs-tx-2021-en-r&anchor=para_118_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r113": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "39",
   "Paragraph": "86",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=39&code=ifrs-tx-2021-en-r&anchor=para_86_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r114": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "40",
   "Paragraph": "76",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2021-en-r&anchor=para_76&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r115": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "40",
   "Paragraph": "79",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2021-en-r&anchor=para_79_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r116": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "40",
   "Paragraph": "79",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2021-en-r&anchor=para_79_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r117": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "41",
   "Paragraph": "50",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=41&code=ifrs-tx-2021-en-r&anchor=para_50&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r118": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "41",
   "Paragraph": "54",
   "Subparagraph": "f",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=41&code=ifrs-tx-2021-en-r&anchor=para_54_f&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r119": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "10",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_10&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r12": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "117",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_117_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r120": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "14",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_14&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r121": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "16",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_16_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r122": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "16",
   "Subparagraph": "f",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_16_f&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r123": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "16",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_16&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r124": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "17",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_17_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r125": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "17",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_17_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r126": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "17",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_17_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r127": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "17",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_17_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r128": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "17",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_17&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r129": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "18",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_18_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r13": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "117",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_117_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r130": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "20",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_20_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r131": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "20",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_20_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r132": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "20",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_20&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r133": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "31",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_31&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r134": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "35",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r135": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "39",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_39&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r136": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "44B",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_44B_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r137": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "44B",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_44B_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r138": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "44B",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_44B&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r139": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "44C",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_44C&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r14": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "117",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_117&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r140": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "44D",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_44D&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r141": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "45",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_45&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r142": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "46",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_46&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r143": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Paragraph": "50",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&anchor=para_50_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r144": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Section": "A Statement of cash flows for an entity other than a financial institution",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&doctype=Illustrative%20Examples&dita_xref=IAS07_IE_A__IAS07_IE_A_TI",
   "URIDate": "2021-03-24"
  },
  "r145": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Section": "C Reconciliation of liabilities arising from financing activities",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&doctype=Illustrative%20Examples&dita_xref=IAS07_IE_C__IAS07_IE_C_TI",
   "URIDate": "2021-03-24"
  },
  "r146": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "7",
   "Section": "Presentation of a statement of cash flows",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IAS07_g10-17_TI",
   "URIDate": "2021-03-24"
  },
  "r147": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "8",
   "Paragraph": "28",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r148": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "8",
   "Paragraph": "30",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=8&code=ifrs-tx-2021-en-r&anchor=para_30_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r149": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "1",
   "Paragraph": "24",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2021-en-r&anchor=para_24_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r15": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "134",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_134&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r150": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "1",
   "Paragraph": "24",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2021-en-r&anchor=para_24_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r151": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "1",
   "Paragraph": "32",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2021-en-r&anchor=para_32_a_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r152": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "1",
   "Paragraph": "32",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2021-en-r&anchor=para_32_a_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r153": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "2",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_2_b_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r154": {
   "Clause": "iv",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "21",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_21_a_iv&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r155": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "22",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_22_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r156": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B10",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B10_b&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r157": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B12",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_i&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r158": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B12",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_ii&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r159": {
   "Clause": "iii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B12",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_iii&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r16": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "136",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_136&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r160": {
   "Clause": "iv",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B12",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_iv&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r161": {
   "Clause": "ix",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B12",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_ix&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r162": {
   "Clause": "v",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B12",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_v&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r163": {
   "Clause": "viii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B12",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B12_b_viii&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r164": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B13",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B13_a&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r165": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B13",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B13_d&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r166": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B13",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B13_g&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r167": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B16",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B16&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r168": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "12",
   "Paragraph": "B4",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B4_b&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r169": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "13",
   "Paragraph": "93",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r17": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "16",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_16&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r170": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "13",
   "Paragraph": "93",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r171": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "13",
   "Paragraph": "93",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r172": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "13",
   "Paragraph": "93",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_93&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r173": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "13",
   "Paragraph": "B6",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_B6&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r174": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "13",
   "Paragraph": "IE63",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2021-en-r&anchor=para_IE63&doctype=Illustrative%20Examples",
   "URIDate": "2021-03-24"
  },
  "r175": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "14",
   "Paragraph": "33",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=14&code=ifrs-tx-2021-en-r&anchor=para_33_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r176": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "15",
   "Paragraph": "115",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2021-en-r&anchor=para_115&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r177": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "15",
   "Paragraph": "120",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2021-en-r&anchor=para_120_b_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r178": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "15",
   "Paragraph": "B89",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2021-en-r&anchor=para_B89_a&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r179": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "15",
   "Paragraph": "B89",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2021-en-r&anchor=para_B89_b&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r18": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "35",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_35&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r180": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "47",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_47_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r181": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r182": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r183": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r184": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r185": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53_g&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r186": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "Subparagraph": "h",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53_h&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r187": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "Subparagraph": "j",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53_j&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r188": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "53",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_53&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r189": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "59",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_59&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r19": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "54",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r190": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "94",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_94&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r191": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Paragraph": "97",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&anchor=para_97&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r192": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Section": "Disclosure",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IFRS16_g51-60_TI",
   "URIDate": "2021-03-24"
  },
  "r193": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "16",
   "Section": "Presentation",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IFRS16_g47-50_TI",
   "URIDate": "2021-03-24"
  },
  "r194": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r195": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r196": {
   "Clause": "iii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_iii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r197": {
   "Clause": "iv",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_iv&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r198": {
   "Clause": "vi",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_vi&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r199": {
   "Clause": "vii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b_vii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r2": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "103",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_103&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r20": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "54",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r200": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r201": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r202": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "45",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_45&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r203": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "47",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_47_a_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r204": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "47",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_47_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r205": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "51",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_51_b_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r206": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "51",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_51_b_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r207": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "2",
   "Paragraph": "52",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_52&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r208": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B64",
   "Subparagraph": "f",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_f_i&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r209": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B64",
   "Subparagraph": "f",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_f&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r21": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "54",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_g&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r210": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B64",
   "Subparagraph": "i",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_i&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r211": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B64",
   "Subparagraph": "q",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_q_i&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r212": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B64",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r213": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B67",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B67_d&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r214": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B67",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B67_e&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r215": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "B67",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B67&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r216": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Paragraph": "IE72",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_IE72&doctype=Illustrative%20Examples",
   "URIDate": "2021-03-24"
  },
  "r217": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "3",
   "Section": "Disclosures application of paragraphs 59 and 61",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&doctype=Appendix&subtype=B&dita_xref=IFRS03_gB64-B67_TI",
   "URIDate": "2021-03-24"
  },
  "r218": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "5",
   "Paragraph": "33",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2021-en-r&anchor=para_33_b_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r219": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "6",
   "Paragraph": "24",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=6&code=ifrs-tx-2021-en-r&anchor=para_24_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r22": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "54",
   "Subparagraph": "i",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r220": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "6",
   "Paragraph": "24",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=6&code=ifrs-tx-2021-en-r&anchor=para_24_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r221": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "6",
   "Section": "Disclosure",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=6&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IFRS06_g23-25_TI",
   "URIDate": "2021-03-24"
  },
  "r222": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "20",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_20_a_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r223": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "21C",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_21C&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r224": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "23A",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_23A&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r225": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "23B",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_23B_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r226": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "23B",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_23B_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r227": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24A",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24A_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r228": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24A",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24A&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r229": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24B",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24B&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r23": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "54",
   "Subparagraph": "n",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_n&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r230": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24C",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24C_a_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r231": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24C",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24C_b_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r232": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24C",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24C_b_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r233": {
   "Clause": "iv",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24C",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24C_b_iv&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r234": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24C",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24C&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r235": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "24E",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24E_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r236": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "25",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_25&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r237": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "31",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_31&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r238": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "32",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_32&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r239": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "33",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_33&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r24": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "54",
   "Subparagraph": "o",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_o&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r240": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "34",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_34&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r241": {
   "Clause": "iii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "35H",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35H_b_iii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r242": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "35H",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35H&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r243": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "35I",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35I&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r244": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "35K",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35K&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r245": {
   "Clause": "iii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "35M",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35M_b_iii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r246": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "35M",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35M&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r247": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "35N",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_35N&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r248": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "36",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_36&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r249": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "39",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_39_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r25": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "55",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_55&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r250": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "39",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_39&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r251": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "40",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_40_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r252": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "42E",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_42E_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r253": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "42I",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_42I&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r254": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "6",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_6&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r255": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "7",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_7&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r256": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "8",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_8_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r257": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "8",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_8_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r258": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "8",
   "Subparagraph": "f",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_8_f&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r259": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "8",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_8_g&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r26": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "56",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_56&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r260": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "8",
   "Subparagraph": "h",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_8_h&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r261": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "B11",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_B11&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r262": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "B35",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_B35_g&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r263": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "B35",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_B35&doctype=Appendix&subtype=B",
   "URIDate": "2021-03-24"
  },
  "r264": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "IG20D",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_IG20D&doctype=Implementation%20Guidance",
   "URIDate": "2021-03-24"
  },
  "r265": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "IG31A",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_IG31A&doctype=Implementation%20Guidance",
   "URIDate": "2021-03-24"
  },
  "r266": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Paragraph": "IG32",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_IG32&doctype=Implementation%20Guidance",
   "URIDate": "2021-03-24"
  },
  "r267": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Section": "Defined terms",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&doctype=Appendix&subtype=A&dita_xref=IFRS07_APPA_TI",
   "URIDate": "2021-03-24"
  },
  "r268": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "7",
   "Section": "Scope",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IFRS07_g3-5A_TI",
   "URIDate": "2021-03-24"
  },
  "r269": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "23",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r27": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "61",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_61_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r270": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "23",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r271": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "23",
   "Subparagraph": "h",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_h&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r272": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "23",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r273": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "24",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_24_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r274": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "28",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r275": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "28",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r276": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "28",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r277": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "28",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r278": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "28",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r279": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "28",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r28": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "61",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_61&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r280": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "32",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_32&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r281": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "33",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_33_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r282": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "33",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_33&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r283": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "34",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_34&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r284": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Paragraph": "IG4",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_IG4&doctype=Implementation%20Guidance",
   "URIDate": "2021-03-24"
  },
  "r285": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "8",
   "Section": "Disclosure",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IFRS08_g20-24_TI",
   "URIDate": "2021-03-24"
  },
  "r286": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Number": "9",
   "Paragraph": "7.2.34",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2021-en-r&anchor=para_7.2.34&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r287": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "109",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_109&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r288": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "109A",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_109A&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r289": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "113",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_113_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r29": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "66",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_66&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r290": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "120",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_120&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r291": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "124",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_124&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r292": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "125",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_125&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r293": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "127",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_127&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r294": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "128",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_128_a_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r295": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "128",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_128_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r296": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "132",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_132_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r297": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "96",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_96_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r298": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "96",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_96_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r299": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "17",
   "Paragraph": "C32",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2021-en-r&anchor=para_C32&doctype=Appendix&subtype=C",
   "URIDate": "2021-03-24"
  },
  "r3": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "104",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_104&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r30": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "68",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_68&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r300": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective 2023-01-01",
   "Number": "9",
   "Paragraph": "7.2.42",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2021-en-r&anchor=para_7.2.42&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r301": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective on first application of IFRS 9",
   "Number": "4",
   "Paragraph": "39L",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2021-en-b&anchor=para_39L_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r302": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective on first application of IFRS 9",
   "Number": "4",
   "Paragraph": "39L",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2021-en-b&anchor=para_39L_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r303": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Effective on first application of IFRS 9",
   "Number": "4",
   "Paragraph": "39M",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2021-en-b&anchor=para_39M&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r304": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "4",
   "Paragraph": "39J",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2021-en-b&anchor=para_39J&doctype=Standard&book=b",
   "URIDate": "2021-03-24"
  },
  "r305": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "7",
   "Paragraph": "22",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_22&doctype=Standard&book=b",
   "URIDate": "2021-03-24"
  },
  "r306": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "7",
   "Paragraph": "23",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_23_c&doctype=Standard&book=b",
   "URIDate": "2021-03-24"
  },
  "r307": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "7",
   "Paragraph": "23",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_23_d&doctype=Standard&book=b",
   "URIDate": "2021-03-24"
  },
  "r308": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "7",
   "Paragraph": "37",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_37_b&doctype=Standard&book=b",
   "URIDate": "2021-03-24"
  },
  "r309": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "7",
   "Paragraph": "8",
   "Subparagraph": "f",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_8_f&doctype=Standard&book=b",
   "URIDate": "2021-03-24"
  },
  "r31": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "69",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_69&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r310": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "7",
   "Paragraph": "IG29",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_IG29_a&doctype=Implementation%20Guidance&book=b",
   "URIDate": "2021-03-24"
  },
  "r311": {
   "IssueDate": "2021-01-01",
   "Name": "IFRS",
   "Note": "Expiry date 2023-01-01",
   "Number": "7",
   "Paragraph": "IG29",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_IG29&doctype=Implementation%20Guidance&book=b",
   "URIDate": "2021-03-24"
  },
  "r312": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12"
  },
  "r313": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r314": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r315": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r316": {
   "Name": "Form 10-K",
   "Number": "249",
   "Publisher": "SEC",
   "Section": "310"
  },
  "r317": {
   "Name": "Form 20-F",
   "Number": "249",
   "Publisher": "SEC",
   "Section": "220",
   "Subsection": "f"
  },
  "r318": {
   "Name": "Form 20-F",
   "Publisher": "SEC",
   "Section": "Item 18",
   "Subsection": "Instruction 2"
  },
  "r319": {
   "Name": "Form 40-F",
   "Number": "249",
   "Publisher": "SEC",
   "Section": "240",
   "Subsection": "f"
  },
  "r32": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "7",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_7&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r320": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1204",
   "Subparagraph": "(1)"
  },
  "r321": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1204",
   "Subparagraph": "(2)"
  },
  "r322": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r323": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(m)",
   "Publisher": "SEC",
   "Section": "4",
   "Subparagraph": "(1)(iii)",
   "Subsection": "08"
  },
  "r33": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "70",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_70&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r34": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "78",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_78_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r35": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "78",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_78_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r36": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "78",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_78&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r37": {
   "Clause": "iv",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "79",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_79_a_iv&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r38": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "79",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_79_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r39": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "81A",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_81A_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r4": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "106",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_106_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r40": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "81A",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_81A_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r41": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "81A",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_81A_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r42": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "82",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r43": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "82",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r44": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "82",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r45": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "85",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_85&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r46": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "90",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_90&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r47": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "91",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_91_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r48": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "91",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_91_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r49": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "92",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_92&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r5": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "106",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_106_d_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r50": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "99",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_99&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r51": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "IG6",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_IG6&doctype=Implementation%20Guidance",
   "URIDate": "2021-03-24"
  },
  "r52": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "10",
   "Paragraph": "21",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=10&code=ifrs-tx-2021-en-r&anchor=para_21&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r53": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "10",
   "Paragraph": "22",
   "Subparagraph": "h",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=10&code=ifrs-tx-2021-en-r&anchor=para_22_h&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r54": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "79",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_79&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r55": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "80",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_80_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r56": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "Subparagraph": "ab",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_ab&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r57": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_c_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r58": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_c_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r59": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r6": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "106",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_106_d_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r60": {
   "Clause": "i",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_g_i&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r61": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_g_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r62": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "Subparagraph": "g",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81_g&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r63": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Paragraph": "81",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&anchor=para_81&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r64": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "12",
   "Section": "Disclosure",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IAS12_g79-88_TI",
   "URIDate": "2021-03-24"
  },
  "r65": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "37",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_37&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r66": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "73",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r67": {
   "Clause": "ii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "73",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73_e_ii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r68": {
   "Clause": "vii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "73",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73_e_vii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r69": {
   "Clause": "viii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "73",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73_e_viii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r7": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "106",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_106&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r70": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "73",
   "Subparagraph": "e",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73_e&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r71": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "73",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_73&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r72": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "75",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_75_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r73": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Paragraph": "75",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&anchor=para_75_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r74": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "16",
   "Section": "Disclosure",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IAS16_g73-79_TI",
   "URIDate": "2021-03-24"
  },
  "r75": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "19",
   "Paragraph": "138",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_138_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r76": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "19",
   "Paragraph": "138",
   "Subparagraph": "d",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_138_d&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r77": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "19",
   "Paragraph": "142",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_142&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r78": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "19",
   "Paragraph": "147",
   "Subparagraph": "c",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_147_c&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r79": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "2",
   "Paragraph": "36",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=2&code=ifrs-tx-2021-en-r&anchor=para_36_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r8": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "106A",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_106A&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r80": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "2",
   "Paragraph": "36",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=2&code=ifrs-tx-2021-en-r&anchor=para_36_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r81": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "2",
   "Paragraph": "37",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=2&code=ifrs-tx-2021-en-r&anchor=para_37&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r82": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "2",
   "Section": "Disclosure",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=2&code=ifrs-tx-2021-en-r&doctype=Standard&dita_xref=IAS02_g36-39__IAS02_g36-39_TI",
   "URIDate": "2021-03-24"
  },
  "r83": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "20",
   "Paragraph": "39",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=20&code=ifrs-tx-2021-en-r&anchor=para_39_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r84": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "21",
   "Paragraph": "52",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=21&code=ifrs-tx-2021-en-r&anchor=para_52_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r85": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "23",
   "Paragraph": "26",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=23&code=ifrs-tx-2021-en-r&anchor=para_26_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r86": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "23",
   "Paragraph": "26",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=23&code=ifrs-tx-2021-en-r&anchor=para_26_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r87": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "24",
   "Paragraph": "17",
   "Subparagraph": "a",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2021-en-r&anchor=para_17_a&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r88": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "24",
   "Paragraph": "17",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2021-en-r&anchor=para_17&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r89": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "24",
   "Paragraph": "18",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2021-en-r&anchor=para_18&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r9": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "1",
   "Paragraph": "107",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_107&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r90": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "24",
   "Paragraph": "19",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2021-en-r&anchor=para_19&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r91": {
   "Clause": "iii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "26",
   "Paragraph": "35",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=26&code=ifrs-tx-2021-en-r&anchor=para_35_b_iii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r92": {
   "Clause": "vi",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "26",
   "Paragraph": "35",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=26&code=ifrs-tx-2021-en-r&anchor=para_35_b_vi&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r93": {
   "Clause": "viii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "26",
   "Paragraph": "35",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=26&code=ifrs-tx-2021-en-r&anchor=para_35_b_viii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r94": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "27",
   "Paragraph": "10",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_10&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r95": {
   "Clause": "iii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "27",
   "Paragraph": "16",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_16_b_iii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r96": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "27",
   "Paragraph": "16",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_16_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r97": {
   "Clause": "iii",
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "27",
   "Paragraph": "17",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_17_b_iii&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r98": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "27",
   "Paragraph": "17",
   "Subparagraph": "b",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_17_b&doctype=Standard",
   "URIDate": "2021-03-24"
  },
  "r99": {
   "IssueDate": "2021-01-01",
   "Name": "IAS",
   "Number": "33",
   "Paragraph": "66",
   "URI": "http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2021-en-r&anchor=para_66&doctype=Standard",
   "URIDate": "2021-03-24"
  }
 },
 "version": "2.1"
}
