Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Net carrying value Reported Value Measurement [Member] Document Fiscal Year Focus Document Fiscal Year Focus Adjustment to Compensation, Amount Adjustment to Compensation Amount Segment Reporting [Abstract] Effect of counterparty netting Derivative Fair Value Of Derivative Amount Effect Of Counter party netting [Member] Derivative Fair Value Of Derivative Amount Effect Of Counter party netting [Member] Common shares at stated value Common stock beginning balance Common stock, ending balance Common Stock, Value, Issued Financing Amounts to related parties included in financing Total financing Interest Expense, Operating and Nonoperating Long-term debt Schedule of Long-Term Debt Instruments [Table Text Block] Employee retirement benefits Retirement Benefits [Text Block] Restatement Determination Date Restatement Determination Date Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Percent of total shares Percentage Of Total Number Of Common Shares Percentage of total number of common shares. Derivative Instrument [Axis] Derivative Instrument [Axis] Amendment Flag Amendment Flag Current liabilities Liabilities, Current [Abstract] Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Finance lease obligations - reduction Finance Lease, Principal Payments Capital and exploration expenditures Capital And Exploration Expenditures Sum of exploration expenses, additions to property, plant, equipment and intangible and additions to capital leases. Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Entity Address, State or Province Entity Address, State or Province Chemical Chemical [Member] Chemical [Member] PEO Total Compensation Amount PEO Total Compensation Amount Investment and other income Investment And Other Income Net Investment and other income net. Weighted-average number of common shares outstanding (millions of shares) Weighted Average Number of Shares Outstanding, Basic Share Repurchase Program [Domain] Share Repurchase Program [Domain] Retirement Benefits [Abstract] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Total current liabilities Liabilities, Current Downstream Downstream [Member] Downstream [Member] Revenue from contracts with customers Revenue from Contract with Customer, Including Assessed Tax Entity Address, City or Town Entity Address, City or Town Postretirement benefits liability adjustment (excluding amortization) Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Statement of Financial Position [Abstract] Normal Course Issuer Bid Effective From June Twenty Ninth Two Thousand And Twenty Six Normal Course Issuer Bid Effective From June Twenty Ninth Two Thousand And Twenty Six [Member] Normal Course Issuer Bid Effective From June Twenty Ninth Two Thousand And Twenty Six Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Level 2 Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] United States Exports UNITED STATES Financial Instruments And Derivatives [Table] Financial Instruments And Derivatives [Table] Financial Instruments And Derivatives [Table] Business segments Segment Reporting [Table Text Block] Related Party, Type [Axis] Related and Nonrelated Parties [Axis] Total Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Total other comprehensive income (loss) Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Income taxes payable Increase (Decrease) in Income Taxes Payable Document Period End Date Document Period End Date Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Cash flows from (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Inventories of crude oil and products Inventory, Finished Goods and Work in Process, Gross ExxonMobil Holdings Corporation ExxonMobil Holdings Corporation [Member] ExxonMobil Holdings Corporation Expenses Costs and Expenses [Abstract] Crude Oil Crude Oil [Member] Eliminations Consolidation, Eliminations [Member] Position [Axis] Position [Axis] Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Lease liability due within one year, Operating leases Operating Lease, Liability, Current Statement of Comprehensive Income [Abstract] Name Outstanding Recovery, Individual Name Per share information (Canadian dollars) Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Total liabilities Liabilities NumberOfReportableSegmentsNotDisclosedFlag NumberOfReportableSegmentsNotDisclosedFlag NumberOfReportableSegmentsNotDisclosedFlag Geographical [Domain] Geographical [Domain] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Income taxes payable Accrued Income Taxes, Current Normal course issuer bid share repurchase term, months Share Repurchase Program, Period in Force Company Selected Measure Name Company Selected Measure Name Amounts reclassified from accumulated other comprehensive income Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Investor [Domain] Investor [Domain] Investor Accumulated Defined Benefit Plans Adjustment Attributable to Parent Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Other obligations Other Sundry Liabilities, Noncurrent Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Weighted-average number of common shares outstanding, assuming dilution (millions of shares) Weighted Average Number of Shares Outstanding, Diluted Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Employee retirement benefits Liability, Defined Benefit Plan, Noncurrent Derivative, nonmonetary notional amount, volume Derivative, Nonmonetary Notional Amount, Volume Underlying Security Market Price Change Underlying Security Market Price Change, Percent Dividends declared Dividends Financial and derivative instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Investment and other income Interest and Other Income [Text Block] Share-based incentive compensation liabilities Deferred Compensation Share-Based Arrangements, Liability, Classified, Noncurrent Effect of employee share-based awards (millions of shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment All other items - net Increase (Decrease) in Other Operating Assets and Liabilities, Net Award Timing Predetermined Award Timing Predetermined [Flag] Products Products Barrels [Member] Products barrels. Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Level 1 Fair Value, Inputs, Level 1 [Member] Financing costs Schedule Of Financing Cost [Table Text Block] Schedule of financing cost All Executive Categories All Executive Categories [Member] Share purchases at stated value Purchases at stated value Stock Repurchased and Retired During Period, Value Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Postretirement benefits liability adjustment (excluding amortization) Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Other comprehensive income (loss), net of income taxes Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Long-term debt, fair value Long-Term Debt, Fair Value Schedule of net benefit costs Schedule of Net Benefit Costs [Table Text Block] Debt-related interest Interest and Debt Expense Other long-term obligations Other Liabilities Disclosure [Text Block] Deferred income tax liabilities Deferred Tax and Other Liabilities, Noncurrent Revenues Realized And Unrealized Revenue On Derivative Instrument Total realized and unrealized revenue on derivative instrument. Calculation of basic and diluted earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Debt Disclosure [Abstract] Business segments Segment Reporting [Text Block] Dividends paid Payments of Ordinary Dividends, Common Stock Expiration Date Trading Arrangement Expiration Date CommonStockSharesIssuedNotDisclosed CommonStockSharesIssuedNotDisclosed CommonStockSharesIssuedNotDisclosed Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Liabilities Liabilities [Abstract] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Amounts to related parties included in production and manufacturing, and selling and general expenses Production And Manufacturing Expense And Selling and General Expense Production And Manufacturing Expense And Selling and General Expense Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Common share activities Schedule of Common Stock Outstanding Roll Forward [Table Text Block] Net benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Other Income and Expenses [Abstract] Common shares authorized (in shares) Authorized (in shares) Common Stock, Shares Authorized Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Exercise Price Award Exercise Price Restructuring Cost [Table] Restructuring Cost [Table] Investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Segment Reporting [Line Items] Segment Reporting [Line Items] Proceeds from asset sales Proceeds from Sales of Assets, Investing Activities Inventories, materials, supplies and prepaid expenses Increase (Decrease) in Inventories Materials and Supplies and Prepaid Expenses The net change during the reporting period in the aggregate value of all inventory, materials and supplies held by the reporting entity, associated with underlying transactions that are classified as operating activities. And the net change during the reporting period in the amount of outstanding money paid in advance for goods or services that bring economic benefits for future periods. Document Quarterly Report Document Quarterly Report Assets Derivative Asset [Abstract] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Segments [Domain] Segments [Domain] Liabilities Derivative Liability [Abstract] Restructuring and Related Costs Restructuring and Related Costs [Table Text Block] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Balance at beginning of period Balance at end of period Restructuring Reserve Equity Component [Domain] Equity Component [Domain] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Total expenses Costs and Expenses Adoption Date Trading Arrangement Adoption Date Other interest Interest Income Expense Other Amount of the cost of borrowed funds accounted for as interest expense. Total shareholders’ equity At beginning of period At end of period Equity, Attributable to Parent Common shares Common Share Information And Schedule Of Earnings Per Share Calculations [Text Block] Common share information and schedule of earnings per share calculations Restructuring Type [Axis] Restructuring Type [Axis] Assets Assets [Abstract] Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Schedule of Other Liabilities [Table] Other Liabilities Disclosure [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Insider Trading Policies and Procedures [Line Items] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Normal course issuer bid share repurchase shares authorized Share Repurchase Program, Authorized, Number of Shares Selling and general Selling, General and Administrative Expense Type of Restructuring [Domain] Type of Restructuring [Domain] Financial Instruments And Derivatives [Line Items] Financial Instruments And Derivatives [Line Items] Financial Instruments And Derivatives [Line Items] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Entity Central Index Key Entity Central Index Key less accumulated depreciation and depletion Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization All Adjustments to Compensation All Adjustments to Compensation [Member] Corporate and other Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Cash flows from (used in) operating activities Cash flows from (used in) operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Shareholders’ equity Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Finance leases Finance Lease, Liability, Noncurrent Intersegment Eliminations Intersegment Eliminations [Member] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Investments and long-term receivables Investments and long-term receivables, related party amount Long-Term Investments and Receivables, Net City Area Code City Area Code Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Name Forgone Recovery, Individual Name Financing costs Financing costs and additional notes and loans payable information [Text Block] The disclosure for the amount of the cost of financing and information relating to notes and loans payable. Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Statement [Line Items] Statement [Line Items] Total assets Assets Assets Defined Benefit Plan [Table] Defined Benefit Plan [Table] Amortization of prior service cost (credit) Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Operating Segments Operating Segments [Member] Energy [Domain] Energy [Domain] Current period change excluding amounts reclassified from accumulated other comprehensive income OCI, before Reclassifications, Net of Tax, Attributable to Parent PEO PEO [Member] Purchases at stated value, (in shares) Stock Repurchased and Retired During Period, Shares Other long-term obligations Total other long-term obligations Other Liabilities, Noncurrent Goodwill Goodwill Retirement Plan Type [Axis] Retirement Plan Type [Axis] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Exxon Mobil Corporation's ownership interest in Imperial Majority Interest Ownership Percentage Majority interest ownership percentage Effect of collateral netting Derivative Fair Value Of Derivative Amount Effect Of Collateral Netting [Member] Derivative Fair Value Of Derivative Amount Effect Of Collateral Netting [Member] Operating lease liability Operating Lease, Liability, Noncurrent Earnings reinvested Retained Earnings [Member] Included contributions to registered pension plans Contribution To Registered Pension Plan Assets The amount of cash contributed to the registered pension plan assets. Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Net income (loss) per common share - diluted (in CAD per share) Net income (loss) per common share (dollars) Earnings Per Share, Diluted Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity Current Reporting Status Entity Current Reporting Status Cash flows from (used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Adjustments for non-cash items: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property, plant and equipment - net Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Interest cost Defined Benefit Plan, Interest Cost Net income (loss) per common share – basic Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Derivative Asset Derivative Asset Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Purchases of crude oil and products Amounts to related parties included in purchases of crude oil and products Purchases of crude oil and products Crude Oil And Product Purchases Purchase cost of crude oil, products and other raw materials, feedstocks, semi finished products, finished products and other merchandise that become part of salable products for oil and gas, refining and marketing and chemical operations. Accounts receivable, net, related party amount Receivables, Net Of Accounts Payable And Accrued Liabilities, Current Receivables, Net Of Accounts Payable And Accrued Liabilities, Current Segment Reporting [Table] Segment Reporting [Table] All Trading Arrangements All Trading Arrangements [Member] Asset retirement obligations and other environmental liabilities in current liabilities Asset Retirement Obligation And Other Environmental Liabilities Current Asset retirement obligation and other environmental liabilities current. Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Current Fiscal Year End Date Current Fiscal Year End Date Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Income tax expense (credit) for components of other comprehensive income (loss) Schedule Of Income Tax Expense For Components Of Comprehensive Income [Table Text Block] Schedule Of Income Tax Expense For Components Of Comprehensive Income Derivative [Line Items] Derivative [Line Items] Loans to equity companies - net Net Movement Related To Loans To Equity Companies Net movement related to loans to equity companies. Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Dividends per common share – declared (dollars) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Service cost Defined Benefit Plan, Service Cost Production and manufacturing Production and manufacturing Production And Manufacturing Expenses Costs, excluding deprecation, incurred to operate and maintain - 1) oil and gas wells, production, transportation and support equipment and facilities; 2) refining manufacturing facilities; and 3) chemical manufacturing facilities. Federal excise tax and fuel charge Taxes, Other Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Measure: Measure [Axis] Other comprehensive income (loss) information Comprehensive Income (Loss) Note [Text Block] Equity Components [Axis] Equity Components [Axis] Accounts receivable Increase (Decrease) in Accounts Receivable Related Party Related Party [Member] Class of Stock [Line Items] Class of Stock [Line Items] Entity Interactive Data Current Entity Interactive Data Current Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities, Current Materials, supplies and prepaid expenses Materials Supplies And Prepaid Expenses Carrying amount as of the balance sheet date for elements of machinery or equipment held for the purpose of replacing similar parts in the course of repair or maintenance. Expenditures made in advance of when the economic benefit of the cost will be realized, and which will be expensed in future periods with the passage of time or when a triggering event occurs. Entity Small Business Entity Small Business Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Book value of asset sales Book Value Of Assets Sold Book Value of Assets Sold Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Depreciation and depletion (includes impairments) Depreciation Depletion and Amortization Excluding Intangible Asset Impairment Charges The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets or depleting assets to periods that benefit from use of the assets but excludes impairment of specifically identified intangible assets associated with carbon emission cap and trade intangible assets. Termination Date Trading Arrangement Termination Date Restructuring liability Restructuring Reserve, Noncurrent Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Other assets, including intangibles - net Other Assets, Noncurrent Document Type Document Type Fair Value as of Grant Date Award Grant Date Fair Value Short Short [Member] (Gain) loss on asset sales Gain (loss) on asset sales, before-tax Gain (Loss) on Disposition of Assets Employee retirement benefit obligations in current liabilities Liability, Defined Benefit Plan, Current Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Local Phone Number Local Phone Number Other postretirement benefits: Other Postretirement Benefits Plan [Member] Miscellaneous financial information Additional Financial Information Disclosure [Text Block] Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Income (loss) before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Amortization of postretirement benefits liability adjustment included in net benefit cost Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax Other long-term obligations Other Noncurrent Liabilities [Table Text Block] Total revenues and other income Revenues Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Property, plant and equipment, Property, Plant, and Equipment, before Accumulated Depreciation, Depletion, and Amortization Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Asset retirement obligations and other environmental liabilities Asset Retirement Obligation And Other Environmental Liabilities Noncurrent Asset retirement obligation and other environmental liabilities, noncurrent. Deferred income taxes and other Deferred Income Taxes and Other The component of income tax expense for the period representing the net change in the entity's deferred tax assets and liabilities pertaining to continuing operations. Prior year Exploration and Exploratory dry hole costs written off as expense in the current year. Entity's net proportionate share for the period of net earnings, less dividends, of its investment to which the equity method of accounting is applied. All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Level 3 Fair Value, Inputs, Level 3 [Member] Summary of common shares Summary Of Common Shares [Table Text Block] Summary of common shares authorized. PEO Name PEO Name Geographical [Axis] Geographical [Axis] Non-service pension and postretirement benefit Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Revenues Amounts from related parties included in revenues Revenues including federal excise tax Revenues Including Federal Excise Tax Total revenue from sales of goods and services during the reporting period, reduced by sales returns and allowances and sales discounts. Also includes federal excise tax which is then deducted as an expense. Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Net interest expense Interest Expense, Debt Payments made Payments for Restructuring Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Derivative collateral receivable Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Not Offset Upstream Upstream [Member] Upstream [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Amounts reclassified out of accumulated other comprehensive income (loss) - before tax income (expense) Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Financing costs and additional notes and loans payable information [Abstract] Financing costs and additional notes and loans payable information Long Long [Member] Capitalized interest Interest Paid, Capitalized, Investing Activity Investor [Axis] Investor [Axis] Investor Summary of estimated fair value of financial instruments Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Net income (loss) per common share - basic (in CAD per share) Net income (loss) per common share (dollars) Earnings Per Share, Basic Common shares purchased Payments for Repurchase of Common Stock Total current assets Assets, Current Insider Trading Arrangements [Line Items] Derivative Instruments, Gain (Loss) Derivative Instruments, Gain (Loss) [Table Text Block] Long-term debt, related party amount Long-term debt Long-Term Debt, Excluding Current Maturities Award Type Award Type [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Earnings reinvested Retained Earnings (Accumulated Deficit) Restructuring and Related Activities [Abstract] Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Pension benefits: Pension Plan [Member] Common shares at stated value Common Stock Common Stock [Member] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Employee Severance Employee Severance [Member] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Gain (loss) on asset sales, after-tax Net Gain (Loss) On Asset Sales After Tax Net gain (loss) on asset sales, after tax. Derivative Contract [Domain] Derivative Contract [Domain] Equity Awards Adjustments Equity Awards Adjustments [Member] Total liabilities and shareholders’ equity Liabilities and Equity Employee Stock Option Share-Based Payment Arrangement, Option [Member] Notes and loans payable Debt, Current Amortization of postretirement benefits liability adjustment included in net benefit cost Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Restructuring charges Additions/adjustments Restructuring Charges Related Party, Type [Domain] Related and Nonrelated Parties [Domain] Tabular List, Table Tabular List [Table Text Block] Curtailment loss (gain) Defined Benefit Plan, Other Cost (Credit) Amortization of postretirement benefits liability adjustment included in net benefit costs Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax Long-term debt Long-Term Debt [Text Block] Name Awards Close in Time to MNPI Disclosures, Individual Name Entity Address, Country Entity Address, Country Additional investments Payments to Acquire Investments Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Accounts receivable - net Receivables, Net, Current Adjustment to Compensation: Adjustment to Compensation [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Interest (paid), net of capitalization. Interest Paid, Excluding Capitalized Interest, Operating Activity Additions to property, plant and equipment Payments to Acquire Productive Assets Statement of Cash Flows [Abstract] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Exploration Exploration Exploration Expense Long-term debt Total long-term debt Long-Term Debt and Lease Obligation Name Measure Name Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Entity Filer Category Entity Filer Category Revenue outside the scope of ASC 606 Revenue Not from Contract with Customer Name Trading Arrangement, Individual Name Cash and cash equivalents Cash and Cash Equivalent Position [Domain] Position [Domain] Energy [Axis] Energy [Axis] Company Selected Measure Amount Company Selected Measure Amount Share purchases in excess of stated value Share Purchases In Excess Of Stated Value Excess of the purchase price of common stock over the stated value charged to retain earnings during the period Depreciation and depletion (includes impairments) Depreciation and depletion Depreciation, Depletion and Amortization Investment and other income Interest and Other Income [Table Text Block] Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Current assets Assets, Current [Abstract] Derivative liabilities Derivative Liability Non-PEO NEO Non-PEO NEO [Member] Entity Address, Address Line One Entity Address, Address Line One Income taxes Income Tax Expense (Benefit) Award Timing Method Award Timing Method [Text Block] Increase (decrease) in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Amortization of actuarial loss (gain) Defined Benefit Plan, Amortization of Gain (Loss) AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Net income (loss) Net income (loss) Net income (loss) for the period Net Income (Loss) Attributable to Parent Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Common shares outstanding (in shares) Common stock beginning balance, (in shares) Common stock, ending balance, (in shares) Common Stock, Other Shares, Outstanding Proceeds from asset sales Proceeds from Sale of Property, Plant, and Equipment Statement [Table] Statement [Table] Restatement Determination Date: Restatement Determination Date [Axis] Changes in accumulated other comprehensive income (loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Master netting arrangements Master netting arrangements [Member] Master netting arrangements [Member] Revenues and other income Revenues [Abstract] Basis of financial statement preparation Basis of Presentation and Significant Accounting Policies [Text Block] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Net income (loss) per common share – diluted Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract]