Accounting Policies [Abstract] Statement [Table] Statement [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 [Member] Accounting Standards Update 2014-09 [Member] Effect of Change [Member] Effect of Change [Member] Effect of change of adoption of ASU 2014-09 [Member] Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2016-02 [Member] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Crude Oil and Condensate Oil and Condensate [Member] Natural Gas Liquids Natural Gas Liquids [Member] Natural Gas Natural Gas, Production [Member] Gathering, Processing and Marketing Natural Gas, Gathering, Transportation, Marketing and Processing [Member] Statement [Line Items] Statement [Line Items] Finance Lease, Liability, Undiscounted Excess Amount Operating Leases, Future Minimum Payments Due Revenues Revenue from Contract with Customer, Including Assessed Tax Total Operating Revenues and Other Revenues Gathering and Processing Costs Gathering and Processing Costs Operating and maintenance expenses and administrative expenses associated with operating gathering and processing assets. Marketing Costs Marketing Costs Costs of purchasing third-party natural gas and crude oil and the related transportation costs. Total Operating Expenses Costs and Expenses Operating Income Operating Income (Loss) Accounts Receivable From Contracts With Customers Accounts Receivable, Net, Current Supplemental Cash Flow Information [Abstract] Net Cash Paid For Interest and Income Taxes Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Public Float Entity Public Float Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Shell Company Entity Shell Company Equity [Abstract] Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Accounting For Certain Long-Lived Assets [Abstract] Schedule of Impaired Long-Lived Assets Held and Used [Table] Schedule of Impaired Long-Lived Assets Held and Used [Table] Impaired Long-Lived Assets Held and Used by Type [Axis] Impaired Long-Lived Assets Held and Used by Type [Axis] Impaired Long-Lived Assets Held and Used, Asset Name [Domain] Impaired Long-Lived Assets Held and Used, Asset Name [Domain] United States UNITED STATES Trinidad TRINIDAD AND TOBAGO Schedule of Impaired Long-Lived Assets Held and Used [Line Items] Schedule of Impaired Long-Lived Assets Held and Used [Line Items] Proved oil and gas properties carrying amount Proved oil and gas properties carrying amount Proved oil and gas properties carrying amount Proved oil and gas properties, other property, plant and equipment, and other assets written down to fair value Proved oil and gas properties, other property, plant and equipment, and other assets written down to fair value Proved oil and gas properties, other property, plant and equipment, and other assets written down to fair value Pretax impairment chages for proved oil and gas properties, other property, plant and equipment and other assets Pretax impairment chages for proved oil and gas properties, other property, plant and equipment and other assets Pretax impairment charges for proved oil and gas properties, other property, plant and equipment and other assets Amortization and Impairments of Unproved Oil and Gas Property Including Amortization of Capitalized Interest Amortization and Impairments of Unproved Oil and Gas Property Including Amortization of Capitalized Interest Amortization and impairments of unproved oil and gas property costs including amortization of capitalized interest Income Statement [Abstract] Gains (Losses) on Mark-to-Market Commodity Derivative Contracts Gains (Losses) On Mark-To-Market Commodity Derivative Contracts [Member] The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of open derivatives, commodity, or energy contracts, held at each balance sheet date, that was included in earnings for the period. Gains (Losses) on Asset Dispositions, Net Gains (Losses) On Asset Dispositions, Net [Member] Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee. Other, Net Other, Net [Member] Other revenues from oil and gas producing activities. Operating Revenues and Other Revenues [Abstract] Total Operating Expenses Cost of Revenue [Abstract] Lease and Well Operating Lease, Expense Transportation Costs Results of Operations, Transportation Costs Exploration Costs Exploration Expense Dry Hole Costs Results of Operations, Dry Hole Costs Impairments Impairment of Oil and Gas Properties Depreciation, Depletion and Amortization Depreciation, Depletion and Amortization General and Administrative General and Administrative Expense Taxes Other Than Income Taxes Other Than Income Taxes other than income taxes, if not included elsewhere, could include, property tax or other selling and distribution-related taxes. Total Operating Income (Loss) Other Income (Expense), Net Other Nonoperating Income (Expense) Income (Loss) Before Interest Expense and Income Taxes Income Before Interest Expense and Income Taxes Income Before Interest Expense and Income Taxes. Interest Expense Interest Expense [Abstract] Incurred Interest Expense, Debt Capitalized Interest Costs Capitalized Net Interest Expense Interest Expense Income (Loss) Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income Tax Provision (Benefit) Income Tax Expense (Benefit) Net Income (Loss) Net Income (Loss) Attributable to Parent Net Income (Loss) Per Share Earnings Per Share, Basic [Abstract] Basic Earnings Per Share, Basic Diluted Earnings Per Share, Diluted Average Number of Common Shares [Abstract] Earnings Per Share, Basic, Other Disclosures [Abstract] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Other Comprehensive Income (Loss) Statement of Comprehensive Income [Abstract] Foreign Currency Translation Adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Other, Net of Tax Other Comprehensive Income, Other, Net of Tax Other Comprehensive Income (Loss) Other Comprehensive Income (Loss), Net of Tax Comprehensive Income (Loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Segment Reporting [Abstract] Selected Information [Table] Schedule of Segment Reporting Information, by Segment [Table] Segment Information [Axis] Segments [Axis] Segment Information [Domain] Segments [Domain] Other International Other International [Member] Selected Information [Line Items] Segment Reporting Information [Line Items] Schedule of Segment Reporting Information By Segment [Abstract] Segment Reporting Information, Revenue for Reportable Segment [Abstract] Operating Revenues and Other Operating Income (Loss) Interest Income Investment Income, Interest and Dividend Other Income Other Nonoperating Income Other Expense Other Nonoperating Expense Net Interest Expense Income (Loss) Before Income Taxes Income Tax Provision (Benefit) Additions to Oil and Gas Properties, Excluding Dry Hole Costs Payments To Acquire Oil And Gas Property And Equipment Excluding Dry Hole Costs The cash outflow to purchase long lived physical asset for use in the normal oil and gas operations and to purchase mineral interests in oil and gas properties not intended for resale, excluding dry hole costs. Total Property, Plant and Equipment, Net Property, Plant and Equipment, Net Total Assets Assets Amount of sales with a single significant purchaser in the United States segment Amount of sales with a single significant purchaser in the United States segment Amount of sales with a single significant purchaser in the United States segment. Amount of sales with a second significant purchaser in the United States segment. Amount of sales with a second significant purchaser in the United States segment. Amount of sales with a second significant purchaser in the United States segment. Amount of sales with a third significant purchaser in the United States segment Amount of sales with a third significant purchaser in the United States segment Amount of sales with a third significant purchaser in the United States segment Reclassification to Deferred Tax Assets Deferred Tax Assets, Net, Noncurrent Business Segment Information Segment Reporting Disclosure [Text Block] Oil and Gas Exploration and Production Industries Disclosures [Abstract] Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Table] Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Table] Statement, Geographical [Axis] Geographical [Axis] Segment, Geographical [Domain] Geographical [Domain] Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items] Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items] Crude Oil and Condensate, Natural Gas Liquids and Natural Gas Revenues Results of Operations, Sales Revenue to Unaffiliated Enterprises Other Results of Operations, Revenue, Other Total Results of Operations, Revenue from Oil and Gas Producing Activities Exploration Costs Results of Operations, Exploration Expense Production Costs Results of Operations, Production or Lifting Costs Impairments Results of Operations, Impairment of Oil and Gas Properties Depreciation, Depletion and Amortization Results of Operations, Depreciation, Depletion and Amortization, and Valuation Provisions Income (Loss) Before Income Taxes Results of Operations, Income before Income Taxes Income Tax Provision (Benefit) Tax Provision (Benefit) Income tax expense for oil and gas producing activities. Results of Operations Results of Operations, Oil and Gas Producing Activities Net Income (Excluding Corporate Overhead and Interest Costs) Asset Retirement Obligations, Noncurrent [Abstract] Carrying Amount at Beginning of Period Asset Retirement Obligation Liabilities Incurred Asset Retirement Obligation, Liabilities Incurred Liabilities Settled (1) Asset Retirement Obligation, Liabilities Settled Accretion Asset Retirement Obligation, Accretion Expense Revisions Asset Retirement Obligation, Revision of Estimate Foreign Currency Translations Asset Retirement Obligation, Foreign Currency Translation Gain (Loss) Carrying Amount at End of Period Current Portion Asset Retirement Obligation, Current Noncurrent Portion Asset Retirement Obligations, Noncurrent Long-Term Debt Related to Yates Transaction Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Other Income and Expenses [Abstract] Other Income (Expense), Net Other Income and Other Expense Disclosure [Text Block] Quarterly Financial Information Disclosure [Abstract] Income (Loss) Before Income Taxes Income Before Income Taxes Sum of operating profit and nonoperating income (expense) before income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Net Income (Loss) Basic (in dollars per share) Diluted (in dollars per share) Provisional Reduction in the Income Tax Provision Provisional Reduction in the Income Tax Provision Provisional reduction in the income tax provision primarily related to the decrease in the tax rate. Capitalized Exploratory Well Costs [Abstract] Exploratory Well Costs Suspended Well Costs Disclosure [Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Oil and Gas Operations Industry Specific Policies, Oil and Gas [Policy Text Block] Other Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Capitalized Interest Costs Interest Capitalization, Policy [Policy Text Block] Accounting for Risk Management Activities Derivatives, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Foreign Currency Translation Foreign Currency Transactions and Translations Policy [Policy Text Block] Net Income (Loss) Per Share Earnings Per Share, Policy [Policy Text Block] Stock-Based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Recently Issued Accounting Standards and Developments New Accounting Pronouncements, Policy [Policy Text Block] Debt Disclosure [Abstract] Long-Term Debt Schedule of Debt [Table Text Block] Oil and Gas Exploration and Production Industries Disclosures Oil and Gas Exploration and Production Industries Disclosures [Text Block] Long-Term Debt Long-term Debt [Text Block] Asset Retirement Obligations Asset Retirement Obligation Disclosure [Text Block] Deferred Income Tax Liabilities, Net Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Components of Income (Loss) Before Income Taxes Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Components of Income Tax Provision (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Summary of Valuation Allowance Summary of Valuation Allowance [Table Text Block] Interest, Net of Capitalized Interest Interest Paid, Excluding Capitalized Interest, Operating Activities Income Taxes, Net of Refunds Received Income Taxes Paid, Net Accrued Capital Expenditures Capital Expenditures Incurred but Not yet Paid Non-cash investing and financing activities from property exchanges. Non-cash investing and financing activities from property exchanges. The increase during the period in non-cash investing and financing activities from property exchanges. Non-Cash Investing From Other Property, Plant and Equipment Non-Cash Investing From Other Property, Plant and Equipment Non-Cash Investing From Other Property, Plant and Equipment Non-cash investing and financing activities from the Yates transaction Noncash or Part Noncash Acquisition, Fixed Assets Acquired Costs Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities [Table] Costs Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities [Table] Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items] Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items] Acquisition Costs of Properties - Unproved Costs Incurred, Acquisition of Unproved Oil and Gas Properties Acquisition Costs of Properties - Proved Costs Incurred, Acquisition of Oil and Gas Properties with Proved Reserves Subtotal Costs Incurred, Acquisition of Oil and Gas Properties Exploration Costs Costs Incurred, Exploration Costs Development Costs Costs Incurred, Development Costs Total Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities Non-Cash Unproved Leasehold Acquisition Costs Related to Property Exchanges Non-Cash Unproved Leasehold Acquisitions Related to Property Exchanges Non-Cash Unproved Leasehold Acquisitions Related to Property Exchanges Non-Cash Proved Property Acquisition Costs Related to Property Exchanges Non-Cash Proved Property Acquisition Costs Related to Property Exchanges Non-Cash Proved Property Acquisition Costs Related to Property Exchanges Asset Retirement Costs Included In Development Asset Retirement Costs Included In Development Amount of asset retirement costs included in Development Costs. Non-Cash Unproved Leasehold Acquisition Costs Related to Yates Transaction Non-Cash Unproved Leasehold Acquisition Costs Related to Yates transaction Non-Cash Unproved Leasehold Acquisition Costs Related to Yates Transaction Non-Cash Proved Property Acquisition Costs Related to Yates Transaction Non-Cash Proved Property Acquisition Costs Related to Yates Transaction Non-Cash Proved Property Acquisition Costs Related to Yates Transaction Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Table] Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Table] Other International (1) Energy [Axis] Energy [Axis] Energy [Domain] Energy [Domain] Crude Oil [Member] Crude Oil [Member] Natural Gas Liquids [Member] Natural Gas [Member] Natural Gas [Member] Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] Future cash inflows Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Cash Inflows Future production costs Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Production Costs Future development costs Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Development Costs Future income taxes Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Income Tax Expense Future net cash flows Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Net Cash Flows Discount to present value at 10% annual rate Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Ten Percent Annual Discount for Estimated Timing of Cash Flows Standardized measure of discounted future net cash flows relating to proved oil and gas reserves Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves Annual Rate of Discount to Present Value Annual Rate of Discount to Present Value Annual Rate of Discount to Present Value Per unit price used to calculate future cash inflows Per unit price used to calculate future cash inflows Per unit price used to calculate future cash inflows. Changes in Standardized Measure of Discounted Future Net Cash Flows [Abstract] Principal Sources of Change in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Abstract] Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward] Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Roll Forward] Balance at Beginning of Period Sales and transfers of oil and gas produced, net of production costs Sales and Transfers of Oil and Gas Produced, Net of Production Costs Net changes in prices and production costs Net Increase (Decrease) in Sales and Transfer Prices and Production Costs Extensions, discoveries, additions and improved recovery, net of related costs Extensions, Discoveries, Additions and Improved Recovery, Less Related Costs Development costs incurred Previously Estimated Development Costs Incurred Revisions of estimated development cost Changes in Estimated Future Development Costs Revisions of previous quantity estimates Revisions of Previous Quantity Estimates Accretion of discount Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves, Accretion of Discount Net change in income taxes Changes in Future Income Tax Expense Estimates on Future Cash Flows Related to Proved Oil and Gas Reserves Purchases of reserves in place Increase Due to Purchases of Minerals in Place Sales of reserves in place Decrease Due to Sales of Minerals in Place Changes in timing and other Standardized Measure of Discounted Future Net Cash Flow of Proved Oil and Gas Reserves, Other Balance at End of Period Statement of Stockholders' Equity [Abstract] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] Retained Earnings [Member] Retained Earnings [Member] Treasury Stock, Common [Member] Treasury Stock, Common [Member] Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Common Stock Issued for the Yates Transaction Common Stock Issued for the Yates Transaction Common Stock Issued for the Yates Transaction Common Stock Issued Under Stock Plans Common Stock Issued Under Stock Plans, Net Common stock issued under stock plans. Dividends, Common Stock Dividends, Common Stock Common Stock Dividends Declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Change in Treasury Stock - Stock Compensation Plans, Net Treasury Stock Issued Under Stock Plans Value of treasury stock reissued during the period in connection with stock-based compensation plans. Upon reissuance, common and preferred stock are outstanding. Excess Tax Benefit from Stock-Based Compensation Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Restricted Stock and Restricted Stock Units, Net Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition Stock-Based Compensation Expenses Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Treasury Stock Issued as Compensation Treasury Stock Issued as Compensation Treasury stock issued as deferred compensation plan distributions. Balance Unaudited Quarterly Financial Information Quarterly Financial Information [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instrument Detail [Abstract] Derivative Instrument Detail [Abstract] Derivative [Table] Derivative [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Midland Differential Basis Swap [Member] Basis Swap [Member] Gulf Coast Differential Basis Swap [Member] Gulf Coast Differential Basis Swap [Member] Interest-rate swap contract where both rates are variable but are tied to different index rates. For example, but not limited to, one party's rate indexed to three-month London Interbank Offered Rate (LIBOR) while the other party's rate is indexed to six-month LIBOR. Price Swap [Member] Swap [Member] Options [Member] Commodity Option [Member] Collars [Member] Collars [Member] Collars [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Schedule of Derivative Instruments Schedule of Derivative Instruments [Table Text Block] Schedule of Derivative Instruments In Statement Of Financial Position, Fair Value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Business Combinations [Abstract] Acquisitions and Divestitures Mergers, Acquisitions and Dispositions Disclosures [Text Block] Statement of Financial Position [Abstract] Common Stock Common Stock Common Stock Common Stock, Par Value (in dollars per share) Common Stock, Par or Stated Value Per Share Common Stock, Shares Authorized (in shares) Common Stock, Shares Authorized Common Stock, Shares Issued (in shares) Common Stock, Shares, Issued Treasury Stock Treasury Stock Treasury Stock Common Stock Held in Treasury (in shares) Treasury Stock, Shares Unaudited Quarterly Financial Information Quarterly Financial Information [Table Text Block] Provisional Net Tax Benefit Increase In Provisional Reduction In The Income Tax Provision Increase In Provisional Reduction In The Income Tax Provision Increase in provisional reduction in the income tax provision primarily related to the decrease in the tax rate. Sequestration Refundable Tax Credits Sequestration Refundable Tax Credits Sequestration Refundable Tax Credits Repatriation Tax Of Foreign Earnings Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount Components of Deferred Tax Assets and Liabilities [Abstract] Components of Deferred Tax Assets and Liabilities [Abstract] Deferred Tax Assets (Liabilities) Net Noncurrent Classification [Abstract] Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Classification [Abstract] Foreign Oil and Gas Exploration and Development Costs Deducted for Tax Under Book Depreciation, Depletion and Amortization Deferred Tax Assets Property Plant And Equipment Foreign For an entities foreign operations, the amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis of capital assets and the basis of capital assets computed in accordance with generally accepted accounting principles. The difference in basis, attributable to different capitalization of costs, depreciation, or amortization methodologies, will increase future taxable income when such basis difference is realized. Foreign Net Operating Loss Deferred Tax Assets, Operating Loss Carryforwards, Foreign Foreign Valuation Allowances Deferred Tax Assets, Valuation Allowance, Noncurrent Foreign Other Deferred Tax Assets Other Foreign For an entities' foreign operations, the tax effect as of the balance sheet date of the amount of estimated future tax deductions arising from other temporary differences not otherwise specified in the taxonomy. Total Net Noncurrent Deferred Income Tax Assets Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Deferred Tax (Assets) Liabilities Net Noncurrent Classification [Abstract] Deferred tax liabilities net noncurrent classification [Abstract] Oil and Gas Exploration and Development Costs Deducted for Tax Over Book Depreciation, Depletion and Amortization Deferred Tax Liabilities, Property, Plant and Equipment Commodity Hedging Contracts Deferred Tax Assets, Derivative Instruments Deferred Compensation Plans Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Accrued Expenses and Liabilities Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Net Operating Loss - Federal Deferred Tax Assets, Operating Loss Carryforwards, Domestic Non-Producing Leasehold Costs Deferred Tax Assets Non Producing Leasehold Costs Deferred tax assets resulting from timing differences in the recognition of non -producing leasehold costs for book and tax purposes Seismic Costs Capitalized for Tax Deferred Tax Assets Seismic Costs Capitalized Deferred tax assets resulting from timing differences in the recognition of seismic costs for book and tax purposes Equity Awards Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Capitalized Interest Deferred Tax Liabilities, Deferred Expense, Capitalized Interest Alternative Minimum Tax Credit Carryforward (3) Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax Undistributed Foreign Earnings Deferred Tax Liabilities, Undistributed Foreign Earnings Other Deferred Tax and Other Liabilities, Noncurrent Total Net Noncurrent Deferred Income Tax Liabilities Deferred Tax Liabilities, Net, Noncurrent Total Net Deferred Income Tax Liabilities Deferred Tax Liabilities, Net Components Income (Loss) Before Income Taxes [Abstract] Results of Operations, Income before Income Taxes [Abstract] United States Income (Loss) from Continuing Operations before Income Taxes, Domestic Foreign Income (Loss) from Continuing Operations before Income Taxes, Foreign Components of Income Tax Benefit [Abstract] Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Current income tax provision (benefit) [Abstract] Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Total Current Income Tax Expense (Benefit) Deferred income tax provision (benefit) [Abstract] Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Total Deferred Income Tax Expense (Benefit) Other Non-Current [Abstract] Other Non-Current [Abstract] Other Non-Current [Abstract] Federal (1) Other Noncurrent Federal Income Tax Amount of other non-current federal tax expense (benefit) pertaining to income (loss) from continuing operations. Income Tax Benefit Results of Operations, Income Tax Expense Federal Statutory and Effective Income Tax Rates [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] Statutory Federal Income Tax Rate (in hundredths) Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State Income Tax, Net of Federal Benefit (in hundredths) Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Income Tax Provision Related to Foreign Operations (in hundredths) Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent Income Tax Provision Related to Trinidad Operations (in hundredths) Income Tax Provision Related to Trinidad Operations (in hundredths) Income Tax Provision Related to Trinidad Operations (in hundredths) Income Tax Provision Related to United Kingdom Operations (in hundredths) Income Tax Provision Related to United Kingdom Operations (in hundredths) Income Tax Provision Related to United Kingdom Operations Income Tax Provision Related to Canadian Operations (in hundredths) Income Tax Provision Related to Canadian Operations (in hundredths) Income Tax Provision Related to Canadian Operations TCJA (in hundredths) Effective Tax Rate Related to TCJA (in hundredths) Effective Tax Rate Related to TCJA Shared-Based Compensation (3) (in hundredths) Effective Tax Rate Related To Shared-Based Compensation Effective tax rate related to shared-based compensation tax benefits and deficiencies. Other (in hundredths) Effective Income Tax Rate Reconciliation Other Items The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to all other items not otherwise disclosed due to materiality Effective Income Tax Rate (in hundredths) Effective Income Tax Rate Reconciliation, Percent Tax NOLs (in hundredths) Tax Net Operating Losses Tax Net Operating Losses Sequestration (in hundredths) Sequestration Effective Sequestration Rate Other Tax Reform Impacts (in hundredths) Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Federal Tax Rate Reduction (in hundredths) Federal Tax Rate Reduction Federal Tax Rate Reduction Federal Repatriation Tax (in hundredths) Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Percent Components of Valuation Allowance [Abstract] Valuation Allowance [Abstract] Beginning Balance Deferred Tax Assets, Valuation Allowance Increase Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Decrease Valuation Allowance Deferred Tax Asset Decrease in Amount Amount of decrease in the valuation allowance for a specified deferred tax asset. Other Valuation Allowance Deferred Tax Asset Other Amount Represents dispositions/revisions/foreign exchange rate variances and the effect of statutory income tax rate changes. Ending Balance Balance of state net operating loss expected to be carried forward Balance of state net operating loss expected to be carried forward Balance of state net operating loss expected to be carried forward. Canadian Net Operating Loss Carryforwards Canadian Net Operating Loss Carryforwards Canadian Net Operating Loss Carryforwards Unrecognized Tax Benefits Balance Unrecognized Tax Benefits Unrecognized Tax Benefits that Would Impact On Earnings Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Foreign and State Deferred Income Taxes Foreign And State Deferred Income Taxes Foreign and state deferred income taxes Fair Value Assets And Liabilities Measured On Recurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Commodity Contract [Member] Commodity Contract [Member] Other Assets [Member] Other Assets [Member] Options/Collars [Member] Basis Swaps [Member] Assets From Price Risk Management Activities [Member] Assets From Price Risk Management Activities [Member] Line item in the statement of financial position in which the fair value amounts of the derivative instruments are included. Liabilities From Price Risk Management Activities [Member] Liabilities From Price Risk Management Activities [Member] Line item in the statement of financial position in which the fair value amounts of the derivative instruments are included. Other Liabilities [Member] Other Liabilities [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Financial Assets: Assets, Fair Value Disclosure [Abstract] Assets, Fair Value Disclosure Assets, Fair Value Disclosure Financial Liabilities: Liabilities, Fair Value Disclosure [Abstract] Liabilities, Fair Value Disclosure Financial and Nonfinancial Liabilities, Fair Value Disclosure Proved Oil and Gas Properties, Other Property, Plant and Equipment and Other Assets [Abstract] Proved Oil and Gas Properties, Other Property, Plant and Equipment and Other Assets [Abstract] Proved Oil and Gas Properties, Other Property, Plant and Equipment and Other Assets [Abstract] Proved oil and gas properties, other property, plant and equipment and other assets, carrying amount Proved Oil And Gas Properties, Other Property, Plant and Equipment and Other Assets, Carrying Amount Net dollar amount capitalized on balance sheet representing an enterprise's interests in proved crude oil (including condensate and natural gas liquids) and/or natural gas properties. Proved oil and gas properties, other property, plant and equipment and other assets written down during the period - fair value at end of period Proved Oil and Gas Properties, Other Property, Plant and Equipment and Other Assets Written Down During the Period - Fair Value at End of Period Fair value of proved oil and gas property and other property, plant and equipment as of the balance sheet date. Pretax impairment charges for proved oil and gas properties and other assets, in which EOG utilized an accepted offer from a third-party purchaser Pretax impairment charges for proved oil and gas properties and other assets, in which EOG utilized an accepted offer from a third-party purchaser The expense recorded to reduce the value of oil and gas assets consisting of proved properties as the estimate of future successful production from these properties is reduced. Pretax impairment charge for a commodity price-related write-down of other assets Pretax impairment charge for a commodity price-related write-down of other assets Pretax impairment charge for a commodity price-related write-down of other assets Pretax impairment charges for proved oil and gas properties, other property, plant and equipment and other assets Impairment Charge For Proved Oil And Gas Properties And Other Property, Plant And Equipment and Other Assets The expense recorded to reduce the value of property, plant and equipment to estimated fair value when circumstances indicate such property, plant and equipment has been impaired and to reduce the value of oil and gas assets consisting of proved properties as the estimate of future successful production from these properties is reduced. Debt Disclosure [Abstract] Aggregate Principal Amount of Current and Long-Term Debt Senior Notes Debt Instrument, Fair Value Disclosure Debt Instrument, Fair Value Disclosure Supplemental Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Selected Financial Information by Reportable Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Fair Value Assets and Liabilities Measured On Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Balance at January 1 Capitalized Exploratory Well Costs Additions Pending the Determination of Proved Reserves Capitalized Exploratory Well Cost, Additions Pending Determination of Proved Reserves Reclassifications to Proved Properties Reclassification to Well, Facilities, and Equipment Based on Determination of Proved Reserves Costs Charged to Expense (1) Capitalized Exploratory Well Cost, Charged to Expense Balance at December 31 Commitments and Contingencies Disclosure [Abstract] Standby letters of credit and guarantees outstanding Financial Standby Letter Of Credit An irrevocable undertaking (typically by a financial institution) to guarantee payment of a specified financial obligation if defined events occur or fail to occur. Subsidiary payment obligations demand for payment Subsidiary guarantees demand for payment Subsidiary guarantees demand for payment Total Minimum Commitments [Abstract] Unrecorded Unconditional Purchase Obligation, Rolling Maturity [Abstract] 2019 Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months 2020 Unrecorded Unconditional Purchase Obligation, Due in Rolling Year Two 2021 Unrecorded Unconditional Purchase Obligation, Due within Three Years 2022 Unrecorded Unconditional Purchase Obligation, Due within Four Years 2023 Unrecorded Unconditional Purchase Obligation, Due within Five Years 2024 and beyond Unrecorded Unconditional Purchase Obligation, Due after Five Years Total Minimum Commitments Unrecorded Unconditional Purchase Obligation Rental expenses associated with existing leases Operating Leases, Rent Expense Average Sales Price and Production Costs Per Unit of Production [Table] Average Sales Price and Production Costs Per Unit of Production [Table] Average Sales Price and Production Costs Per Unit of Production [Line Items] Average Sales Price and Production Costs Per Unit of Production [Line Items] Production costs per barrel of oil equivalent Average Production Costs Per Barrel of Oil Equivalents (BOE) Acquisitions and Divestitures [Abstract] Acquisitions and Divestitures [Abstract] Preliminary Allocation of Total Purchase Price Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Debt Instrument Table [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 6.875% Senior Notes due 2018 Senior Notes Due 2018 [Member] 5.625% Senior Notes due 2019 Senior Notes Due 2019 [Member] 4.40% Senior Notes due 2020 4.40% Senior Notes Due 2020 [Member] 2.45% Senior Notes due 2020 Senior Notes Due 2020 [Member] 4.100% Senior Notes due 2021 Senior Notes Due 2021 [Member] 2.625% Senior Notes due 2023 Senior Notes Due 2023 [Member] senior notes due 2023 3.15% Senior Notes due 2025 Senior Notes Due 2025 [Member] Senior Notes Due 2025 [Member] 4.15% Senior Notes due 2026 Senior Notes Due 2026 [Member] Senior Notes Due 2026 [Member] 6.65% Senior Notes due 2028 Senior Notes Due 2028 [Member] 3.90% Senior Notes due 2035 Senior Notes Due 2035 [Member] Senior Notes Due 2035 [Member] 5.10% Senior Notes Due 2036 Senior Notes Due 2036 [Member] Senior Notes Due 2036 [Member] 5.875% Senior Notes due 2017 Senior Notes Due 2017 [Member] Debt Instrument Table [Line Items] Debt Instrument Table [Line Items] Long-Term Debt Long-term Debt, Gross Capital Lease Obligation Capital Lease Obligations Less: Current Portion of Long-Term Debt Long-term Debt, Current Maturities Unamortized Debt Discount Debt Instrument, Unamortized Discount Debt Issuance Costs Debt Issuance Costs, Net Total Long-Term Debt Long-term Debt, Excluding Current Maturities Debt Instrument Issuance [Abstract] Debt Instrument Issuance [Abstract] Debt Instrument Issuance Face Amount Debt Instrument, Face Amount Debt Instrument Issuance Interest Rate Debt Instrument, Interest Rate, Stated Percentage Long-Term Debt by Maturity [Abstract] Long-term Debt, Fiscal Year Maturity [Abstract] Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2019 Long-term Debt, Maturities, Repayments of Principal in Year Two Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2020 Long-term Debt, Maturities, Repayments of Principal in Year Three Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2021 Long-term Debt, Maturities, Repayments of Principal in Year Four Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2022 Long-term Debt, Maturities, Repayments of Principal in Year Five Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2023 Long-term Debt, Maturities, Repayments of Principal after Year Five Line of Credit Facility [Table] Line of Credit Facility [Table] Line of Credit Facility [Axis] Lender Name [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Revolving Credit Agreement 2020 Revolving Credit Agreement 2020 [Member] Uncommitted Credit Facilities Uncommitted Credit Facility [Member] Commercial Paper Commercial Paper [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Eurodollar [Member] Eurodollar [Member] Base Rate [Member] Base Rate [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Current Borrowings Outstanding Line of Credit Facility, Current Borrowing Capacity Average Borrowings Outstanding Short-term Debt, Average Outstanding Amount Short-term Debt, Weighted Average Interest Rate, over Time Short-term Debt, Weighted Average Interest Rate, over Time Line of Credit Facility, Expiration Date Line of Credit Facility, Expiration Date Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Maximum total debt-to-total capitalization ratio allowed under financial covenant (in hundredths) Maximum Total Debt To Total Capitalization Ratio Allowed Under Financial Covenant Amount specified in the debt agreement of the maximum debt-to-total capitalization level which the entity is allowed to reach without impacting the entity's ability to borrow under the agreement. Effective Interest Rate (in hundredths) Debt Instrument, Interest Rate, Effective Percentage Capital Lease [Abstract] Capital Lease [Abstract] Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table] Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table] Reserve Quantities by Type of Reserve [Axis] Petroleum Reserves [Axis] Type of Reserve [Domain] Type of Reserve [Domain] Crude Oil (MBbl) Oil [Member] Natural Gas (MMcf) Oil Equivalents (MBoe) Oil Equivalents (MBoe) [Member] Oil Equivalents (MBoe) [Member] Reserve Quantities [Line Items] Reserve Quantities [Line Items] Net Proved Reserves [Abstract] Net Proved Reserves [Abstract] Proved Developed Reserves [Rollforward] Proved Developed and Undeveloped Reserves [Roll Forward] Net proved reserves - beginning of period Proved Developed and Undeveloped Reserves, Net Revisions of previous estimates Proved Developed and Undeveloped Reserves, Revisions of Previous Estimates Purchases in place Proved Developed and Undeveloped Reserves, Purchases of Minerals in Place Extensions, discoveries and other additions Proved Developed and Undeveloped Reserves, Extensions, Discoveries, and Additions Sales in place Proved Developed and Undeveloped Reserves, Sales of Minerals in Place Production Proved Developed and Undeveloped Reserves, Production Net proved reserves - end of period Proved Developed Reserves (MBoe) [Roll Forward] Proved Developed Reserves (MBoe) [Roll Forward] Proved Developed Reserves (MBoe) [Roll Forward] Net proved reserves - beginning of period Proved Developed Reserves (stated in MBOE) The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable. Revisions of previous estimates Revisions of previous estimates (stated in MBOE) Revisions of previous estimates (stated in MBOE) Purchases in place Purchases in place (stated in MBOE) Purchases in place (stated in MBOE) Extensions, discoveries and other additions Extensions, discoveries and other additions (stated in MBOE) Extensions, discoveries and other additions (stated in MBOE) Sales in place Sales in place (stated in MBOE) Sales in place (stated in MBOE) Production Production (stated in MBOE) Production (stated in MBOE) Net proved reserves - end of period Net proved developed reserves Proved Developed Reserves (Volume) Net proved developed reserves (MBOE) Proved Developed Reserves (Energy) Net Proved Undeveloped Reserves [Abstract] Net Proved Developed and Undeveloped Reserves [Abstract] Net Proved Undeveloped Reserves (MBOE) [Rollforward] Increase Decrease In Proved Developed And Undeveloped Reserves (BOE) [Abstract] A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. Balance at January 1 Proved Undeveloped Reserves Beginning Balance Proved Undeveloped Reserves Beginning Balance (MBOE) Extensions and Discoveries Proved Undeveloped Extensions and Discoveries Proved Undeveloped Extensions and Discoveries (MBOE) Revisions Proved Undeveloped Reserves Revisions Proved Undeveloped Reserves Revisions (MBOE) Acquisition of Reserves Acquisition of Reserves (MBOE) Acquisition of Reserves (MBOE) Sales of Reserves Proved Undeveloped Reserves Sales of Reserves Proved Undeveloped Reserves Sales of Reserves (MBOE) Conversion to Proved Developed Reserves Proved Undeveloped Conversion to Proved Developed Reserves Proved Undeveloped Conversion to Proved Developed Reserves (MBOE) Balance at December 31 Proved Undeveloped Reserves Ending Balance Proved Undeveloped Reserves Ending Balance (MBOE) Net proved undeveloped reserves Proved Undeveloped Reserve (Volume) Net proved undeveloped reserve (MBOE) Proved Undeveloped Reserves (Energy) Capitalized Costs, Oil and Gas Producing Activities, Gross [Abstract] Capitalized Costs, Oil and Gas Producing Activities, Gross [Abstract] Proved properties Capitalized Costs, Proved Properties Unproved properties Capitalized Costs, Unproved Properties Total Capitalized Costs, Oil and Gas Producing Activities, Gross Accumulated depreciation, depletion and amortization Capitalized Costs, Accumulated Depreciation, Depletion, Amortization and Valuation Allowance Relating to Oil and Gas Producing Activities Net capitalized costs Capitalized Costs, Oil and Gas Producing Activities, Net Proceeds from Sale of Producing Properties Proceeds from Sale of Oil and Gas Property and Equipment Book value of assets held-for-sale Assets Held For Sale Long Lived Book Value Book value portion of assets classified as held for sale. Book value of asset retirement obligations Book Value Liabilities Measured On Recurring Basis Obligations Book value of obligations measured on a recurring basis. Proceeds from Sales of Producing Properties EstimatedProceedsFromSalesOfProducingPropertiesAndAcreage Estimated proceeds from the sale of producing properties and acreage. Stock Issued During Period, Shares, Acquisitions (in shares) Stock Issued During Period, Shares, Acquisitions Payments to Acquire Businesses, Gross Payments to Acquire Businesses, Gross Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Business Combination, Consideration Transferred Cash Acquired from Acquisition Business Combination, Separately Recognized Transactions [Table] Business Combination, Separately Recognized Transactions [Table] Business Combination, Separately Recognized Transactions [Axis] Business Combination, Separately Recognized Transactions [Axis] Business Combination, Separately Recognized Transactions [Domain] Business Combination, Separately Recognized Transactions [Domain] Business Combination, Separately Recognized Transactions [Line Items] Business Combination, Separately Recognized Transactions [Line Items] (Gain) Loss on Disposition of Assets Gain (Loss) on Disposition of Assets Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed Cash and Equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Accounts Receivable, Net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Inventories Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Other Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other Total Current Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Oil and Gas Properties (Successful Efforts Method) Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Oil and Gas Properties (Successful Efforts Method) Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Oil and Gas Properties (Successful Efforts Method) Other Property, Plant and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Property, Plant and Equipment Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Other Property, Plant And Equipment Total Property, Plant and Equipment, Net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Other Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Total Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Accounts Payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued Taxes Payable Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Accrued Taxes Payable Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Accrued Taxes Payable Other Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other Total Current Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Long-Term Debt Asset Retirement Obligations Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Asset Retirement Obligations Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Asset Retirement Obligations Off-Market Transportation Contracts Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Off-Market Transportation Contracts Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Off-Market Transportation Contracts Other Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Deferred Income Taxes Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent Total Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Total Consideration Transferred Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Vesting Schedule Vesting Schedule [Table Text Block] [Table Text Block] for Vesting Schedule [Table] Weighted Average Fair Values and Valuation Assumptions Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Share Based Compensation Arrangement By Share Based Payment Award Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Stock Options and SARs Outstanding and Exercisable Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block] ESPP Activity Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity [Table Text Block] Restricted Stock and Restricted Stock Unit Transactions Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Weighted Average Fair Values and Valuation Assumptions for Performance Units/Stocks Performance Units and Performance Stock Grants Weighted Average Fair Values and Valuation Assumptions [Table Text Block] Performance Units and Performance Stock Grants Weighted Average Fair Values and Valuation Assumptions [Table Text Block] Performance Unit and Performance Stock Transactions Share-based Compensation, Performance Shares Award Outstanding Activity [Table Text Block] Net Changes in Capitalized Exploratory Well Costs Net Changes In Suspended Well Costs This summarizes the net changes in the suspended well costs. Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Earnings Per Share [Abstract] Computation of Net Income (Loss) Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Interest income Interest Income, Other Adjustment to Deferred Compensation Expense Adjustment to deferred compensation expense Adjustment to deferred compensation expense Net Foreign Currency Transaction Gains (Losses) Foreign Currency Transaction Gain (Loss), Realized Equity income from investments in Trinidad Income (Loss) from Equity Method Investments Stockholders' Equity Note [Abstract] Stockholder's Equity Stockholders' Equity Note Disclosure [Text Block] Asset Retirement Obligation Rollforward Analysis Schedule of Asset Retirement Obligations [Table Text Block] Net Income (Loss) Per Share Earnings Per Share [Text Block] Dividends, Common Stock An aggregate maximum of shares of common stock authorized for repurchase Treasury Stock Acquired Repurchase Shares Authorization Maximum number of shares authorized for repurchase under a share repurchase program authorized by an entity's Board of Directors. Remaining shares available for purchase under share repurchase authorization Treasury Stock Acquired Repurchase Shares Authorization Available Remaining number of shares available for repurchase under a share repurchase program authorized by an entity's Board of Directors. Dividends Common Stock Declared Per Share Dividends Common Stock Declared Per Share Aggregate dividends declared during the period for each share of common stock outstanding Dividends Payable, Amount Per Share After Increase Dividends Payable, Amount Per Share After Increase The per share amount of a dividend declared, but not paid. Percentage increase of cash dividend on common stock Percentage increase of cash dividend on common stock Percentage increase of cash dividend on common stock. Common Stock, Shares Authorized Common Stock, Dividends, Per Share, Cash Paid Common Stock, Dividends, Per Share, Cash Paid Common Stock Activity [Abstract] Common Stock Activity [Abstract] Common Stock Activity [Table] Common Stock Activity [Table] Schedule detailing information related to common stock activity. Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Shares, Outstanding [Member] Common Shares, Outstanding [Member] Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Common Shares, Treasury [Member] Treasury Stock [Member] Common Shares, Issued [Member] Common Shares, Issued [Member] Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. Common Stock Activity [Line Items] Common Stock Activity [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Balance (in shares) Common Stock Issued Under Stock-Based Compensation Plans (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Treasury Stock Purchased (1) (in shares) Treasury Stock, Shares, Acquired Common Stock Issued Under Employee Stock Purchase Plan (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Treasury Stock Issued Under Stock-Based Compensation Plans (in shares) Treasury Stock Issued Under Other Equity Compensation Plans Number of treasury shares issued during the period as a result of other equity compensation plans. Upon reissuance, these are common shares outstanding. Balance (in shares) Preferred Stock, Shares Outstanding Preferred Stock, Shares Outstanding Net Proved and Proved Developed Oil and Gas Reserve Quantities Schedule of Net Proved and Proved Developed Oil and Gas Reserve Quantities [Table Text Block] Tabular disclosure of the net quantities of an enterprise's interests in net proved and proved developed of (a) crude oil (including condensate and natural gas liquids), (b) natural gas (including coal bed methane), (c) synthetic oil, (d) synthetic gas, and (e) other nonrenewable natural resources that are intended to be upgraded during the period as of the beginning of the period, changes in quantities during the period, and as of the end of the period. Net Proved Developed and Net Proved Undeveloped Oil and Gas Reserve Quantities Schedule of Net Proved Developed and Net Proved Undeveloped Oil and Gas Reserve Quantities [Table Text Block] Tabular disclosure of the net quantities of an enterprise's interests in net proved developed and net proved undeveloped of (a) crude oil (including condensate and natural gas liquids), (b) natural gas (including coal bed methane), (c) synthetic oil, (d) synthetic gas, and (e) other nonrenewable natural resources that are intended to be upgraded during the period as of the beginning of the period, changes in quantities during the period, and as of the end of the period. Net Proved Undeveloped Reserves Net Proved Undeveloped Reserves [Table Text Block] Net Proved Undeveloped Reserves [Table Text Block] Capitalized Costs Relating to Oil and Gas Producing Activities Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Table Text Block] Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure [Table Text Block] Results of Operations for Oil and Gas Producing Activities Results of Operations for Oil and Gas Producing Activities Disclosure [Table Text Block] Production Costs Per Barrel of Oil Equivalent Production Costs Per Barrel Of Oil Equivalent Text Block Information related to the average production costs per barrel of oil equivalent for oil and gas producing activities. Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves Table Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure [Table Text Block] Changes in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Reserves Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows [Table Text Block] Statement of Cash Flows [Abstract] Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net Income (Loss) Items Not Requiring (Providing) Cash Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Stock-Based Compensation Expenses Share-based Compensation Deferred Income Taxes (Gains) Losses on Asset Dispositions, Net Other, Net Other Noncash Income (Expense) Mark-to-Market Commodity Derivative Contracts Unrealized Gain (Loss) on Derivatives and Commodity Contracts [Abstract] Total (Gains) Losses Unrealized Gain (Loss) on Derivatives and Commodity Contracts Net Cash Received from (Payments for) Settlements of Commodity Derivative Contracts Realized Gains (Losses) This element reflects realized gain (loss) on the settlement of financial commodity derivative instruments. Excess Tax Benefits from Stock-Based Compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Other, Net Other, Net Excluding Gains Losses The cash inflows/outflows from operating activities not classfied elsewhere. Changes in Components of Working Capital and Other Assets and Liabilities Increase (Decrease) in Operating Capital [Abstract] Accounts Receivable Increase (Decrease) in Receivables Inventories Increase (Decrease) in Inventories Accounts Payable Increase (Decrease) in Accounts Payable Accrued Taxes Payable Increase (Decrease) in Accrued Taxes Payable Other Assets Increase (Decrease) in Other Operating Assets Other Liabilities Increase (Decrease) in Other Operating Liabilities Changes in Components of Working Capital Associated with Investing and Financing Activities Changes in Components of Working Capital Associated with Investing and Financing Activities The net change during the reporting period of all current assets and liabilities used in investing and financing activities. Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities Investing Cash Flows Net Cash Provided by (Used in) Investing Activities [Abstract] Additions to Oil and Gas Properties Payments to Acquire Oil and Gas Property and Equipment Additions to Other Property, Plant and Equipment Payments to Acquire Other Property, Plant, and Equipment Proceeds from Sales of Assets Payments to Acquire Businesses, Net of Cash Acquired Payments to Acquire Businesses, Net of Cash Acquired Payments for (Proceeds from) Other Investing Activities Payments for (Proceeds from) Other Investing Activities Changes in Components of Working Capital Associated with Investing Activities Changes in Components of Working Capital Associated with Investing Activities The net change during the reporting period of all current assets and liabilities used in investing and financing activities. Net Cash Used in Investing Activities Net Cash Provided by (Used in) Investing Activities Financing Cash Flows Net Cash Provided by (Used in) Financing Activities [Abstract] Net Commercial Paper (Repayments) Borrowings Repayments of Commercial Paper Long-Term Debt Borrowings Proceeds from Issuance of Long-term Debt Long-Term Debt Repayments Repayments of Long-term Debt Dividends Paid Payments of Ordinary Dividends Excess Tax Benefits from Stock-Based Compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Treasury Stock Purchased Payments for Repurchase of Common Stock Proceeds from Stock Options Exercised and Employee Stock Purchase Plan Proceeds from Stock Options Exercised Debt Issuance Costs Payments of Debt Issuance Costs Repayment of Capital Lease Obligation Repayments of Long-term Capital Lease Obligations Other, Net Proceeds from (Payments for) Other Financing Activities Net Cash Used in Financing Activities Net Cash Provided by (Used in) Financing Activities Effect of Exchange Rate Changes on Cash Effect of Exchange Rate on Cash and Cash Equivalents Increase (Decrease) in Cash and Cash Equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and Cash Equivalents at Beginning of Year Cash and Cash Equivalents, at Carrying Value Cash and Cash Equivalents at End of Year Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Assets [Member] Assets [Member] Call Option [Member] Call Option [Member] Put Option [Member] Put Option [Member] Liability [Member] Liability [Member] Derivatives, Fair Value, by Derivative Instrument Risk [Axis] Derivative, Name [Domain] Derivative Contracts - January through December (closed) [Member] Derivative Contracts - January through December (closed) [Member] Derivative Contracts - January through December (closed) Derivative Contracts - Year Two - January (closed) [Member] Derivative Contracts - Year Two - January (closed) [Member] Derivative Contracts - Year Two - January (closed) Derivative Contracts - Year Two - February through December [Member] Derivative Contracts - Year Two - February through December [Member] The derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. Derivative Contracts - January through September (closed) [Member] Derivative Contracts January - September (closed) [Member] Derivative Contracts - January through September (closed) Derivative Contracts - October through December (closed) [Member] Derivative Contracts - October through December (closed) [Member] Derivative Contracts - October through December (closed) Derivative Contracts - January through November (closed) [Member] Derivative Contracts - January through November (closed) [Member] Derivative Contracts - January through November (closed) Derivative Contracts - March through November (closed) [Member] Derivative Contracts - March through November (closed) [Member] Derivative Contracts - March through November (closed) Price Risk Derivative [Member] Price Risk Derivative [Member] Derivative Contracts - December (closed) [Member] Derivative Contracts - December (closed) [Member] Derivative Contracts - December (closed) Crude Oil Derivative Contracts - December (closed) [Member] Crude Oil Derivative Contracts - December (closed) [Member] Volume (Bbld) Derivative, Nonmonetary Notional Amount, Volume Derivative, Swap Type, Average Fixed Price Derivative, Swap Type, Average Fixed Price Derivative, Cash Received For Offsetting Hedges Derivative, Cash Received For Offsetting Hedges The amount of cash received during the period for offsetting hedges. volume (MMBTU) Derivative, Nonmonetary Notional Amount, Energy Measure Derivative, Average Price Risk Option Strike Price Derivative, Average Price Risk Option Strike Price Assets from Price Risk Management Activities Derivative Asset, Current Other Assets Derivative Asset, Noncurrent Liabilities from Price Risk Management Activities Derivative Liability, Current Other Liabilities Derivative Liability, Noncurrent Receivable Major Customer Percentage Receivable Major Customer Percentage Percent of total receivables represented by amounts due from a single external customer. Gains (Losses) on Mark-to-Market Commodity Derivative Contracts Net Cash Received from (Payments for) Settlements of Commodity Derivatives Contracts Derivative Collateral [Abstract] Derivative, Collateral [Abstract] Collateral Held on Derivative Derivative, Collateral, Obligation to Return Cash Collateral Had on Derivaitve Derivative, Collateral, Right to Reclaim Cash Accounting For Certain Long-Lived Assets Accounting for Certain Long-Lived Assets For long-lived assets to be held and used by an entity, disclosures may include a description of the impaired long-lived asset and facts and circumstances leading to the impairment, amount of the impairment loss and where the loss is located in the income statement, method(s) for determining fair value, and the segment in which the impaired long-lived asset is reported. Common stock activity Schedule Of Common Stock Activity [TextBlock] This element is used to capture the disclosure pertaining to an entity's common stock activity. An entity's common stock activity includes shares issued, shares held in treasury, and shares outstanding. Minimum commitments for unrecorded unconditional purchase obligations Unrecorded Unconditional Purchase Obligations Disclosure [Table Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Foreign Currency Translation Adjustment [Member] Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Other [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Loss Before Reclassifications Other Comprehensive Income (Loss), before Reclassifications, before Tax Tax Effects Other Comprehensive Income (Loss), Tax Significant Amount Reclassified Out of AOCI Significant amounts reclassified out of AOCI Significant amounts reclassified out of AOCI Share-based Arrangements with Employees and Nonemployees [Abstract] Share-based Arrangements with Employees and Nonemployees [Abstract] Employee Service Share-based Compensation, Aggregate Disclosures [Abstract] Employee Service Share-based Compensation, Aggregate Disclosures [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Lease And Well [Member] Lease And Well [Member] Name or caption of a line item on the balance sheet or income statement which was increased or decreased by share-based compensation costs during the period. Specifically, the Lease and Well category. Gathering And Processing Costs [Member] Gathering And Processing Costs [Member] Name or caption of a line item on the income statement which was increased or decreased by share-based compensation costs during the period. Specifically, the Gathering and Processing Costs category. Exploration Costs [Member] Exploration Costs [Member] Name or caption of a line item on the income statement which was increased or decreased by share-based compensation costs during the period. Specifically, the Exploration cost category. General And Administrative [Member] General And Administrative [Member] Name or caption of a line item on the income statement which was increased or decreased by share-based compensation costs during the period. Specifically, the General and Administrative category. Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Stock Options and Sars [Member] Stock Options And Sars [Member] Stock options and stock-settled stock appreciations rights (SARS) ESPP [Member] Employee Stock [Member] Restricted Stock and Restricted Stock Units [Member] Restricted Stock And Restricted Stock Units [Member] Restricted Stock and Units which are not vested because the agreed upon employee services have not been received. Performance Units and Performance Stock [Member] Performance Shares [Member] Stock Options/SARs and Employee Stock Purchase Plan (ESPP) Disclosures [Line Items] Employee Stock Purchase Plan (ESPP) Disclosures [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Common Shares Available for Grant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Maximum term of stock options and SARs granted Share Based Compensation Arrangement By Share Based Payment Award Award Expiration Term Maximum Reflects maximum term as to when the share-based award expires as specified in the award agreement, which may be presented in a variety of ways (for example, number of years, number of months, days, quarters and quarters of a year). Percentage of fair market value at which employees may purchase company stock via the ESPP Percentage of fair market value at which employees may purchase company stock via the ESPP Percentage of fair market value at which employees may purchase company stock via the ESPP Maximum Percentage Of Employee Pay Eligible For Contribution To ESPP Percentage Maximum Percentage Of Employee Pay Eligible For Contribution To Espp Percentage Maximum percentage of an employee's pay that is eligible for participation in the company's ESPP. Share-based Compensation Expense Related To Stock Options, SAR and ESPP Grants Allocated Share-based Compensation Expense Stock Options/SARs Vested or Expected to Vest (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Weighted average grant price for stock options/SARs vested or expected to vest (per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Intrinsic value of stock options/SARs vested or expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Weighted Average Remaining Contractual Life for Stock Options/SARs Vested or Expected to Vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Unrecognized compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted average period over which unrecognized compensation expense will be recognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Intrinsic Value Of Stock Options/SARs Exercised During The Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Weighted Average Fair Value And Valuation Assumptions Used To Value Stock Options/SARs, ESPP, and Performance Units/Stock-Based Compensation [Abstract] Weighted Average Fair Value And Valuation Assumptions Used To Value Stock Based Compensation [Abstract] Weighted Average Fair Value of Grants (price per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Expected Volatility (in hundredths) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Risk-Free Interest Rate (in hundredths) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Dividend Yield (in hundredths) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected Life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Stock Options and SARs Rollforward [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at January 1 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Exercised (1) (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding at December 31 (in shares) Stock Options/SARs Exercisable at December 31 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Stock Options/SARs Exercisable at December 31 (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Approximate Number of Participants Approximate Number Of Participants In Espp The approximate number of employees participating in the employee stock purchase plan. Shares Purchased Employee Stock Purchase Plan Espp Shares Contributed To Espp An entity often discloses the number of shares provided to the ESPP during the period. Aggregate Purchase Price Employee Stock Purchase Plan Espp Cash Contributions To Espp An entity often discloses the amount of cash contributions paid to the ESPP. Weighted Average Grant Price Stock Option and SARs [Rollfoward] Share Based Compensation Arrangement By Share Based Payment Award Options And Stock Appreciation Rights Additional Disclosures Abstract [Abstract] Outstanding at January 1 (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Outstanding at December 31 (in dollars per share) Number of Shares and Units [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding at January 1 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Granted for Performance Multiple (1) (in shares) Granted for Performance Multiple (1) Granted for Performance Multiple Released (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding at December 31 (in shares) Weighted Average Grant Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Outstanding at January 1 (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Granted for Performance Multiple (1) (in dollars per share) Granted for Performance Multiple (1) (in dollars per share) Granted for Performance Multiple Released (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Outstanding at December 31 (in dollars per share) Performance Units and Performance Stock [Abstract] Performance Units and Performance Stock [Abstract] Performance Units and Performance Stock Minimum Performance Multiple at the Completion Performance Period Minimum Performance Multiple at the Completion of the Performance Period Minimum Performance Multiple to be Applied to Performance Stock/Units Granted at the Completion of the Performance Period Maximum Performance Multiple at the Completion Performance Period Maximum Performance Multiple at the Completion of the Performance Period Maximum Performance Multiple to be Applied to Performance Stock/Units Granted at the Completion of the Performance Period Minimum Performance Units and Stock Allowed to be Outstanding Minimum Performance Units and Stock Allowed to be Outstanding Minimum Performance Units and Stock Allowed to be Outstanding Maximum Performance Units and Stock Allowed to be Outstanding Maximum Performance Units and Stock Allowed to be Outstanding Maximum Performance Units and Stock Allowed to be Outstanding Additional Performance Awards Granted Additional Performance Awards Granted Additional Performance Awards Granted Compensation expense related to the company's stock-based compensation plans Performance Period Performance Period Performance period relative to the total shareholder return of a designated group of peer companies. Intrinsic value released during the year Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested Aggregate intrinsic value of stock and unit outstanding Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Shares Outstanding, By Grant Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] $ 50.00 to $ 82.99 Grant Price Range 1 [Member] This element represents exercise price range 1 of shares authorized and outstanding at the end of period. 83.00 to 95.99 Grant Price Range 2 [Member] This element represents exercise price range 2 of shares authorized and outstanding at the end of period. 96.00 to 96.99 Grant Price Range 3 [Member] This element represents exercise price range 3 of shares authorized and outstanding at the end of period. 97.00 to 125.99 Grant Price Range 4 [Member] This element represents exercise price range 4 of shares authorized and outstanding at the end of period. 126.00 to 129.99 Grant Price Range 5 [Member] This element represents exercise price range 5 of shares authorized and outstanding at the end of period. Summary Information By Grant Price Range For Stock Options And SARs Outstanding And Exercisable At End Of Period [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Stock Options and SARs Outstanding Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Weighted Average Remaining Life for Outstanding Options and SARs Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted Average Grant Price For Outstanding Options and SARs Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price Aggregate Intrinsic Value For Outstanding Options and SARs Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Stock Options and SARs Exercisable Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options Weighted Average Remaining Life For Exercisable Units Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Weighted Average Grant Price For Exercisable Options and SARs Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price Aggregate Intrinsic Value For Exercisable Units Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Retirement Benefits [Abstract] Retirement Benefits [Abstract] Schedule of Defined Benefit and Defined Contribution Plans Disclosures [Table] Schedule of Defined Benefit and Defined Contribution Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Plans [Member] Pension Plan [Member] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Total pension plan costs Pension and Other Postretirement Benefits Cost (Reversal of Cost) Company contributions to foreign pension plans Defined Benefit and Contribution Plan Contributions By Employer The amount of contributions made by the employer in connection with foreign defined benefit and contribution plans. Defined Benefit Plan, Benefit Obligation Defined Benefit Plan, Benefit Obligation Fair value of foreign pension plan assets Defined Benefit Plan, Plan Assets, Amount Accrued benefit cost Liability, Other Postretirement Defined Benefit Plan Schedule of Impact of Adoption of New Accounting Revenue Recognition Standard (Tables) Schedule of Prospective Adoption of New Accounting Pronouncements [Table Text Block] ASSETS Assets [Abstract] Current Assets Cash and Cash Equivalents, at Carrying Value [Abstract] Cash and Cash Equivalents Accounts Receivable, Net Receivables, Net, Current Inventories Inventory, Net Income Taxes Receivable Income Taxes Receivable, Current Other Other Assets, Current Total Assets, Current Property, Plant and Equipment Property, Plant and Equipment, Net [Abstract] Oil and Gas Properties (Successful Efforts Method) Oil and Gas Property, Successful Effort Method, Gross Other Property, Plant and Equipment Property, Plant and Equipment, Other, Gross Total Property, Plant and Equipment Property, Plant and Equipment, Gross Less: Accumulated Depreciation, Depletion and Amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total Property, Plant and Equipment, Net Deferred Income Taxes Other Assets Other Assets, Noncurrent Total Assets Current Liabilities Liabilities, Current [Abstract] Accounts Payable Accounts Payable, Current Accrued Taxes Payable Taxes Payable, Current Dividends Payable Dividends Payable Liabilities from Price Risk Management Activities Current Portion of Long-Term Debt Other Other Liabilities, Current Total Liabilities, Current Long-Term Debt Other Liabilities Other Liabilities, Noncurrent Deferred Income Taxes Commitments and Contingencies (Note 8) Commitments and Contingencies Stockholders' Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common Stock, $0.01 Par, 1,280,000,000 Shares Authorized and 580,408,117 Shares and 578,827,768 Shares Issued at December 31, 2018 and 2017, respectively Common Stock, Value, Issued Additional Paid in Capital Additional Paid in Capital Accumulated Other Comprehensive Loss Retained Earnings Retained Earnings (Accumulated Deficit) Common Stock Held in Treasury, 385,042 Shares and 350,961 Shares at December 31, 2018 and 2017, respectively Treasury Stock, Value Total Stockholders' Equity Total Liabilities and Stockholders' Equity Liabilities and Equity Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Restricted Stock/Units and Performance Units/Stock [Member] Restricted Stock, Restricted Stock Units and Performance Units [Member] Restricted Stock, Restricted Stock Units and Performance Units [Member] Earnings Per Share [Line Items] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Numerator for Basic and Diluted Earnings per Share - [Abstract] Earnings Per Share, Basic and Diluted [Abstract] Denominator for Basic Earnings per Share - [Abstract] Weighted Average Shares Potential Dilutive Common Shares -[Abstract] Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract] Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangments Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Denominator for Diluted Earnings per Share - [Abstract] Denominator For Diluted Earnings Per Share [Abstract] Adjusted Diluted Weighted Average Shares Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract] Antidilutive Securities Excluded from Computation of Earnings Per Share [Abstract] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Anti-dilutive Securities excluded from Diluted Earnings Per Share Calculation Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Net Income (Loss) Per Share [Abstract] Net Income Loss Available To Common Stockholders [Abstract] Risk Management Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block]