Statement of Financial Position [Abstract] Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common Stock, Shares, Issued Common Stock, Shares, Issued Treasury Stock, Shares Treasury Stock, Shares Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis Of Presentation Basis of Presentation and Significant Accounting Policies [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Reported Value Measurement [Member] Reported Value Measurement [Member] Estimate of Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Investments Investments Current portion of long-term debt Long-term Debt, Current Maturities Long-term Debt, Excluding Current Maturities Long-term Debt, Excluding Current Maturities Exploratory Cost Disclosure [Abstract] -- None. No documentation exists for this element. -- Projects with Exploratory Well Costs Capitalized for More than One Year [Table] Projects with Exploratory Well Costs Capitalized for More than One Year [Table] Project [Axis] Project [Axis] Project [Domain] Project [Domain] Colorado [Member] Colorado [Member] Colorado [Member] Eagle Ford Shale [Member] Eagle Ford Shale [Member] Eagle Ford Shale [Member] Nuna [Member] Nuna [Member] Nuna [Member] Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items] Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items] Capitalized Exploratory Well and Project Activity [Table] Capitalized Exploratory Well and Project Activity [Table] Capitalized Exploratory Well and Project Activity [Table] Capitalized exploratory costs [Member] Capitalized exploratory costs [Member] Capitalized exploratory costs [Member] Statement [Line Items] Statement [Line Items] Beginning capitalized exploratory costs Capitalized Exploratory Well Costs Additions to exploratory costs pending the determination of proved reserves Capitalized Exploratory Well Cost, Additions Pending Determination of Proved Reserves Reclassification due to determination of proved reserves Reclassification to Well, Facilities, and Equipment Based on Determination of Proved Reserves Capitalized Exploratory Well Cost Assets Disposition Capitalized Exploratory Well Cost Assets Disposition Capitalized Exploratory Well Cost Assets Disposition Exploratory well costs charged to exploration expense Capitalized Exploratory Well Cost, Charged to Expense Ending capitalized exploratory costs Fair Value of Assets Classified as Held for Sale [Abstract] Fair Value of Assets Classified as Held for Sale [Abstract] Long Lived Assets Held-for-sale by Asset Type [Axis] Long Lived Assets Held-for-sale by Asset Type [Axis] Long Lived Assets Held-for-sale, Name [Domain] Long Lived Assets Held-for-sale, Name [Domain] Hugoton field [Member] Hugoton field [Member] Hugoton field [Member] Barnett Shale Field [Member] Barnett Shale Field [Member] Barnett Shale Field [Member] Pioneer Alaska [Member] Pioneer Alaska [Member] Pioneer Alaska [Member] Operating Activities [Axis] Operating Activities [Axis] Operating Activities [Domain] Operating Activities [Domain] Discontinued Operations [Member] Discontinued Operations [Member] Fair Value of Asset Group Fair Value of Asset Group Fair Value of Asset Group Commitments and Contingencies Disclosure [Abstract] Commitments And Contingencies Commitments and Contingencies Disclosure [Text Block] Interest and Other Income [Abstract] Interest income Other Interest and Dividend Income Income Tax Credits and Adjustments Income Tax Credits and Adjustments Deferred compensation plan income Deferred Compensation Plan Income Deferred Compensation Plan Income Equity interest in income of unconsolidated affiliate Income (Loss) from Equity Method Investments Other income Other Income Total interest and other income Other Nonoperating Income Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Defined Contribution Pension and Other Postretirement Plans Disclosure [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] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Restricted Stock Liability Awards [Member] Restricted Stock Liability Awards [Member] Restricted Stock Liability Awards [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Deferred Compensation Arrangement with Individual, Compensation Expense Deferred Compensation Arrangement with Individual, Compensation Expense Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Accounts Payable, Current Accounts Payable, Current Postretirement benefit obligation Defined Benefit Plan, Benefit Obligation Asset Retirement Obligation [Abstract] Schedule of asset retirement obligations Schedule of Asset Retirement Obligations [Table Text Block] Acquisitions and Divestitures [Abstract] Acquisitions and Divestitures [Abstract] Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block] Disposal Groups, Including Discontinued Operations [Table Text Block] Discontinued Operations Assets and Liabilities Included in Assets and Liabilities Held for Sale [Table Text Block] Discontinued Operations Assets and Liabilities Included in Assets and Liabilities Held for Sale [Table Text Block] [Table Text Block] for Discontinued Operations Assets and Liabilities Included in Assets and Liabilities Held for Sale [Table] Income Tax Disclosure [Abstract] Current income taxes Current Income Tax Expense (Benefit) Deferred income taxes Deferred Income Tax Expense (Benefit) Income tax benefit (provision) Income Tax Expense (Benefit) Effective Tax Rate Effective Income Tax Rate Reconciliation, Percent Statutory Tax Rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, Deduction, Amount Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount Unrecognized tax benefit recognized in period Unrecognized tax benefit recognized in period Unrecognized tax benefit recognized in period Unrecognized Tax Benefits Unrecognized Tax Benefits Asset Retirement Obligations Asset Retirement Obligation Disclosure [Text Block] Schedule of oil derivative contracts volume and weighted average price Schedule of Oil Derivative Contracts volume and weighted average price [Table Text Block] Schedule of Oil Derivative Contracts Volume and Weighted Average Price [Text Block] Schedule of NGL derivative volumes and weighted average prices Schedule of NGL Derivative Volumes and Weighted Average Prices [Table Text Block] Schedule of NGL Derivative Volumes and Weighted Average Prices [Table Text Block] Schedule of gas derivative volume and weighted average prices Schedule Of Gas Volume And Weighted Average Prices [Table Text Block] Schedule Of Gas Volume And Weighted Average Prices [Table Text Block] Offsetting Asset and Liability Offsetting Asset and Liability [Table Text Block] Offsetting Asset and Liability [Table Text Block] Schedule of derivative gains and losses recognized on statement of operations Schedule of Derivative Gains and Losses Recognized on Statement of Operations [Table Text Block] Schedule of Derivative Gains and Losses Recognized on Statement of Operations [Text Block] Income Statement [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Retained Earnings [Member] Retained Earnings [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Revenues and other income: Revenues [Abstract] Oil and gas Oil and Gas Revenue Sales of purchased oil and gas Revenue from Purchased Oil and Gas Interest and other Derivative gains, net Gain (Loss) on Derivative Instruments, Net, Pretax Gain (loss) on disposition of assets, net Gain (Loss) on Disposition of Property Plant Equipment Total revenues and other income Revenues Costs and expenses: Costs and Expenses [Abstract] Oil and gas production Oil and Gas Production Expense Production and ad valorem taxes Taxes, Miscellaneous Depletion, depreciation and amortization Depreciation, Depletion and Amortization Purchased oil and gas Cost of Purchased Oil and Gas Impairment of oil and gas properties Impairment of Oil and Gas Properties Exploration and abandonments Exploration Abandonment and Impairment Expense General and administrative General and Administrative Expense Accretion of discount on asset retirement obligations Asset Retirement Obligation, Accretion Expense Interest Interest Expense Other Other Nonoperating Expense Costs and Expenses Costs and Expenses Income (loss) from continuing operations before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax provision Net income (loss) attributable to common stockholders Net Income (Loss) Attributable to Parent Basic earnings per share: Earnings Per Share, Basic [Abstract] Income from continuing operations Income (Loss) from Continuing Operations, Per Basic Share Basic and diluted net loss per share attributable to common stockholders Earnings Per Share, Basic and Diluted Diluted earnings per share: Earnings Per Share, Diluted [Abstract] Income from continuing operations Income (Loss) from Continuing Operations, Per Diluted Share Net income Earnings Per Share, Diluted Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic weighted average shares outstanding Weighted Average Number of Shares Outstanding, Basic Diluted Weighted Average Number of Shares Outstanding, Diluted Dividends declared per share Common Stock, Dividends, Per Share, Declared Derivative [Table] Derivative [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Oil contracts [Member] Oil contracts [Member] Oil contracts [Member] Oil contracts, price per bbl [Member] Oil contracts, price per bbl [Member] Oil contracts, price per bbl [Member] Short Put [Member] Short Put [Member] Short Put [Member] Trading Activity [Axis] Trading Activity [Axis] Trading Activity, by Type [Domain] Trading Activity, by Type [Domain] Collar Contract For Second Quarter of Year One [Member] Collar Contract For Second Quarter of Year One [Member] Collar Contract For Second Quarter of Year One [Member] Collar Contract For Third Quarter of Year One [Member] Collar Contract For Third Quarter of Year One [Member] Collar Contract For Third Quarter of Year One [Member] Collar Contract For Fourth Quarter of Year One [Member] Collar Contract For Fourth Quarter of Year One [Member] Collar Contract For Fourth Quarter of Year One [Member] Collar Contracts for Year 2 [Member] Collar Contracts for Year 2 [Member] Collar Contracts for Year 2 [Member] Collar Contracts for Year 3 [Member] Collar Contracts for Year 3 [Member] Collar Contracts for Year 3 [Member] Collar Contracts With Short Puts For Second Quarter of Year One [Member] Collar Contracts With Short Puts For Second Quarter of Year One [Member] Collar Contracts With Short Puts For Second Quarter of Year One [Member] Collar Contracts With Short Puts For Third Quarter of Year One [Member] Collar Contracts With Short Puts For Third Quarter of Year One [Member] Collar Contracts With Short Puts For Third Quarter of Year One [Member] Collar Contracts With Short Puts For Fourth Quarter of Year One [Member] Collar Contracts With Short Puts For Fourth Quarter of Year One [Member] Collar Contracts With Short Puts For Fourth Quarter of Year One [Member] Collar Contracts With Short Puts for Year 2 [Member] Collar Contracts With Short Puts for Year 2 [Member] Collar Contracts With Short Puts for Year 2 [Member] Collar Contracts With Short Puts for Year 3 [Member] Collar Contracts With Short Puts for Year 3 [Member] Collar Contracts With Short Puts for Year 3 [Member] Rollfactor Swap Contracts For First Quarter of Year One [Member] Rollfactor Swap Contracts For First Quarter of Year One [Member] Rollfactor Swap Contracts For First Quarter of Year One [Member] Rollfactor Swap Contracts For Second Quarter of Year One [Member] Rollfactor Swap Contracts For Second Quarter of Year One [Member] Rollfactor Swap Contracts For Second Quarter of Year One [Member] Rollfactor Swap Contracts For Fourth Quarter of Year One [Member] Rollfactor Swap Contracts For Fourth Quarter of Year One [Member] Rollfactor Swap Contracts For Fourth Quarter of Year One [Member] Rollfactor Swap Contracts for Year 2 [Member] Rollfactor Swap Contracts for Year 2 [Member] Rollfactor Swap Contracts for Year 2 [Member] Rollfactor Swap Contracts for Year 3 [Member] Rollfactor Swap Contracts for Year 3 [Member] Rollfactor Swap Contracts for Year 3 [Member] Basis Swap Contracts for Year 2 [Member] Basis Swap Contracts for Year 2 [Member] Basis Swap Contracts for Year 2 Basis Swap Contracts for Fourth Quarter of Year One [Member] Basis Swap Contracts for Fourth Quarter of Year One [Member] Basis Swap Contracts for Fourth Quarter of Year One [Member] Swap Contracts for Year 2 [Member] Swap Contracts for Year 2 [Member] Swap Contracts for Year 2 [Member] Swap Contracts For Second Quarter of Year One [Member] Swap Contracts For Second Quarter of Year One [Member] Swap Contracts For Second Quarter of Year One [Member] Swap Contracts For Third Quarter of Year One [Member] Swap Contracts For Third Quarter of Year One [Member] Swap Contracts For Third Quarter of Year One [Member] Swap Contracts For Fourth Quarter of Year One [Member] Swap Contracts For Fourth Quarter of Year One [Member] Swap Contracts For Fourth Quarter of Year One [Member] Collar Contracts With Short Puts for Current Year [Member] Collar Contracts With Short Puts for Current Year [Member] Collar Contracts With Short Puts for Current Year [Member] Swap Contracts for Current Year [Member] Swap Contracts for Current Year [Member] Swap Contracts for Current Year [Member] Swap Contracts for Year 3 [Member] Swap Contracts for Year 3 [Member] Swap Contracts for Year 3 [Member] Rollfactor Swap Contracts for Current Year [Member] Rollfactor Swap Contracts for Current Year [Member] Rollfactor Swap Contracts for Current Year [Member] Derivative [Line Items] Derivative [Line Items] Premium Paid on Derivative Contract Premium Paid on Derivative Contract Premium Paid on Derivative Contract Derivative, Nonmonetary Notional Amount Derivative, Nonmonetary Notional Amount Derivative, Average Cap Price Derivative, Average Cap Price Derivative, Average Floor Price Derivative, Average Floor Price Derivative, Notional Amount, Price Per Unit Derivative, Notional Amount, Price Per Unit The price per unit of the notional amount of the derivative contract expressed in nonmonetary units. For example, the price per barrel specified in a fuel oil forward purchase contract. Derivative, Swap Type, Average Fixed Price Derivative, Swap Type, Average Fixed Price Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Earnings Per Share [Abstract] Reconciliation of earnings attributable to common stockholders, basic and diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Reconciliation Of Basic To Diluted Weighted Average Common Shares Outstanding Schedule of Weighted Average Number of Shares [Table Text Block] Reconciliation of Basic Weighted Average Shares to Diluted Weighted Average Shares [Table] Reconciliation of Basic Weighted Average Shares to Diluted Weighted Average Shares [Table] Reconciliation of Basic Weighted Average Shares to Diluted Weighted Average Shares [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Performance Shares [Member] Performance Shares [Member] Stock Options [Member] Employee Stock Option [Member] Weighted Average Number of Shares Outstanding Reconciliation [Line Items] Weighted Average Number of Shares Outstanding Reconciliation [Line Items] Weighted Average Number of Shares Outstanding Reconciliation [Line Items] Convertible senior notes dilution Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Diluted Debt Disclosure [Abstract] Long-Term Debt Long-term Debt [Text Block] Statement of Stockholders' Equity [Abstract] Pending Future Environmental Sanction Individual Pending Future Environmental Sanction Individual Pending Future Environmental Sanction Individual Pending Future Environmental Sanction Aggregate Pending Future Environmental Sanction Aggregate Pending Future Environmental Sanction Aggregate Future Rent Expense Future Rent Expense Future Rent Expense [Line Items] Other Expense [Abstract] Other Expense [Abstract] Schedule of components of other expense Schedule of Components of Other Expense Text Block Schedule of Components of Other Expense Text Block Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Commodity Price Derivatives [Member] Commodity Contract [Member] Interest Rate Derivatives [Member] Interest Rate Contract [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Derivatives - Current [Member] Derivative Current [Member] Derivative Current [Member] Derivatives - Noncurrent [Member] Derivative Noncurrent [Member] Derivative Noncurrent [Member] Total derivatives, Asset, Gross Derivative Asset, Fair Value, Gross Asset Derivative Liability, Fair Value, Gross Liability Derivative Liability, Fair Value, Gross Liability Derivative Assets Offset In Balance Sheet Derivative Assets Offset In Balance Sheet Derivative Assets Offset In Balance Sheet Derivative Liabilities Offset In Balance Sheet Derivative Liabilities Offset In Balance Sheet Derivative Liabilities Offset In Balance Sheet Derivative Assets, Current Derivative Asset, Current Derivative Assets, Noncurrent Derivative Asset, Noncurrent Derivative Asset, Fair Value, Net Derivative Asset, Fair Value, Amount Not Offset Against Collateral Derivative Liabilities, Current Derivative Liability, Current Derivative Liabilities, Noncurrent Derivative Liability, Noncurrent Derivative Liability, Fair Value, Net Derivative Liability, Fair Value, Amount Not Offset Against Collateral Restructuring and Related Activities [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Employee Severance [Member] Employee Severance [Member] Contract Termination [Member] Contract Termination [Member] Employee Relocation [Member] Employee Relocation [Member] Restructuring Plan [Axis] Restructuring Plan [Axis] Restructuring Plan [Domain] Restructuring Plan [Domain] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Domain] Other Comprehensive Income Location [Domain] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring Charges Restructuring and Related Cost, Incurred Cost Restructuring and Related Cost, Expected Cost Remaining Restructuring and Related Cost, Expected Cost Remaining Restructuring Reserve Restructuring Reserve Schedule of assets and liabilities measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Fair Value Measurements, Nonrecurring [Table Text Block] Fair Value Measurements, Nonrecurring [Table Text Block] Fair Value of Assets Classified as Held for Sale [Table Text Block] Fair Value of Assets Classified as Held for Sale [Table Text Block] Fair Value of Assets Classified as Held for Sale [Table Text Block] Schedule of carrying values and financial instruments not carried at fair value Fair Value, by Balance Sheet Grouping [Table Text Block] Cash, Cash Equivalents and Investments [Table Text Block] Cash, Cash Equivalents and Investments [Table Text Block] Asset Area [Axis] Asset Area [Axis] Asset Area [Axis] Asset Area [Domain] Asset Area [Domain] [Domain] for Asset Area [Axis] Gulf Coast [Member] Gulf Coast [Member] Gulf Coast [Member] Mid-Continent [Member] Mid-Continent [Member] Mid-Continent [Member] Permian Basin [Member] Permian Basin [Member] Permian Basin [Member] Basis Swap Contracts for Second Quarter of Year One [Member] Basis Swap Contracts for Second Quarter of Year One [Member] Basis Swap Contracts for Second Quarter of Year One [Member] Basis Swap Contracts for Third Quarter of Year One [Member] Basis Swap Contracts for Third Quarter of Year One [Member] Basis Swap Contracts for Third Quarter of Year One [Member] Basis Swap Contracts for Year 3 [Member] Basis Swap Contracts for Year 3 [Member] Basis Swap Contracts for Year 3 [Member] Basis Swap Contracts for Current Year [Member] Basis Swap Contracts for Current Year [Member] Basis Swap Contracts for Current Year So Cal Basis Swap Contracts for Current Year [Member] So Cal Basis Swap Contracts for Current Year [Member] So Cal Basis Swap Contracts for Current Year [Member] So Cal Basis Swap Contracts for Year 2 [Member] So Cal Basis Swap Contracts for Year 2 [Member] So Cal Basis Swap Contracts for Year 2 [Member] So Cal Basis Swap Contracts for Year 3 [Member] So Cal Basis Swap Contracts for Year 3 [Member] So Cal Basis Swap Contracts for Year 3 [Member] Gas contracts, in MMBTU [Member] Gas contracts, in MMBTU [Member] Gas contracts, in MMBTU [Member] Gas contracts, price per MMBTU [Member] Gas contracts, price per MMBTU [Member] Gas contracts, price per MMBTU [Member] Derivative, Swap Type, Price Differential Derivative, Swap Type, Price Differential Derivative, Swap Type, Price Differential Document And Entity Information [Abstract] Document and Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol 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 Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Line Items] Business Acquisition [Line Items] Gas and Oil Area, Developed, Net Gas and Oil Area, Developed, Net Production, Barrels of Oil Equivalents Production, Barrels of Oil Equivalents Payments to Acquire Businesses, Net of Cash Acquired Payments to Acquire Businesses, Net of Cash Acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings AssetRetirementObligationLiabilitiesAcquiredInBusinessCombination Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Business Acquisition, Transaction Costs Business Acquisition, Transaction Costs Capitalized exploratory well and project activity Capitalized Exploratory Well and Project Activity [Table Text Block] Capitalized Exploratory Well and Project Activity [Table Text Block] Capitalized Exploratory Costs And The Number Of Projects For Which Exploratory Costs Have Been Capitalized Schedule of Projects with Exploratory Well Costs Capitalized for More than One Year [Table Text Block] Fair Value Measurements Fair Value Disclosures [Text Block] Net Income Per Share Earnings Per Share [Text Block] Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract] Incentive Plans Compensation and Employee Benefit Plans [Text Block] Diesel Swap Current Year [Member] Diesel Swap Current Year [Member] Diesel Swap Current Year [Member] Diesel Swap Year 2 [Member] Diesel Swap Year 2 [Member] Diesel Swap Year 2 [Member] March 15, 2022 Interest Rate Swaps [Member] March 15, 2022 Interest Rate Swaps [Member] March 15, 2022 Interest Rate Swaps [Member] March 2016 Interest Rate Swaps [Member] March 2016 Interest Rate Swaps [Member] March 2016 Interest Rate Swaps [Member] Trading Activity, Gains and Losses, Net [Line Items] Trading Activity, Gains and Losses, Net [Line Items] Proceeds from Termination of Diesel Derivatives Proceeds from Termination of Diesel Derivatives Proceeds from Termination of Diesel Derivatives Derivative, Nonmonetary Notional Amount Derivative, Swap Type, Fixed Price Derivative, Swap Type, Fixed Price Proceeds from Termination of Interest Rate Derivatives Proceeds from Termination of Interest Rate Derivatives Proceeds from Termination of Interest Rate Derivatives Derivative, Fixed Interest Rate Derivative, Fixed Interest Rate Derivative, Average Variable Interest Rate Derivative, Average Variable Interest Rate Notional amount of debt Swap Contract Notional Amount Fixed Rate of Interest and Variable LIBOR Swap Contract Notional Amount Fixed Rate of Interest and Variable LIBOR Notional amount of debt Swap Contract Notional Amount Fixed Rate of Interest and Variable On-The-Run 10-yr Treasury Rate Swap Contract Notional Amount Fixed Rate of Interest and Variable On-The-Run 10-yr Treasury Rate ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents, at Carrying Value Cash and Cash Equivalents, at Carrying Value Short-term Investments Short-term Investments Accounts receivable: Accounts Receivable, Net, Current [Abstract] Trade, net Accounts Receivable, Net, Current Due from affiliates Due from Affiliate, Current Income taxes receivable Income Taxes Receivable, Current Inventories Inventory, Net Prepaid expenses Prepaid Expense, Current Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Current Assets held for sale Disposal Group, Including Discontinued Operation, Assets Other current assets: Other Assets, Current [Abstract] Other Assets, Current [Abstract] Notes receivable Notes, Loans and Financing Receivable, Gross, Current Derivatives Assets, Current Other Other Assets, Current Total current assets Assets, Current Property, plant and equipment, at cost: Property, Plant and Equipment, Net [Abstract] Oil and gas properties, using the successful efforts method of accounting: Oil and Gas Property, Successful Effort Method, Net [Abstract] Proved properties Proved Oil and Gas Property, Successful Effort Method Unproved properties Unproved Oil and Gas Property, Successful Effort Method Accumulated depletion, depreciation and amortization Oil and Gas Property, Successful Effort Method, Accumulated Depreciation, Depletion and Amortization Total property, plant and equipment Oil and Gas Property, Successful Effort Method, Net Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Long-term Investments Long-term Investments Goodwill Goodwill Property, Plant and Equipment, Net Property, Plant and Equipment, Net Other assets: Other Assets, Noncurrent [Abstract] Derivative Assets, Noncurrent Other, net Other Assets, Noncurrent Assets, Total Assets LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable: Accounts Payable, Current [Abstract] Trade Accounts Payable, Trade, Current Due to affiliates Due to Affiliate, Current Interest payable Interest Payable, Current Income taxes payable Accrued Income Taxes, Current Deferred Tax Liabilities, Net, Current Deferred Tax Liabilities, Net, Current Liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Other current liabilities: Other Liabilities, Current [Abstract] Derivative Liabilities, Current Other Other Liabilities, Current Total current liabilities Liabilities, Current Derivative Liabilities, Noncurrent Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Other liabilities Other Liabilities, Noncurrent Stockholders' equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock, $.01 par value Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Treasury stock at cost Treasury Stock, Value Retained earnings Retained Earnings (Accumulated Deficit) Total equity attributable to common stockholders Stockholders' Equity Attributable to Parent Noncontrolling interests in consolidating subsidiaries Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Commitments and contingencies Commitments and Contingencies Liabilities and Equity, Total Liabilities and Equity Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Groups, Including Discontinued Operations, Name [Domain] Disposal Group Name [Domain] Assets of Disposal Group, Including Discontinued Operation, Current Disposal Group, Including Discontinued Operation, Assets, Current Disposal Group, Including Discontinued Operation, Property, Plant and Equipment Disposal Group, Including Discontinued Operation, Property, Plant and Equipment Assets held for sale Liabilities of Disposal Group, Including Discontinued Operation, Current Disposal Group, Including Discontinued Operation, Liabilities, Current Disposal Group, Including Discontinued Operation, Other Liabilities Disposal Group, Including Discontinued Operation, Other Liabilities Liabilities held for sale Acquisitions and Divestitures [Table] Gain (loss) on sale of assets [Table] Gain (loss) on sale of assets [Table] Proceeds Received Prior Year [Member] Proceeds Received Prior Year [Member] Proceeds Received Prior Year [Member] Proceeds Received Current Year [Member] Proceeds Received Current Year [Member] Proceeds Received Current Year [Member] Proceeds To Be Received In Future Year [Member] [Member] Proceeds To Be Received In Future Period [Member] Proceeds To Be Received In Future Period Sendero [Member] Sendero [Member] Sendero [Member] Other Ownership Interests Name [Axis] Other Ownership Interests Name [Axis] Other Ownership Interests, Name [Domain] Other Ownership Interests, Name [Domain] Limited Partner Interest [Member] Limited Partner Interest [Member] Limited Partner Interest [Member] Martin County [Member] Martin County [Member] Martin County [Member] Wolfcamp [Member] Wolfcamp [Member] Wolfcamp [Member] West Panhandle [Member] West Panhandle [Member] West Panhandle [Member] Acquisitions and Divestitures [Line Items] Gain Loss on Sale of Assets [Line Items] Gain Loss on Sale of Assets [Line Items] Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Equity Method Investment, Net Sales Proceeds Proceeds from Sale of Equity Method Investments Equity Method Investment, Realized Gain (Loss) on Disposal Equity Method Investment, Realized Gain (Loss) on Disposal Proceeds from Divestiture of Interest in Consolidated Subsidiaries Proceeds from Divestiture of Interest in Consolidated Subsidiaries Goodwill, Written off Related to Sale of Business Unit Goodwill, Written off Related to Sale of Business Unit Significant Acquisition and Disposal, Acquisition Costs or Sales Proceeds Disposal Group, Including Discontinued Operation, Consideration Maximum Payments From Related Party For Exploration Drilling And Completion Costs Maximum Payments From Related Party For Exploration Drilling And Completion Costs Maximum Payments From Related Party For Exploration Drilling And Completion Costs Payments From Related Party For Exploration Drilling And Completion Costs Percent Payments From Related Party For Exploration Drilling And Completion Costs Percent Payments From Related Party For Exploration Drilling And Completion Costs Percent Maximum Distribution Made to Limited Partner, Distributions Declared, Per Unit Maximum Distribution Made to Limited Partner, Distributions Declared, Per Unit Maximum Distribution Made to Limited Partner, Distributions Declared, Per Unit Joint Venture Investment Ownership Percentage Joint Venture Investment Ownership Percentage Investment in Joint Venture Proceeds from Sale of Productive Assets Proceeds from Sale of Productive Assets Marketing Gas contracts, in MMBTU [Member] Marketing Gas contracts, in MMBTU [Member] Marketing Gas contracts, in MMBTU [Member] Marketing gas contracts, price per MMBTU [Member] Marketing gas contracts, price per MMBTU [Member] Marketing gas contracts, price per MMBTU [Member] Marketing Oil contracts, in BBL [Member] Marketing Oil contracts, in BBL [Member] Marketing Oil contracts, in BBL [Member] Marketing oil contracts, price per BBL [Member] [Member] Marketing oil contracts, price per BBL [Member] Marketing oil contracts, price per BBL [Member] NonRecurring Fair Value Disclosures [Abstract] NonRecurring Fair Value Disclosures [Abstract] 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] Raton Field [Member] Raton Field [Member] Raton Field [Member] South Texas Eagle Ford Shale [Member] South Texas Eagle Ford Shale [Member] South Texas Eagle Ford Shale [Member] South Texas Edwards And Austin Chalk [Member] South Texas Edwards And Austin Chalk [Member] SouthTexasEdwardsAndAustinChalkMember Tangible Asset Impairment Charges Tangible Asset Impairment Charges Inventory Write-down Inventory Write-down Impairment of oil and gas properties Management oil price outlook Management oil price outlook Management oil price outlook Management gas price outlook Management gas price outlook Management gas price outlook Impairment of Long-Lived Assets Held-for-use Impairment of Long-Lived Assets Held-for-use Other Expense Other Operating Expenses Text Block Other Operating Expenses [Text Block] Acquisition and Divestitures Mergers, Acquisitions and Dispositions Disclosures [Text Block] Transportation commitment charges Transportation Commitment Loss Transportation Commitment Loss Third-party vertical integration services Third-party vertical integration services Third-party vertical integration services (b) Above market and idle drilling and well services equipment charges Idle Rig Expense Expenses from idle and terminate rigs. Terminated drilling rig contract charges Terminated Drilling Rig Expense Terminated Drilling Rig Expense Other Other General Expense Contingency and environmental accrual adjustments Change In Accrual For Legal And Environmental Contingencies Change in Accrual for Legal and Environmental Contingencies. Total other expense GrossRevenuesIncludedInThirdPartyLossFromVerticalIntegrationServices GrossRevenuesIncludedInThirdPartyLossFromVerticalIntegrationServices GrossRevenuesIncludedInThirdPartyLossFromVerticalIntegrationServices GrossExpensesIncludedInThirdPartyLossFromVerticalIntegrationServices GrossExpensesIncludedInThirdPartyLossFromVerticalIntegrationServices GrossExpensesIncludedInThirdPartyLossFromVerticalIntegrationServices Common Stock [Member] Common Stock [Member] Additional Paid-In Capital [Member] Additional Paid-in Capital [Member] Treasury Stock [Member] Treasury Stock [Member] Noncontrolling Interests [Member] Noncontrolling Interest [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance, shares Shares, Outstanding Beginning Balance Stock Issued During Period, Shares, New Issues Stock Issued During Period, Shares, New Issues Stock Issued During Period, Value, New Issues Stock Issued During Period, Value, New Issues Dividends declared ($0.04 per share) Dividends, Cash Exercise of long-term incentive plan stock options and employee stock purchases, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercise of long-term incentive plan stock options and employee stock purchases Stock Issued During Period, Value, Stock Options Exercised Treasury stock purchases, shares Treasury Stock, Shares, Acquired Treasury stock purchases Treasury Stock, Value, Acquired, Cost Method Tax benefit related to stock-based compensation Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Pioneer Southwest merger transaction costs Adjustments to Additional Paid in Capital, Other Compensation costs: Share-based Compensation [Abstract] Vested compensation awards, shares Stock Issued Or Vested During Period Shares Stock Awards Number of common stock issued as a result of granting or vesting of employee stock awards (including income tax benefits), and the shares of treasury stock purchases related to withholding taxes. Vested compensation awards Stock Issued Or Vested During Period Value Stock Awards Par value of share-based payments that vest or lapse during the period. Compensation costs included in net income Allocated Share-based Compensation Expense Cash distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Net Income (Loss) Attributable to Parent Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Ending Balance, shares Ending Balance Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Six Point Six Five Percent Senior Notes Due Two Thousand Seventeen [Member] Six Point Six Five Percent Senior Notes Due Two Thousand Seventeen [Member] Six Point Six Five Percent Senior Notes Due Two Thousand Seventeen [Member] Six Point Eight Seven Five Percent Senior Notes Due Two Thousand Eighteen [Member] Six Point Eight Seven Five Percent Senior Notes Due Two Thousand Eighteen [Member] Six Point Eight Seven Five Percent Senior Notes Due Two Thousand Eighteen [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Outstanding borrowing Long-term Line of Credit Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Repayments of Long-term Debt Repayments of Long-term Debt Senior Notes Senior Notes Commodity Derivatives [Member] Commodity [Member] Diesel [Member] Diesel [Member] Diesel [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Trading Securities, Fair Value Disclosure Trading Securities Investments, Fair Value Disclosure Investments, Fair Value Disclosure Derivative Asset, Fair Value, Net Deferred Compensation Plan Assets Deferred Compensation Plan Assets Assets, Fair Value Disclosure Assets, Fair Value Disclosure Liabilities, Fair Value Disclosure Financial and Nonfinancial Liabilities, Fair Value Disclosure Recurring Measurements, (Fair Value, Total) Recurring Measurements, (Fair Value, Net) Recurring Measurements, (Fair Value, Net). Schedule of Other Ownership Interests [Table] Schedule of Other Ownership Interests [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Pioneer Southwest [Member] Pioneer Southwest [Member] Relating to Pioneer Southwest. General Partner Interest [Member] General Partner Interest [Member] General Partner Interest [Member] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Proceeds from issuance of common stock, net of issuance costs Proceeds from Issuance of Common Stock Interest And Other Income Other Income and Other Expense Disclosure [Text Block] Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income (loss) Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Impairment of Inventory and Other Property and Equipment Impairment of Inventory and Other Property and Equipment Impairment of Inventory and Other Property and Equipment Exploration expenses, including dry holes Dry Hole Expense The amount of noncash dry hole and unproved property abandonment expense during the period. Deferred income taxes Gain on disposition of assets, net Interest expense Amortization of Debt Issuance Costs and Discounts Derivative related activity Noncash Gain Loss On Derivative Instruments Aggregate net noncash gain (loss) on commodity and interest rate derivative instruments. Amortization of stock-based compensation Amortization Stock Based Compensation Non-cash amortization of unvested stock-based compensation during the operating period. Other Other Operating Activities, Cash Flow Statement Change in operating assets and liabilities, net of effects from acquisitions and dispositions: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable, net Increase (Decrease) in Accounts Receivable Income taxes receivable Increase (Decrease) in Income Taxes Receivable Inventories Increase (Decrease) in Inventories Prepaid expenses Increase (Decrease) in Prepaid Expense Derivatives Increase (Decrease) in Derivative Assets and Liabilities Increase Decrease in Investments Increase Decrease in Investments Increase Decrease in Investments Other current assets Increase (Decrease) in Other Current Assets Accounts payable Increase (Decrease) in Accounts Payable Interest payable Increase (Decrease) in Interest Payable, Net Income taxes payable Increase (Decrease) in Income Taxes Payable Other current liabilities Increase (Decrease) in Other Current Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Proceeds from disposition of assets, net of cash sold Business acquisition Proceeds from Sale and Maturity of Held-to-maturity Securities Proceeds from Sale and Maturity of Held-to-maturity Securities Purchase of investment securities Payments to Acquire Held-to-maturity Securities Additions to oil and gas properties Payments to Acquire Oil and Gas Property Additions to other assets and other property and equipment, net Payments to Acquire Other Productive Assets Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Borrowings under long-term debt Proceeds from Issuance of Long-term Debt Principal payments on long-term debt Distributions to noncontrolling interests Payments of Distributions to Affiliates Borrowings of other liabilities Borrowings Payments of Other Liabilities Borrowings and payments of other liabilities Exercise of long-term incentive plan stock options and employee stock purchases Proceeds from Stock Options Exercised Purchases of treasury stock Payments for Repurchase of Common Stock Tax (provision) benefits related to stock-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Payments of financing fees Payments of Financing Costs Dividends paid Payments of Dividends Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Income Taxes Income Tax Disclosure [Text Block] Income tax (provisions) benefits attributable to income from continuing operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Derivative Gains (Losses), Net [Member] Derivative Gains Losses [Member] Derivative gains (losses) [Member] Derivative gains, net Asset Retirement Obligation [Table] Asset Retirement Obligation [Table] Asset Retirement Obligation [Table] Asset Retirement Obligation [Line Items] Asset Retirement Obligation [Line Items] [Line Items] for Asset Retirement Obligation [Table] Asset Retirement Obligation Accretion Expense From Discontinued Operations Included in Asset Retirement Obligation Balance At End of Period Asset Retirement Obligation Accretion Expense From Discontinued Operations Included in Asset Retirement Obligation Balance At End of Period Asset Retirement Obligation Accretion Expense From Discontinued Operations Included in Asset Retirement Obligation Balance At End of Period Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Beginning asset retirement obligations Asset Retirement Obligation AssetRetirementObligationLiabilitiesAcquiredInBusinessCombination AssetRetirementObligationLiabilitiesAcquiredInBusinessCombination AssetRetirementObligationLiabilitiesAcquiredInBusinessCombination Asset Retirement Obligation, Liabilities Incurred Asset Retirement Obligation, Liabilities Incurred Changes in estimates Asset Retirement Obligation, Revision of Estimate Disposition of wells Asset Retirement Obligations Written Off Through Disposition Of Wells Asset Retirement Obligations Written Off Through Disposition of Wells. Liabilities settled Asset Retirement Obligation, Liabilities Settled Accretion of discount from continuing operations Accretion of discount from integrated services Asset Retirement Obligation Accretion Expense Integrated Services Asset Retirement Obligation Accretion Expense related to Integrated Services Ending asset retirement obligations Asset retirement obligations, current portions Asset Retirement Obligation, Current Schedule of Share Based Incentive Award Activity Schedue of Share Based Incentive Award Activity [Table Text Block] Schedue of Share Based Incentive Award Activity [Table Text Block] Components of interest and other income Interest and Other Income [Table Text Block] Share-based Award Activity [Abstract] Share-based Award Activity [Abstract] Restricted Stock Equity Awards [Member] Restricted Stock Equity Awards [Member] Restricted Stock-Equity Awards [Member] Performance Units [Member] Performance Units [Member] Performance Units [Member] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Oil and Gas Production Type [Axis] Oil and Gas Production Type [Axis] Production Type [Domain] Production Type [Domain] Butane [Member] Butane [Member] Butane [Member] Propane [Member] Propane [Member] Ethane [Member] Ethane [Member] Ethane [Member] NGL contract, in BBLS [Member] NGL contract, in BBLS [Member] NGL contract, in BBLS [Member] NGL contracts, price per BBL [Member] NGL contracts, price per BBL [Member] NGL contracts, price per BBL [Member] NGL contract, MMBtu Equivalent [Member] NGL contract, MMBtu Equivalent [Member] NGL contract, in MMBtu [Member] NGL contract, price per MMBtu Equivalent [Member] NGL contract, price per MMBtu Equivalent [Member] NGL contract, price per MMBtu Equivalent [Member] Collar Contracts for Current Year [Member] Collar Contracts for Current Year [Member] Collar Contracts for Current Year [Member] Proceeds from Termination of Butane Swap Contracts Proceeds from Termination of Butane Swap Contracts Proceeds from Termination of Butane Swap Contracts Exploratory Costs Oil and Gas Exploration and Production Industries Disclosures [Text Block] Subsequent Events [Text Block] Subsequent Events [Text Block] Presentation Consolidation, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Capitalized Exploratory Well Costs that Have Been Capitalized for Period of One Year or Less Capitalized Exploratory Well Costs that Have Been Capitalized for Period of One Year or Less Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year Capitalized Exploratory Well Costs Projects that have Exploratory Well Costs that have been Capitalized for Period Greater than One Year, Number of Projects Projects that have Exploratory Well Costs that have been Capitalized for Period Greater than One Year, Number of Projects Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Table] Continuing Operations [Member] Continuing Operations [Member] Statement Operating Activities Segment [Line Items] Statement Operating Activities Segment [Line Items] Statement Operating Activities Segment [Line Items] Income (loss) from continuing operations attributable to parent Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Participating Securities, Distributed and Undistributed Earnings, Basic Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Basic income (loss) from continuing operations attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Diluted income (loss) from continuing operations attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Diluted Investments, Debt and Equity Securities [Abstract] Schedule of Held-to-maturity Securities [Table] Schedule of Held-to-maturity Securities [Table] Debt Security [Axis] Debt Security [Axis] Major Types of Debt Securities [Domain] Major Types of Debt Securities [Domain] Cash and Cash Equivalents [Member] Cash and Cash Equivalents [Member] Commercial Paper [Member] Commercial Paper [Member] Corporate Bond Securities [Member] Corporate Bond Securities [Member] Bank Time Deposits [Member] Bank Time Deposits [Member] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Cash, Cash Equivalents, and Short-term Investments Cash, Cash Equivalents, and Short-term Investments Organization And Nature Of Operations Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]