Dividends declared Increase (Decrease) Through Dividends Declared Liabilities Arising From Financing Activities Increase decrease through dividends declared liabilities arising from financing activities. Schedule of Geographical Information Disclosure of geographical areas [text block] Items That may be Reclassified to Profit or Loss: Components of other comprehensive income that will be reclassified to profit or loss, net of tax [abstract] Fair value, beginning of year Fair value, end of year Risk management asset Financial assets, at fair value Stock Option Plan Stock Option Plan [Member] Stock option plan. Statistical Measurement [Domain] Statistical Measurement [Domain] Revolving Term Debt Non-current portion of other non-current borrowings Disclosure of geographical areas [line items] Disclosure of geographical areas [line items] Purchase of Common Shares Under NCIB Common Shares Repurchased, Under NCIB Common Shares Repurchased, Under NCIB Transfer from E&E (Note 11) Increase (decrease) in property, plant and equipment Disclosure Of Exploration And Evaluation Assets [Abstract] Disclosure of exploration and evaluation assets abstract. Major business combination Major business combination [member] Target net debt to adjusted EBITDA ratio Target Net Debt To Adjusted Earnings Before Interest Taxes Depreciation Depletion And Amortization Ratio Target net debt to adjusted earnings before interest taxes depreciation depletion and amortization ratio. Foreign Currency Translation Adjustment Reserve of exchange differences on translation [member] WCS and Condensate Differential WCS and Condensate Differential [Member] WCS and Condensate Differential Liabilities Incurred New provisions, other provisions Athabasca Oil Corporation Athabasca Oil Corporation [Member] Athabasca Oil Corporation Disclosure of detailed information about business combination [line items] Disclosure of detailed information about business combination [line items] Transportation And Storage Assets Transportation And Storage Assets [Member] Transportation And Storage Assets Business Combinations [Abstract] Business Combination [Abstract] Business Combinations [Abstract] Deferred Tax Expense (Recovery) Deferred tax expense (income) Fair Value of Contracts Realized During the Period Settlements Fair Value Measurement Assets Liabilities Including Discontinued Operations Settlements fair value measurement assets liabilities including discontinued operations. Levels of fair value hierarchy Levels of fair value hierarchy [domain] Operating Operating expense Preferred Shares Redeemed Number Of Common Shares Purchased And Cancelled, Amount Number Of Common Shares Purchased And Cancelled, Amount Classes of share capital [axis] Classes of share capital [axis] Common shares issued under stock option plans (in shares) Number of shares issued for stock options exercised (in shares) Number of share options exercised in share-based payment arrangement Total finance costs Finance Costs, Including Capitalized Interest Finance Costs, Including Capitalized Interest Settlement of Decommissioning Liabilities Payments For Decommissioning, Restoration And Rehabilitation Costs Payments For Decommissioning, Restoration And Rehabilitation Costs 3 Years Later than two years and not later than three years [member] Dividends paid, other shares Dividends paid, other shares Unrealized (Gain) Loss on Risk Management Adjustments for gains (losses) on change in fair value of derivatives Less: Current Portion Current Portion of Long-Term Debt Current portion of non-current borrowings Schedule of Reconciliation of Liabilities to Cash Flows from Financing Activities Disclosure of reconciliation of liabilities arising from financing activities [text block] Percentage of total consideration transferred Percentage Of Total Consideration Transferred Percentage Of Total Consideration Transferred Shareholders’ Equity Beginning balance Ending balance Equity Provisions for Onerous and Unfavourable Contracts Onerous contracts provision Property, Plant and Equipment, Net Property, plant and equipment Beginning balance Ending balance Property, plant and equipment Change in the fair value of equity instruments at FVOCI Other comprehensive income, net of tax, gains (losses) from investments in equity instruments Exploration and Evaluation Assets, Net Intangible exploration and evaluation assets Beginning Balance Ending Balance Intangible exploration and evaluation assets Purchased Product, Transportation and Blending Purchased Product, Transportation and Blending Purchased Product, Transportation and Blending Purchased Product, Transportation and Blending Schedule of Right of Use Assets, Net Disclosure of quantitative information about right-of-use assets [text block] Natural Gas and Other Revenue From Sale Of Natural Gas And Other Revenue From Sale Of Natural Gas And Other Disclosure of detailed information about borrowings [table] Disclosure of detailed information about borrowings [table] Number of share units, vested and exercised/paid out (in shares) Number of other equity instruments exercised or vested in share-based payment arrangement Disclosure Of Levels Of Fair Value Hierarchy [Line Items] Disclosure Of Levels Of Fair Value Hierarchy [Line Items] Disclosure of levels of fair value hierarchy. Number of shares issued in business combination Number Of Shares Issued In Business Combination Number Of Shares Issued In Business Combination Realized (Gain) Loss Realised gain (loss) [Member] Realised gain (loss) Maximum percentage of preferred stock upon issuance or outstanding of common stock Percentage Of Outstanding Shares Authorized For Issuance Percentage of outstanding shares authorized for issuance. Statement of changes in equity [line items] Statement of changes in equity [line items] Redemption of Preferred Shares Payment For Redemption Of Preferred Shares Payment For Redemption Of Preferred Shares Modifications Increase (decrease) in right-of-use assets Percentage of accounts receivable outstanding, less than 60 days Percentage Of Accounts Receivable Outstanding, Less than 60 Days Percentage Of Accounts Receivable Outstanding, Less than 60 Days Items That Will not be Reclassified to Profit or Loss: Components of other comprehensive income that will not be reclassified to profit or loss, net of tax [abstract] Schedule of Reconciliation of Changes in the Fair Value of Available for Sale Financial Assets Disclosure Of Reconciliation Of Changes In Fair Value Measurement Of Assets Explanatory [Table Text Block] Disclosure of reconciliation of changes in fair value measurement of assets. Number of share options, granted (in shares) Number of share options granted in share-based payment arrangement Downstream Downstream [Abstract] Downstream Schedule of Reconciliation of Changes in the Fair Value of Cenovus's Risk Management Assets and Liabilities Disclosure Of Reconciliation Of Changes In Fair Value Measurement Assets Liabilities Explanatory [Table Text Block] Disclosure of reconciliation of changes in fair value measurement assets liabilities. Disclosure of detailed information about property, plant and equipment [line items] Disclosure of detailed information about property, plant and equipment [line items] Capitalized Interest Capitalized Interest Capitalized Interest Disclosure of geographical areas [table] Disclosure of geographical areas [table] Accounts Receivable and Accrued Revenues Adjustments for decrease (increase) in trade accounts receivable Level 2 of fair value hierarchy Level 2 of fair value hierarchy [member] Disclosure of non-adjusting events after reporting period [abstract] Disclosure of non-adjusting events after reporting period [abstract] Dividends Paid Dividends paid, classified as financing activities Inflation rate Inflation Rate Inflation Rate Weighted average exercise price (in CAD per share) Weighted average exercise price of share options outstanding in share-based payment arrangement Provision for decommissioning, restoration and rehabilitation costs [abstract] Investment grade counterparties Investment Grade Counterparties [Member] Investment grade counterparties. Balance Sheets Statement of financial position [abstract] Distributed Under Employee Benefit Plan (in shares) Number Of Common Shares, Market Distributed, Shares Number Of Common Shares, Market Distributed, Shares DIVESTITURE Disclosure Of Divestitures [Text Block] Disclosure Of Divestitures Cover [Abstract] Purchase of Common Shares Under NCIB NCIB, shares redeemed, amount Payments to acquire or redeem entity's shares Maximum Maximum [Member] Disclosure Of Income Tax Expense Continuing Operations [Abstract] Disclosure Of Income Tax Expense Continuing Operations [Abstract] Disclosure of income tax expense continuing operations. Liabilities Divested Increase (decrease) through transfers and other changes, other provisions Exchange Rate Movements and Other Increase Decrease Of Lease Liabilities Through Foreign Currency Translation And Other Increase (decrease) of lease liabilities through foreign currency translation and other. Unrealized (Gain) Loss on Risk Management Unrealized (Gain) Loss Unrealised gain (loss) [Member] Unrealised gain (loss) Adjustment to purchase price allocation Measurement period adjustments recognised for particular assets, liabilities, non-controlling interests or items of consideration Schedule of Lease Liabilities Disclosure Of Lease Liabilities Explanatory [Table Text Block] Disclosure of lease liabilities explanatory. Other Other adjustments for non-cash items Total Current Liabilities Total Current Liabilities Current liabilities Maximum debt to capitalization ratio Maximum Debt To Capitalization Ratio Percentage The debt to capitalization ratio the company cannot exceed under the committed credit facility agreement. Pension and Other Post-Employment Benefit Plan Net Liabilities Of Defined Benefit Plan And Other Post Employment Benefit Plan Net liabilities of defined benefit plan and other post employment benefit plan. Investments in Equity-Accounted Affiliates Investments in joint ventures accounted for using equity method, noncurrent Investments in joint ventures accounted for using equity method, noncurrent Processing, Transportation and Storage Assets Processing, Transportation And Storage Assets [Member] Processing, Transportation And Storage Assets Proceeds From Divestitures Proceeds Adjustments From Disposal Of Oil And Gas Assets Proceeds (adjustments) from disposal of oil and gas assets. Inventories Current inventories Pension and Other Post-Employment Benefits Defined Benefit Pension Plan [Member] Defined benefit pension plan. Financing Activities Cash flows from (used in) financing activities [abstract] Disclosure of Derivative Financial Instruments [Line Items] Disclosure Of Derivative Financial Instruments [Line Items] Disclosure of derivative financial instruments. Dilutive effect of warrants (in shares) Dilutive effect of warrants on weighted average number of ordinary shares Inventories Adjustments for impairment loss (reversal of impairment loss) recognised in profit or loss, inventories Classes of liabilities [domain] Classes of liabilities [domain] Repurchase Agreements Payable Repurchase Agreements Payable [Member] Repurchase Agreements Payable Disclosure of quantitative information about right-of-use assets [line items] Disclosure of quantitative information about right-of-use assets [line items] Paid in Surplus Additional paid-in capital [member] U.S. to Canadian Dollar Exchange Rate U.S. to Canadian Dollar Exchange Rate [Member] U.S. to Canadian Dollar Exchange Rate Deferred Share Units Deferred Share Units [Member] Deferred share units. Revenues from Construction and Management Services Revenue from rendering of services, related party transactions Comprehensive Income (Loss) Comprehensive income Statement of changes in equity [abstract] Foreign Exchange Contracts Foreign Exchange Contracts [Member] Interest rate, foreign exchange or cross currency interest rate swap. Expenses Expenses Material income and expense [abstract] Retained earnings Retained earnings Schedule of Disclosure Of Net To Adjusted Funds Flow Explanatory Disclosure Of Net Debt To Adjusted Funds Flow Explanatory [Table Text Block] Disclosure Of Net Debt To Adjusted Funds Flow Explanatory Natural Gas Commodity Price Natural Gas Commodity Price [Member] Natural Gas Commodity Price Change in Fair Value of Contracts in Place, Beginning of Year Gains Losses On Change In Fair Value Of Contracts Gains losses on change in fair value of contracts. Shares Issued In Amount Under Arrangement Shares Issued In Amount Under Arrangement Shares Issued In Amount Under Arrangement BASIS OF PREPARATION AND STATEMENT OF COMPLIANCE Disclosure of basis of preparation of financial statements [text block] Change in Decommissioning Liabilities Increase Decrease Through Decommissioning Liabilities Property Plant And Equipment Increase decrease through decommissioning liabilities property plant and equipment. Disclosure Of Effect Of Changes In Foreign Exchange Rates Gain Loss [Table] Disclosure Of Effect Of Changes In Foreign Exchange Rates Gain Loss [Table] Disclosure of effect of changes in foreign exchange rates gain loss table. Net Change in Non-Cash Working Capital Increase Decrease In Working Capital Classified As Investing Activities Increase (decrease) in working capital classified as investing activities. Disclosure of detailed information about financial instruments [Line Items] Disclosure of detailed information about financial instruments [line items] Disclosure of detailed information about financial instruments [line items] Document Fiscal Period Focus Document Fiscal Period Focus Total Assets Assets Assets Number of share units, granted (in shares) Number of other equity instruments granted in share-based payment arrangement Purchased Under Employee Benefit Plan (in shares) Number Of Common Shares, Market Purchase, Shares Number Of Common Shares, Market Purchase, Shares Net Change in Investments and Other Other inflows (outflows) of cash, classified as investing activities Disclosure Of Components Of Tax Expense Income [Table] Disclosure Of Components Of Tax Expense Income [Table] Schedule disclosing information related to components of tax expense income. Percentage of consideration transferred in shares Percentage Of Consideration Transferred In Shares Percentage Of Consideration Transferred In Shares Less: Royalties Royalty expense Types of risks Types of risks [domain] Net Change in Non-Cash Working Capital Net Change in Non-Cash Working Capital Increase (Decrease) in Working Capital, Operating Activities Increase (Decrease) in Working Capital, Operating Activities Financial Instruments Financial Instruments [Axis] Financial instruments. Debt, fair value Fair Value Debt Carried At Amortized Cost Fair value debt carried at amortized cost. Number of share units, outstanding (in shares) Number of other equity instruments outstanding in share-based payment arrangement Credit risk Credit risk [member] Exchange Rate Movements and Other Increase (Decrease) Through Foreign Exchange And Other Movements Right Of Use Asset Net Earnings (Loss) – Basic Profit (loss), attributable to ordinary equity holders of parent entity, used in calculating basic earnings per share Depreciation, Depletion, Amortization and Exploration Expense Depreciation, Amortisation, Impairment And Exploration Loss (Reversal Of Impairment Loss) Recognised In Profit Or Loss Depreciation, Amortisation, Impairment And Exploration Loss (Reversal Of Impairment Loss) Recognised In Profit Or Loss Refining Assets Refining Assets [Member] Refining Assets Geographical [Domain] Geographical [Domain] Revenues Revenue Refined Products Refined Products [Member] Refined Products Common Shares Issued capital [member] Geographical areas [axis] Geographical areas [axis] Current borrowings Beginning balance, short-term borrowings Ending balance, short term borrowings Current borrowings Other Liabilities Other liabilities Other non-current liabilities Divestiture of Short-Term Borrowings Divestiture Of Short-Term Borrowings Divestiture Of Short-Term Borrowings Beginning balance, long-term debt Ending balance, long-term debt Liabilities arising from financing activities Private Equity Investments Reserve of gains and losses from investments in equity instruments [member] Dividends Paid Increase (decrease) through financing cash flows, liabilities arising from financing activities Canadian Dollar Unsecured Notes Canadian Dollar Unsecured Notes [Member] Canadian Dollar Unsecured Notes Lease Liabilities Non-current lease liabilities Disclosure of quantitative information about right-of-use assets [table] Disclosure of quantitative information about right-of-use assets [table] Common shares issued in exercise of other equity instruments (in shares) Common shares issued in exercise of other equity instruments Common shares issued in exercise of other equity instruments Net Debt Net Debt Net debt Disclosure of fair value measurement of assets [table] Disclosure of fair value measurement of assets [table] Schedule of Earnings Impact of (Gain) Loss from Risk Management Positions Disclosure Of Gains Losses On Change In Fair Value Of Derivatives Explanatory [Table Text Block] Disclosure of gains losses ​on change in fair value of derivatives. AOCI Accumulated other comprehensive income [member] Financial instruments measured at fair value through profit or loss because credit derivative is used to manage credit risk [domain] Financial instruments measured at fair value through profit or loss because credit derivative is used to manage credit risk [domain] Employee Long-Term Incentives Non Current Liabilities From Share Based Payment Transactions2011 Non current liabilities from share-based payment transactions 2011. Segments Segments [domain] Cash and Cash Equivalents Cash and Cash Equivalents, Beginning of Period Cash and Cash Equivalents, End of Period Less: Cash and Cash Equivalents Cash and cash equivalents Undrawn borrowing facilities, outstanding Undrawn Borrowing Facilities, Outstanding Undrawn Borrowing Facilities, Outstanding Capital Investment Purchase of exploration and evaluation assets, and property, plant, and equipment Purchase of exploration and evaluation assets, and property, plant, and equipment Divestitures Disposals, property, plant and equipment Disclosure of maturity analysis for derivative financial liabilities [table] Disclosure of maturity analysis for derivative financial liabilities [table] Purchase of Common Shares Under ASPP Common Shares Repurchased, Under ASPP Common Shares Repurchased, Under ASPP Disclosure of non-adjusting events after reporting period [line items] Disclosure of non-adjusting events after reporting period [line items] Joint operations [axis] Joint operations [axis] Assets Assets [abstract] Net Debt Premiums (Discounts) and Transaction Costs Debt Discounts And Transaction Costs Debt discounts and transaction costs. Commitments approved and not yet in service Commitments approved and not yet in service [Member] Commitments approved and not yet in service Beginning balance. dividend payables Ending balance. dividend payables Dividend payables Basis Of Preparation And Statement Of Compliance [Abstract] Basis of preparation and statement of compliance. Shares available for future issuance (in shares) Number of shares reserved for issue under options and contracts for sale of shares Foreign Exchange Gains Losses: Foreign Exchange Gains Losses [Abstract] Foreign exchange gains losses. Upstream Upstream [Member] Upstream. Schedule of Short-Term and Long-Term Debt Disclosure of detailed information about borrowings [text block] Total Liabilities and Equity Equity and liabilities Committed Credit Facilities, Maturing November 10, 2026 Committed Credit Facilities, Maturing November 10, 2026 [Member] Committed Credit Facilities, Maturing November 10, 2026 United States UNITED STATES Exchange Rate Movements Increase (decrease) through net exchange differences, other provisions Business combinations [axis] Business combinations [axis] Types Of Financial Instruments Types Of Financial Instruments [Axis] Types of financial instruments. Schedule of Exploration and Valuation Assets, Net Disclosure Of Changes In Exploration And Evaluation Assets Explanatory [Table Text Block] Disclosure ​of changes in exploration​ and ​evaluation ​assets. Other financial positions Other Financial Positions [Member] Other financial positions. External credit grades [axis] External credit grades [axis] Potential ordinary share transactions Potential ordinary share transactions [member] Business combinations Business combinations [domain] Current Assets Current assets [abstract] Series 1 And 2 First Preferred Shares Series 1 And 2 First Preferred Shares [Member] Series 1 And 2 First Preferred Shares Revenues Revenue [abstract] Disclosure of analysis of single amount of discontinued operations [line items] Disclosure of analysis of single amount of discontinued operations [line items] Schedule of Finance Cost Disclosure of finance cost [text block] Disclosure of Nature and Extent of Risks Arising from Financial Instruments [Line Items] Disclosure of nature and extent of risks arising from financial instruments [line items] Balance at beginning of period Balance at end of period Accumulated Depreciation Right Of Use Asset Joint Operations Receivables Current Joint Operations Receivables Current joint operations receivables. General and Administrative General and Administrative Expenses General and administrative expense Expired Common Shares Issued In Amount Upon Expired of Warrants Common Shares Issued In Amount Upon Expired of Warrants E&E Assets Exploration and evaluation assets [member] Product and Service [Domain] Product and Service [Domain] U.S. Dollar Debt Long-Term Debt Long-term borrowings [member] Purchased Product Raw materials and consumables used Intersegment Sales Intersegment Sales [Member] Intersegment Sales Crude Oil and Natural Gas Properties Oil and gas assets [member] Credit facilities, maximum borrowing capacity Borrowing Facilities, Maximum Borrowing Capacity Borrowing Facilities, Maximum Borrowing Capacity Joint ventures Joint ventures [domain] Joint operations Joint operations [domain] Number of ethanol plants Number Of Ethanol Plants Number Of Ethanol Plants Disclosure of related party [Abstract] Disclosure of related party [Abstract] Disclosure of related party [Abstract] Exchange Rate Movements and Other Increase (decrease) through effect of changes in foreign exchange rates, liabilities arising from financing activities Crude Oil, Natural Gas, Condensate and Refined Products Crude Oil, Natural Gas, Condensation, and Refined Products [Member] Crude Oil, Natural Gas, Condensation, and Refined Products Disclosure of accumulated other comprehensive income loss [line items] Disclosure Of Accumulated Other Comprehensive Income Loss [Line Items] Disclosure of accumulated other comprehensive income loss. Exploration Expense Write-downs Expense arising from exploration for and evaluation of mineral resources Unrealized Foreign Exchange (Gain) Loss Unrealized Foreign Exchange Gain Loss Unrealized foreign exchange gain loss. Unwinding of Discount on Decommissioning Liabilities (Note 6) Increase through adjustments arising from passage of time, other provisions Divestitures Right Of Use Asset, Divestitures Right Of Use Asset, Divestitures Depreciation, Depletion and Amortization Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss Corporate and Eliminations Corporate and Eliminations Corporate And Eliminations Segment [Member] Corporate and eliminations segment. Power Swap Contracts Power Swap Contracts [Member] Power Swap Contracts Stock-Based Compensation Expense (Recovery) Expense Recovery From Share Based Payment Transactions Expense (recovery) from share-based payment transactions. Thereafter Later than five years [member] Investing Activities Cash flows from (used in) investing activities [abstract] Deferred Income Tax Expense (Recovery) Adjustments for deferred tax expense Commodity price risk Commodity price risk [member] RELATED PARTY TRANSACTIONS Disclosure of related party [text block] Disclosure Of Supplementary Cash Flow Information [Line Items] Disclosure Of Supplementary Cash Flow Information [Line Items] Disclosure Of Supplementary Cash Flow Information [Line Items] Disclosure Of Recurring Fair Value Measurement Of Assets And Liabilities [Line Items] Disclosure Of Recurring Fair Value Measurement Of Assets And Liabilities [Line Items] Disclosure of recurring fair value measurement of assets and liabilities. Dividends declared (in CAD per share) Dividends proposed or declared before financial statements authorised for issue but not recognised as distribution to owners per share Disclosure Of Reportable Segments [Table] Disclosure Of Reportable Segments [Table] Disclosure of reportable segments. Gasoline Revenue From Sale Of Gasoline Revenue From Sale Of Gasoline U.S Refining U.S Refining [Member] U.S Refining Conventional Conventional Conventional Segment [Member] Conventional. Schedule of Undiscounted Cash Outflows Relating to Financial Liabilities Disclosure Of Maturity Analysis For Derivative And Non Derivative Financial Liabilities Explanatory [Table Text Block] Level 3 of fair value hierarchy Level 3 of fair value hierarchy Level 3 of fair value hierarchy [member] Number of instruments or interests issued or issuable Number of instruments or interests issued or issuable Atlantic Region Atlantic Region [Member] Atlantic Region Income Tax (Expense) Recovery Income tax relating to components of other comprehensive income (Gain) Loss on Risk Management Gains (losses) on change in fair value of derivatives Interest Expense – Lease Liabilities (Note 13) Interest expense on lease liabilities Repayment of Long-Term Debt Repayments of non-current borrowings Stock-Based Compensation Expense Increase (decrease) through share-based payment transactions, equity Decommissioning Liabilities Beginning balance Ending balance Provision for decommissioning, restoration and rehabilitation costs Lease liabilities [abstract] Disclosure of classes of share capital [table] Disclosure of classes of share capital [table] Foreign Currency Translation Adjustment Other comprehensive income, net of tax, exchange differences on translation of foreign operations Number of other equity instruments exercised or vested in share-based payment arrangement, settled for common shares (in shares) Number of other equity instruments exercised or vested in share-based payment arrangement, settled for common shares Number of other equity instruments exercised or vested in share-based payment arrangement, settled for common shares Finance Costs, Net Disclosure Of Borrowing Costs Netof Discount Premium On Redemptions [Text Block] The disclosure of borrowing costs net of (discount) premium on redemptions. WTI Fixed - Buy West Texas Intermediate Fixed Buy [Member] West texas intermediate fixed buy. RINs included in other liabilities, gross RINs Included In Other Liabilities, Gross RINs Included In Other Liabilities, Gross Effect of Stock-Based Compensation Adjustment To Profit (Loss) For Stock Based Compensation, Value Adjustment To Profit (Loss) For Stock Based Compensation, Value Effect of Cumulative Dividends on Preferred Shares Adjustment to profit (loss) for preference share dividends Net Change in Non-Cash Working Capital – Investing Activities Increase (Decrease) in Working Capital from Investing Activities Increase (Decrease) in Working Capital from Investing Activities Classes of property, plant and equipment [axis] Classes of property, plant and equipment [axis] Foreign Exchange (Gain) Loss, Net Foreign Exchange (Gain) Loss, Net Total Foreign exchange gain (loss) Schedule of Capital Expenditures Disclosure Of Additions To Noncurrent Assets By Reportable Segments Explanatory [Table Text Block] Disclosure​ of additions to noncurrent assets​ by reportable​ segments​. Proceeds From Exercise of Warrants Proceeds from exercise of warrants Classes of property, plant and equipment [domain] Classes of property, plant and equipment [domain] Other (Income) Loss, Net Other gains (losses) SUPPLEMENTARY CASH FLOW INFORMATION Disclosure Of Supplementary Cash Flow Information Explanatory [Text Block] Disclosure of supplementary cash flow information. Weighted Average Price Weighted Average Price Of Financial Instrument Weighted average price of financial instrument. Husky Midstream Limited Partnership Husky Midstream Limited Partnership [Member] Husky Midstream Limited Partnership [Member] Accounts Receivable and Accrued Revenues Disclosure of trade and other receivables [text block] U.S. Dollar Denominated Unsecured Notes U S Dollar Denominated Unsecured Notes [Member] US dollar denominated unsecured notes. Common Shares Issued Under Employee Benefit Plan Common Shares Issued Under Employee Benefit Plan Common Shares Issued Under Employee Benefit Plan Accounts Payable and Accrued Liabilities Adjustments For Increase (Decrease) in Accounts Payable And Accrued Liabilities Adjustments For Increase (Decrease) in Accounts Payable And Accrued Liabilities Capital Investment Additions Other Than Through Business Combinations Property Plant And Equipment And Exploration And Evaluation Assets Additions other than through business combinations property plant and equipment and exploration and evaluation assets. Crude Oil Revenue from sale of crude oil Effect of Foreign Exchange on Cash and Cash Equivalents Effect of exchange rate changes on cash and cash equivalents Series Of Share Capital Shares [Axis] Series Of Share Capital Shares [Axis] Series Of Share Capital Shares [Axis] Proceeds from disposal of oil and gas assets Proceeds from disposal of oil and gas assets Cash From (Used in) Operating Activities Cash From (Used in) Operating Activities Cash flows from (used in) operating activities Fair value of derivative financial instruments Fair Value Of Derivative Financial Instruments Fair Value Of Derivative Financial Instruments Disclosure of terms and conditions of share-based payment arrangement [Line Items] Disclosure of terms and conditions of share-based payment arrangement [line items] Disclosure of contingent liabilities in business combination [line items] Disclosure of contingent liabilities in business combination [line items] BP Canada BP Canada [Member] BP Canada Total Capital Expenditures Increase (decrease) in property, plant and equipment, and exploration and evaluation assets Increase (decrease) in property, plant and equipment, and exploration and evaluation assets STOCK-BASED COMPENSATION PLANS Disclosure of share-based payment arrangements [text block] Disclosure of detailed information about financial instruments [table] Disclosure of detailed information about financial instruments [table] Renewable Power Contracts Renewable Power Contracts [Member] Renewable Power Contracts Geographical areas Geographical areas [domain] (Gain) Loss on Divestiture of Assets Adjustments for losses (gains) on disposal of non-current assets Real Estate Real Estate Lease [Member] Real Estate Lease Other Products and Services Revenue From Sale Of Other Products And Services Revenue From Sale Of Other Products And Services Document Fiscal Year Focus Document Fiscal Year Focus Accounts Receivable and Accrued Revenues Accounts Receivable and Accrued Revenues Trade and other current receivables Preferred Shares Redeemed Preferred Shares Redeemed Preferred Shares Redeemed RISK MANAGEMENT Disclosure of financial risk management [text block] Risk Management [Abstract] Disclosure of derivative financial instruments. Schedule of Other Liabilities Disclosure of other liabilities [text block] Gross Sales Gross Sales Revenue From Gross Sales Income before the deduction of royalty expense. Average crude oil price Average Crude Oil Price Average crude oil price. Levels of fair value hierarchy [axis] Levels of fair value hierarchy [axis] U.S. Refining U.S Manufacturing [Member] U.S Manufacturing Finance Costs, Net Finance Costs, Net Finance costs Finance costs Income Tax Payable Adjustments for income tax expense Preferred Shares, Price Per Share Preferred Shares, Price Per Share Preferred Shares, Price Per Share Acquisitions Acquisitions through business combinations, property, plant and equipment Schedule of Assets by Segment Disclosure Of Assets By Reportable Segments Explanatory [Table Text Block] Disclosure​ of assets​ by reportable​ segments​. Net Debt to Adjusted Funds Flow (times) Net Debt To Adjusted Funds Flow Net Debt To Adjusted Funds Flow Weighted average exercise price of other equity instruments exercised or vested in share-based payment arrangement, settled for common shares (in CAD per share) Weighted average exercise price of other equity instruments exercised or vested in share-based payment arrangement, settled for common shares Weighted average exercise price of other equity instruments exercised or vested in share-based payment arrangement, settled for common shares GENERAL AND ADMINISTRATIVE General And Administrative Expense Explanatory [Text Block] General and administrative expense. NCIB, reduction to retained earnings Share Repurchase Program, Reduction To Retained Earnings Share Repurchase Program, Reduction To Retained Earnings Number of shares authorized (in shares) Share Repurchase Program, Authorized, Number of Shares Schedule of Changes in Inputs to Option Pricing Model, Resulted in Unrealized Gains (Losses) Impacting Earnings Before Income Tax Sensitivity analysis for types of market risk [text block] Number of Common Shares Number of Warrants Number of shares issued [abstract] Customer [Domain] Customer [Domain] Entity Central Index Key Entity Central Index Key Other Other finance cost Number of share options, outstanding (in shares) Number of share options outstanding in share-based payment arrangement Common shares Ordinary shares [member] Common Share Warrants Common Share Warrants [Member] Common Share Warrants Commitments And Contingencies [Abstract] Commitments And Contingencies [Abstract] Commitments And Contingencies [Abstract] Transaction costs Acquisition-related costs for transaction recognised separately from acquisition of assets and assumption of liabilities in business combination PER SHARE AMOUNTS Disclosure of earnings per share [text block] COST Gross carrying amount [member] Accounts Payable and Accrued Liabilities Trade and other current payables Liabilities and Equity Equity and liabilities [abstract] Unwinding of Discount on Decommissioning Liabilities Adjustments for finance costs Common Shares Issued Under Stock Option Plans Proceeds from issuing shares Less than 1 Year Remainder of Year Not later than one year [member] Disclosure Of Exploration And Evaluation Assets [Line Items] Disclosure Of Exploration And Evaluation Assets [Line Items] Disclosure of exploration and evaluation assets line items. Disclosure of detailed information about property, plant and equipment [abstract] Additions Additions other than through business combinations, property, plant and equipment Changes in Fair Value Increase (decrease) in fair value measurement, assets Credit-adjusted risk-free rate Credit Adjusted Risk Free Rate Credit adjusted risk free rate. Trade and other current receivables [abstract] Other Other current receivables Purchase of Common Shares Under Employee Benefit Plan Purchase Of Equity, Common Shares Under Employee Benefit Plan Purchase Of Equity, Common Shares Under Employee Benefit Plan Other Long-Term Commitments Other long term commitments Other long term commitments Preferred shares redeemed (in shares) Number Of Common Shares Purchased And Cancelled, Shares Number Of Common Shares Purchased And Cancelled, Shares Long-Term Debt Long-Term Portion of Long-Term Debt Non-current portion of non-current borrowings Property, Plant and Equipment Property, plant and equipment [member] Cash transferred Cash transferred Deferred Income Taxes Net deferred tax liabilities Total Purchase Consideration Consideration transferred, acquisition-date fair value LEASES Disclosure of leases [text block] Proceeds on Repurchase Agreements Proceeds from borrowings, classified as financing activities Disclosure of Maturity Analysis for Financial Liabilities [Line Items] Disclosure Of Maturity Analysis For Financial Liabilities [Line Items] Principal Repayment of Leases Principal Repayment of Leases Payments of lease liabilities, classified as financing activities Renewable volume obligation, net Other Liabilities, Renewable Volume Obligation, Net Other Liabilities, Renewable Volume Obligation, Net Schedule of Minimum Future Payments, Commitments And Contingent Liabilities Minimum Future Payments, Commitments And Contingent Liabilities [Table Text Block] Minimum Future Payments, Commitments And Contingent Liabilities MEG ENERGY CORP. ACQUISITION Disclosure of business combinations [text block] Entity Registrant Name Entity Registrant Name Net earnings (loss) per share — basic (CAD per share) Net earnings (loss) per common share — basic (CAD per share) Basic earnings (loss) per share Unrealized Foreign Exchange (Gain) Loss Adjustments for unrealised foreign exchange losses (gains) Stock Options With Associated Net Settlement Rights Net Settlement Rights [Member] Net settlement rights. Disclosure of risk management strategy related to hedge accounting [table] Disclosure of risk management strategy related to hedge accounting [table] Statement of cash flows [abstract] Diluted – weighted average number of shares (in shares) Weighted average number of ordinary shares used in calculating diluted earnings per share (Gain) Loss on Divestiture of Assets Revaluation Gains (Losses) Revaluation Gains (Losses) Beginning balance Ending balance Accumulated other comprehensive income Unwinding of Discount on Decommissioning Liabilities (Note 15) Expense arising from passage of time on other provisions Number of share units, exercisable (in shares) Number of other equity instruments exercisable in share-based payment arrangement External Sales External Sales [Member] External Sales Schedule of Foreign Exchange Gain Loss Net Disclosure Of Effect Of Changes In Foreign Exchange Rates Gain Loss Explanatory [Table Text Block] The disclosure of effect of changes in foreign exchange rates gain loss explanatory. General And Administrative Expenses [Abstract] General and administrative expenses. Financial instruments measured at fair value through profit or loss because credit derivative is used to manage credit risk [axis] Financial instruments measured at fair value through profit or loss because credit derivative is used to manage credit risk [axis] Renewed NCIB Renewed NCIB [Member] Renewed NCIB Net Debt to Capitalization (percent) Net Debt To Capitalization Net debt to capitalization. Series 2 First Preferred Shares Series 2 Preferred Shares [Member] Series 2 Preferred Shares [Member] Restricted Cash Non-current restricted cash and cash equivalents Non-Controlling Interest Non-controlling interests Current Liabilities Current liabilities [abstract] Performance Share Units Performance Share Units [Member] Performance share units. Warrants Warrants [member] Depreciation, Depletion and Amortization Adjustments for depreciation and amortisation expense and impairment loss (reversal of impairment loss) recognised in profit or loss Disclosure of detailed information about financial instruments [abstract] Series 1 Preferred Shares Series 1 Preferred Shares [Member] Series 1 Preferred Shares [Member] ACCUMULATED DEPRECIATION Accumulated Depreciation [Member] Disclosure of fair value measurement of assets [Line Items] Disclosure of fair value measurement of assets [line items] Disclosure of transactions between related parties [line items] Disclosure of transactions between related parties [line items] Adjusted funds flow Adjusted Funds Flow Adjusted Funds Flow Repurchase Agreements Payable - RINs Repurchase Agreements Payable - RINs [Member] Repurchase Agreements Payable - RINs Notional Volumes Financial Instruments Notional Volume Financial​ instruments​​ notional​ volume. Other Comprehensive Income (Loss), Net of Tax Other comprehensive income [abstract] Salaries and Benefits Salaries and benefits Salaries and benefits Canada CANADA Taxes paid Share Repurchase Program, Reduction To Contributed Surplus, Taxes Paid Share Repurchase Program, Reduction To Contributed Surplus, Taxes Paid Proportion of ownership interest in joint operation Proportion of ownership interest in joint operation Purchase of Common Shares Under Employee Benefit Plan Purchase Of Common Shares Under Employee Benefit Plan Purchase Of Common Shares Under Employee Benefit Plan Real Estate Real Estate Commitments Real Estate Commitments Five Point Three Eight Percentage Due July 15, 2025 Five Point Three Eight Percentage Due July Fifteen Two Thousand Twenty Five [Member] 5.38% due July 15, 2025. Financial instruments Non-derivative financial liabilities, undiscounted cash flows Amount Value of shares issued [Abstract] Value of shares issued Classes of share capital Classes of share capital [domain] Canadian Refining Canadian Manufacturing [Member] Canadian Manufacturing Purchased Under Employee Benefit Plan Number Of Common Shares, Market Purchase, Amount Number Of Common Shares, Market Purchase, Amount China CHINA Schedule of Accumulated Other Comprehensive Income (Loss) Disclosure Of Accumulated Other Comprehensive Income Loss Explanatory [Table Text Block] Disclosure of accumulated other comprehensive income loss. Miscellaneous non-current liabilities [abstract] Summary of General and Administrative Expenses Disclosure of general and administrative expense [text block] Integration, Transaction and Other Costs Integration costs Integration costs Additions Additions to right-of-use assets Schedule of Decommissioning Provision Disclosure of other provisions [text block] Acquisitions, Net of Cash Acquired Acquisition Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities Obligation to Fund HCML Commitments in relation to joint ventures Other Comprehensive Income (Loss), Before Tax Other comprehensive income, before tax Dilutive effect for stock based compensation (in shares) Dilutive effect of contingently issuable shares on weighted average number of ordinary shares ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Disclosure of analysis of other comprehensive income by item [text block] Disclosure Of Accumulated Other Comprehensive Income Loss [Abstract] Disclosure of accumulated other comprehensive income loss. WTI Fixed - Sell West Texas Intermediate Fixed Sell [Member] West texas intermediate fixed sell. Lease Payments Cash outflow for leases Other International Other International [Member] Other International Disclosure Of Supplementary Cash Flow Information [Abstract] Disclosure of supplementary cash flow information abstract. Other Others [Member] Others. Disclosure of contingent liabilities in business combination [abstract] DEBT AND CAPITAL STRUCTURE Disclosure Of Borrowings And Capital Structure Explanatory [Text Block] The entire disclosure of borrowings and capital structure. Lease liabilities Beginning balance, lease liabilities Ending balance, lease liabilities Lease liabilities Exchange Rate Movements and Other Increase Decrease Through Foreign Exchange And Other Movements Assets Finance and Transaction Costs Increase (decrease) through other changes, liabilities arising from financing activities Net Issuance (Repayment) of Short-Term Borrowings Cash flows from (used in) increase (decrease) in current borrowings Types of financial liabilities [axis] Types of financial liabilities [axis] Share Repurchase, By Plan [Axis] Share Repurchase, By Plan [Axis] Share Repurchase, By Plan Dividends Payable Dividends Payable [Member] Dividends payable. Crude Oil Contracts Crude Oil Contracts [Member] Crude oil contracts. Other Assets Retail And Other Assets [Member] Retail And Other Assets Acquisitions Purchases, fair value measurement, assets Major Components Of Tax Expense Income [Line Items] Major Components Of Tax Expense Income [Line Items] Major components of tax expense income. Net Earnings (Loss) – Diluted Profit (loss), attributable to ordinary equity holders of parent entity, used in calculating diluted earnings per share Total Liabilities Liabilities Additions Lease Additions Lease Addition Lease addition. Outstanding, Beginning of Year Outstanding, End of Period Issued capital Refining Assets Manufacturing Assets [Member] Manufacturing Assets Disclosure of reconciliation of liabilities arising from financing activities [line items] Disclosure of reconciliation of liabilities arising from financing activities [line items] Disclosure Of Commitments And Contingent Liabilities [Line Items] Disclosure Of Commitments And Contingent Liabilities [Line Items] Disclosure Of Commitments And Contingent Liabilities [Line Items] Common Shares Issued Under Stock Option Plans Increase (decrease) through exercise of options, equity Realized Foreign Exchange (Gain) Loss Realized Foreign Exchange Gain Loss Realized foreign exchange (gain) loss. Transportation and storage Contractual Commitments For Transportation and Storage Contractual Commitments For Transportation and Storage Disclosure of contingent liabilities in business combination [table] Disclosure of contingent liabilities in business combination [table] Capitalization Net Debt And Equity Net debt and equity. Income Tax Payable Current tax liabilities, current Financial liabilities at amortised cost Financial liabilities at amortised cost Exercise price of warrants issued (in CAD per share) Exercise price, share options granted Risk management net asset (liability) Fair value of derivative financial instruments net As at December 31, 2025 As at September 30, 2026 Fair Value Of Derivative Financial Instruments Net Fair value of derivative financial instruments net. Shares outstanding (in shares) Outstanding, Beginning of Year (in shares) Outstanding, End of Period (in shares) Number of shares outstanding Net Cash Provided (Used) Before Financing Activities Net Cash From Used In Before Financing Activities Net cash from (used in) before financing activities. Disclosure Of Accumulated Other Comprehensive Income Loss [Table] Disclosure Of Accumulated Other Comprehensive Income Loss [Table] Disclosure of accumulated other comprehensive income loss. Net Issuance (Repayment) of Short-Term Borrowings Net Issuance (Repayment) Of Short Term Borrowings Net issuance (repayment) of short-term borrowings. Types of financial liabilities Types of financial liabilities [domain] Products and services [axis] Products and services [axis] Disclosure of nature and extent of risks arising from financial instruments [table] Disclosure of nature and extent of risks arising from financial instruments [table] Income Tax Expense (Recovery) Tax Expense (Recovery) From Continuing Operations Tax expense (income) Lease Liabilities Lease liabilities [member] SUBSEQUENT EVENT Disclosure of events after reporting period [text block] Schedule of Stock-Based Compensation Explanation Of Effect Of Share Based Payments On Profit Or Loss And Financial Positions Explanatory [Table Text Block] Explanation of effect of share-based payments on profit or loss and financial positions. Net Change in Non-Cash Working Capital – Operating Activities Increase (Decrease) in Working Capital from Operating Activities Increase (Decrease) in Working Capital from Operating Activities Operating Activities Cash flows from (used in) operating activities [abstract] DECOMMISSIONING LIABILITIES Disclosure of other provisions, contingent liabilities and contingent assets [text block] OTHER LIABILITIES Disclosure of other non-current liabilities [text block] Number of voting equity interests acquired, amount Number Of Voting Equity Interests Acquired, Amount Number Of Voting Equity Interests Acquired, Amount Decrease Theoretical Impact To Profit Loss From Decrease In Commodity Sensitivity Theoretical impact to profit loss from decrease in commodity sensitivity. Other Other Noncurrent Liabilities, Other Other noncurrent liabilities other. Risk management liability Financial liabilities, at fair value Document Period End Date Document Period End Date Interest Rate Contracts Or Cross Currency Interest Rate Swaps Interest Rate Contracts Or Cross Currency Interest Rate Swaps [Member] Interest Rate Contracts Or Cross Currency Interest Rate Swaps Current Tax Expense (Recovery) Current tax expense (income) Non-adjusting events after reporting period [axis] Non-adjusting events after reporting period [axis] Non-adjusting events after reporting period Non-adjusting events after reporting period [domain] Disclosure of classes of share capital [Line Items] Disclosure of classes of share capital [line items] FOREIGN EXCHANGE (GAIN) LOSS, NET Disclosure of effect of changes in foreign exchange rates [text block] Maturity [axis] Maturity [axis] Contingent Payments Disclosure of contingent liabilities in business combination [text block] Maximum Top of range [member] Schedule of Unrealized Risk Management Positions Disclosure Of Fair Value Measurement Of Assets Liabilities Explanatory [Table Text Block] Disclosure of fair value measurement of assets liabilities. Classes of financial instruments [axis] Classes of financial instruments [axis] Goodwill Goodwill Other Assets Other non-current assets Exchange Rate Movements and Other Increase (decrease) through other changes, property, plant and equipment 4 Years Later than three years and not later than four years [member] Net Proceeds (Repayments) on Repurchase Agreements Proceeds (Repayments) From Borrowings, Classified As Financing Activities Proceeds (Repayments) From Borrowings, Classified As Financing Activities Actuarial Gain (Loss) Relating to Pension and Other Post-Employment Benefits Other comprehensive income, net of tax, gains (losses) on remeasurements of defined benefit plans Document Type Document Type Stock-Based Compensation Expense (Recovery) Expense from share-based payment transactions with employees Product and Service [Axis] Product and Service [Axis] Term Loan Facility Non-current portion of non-current loans received Total Debt Principal, (CAD equivalent) Notes and debentures issued (Income) Loss From Equity-Accounted Affiliates Share of profit (loss) of joint ventures accounted for using equity method Profit or loss [abstract] Committed Credit Facilities, Maturing November 10, 2025 Committed Credit Facilities, Maturing November 10, 2025 [Member] Committed Credit Facilities, Maturing November 10, 2025 Statistical Measurement [Axis] Statistical Measurement [Axis] Disclosure of analysis of single amount of discontinued operations [table] Disclosure of analysis of single amount of discontinued operations [table] Working Capital Working Capital Working Capital Non-current assets Non-current assets other than financial instruments, deferred tax assets, post-employment benefit assets, and rights arising under insurance contracts Financial Instruments [Domain] Financial Instruments [Domain] Financial Instruments [Domain] Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Joint ventures [axis] Joint ventures [axis] Classes of assets [axis] Classes of assets [axis] HMLP HMLP [Member] HMLP Non-Cash Changes: Non-cash changes [Abstract] Non-cash changes Instruments excluded from calculation, shares (in shares) Instruments With Potential Future Dilutive Effect Not Included In Calculation Of Diluted Earnings Per Share, Shares Instruments With Potential Future Dilutive Effect Not Included In Calculation Of Diluted Earnings Per Share, Shares Schedule of Disclosure Of Changes In Non-Cash Working Capital Items Disclosure Of Changes In Non-Cash Working Capital Items [Table Text Block] Disclosure Of Changes In Non-Cash Working Capital Items 5 Years Later than four years and not later than five years [member] Series Of Share Capital Shares [Domain] Series Of Share Capital Shares [Domain] Series Of Share Capital Shares [Domain] Borrowings by name Borrowings by name [domain] Types of share-based payment arrangements Types of share-based payment arrangements [domain] Trade Receivables Trade receivables [member] Currency risk Currency risk [member] Net Earnings (Loss) Per Common Share ($) Earnings per share [abstract] Range [axis] Range [axis] Divestiture Proceeds Receivable (Note 8) Current receivables from sale of properties Schedule of Segment and Operational Information Disclosure Of Reportable Segments Explanatory [Table Text Block] Disclosure of reportable segments. Components of equity [axis] Components of equity [axis] Restricted Share Units Restricted share units [member] Issued Under the Arrangement, net of Issuance Costs (in shares) Number Of Shares Issued Under Arrangement Number Of Shares Issued Under Arrangement Cenovus Replacement Stock Options Cenovus Replacement Stock Options [Member] Cenovus Replacement Stock Options Purchase of Common Shares Under NCIB Repurchase Of Equity Repurchase Of Equity Geographical [Axis] Geographical [Axis] Earnings (Loss) Before Income Tax Earnings (Loss) Before Income Tax Profit (loss) before tax Total Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income (Loss), Net of Tax Other comprehensive income Classes of liabilities [axis] Classes of liabilities [axis] Fair Value Derivative Financial Instruments Fair Value Derivative Financial Instruments [Member] Fair Value Derivative Financial Instruments Lease Divestitures Lease Divestitures Lease Divestitures Treasury Shares Treasury shares [member] Disclosure Of Derivative Financial Instruments [Table] Disclosure Of Derivative Financial Instruments [Table] Disclosure of derivative financial instruments. Types of share-based payment arrangements [axis] Types of share-based payment arrangements [axis] Transportation commitments subject to regulatory approval or approved but not yet in service term Transportation Commitments Subject To Regulatory Approval Or Approved But Not Yet In Service Term Transportation Commitments Subject To Regulatory Approval Or Approved But Not Yet In Service Term Asia Pacific Asia Pacific [Member] SHARE CAPITAL AND WARRANTS Disclosure of share capital, reserves and other equity interest [text block] Distillates Revenue from sale of petroleum and petrochemical products Number of days outstanding for accruals, joint operations, trade receivables and net investment in finance leases Number Of Days Outstanding For Credit Exposures Using External Credit Grading System Number of days outstanding for credit exposures using external credit grading system. Disclosure Of Effect Of Changes In Foreign Exchange Rates Gain Loss [Line Items] Disclosure Of Effect Of Changes In Foreign Exchange Rates Gain Loss [Line Items] Disclosure of effect of changes in foreign exchange rates gain loss line items. Interest Expense – Short-Term Borrowings and Long-Term Debt Interest expense on borrowings Realized Foreign Exchange (Gain) Loss on Non-Operating Items Adjustments For Realised Foreign Exchange Losses Gains Adjustments for realised foreign exchange losses (gains). Joint ventures where entity is venturer Joint ventures where entity is venturer [member] Categories of related parties Categories of related parties [domain] Common Shares Issued Under Employee Benefit Plan Issue of equity Finance Costs [Abstract] Oil Sands Oil Sands Oil Sands Segment [Member] Oil sands segment. Sensitivity Range Change In Price Estimation Under Sensitivity Analysis Change in price estimation under sensitivity analysis. Classes of financial instruments Classes of financial instruments [domain] Disclosure of detailed information about business combination [table] Disclosure of detailed information about business combination [table] NGLs Revenue From Sale Of Natural Gas Liquids Revenue from sale of natural gas liquids. INCOME TAXES Disclosure Of Income Tax Expense Continuing Operations Explanatory [Text Block] The entire disclosure of income tax expense continuing operations. Distributions Received From Equity-Accounted Affiliates Distribution received from joint ventures accounted for using equity method Distribution received from joint ventures accounted for using equity method Disclosure of objectives, policies and processes for managing capital [table] Disclosure of objectives, policies and processes for managing capital [table] Products and services Products and services [domain] Repayment of Repurchase Agreements Repayments of borrowings, classified as financing activities Disclosure Of Levels Of Fair Value Hierarchy [Table] Disclosure Of Levels Of Fair Value Hierarchy [Table] Disclosure of levels of fair value hierarchy table. Issued Upon Exercise of Warrants Exercised Common Shares Issued In Amount Upon Exercise of Warrants Common Shares Issued In Amount Upon Exercise of Warrants Basic – weighted average number of shares (in shares) Weighted average number of ordinary shares used in calculating basic earnings per share Administrative and Other Administrative And Other Expenses Administrative and other expenses. Number of voting equity interests acquired (in shares) Number Of Voting Equity Interests Acquired, Shares Number Of Voting Equity Interests Acquired, Shares Disclosure Of Recurring Fair Value Measurement Of Assets And Liabilities [Table] Disclosure Of Recurring Fair Value Measurement Of Assets And Liabilities [Table] Disclosure Of Recurring Fair Value Measurement Of Assets And Liabilities table. Borrowings by name [axis] Borrowings by name [axis] Share Repurchase, By Plan [Domain] Share Repurchase, By Plan [Domain] Share Repurchase, By Plan [Domain] Modifications Lease Modifications Lease Modifications Schedule of Share Capital Disclosure of classes of share capital [text block] Schedule of Net Debt to Capitalization Disclosure Of Net Debt To Capitalization Explanatory [Table Text Block] Disclosure of net debt to capitalization. Total Debt Borrowings Schedule of Net Fair Value of Risk Management Positions Disclosure Of Fair Value Of Derivative Financial Instruments Net Explanatory [Table Text Block] Disclosure of fair value of derivative financial instruments net. Schedule of Options Outstanding and Exercisable Disclosure Of Options Outstanding Exercisable Granted And Vested [Table Text Block] Disclosure of options outstanding exercisable granted and vested. NCIB, shares authorized for repurchase (in shares) Stock Repurchase Program, Number of Shares Authorized to be Repurchased1 Stock Repurchase Program, Number of Shares Authorized to be Repurchased1 COMMITMENTS AND CONTINGENCIES Disclosure of commitments and contingent liabilities [text block] FINANCIAL INSTRUMENTS Disclosure of financial instruments [text block] Schedule of Property, Plant and Equipment Disclosure of detailed information about property, plant and equipment [text block] NCIB, shares repurchased, price per share (in CAD per share) Share Repurchase Program, Price Per Share Share Repurchase Program, Price Per Share Number of share options, exercisable (in shares) Number of share options exercisable in share-based payment arrangement Expired (in shares) Number Of Common Shares Issued Upon Expired of Warrants Number Of Common Shares Issued Upon Expired of Warrants Long-term debt, interest rate Borrowings, interest rate Cash From (Used in) Investing Activities Cash flows from (used in) investing activities Other tangible or intangible assets transferred Other tangible or intangible assets transferred Increase (Decrease) in Cash and Cash Equivalents Increase (decrease) in cash and cash equivalents after effect of exchange rate changes Percent of accounts receivable held with investment grade counterparties Percentage Of Credit Exposures Using External Credit Grading System Percentage of credit exposures using external credit grading system. Repayment of principal Borrowing, Repayment Of Principal Borrowing, Repayment Of Principal Update To Significant Accounting Policies [Abstract] Significant Accounting Policies [Abstract] Update to significant accounting policies. Short-Term Borrowings Short-term borrowings [member] Weighted average exercise price of other equity instruments exercised or vested in share-based payment arrangement (in CAD per share) Weighted average exercise price of other equity instruments exercised or vested in share-based payment arrangement Cash From (Used in) Financing Activities Cash flows from (used in) financing activities Types Of Financial Instruments [Domain] Types Of Financial Instruments [Domain] Types Of Financial Instruments [Domain] Warrants Expired Warrants Purchased And Cancelled, Equity Warrants Purchased And Cancelled, Equity (Gain) Loss on Divestiture of Assets Gains (losses) on divestiture of assets Gains (losses) on disposals of non-current assets Preferred Shares Preference shares [member] Disclosure Of Reportable Segments [Abstract] Disclosure of reportable segments. Beginning balance, Repurchase agreements payable Ending balance, Repurchase agreements payable Repurchase Agreements Payable Repurchase Agreements Payable Total Change in Non-Cash Working Capital Increase (decrease) in working capital Total Current Assets Total Current Assets Current assets Years 2 and 3 Later than one year and not later than three years [member] Disclosure Of Commitments And Contingent Liabilities [Table] Disclosure Of Commitments And Contingent Liabilities [Table] Disclosure Of Commitments And Contingent Liabilities [Table] Customer [Axis] Customer [Axis] Disclosure of operating segments [table] Disclosure of operating segments [table] Statement of changes in equity [table] Statement of changes in equity [table] Upstream Upstream [Abstract] Upstream Schedule of Revenues by Product Disclosure of products and services [text block] Purchase of Common Shares Under ASPP (in shares) Stock Repurchase Program, Repurchased Amount, Shares Under ASPP Stock Repurchase Program, Repurchased Amount, Shares Under ASPP Operating Margin Operating Margin Revenues less purchased product, transportation and blending, operating expenses, production and mineral taxes plus realized gains less realized losses on risk management activities. Disclosure of classes of share capital [abstract] Disclosure of classes of share capital [abstract] Offshore Offshore [Member] Offshore Total Non-operating (Income) Expense Corporate And Eliminations Reportable Segment Costs Corporate and eliminations reportable segment costs. Disclosure Of Supplementary Cash Flow Information [Table] Disclosure Of Supplementary Cash Flow Information [Table] Disclosure of supplementary cash flow information table.. Segments [axis] Segments [axis] Types of risks [axis] Types of risks [axis] Long-Term Debt Long-term debt Current borrowings and current portion of non-current borrowings Accounts payable and accrued liabilities Accounts Payables And Accrued Liabilities [Member] Accounts payables and accrued liabilities. WRB Refining LP WRB Refining LP [Member] WRB Refining LP Downstream Downstream [Member] Downstream Classes of assets Classes of assets [domain] Current Fiscal Year End Date Current Fiscal Year End Date Additions Additions Of Exploration And Evaluation Assets Additions of exploration and evaluation assets. Indonesia INDONESIA Dividends paid (in CAD per share) Dividends paid, ordinary shares per share Increase Theoretical Impact To Profit Loss From Increase In Commodity Sensitivity Theoretical impact to profit loss from increase in commodity sensitivity. Disclosure of transactions between related parties [table] Disclosure of transactions between related parties [table] Minimum Bottom of range [member] Share of equity investment Proportion of ownership interest in joint venture MEG Energy Corp MEG Energy Corp [Member] MEG Energy Corp Depreciation, Depletion and Amortization Depreciation, property, plant and equipment Income Tax Receivable Current tax assets, current Categories of related parties [axis] Categories of related parties [axis] Schedule of Provision for Income Taxes Disclosure Of Components Of Income Tax Expense Continuing Operations Explanatory [Table Text Block] The disclosure of components of income tax expense continuing operations. Disclosure of detailed information about borrowings [line items] Disclosure of detailed information about borrowings [line items] Prepaids and Deposits Current Prepaids And Deposits Current prepaids and deposits. Canadian Refining Canadian Refining [Member] Canadian Refining Thereafter Later than five years and not later than ten years [member] Reclassification on Divestiture (Note 8) Reclassifications On Divestitures Relating To Components Of Other Comprehensive Income Reclassifications On Divestitures Relating To Components Of Other Comprehensive Income Years 4 and 5 Later than three years and not later than five years [member] Natural Gas Contracts Natural Gas Contracts [Member] Natural Gas Contracts Disclosure of non-adjusting events after reporting period [table] Disclosure of non-adjusting events after reporting period [table] Divestitures (Note 8) Lease Liabilities, Divestitures Lease Liabilities, Divestitures PROPERTY, PLANT AND EQUIPMENT, NET Disclosure of property, plant and equipment [text block] RVO included in other liabilities, gross RVO Included In Other Liabilities, Gross RVO Included In Other Liabilities, Gross Net Earnings (Loss) Net Earnings (Loss) Profit (loss) Renewable Power Contracts Renewable Energy Contracts [Member] Renewable Energy Contracts Deferred Income Taxes Net deferred tax assets Asphalt Revenue From Sale Of Asphalt Revenue From Sale Of Asphalt Amount of undrawn facilities for general purposes Undrawn Borrowing Facilities For General Purposes Amount of undrawn borrowing facilities that may be available for general purposes. Rolling Twelve Month Basis Rolling Twelve Month Basis [Member] Rolling twelve month basis. Capital requirements [axis] Capital requirements [axis] Power Commodity Power Commodity [Member] Power Commodity Amendment Flag Amendment Flag Components of equity Components of equity [domain] Dividends paid Dividends paid on common shares Dividends recognised as distributions to owners Disclosure of operating segments [line items] Disclosure of operating segments [line items] Acquisitions Acquisitions Other Than Through Business Combinations Property Plant And Equipment And Exploration And Evaluation Assets Acquisitions other than through business combinations property plant and equipment and exploration and evaluation assets. Schedule of Accounts Receivable and Accrued Revenues Disclosure Of Detailed Information About Trade And Other Receivables Explanatory [Table Text Block] Disclosure of detailed information about trade and other receivables explanatory. UPDATE TO ACCOUNTING POLICIES Disclosure Of Update To Significant Accounting Policies [Text Block] The entire disclosure for update to significant accounting policies. Purchase of Common Shares Under NCIB (in shares) Purchases of common shares under NCIB (in shares) Stock Repurchase Program, Repurchased Amount, Shares Under NCIB Stock Repurchase Program, Repurchased Amount, Shares Under NCIB Revolving Term Debt Revolving Term Debt [Member] Revolving term debt. DESCRIPTION OF BUSINESS AND SEGMENTED DISCLOSURES Disclosure of entity's operating segments [text block] Depreciation Depreciation, right-of-use assets Liabilities Settled Provision used, other provisions Divestitures [Abstract] Divestitures [Abstract] Divestitures [Abstract] Schedule of Fair Value Hierarchy for Risk Management Assets and Liabilities Carried at Fair Value Disclosure Of Levels Of Fair Value Hierarchy Explanatory [Table Text Block] Disclosure of levels of fair value hierarchy. Range Range [domain] Total Commitments Total commitments Capital commitments ACCUMULATED DEPRECIATION, DEPLETION AND AMORTIZATION Accumulated depreciation and amortisation [member] Retained Earnings Retained earnings [member] Target net debt Target net debt Target net debt Borrowings [abstract] Borrowings [abstract] Other Assets Retail And Other Property, Plant And Equipment [Member] Retail And Other Property, Plant And Equipment Interest income Interest income 2 Years Later than one year and not later than two years [member] Crude Oil and Condensate Contracts Crude Oil And Condensate Contracts [Member] Crude oil and condensate contracts. Uncommitted Demand Facility Uncommitted Demand Facility [Member] Uncommitted demand facility. Changes From Financing Cash Flows: Disclosure of reconciliation of liabilities arising from financing activities [abstract] Capital requirements Capital requirements [domain] Committed credit facilities Committed Credit Facilities [Member] Committed Credit Facilities Average expected credit loss rate Expected credit loss rate Average carrying value Share Repurchase Program, Reduction To Contributed Surplus, Average Carrying Value, Amount Share Repurchase Program, Reduction To Contributed Surplus, Average Carrying Value, Amount Segment Income (Loss) Reportable Segment Profit Loss The profit (loss) from reportable segment. Stock-Based Compensation, Net of Payments Expense from share-based payment transactions Warrants Exercised Increase (decrease) through exercise of warrants, equity External credit grades External credit grades [domain] Issued Upon Exercise of Warrants (in shares) Exercised (in shares) Number Of Common Shares Issued Upon Exercise of Warrants Number Of Common Shares Issued Upon Exercise of Warrants Carrying amount Carrying amount [member] Income Tax Receivable Current tax assets, non-current Notional value Notional amount Foreign Exchange Rate Contracts Exchange Rate Contracts [Member] Exchange Rate Contracts Lease Liabilities Current lease liabilities Transportation Expenses Purchases of goods, related party transactions Settled liabilities, contingent liabilities recognised in business combination Settled liabilities, contingent liabilities recognised in business combination Term Loan Facility Term Loan Facility [Member] Term Loan Facility Income Tax Receivable Adjustments for decrease (increase) in income tax receivables Adjustments for decrease (increase) in income tax receivables Trade and Accruals (1) Current Trade Receivables And Accrued Income Current Trade Receivables And Accrued Income Disclosure of terms and conditions of share-based payment arrangement [abstract] Net earnings (loss) per share — diluted (CAD per share) Net earnings (loss) per common share — diluted (CAD per share) Diluted earnings (loss) per share WCS Hardisty WCS Hardisty [Member] WCS Hardisty Change in Fair Value of Contracts Entered Into During the Period Fair Value Of Contracts Entered Into During Period Fair Value Of Contracts Entered Into During Period Maturity Maturity [domain] Right-of-Use Assets, Net Right-of-use assets Balance at beginning of period Balance at end of period Right-of-use assets Disclosure of terms and conditions of share-based payment arrangement [table] Disclosure of terms and conditions of share-based payment arrangement [table] Outstanding letters of credit Letters Of Credit Issued As Security For Performance Letters of credit issued as security for performance. Issued Under Stock Option Plans (in shares) Number Of Common Shares Issued Under Stock Options Plan Number of common shares issued under stock options plan. Disclosure Of Reportable Segments [Line Items] Disclosure Of Reportable Segments [Line Items] Disclosure of reportable segments. EXPLORATION AND EVALUATION ASSETS, NET Disclosure of exploration and evaluation assets [text block] Average contract financial term Average Contract Financial Term Average Contract Financial Term Disclosure Of Exploration And Evaluation Assets [Table] Disclosure Of Exploration And Evaluation Assets [Table] Disclosure of exploration and evaluation assets. Schedule Representing Per Share Amounts Earnings per share [text block] Distributed Under Employee Benefit Plan Number Of Common Shares, Market Distributed, Amount Number Of Common Shares, Market Distributed, Amount Canadian Refining Segment Canadian Refining Segment [Member] Canadian Refining Segment Disclosure of detailed information about property, plant and equipment [table] Disclosure of detailed information about property, plant and equipment [table] Transportation and Blending Transportation And Blending Expense The amount of expense arising from transportation services and cost of diluent used for blending. Issued Under Stock Option Plans Common Shares Issued In Amount Under Stock Option Plan Common shares issued in amount under stock option plan. Disclosure of objectives, policies and processes for managing capital [line items] Disclosure of objectives, policies and processes for managing capital [line items]