Basis Of Presentation [Abstract] Basis Of Presentation [Abstract] Derivative [Table] Derivative [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Pioneer Southwest Ltip [Member] Pioneer Southwest Ltip [Member] Pioneer Southwest Ltip [Member] Derivative [Line Items] Derivative [Line Items] Pioneer Southwest's credit-adjusted risk-free rate curve basis Derivative, Description of Variable Rate Basis Pioneer Southwest's credit-adjusted risk-free rate curve, spread on variable rate Derivative, Basis Spread on Variable Rate 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 Schedule of Goodwill [Table] Schedule of Goodwill [Table] Business Segments [Axis] Business Segments [Axis] Segment [Domain] Segment [Domain] Barnett Shale Field [Member] Barnett Shale Field [Member] Barnett Shale Field [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill Goodwill Earnings Per Share [Abstract] 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] Stock Options [Member] Stock Options [Member] Unvested Performance units [Member] Unvested Performance units [Member] Unvested Performance units [Member] Conversion rights [Member] Conversion rights [Member] Conversion rights [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] Basic Weighted Average Number of Shares Outstanding, Basic Dilutive common stock options Incremental Common Shares Attributable to Call Options and Warrants Convertible senior notes dilution Incremental Common Shares Attributable to Conversion of Debt Securities Contingently issuable performance unit shares Incremental Common Shares Attributable to Contingently Issuable Shares Diluted Weighted Average Number of Shares Outstanding, Diluted Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Derivative Assets and Liabilities by Counterparty [Abstract] Derivative Assets and Liabilities by Counterparty [Abstract] Schedule of Derivative Assets and Liabilities by Counterparty [Table] Schedule of Derivative Assets and Liabilities by Counterparty [Table] Schedule of Derivative Assets and Liabilities by Counterparty [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Citibank, N.A. Counterparty [Member] Citibank, N.A. Counterparty [Member] Citibank, N.A. Counterparty [Member] JP Morgan Chase Counterparty [Member] JP Morgan Chase Counterparty [Member] JP Morgan Chase Counterparty [Member] Barclays Capital Counterparty [Member] Barclays Capital Counterparty [Member] Barclays Capital Counterparty [Member] BMO Financial Group [Member] BMO Financial Group [Member] BMO Financial Group [Member] J. Aron & Company [Member] J. Aron & Company [Member] J. Aron & Company [Member] BNP Paribas [Member] BNP Paribas [Member] BNP Paribas [Member] Credit Suisse [Member] Credit Suisse [Member] Credit Suisse [Member] Wells Fargo Bank, N.A. Counterparty [Member] Wells Fargo Bank, N.A. Counterparty [Member] Wells Fargo Bank, N.A. Counterparty [Member] Societe Generale [Member] Toronto Dominion Counterparty [Member] Toronto Dominion Counterparty Merrill Lynch [Member] Societe Generale [Member] Societe Generale [Member] Merrill Lynch [Member] Merrill Lynch [Member] Merrill Lynch [Member] Morgan Stanley [Member] Morgan Stanley [Member] Morgan Stanley [Member] Den Norske Bank [Member] Den Norske Bank [Member] Den Norske Bank [Member] Credit Agricole [Member] Credit Agricole [Member] Credit Agricole [Member] Deutsche Bank [Member] Deutsche Bank [Member] Deutsche Bank [Member] Vitol [Member] BP Corporation North America [Member] BP Corporation North America [Member] Macquarie Bank [Member] Macquarie Bank [Member] Macquarie Bank [Member] Royal Bank of Canada [Member] Royal Bank of Canada [Member] Royal Bank of Canada [Member] UBS [Member] UBS [Member] UBS [Member] Vitol [Member] Vitol [Member] Vitol [Member] Schedule of Derivative Assets and Liabilities by Counterparty [Line Items] Schedule of Derivative Assets and Liabilities by Counterparty [Line Items] Schedule of Derivative Assets and Liabilities by Counterparty [Line Items] Derivative Assets Derivative Assets Derivative Liabilities Derivative Liabilities Derivative Assets (Liabilities), at Fair Value, Net Derivative Assets (Liabilities), at Fair Value, Net Fair Value Disclosures [Abstract] Schedule of assets and liabilities measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Schedule of carrying values and financial instruments not carried at fair value Fair Value, by Balance Sheet Grouping [Table Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Covenant [Axis] Covenant [Axis] Covenant [Axis] Covenant [Domain] Covenant [Domain] Covenant [Domain] Maximum Leverage Ratio [Member] Maximum Leverage Ratio [Member] Maximum Leverage Ratio [Member] Net Present Value of Cash Flow to Total Debt [Member] Net Present Value of Cash Flow to Total Debt [Member] Net Present Value of Cash Flow to Total Debt [Member] Debt Conversion Description [Axis] Debt Conversion Description [Axis] Debt Conversion, Name [Domain] Debt Conversion, Name [Domain] Non-Cash [Member] Noncash [Member] Noncash Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Pioneer Southwest Credit Facility [Member] Pioneer Southwest Credit Facility [Member] Pioneer Southwest Credit Facility [Member] If Converted [Member] If Converted [Member] If Converted Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] 3.95 percent Senior Notes Due 2022 [Member] Three Point Nine Five Percent Senior Notes Due 2022 [Member] 3.95 percent Senior Notes Due 2022 [Member] 2.875% Convertible Senior Notes Due 2038 [Member] Two Point Eight Seven Five Percent Senior Convertible Notes Due Two Thousand Thirty Eight [Member] Two Point Eight Seven Five Percent Senior Convertible Notes Due Two Thousand Thirty Eight [Member] PXD Credit Facility [Member] Pxd Credit Facility [Member] PXD Credit Facility Debt Instrument [Line Items] Debt Instrument [Line Items] Outstanding borrowing Line of Credit Facility, Amount Outstanding Undrawn letters of credit Undrawn Letters Of Credit Undrawn Letters Of Credit Unused borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Undrawn Letters Of Credit Cancelled Undrawn Letters Of Credit Cancelled Undrawn Letters Of Credit Cancelled Debt Instrument Covenant, Maximum Leverage Ratio Debt Instrument Covenant, Maximum Leverage Ratio Debt Instrument Covenant, Maximum Leverage Ratio Debt Instrument Covenant, Net Present Value of Cash Flow to Total Debt Ratio Debt Instrument Covenant, Net Present Value of Cash Flow to Total Debt Ratio Debt Instrument Covenant, Net Present Value of Cash Flow to Total Debt Ratio Aggregate loan commitments Line of Credit Facility, Maximum Borrowing Capacity Senior Notes Senior Notes Convertible Debt Convertible Debt Senior notes, interest rate, percentage Debt Instrument, Interest Rate, Stated Percentage Value of shares received for conversion of debt Debt Conversion, Converted Instrument, Amount Shares issued for conversion of debt Debt Conversion, Converted Instrument, Shares Issued Cash Paid To Conversion Of Convertible Senior Notes Cash Paid To Conversion Of Convertible Senior Notes Cash Paid To Conversion Of Convertible Senior Notes Cash received from note holders Cash Received From Conversion Of Convertible Senior Note Cash Received From Conversion Of Convertible Senior Note Senior Note Debt Instrument Maturity Date Senior Note Debt Instrument Maturity Date Senior Note Debt Instrument Maturity Date Debt Instrument, Unamortized Discount Debt Instrument, Unamortized Discount Proceeds from Issuance of Long-term Debt Proceeds from Issuance of Long-term Debt Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] 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] Treasury Stock [Member] Treasury Stock [Member] Retained Earnings [Member] Retained Earnings [Member] Accumulated Other Comprehensive Loss [Member] Accumulated Other Comprehensive Income (Loss) [Member] Noncontrolling Interests [Member] Noncontrolling Interest [Member] Statement [Line Items] Statement [Line Items] Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance, shares Shares, Outstanding Dividends declared ($0.04 per share) Dividends, Cash Exercise of long-term incentive plan stock options Stock Issued During Period, Value, Stock Options Exercised Exercise of long-term incentive plan stock options, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Treasury stock purchases Treasury Stock, Value, Acquired, Cost Method Treasury stock purchases, shares Treasury Stock, Shares, Acquired Conversion of 2.875% senior convertible notes Stock Issued During Period, Value, Conversion of Convertible Securities Tax benefit related to stock-based compensation Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Deferred tax provision attributable to 2008 Pioneer Southwest initial public offering Subsidiary or Equity Method Investee, Deferred Income Tax Provision on Gain (Loss) Recognized, Amount Compensation costs: Share-based Compensation [Abstract] Vested compensation awards, net Stock Issued Or Vested During Period Value Stock Awards Par value of share-based payments that vest or lapse during the period. Vested compensation awards, net, 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. Compensation costs included in net income Share based compensation award compensation cost Share based compensation award compensation cost Cash distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Other comprehensive activity: Other Comprehensive Income (Loss), Net of Tax [Abstract] Deferred hedging activity, net of tax: Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract] Net hedge losses included in continuing operations Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax Balance Balance, shares Impairment [Abstract] Impairment [Abstract] Impairment Impairment of Long-Lived Assets Held and Used by Asset [Text Block] Impairment of Long-Lived Assets Held and Used by Asset [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Derivative Instrument Risk [Axis] Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Derivative Contract Type [Domain] 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 Derivative Asset, Fair Value, Gross Asset Total derivatives, Liability Derivative Liability, Fair Value, Gross Liability Basis Of Presentation Basis Of Presentation Disclosure Text Block Disclosure related to the basis of presentation of financial statements, recently adopted and other recent accounting pronouncements, and to selected earnings per common share information. Trading Activity [Axis] Trading Activity [Axis] Trading Activity, by Type [Domain] Trading Activity, by Type [Domain] Two Thousand Twelve Fourth Quarter Index Basis Swap Contracts [Member] Two Thousand Twelve Fourth Quarter Index Basis Swap Contracts [Member] Two Thousand Twelve Fourth Quarter Index Basis Swap Contracts [Member] Two Thousand And Thirteen Index Basis Swap Contracts [Member] Two Thousand And Thirteen Index Basis Swap Contracts [Member] Two Thousand and Thirteen Idex Basis Swap Contracts Two Thousand Twelve Fourth Quarter Short Index Basis Swap Contracts [Member] [Member] Two Thousand Twelve Fourth Quarter Short Index Basis Swap Contracts [Member] [Member] Two Thousand Twelve Fourth Quarter Short Index Basis Swap Contracts [Member] [Member] Two Thousand Thirteen Short Index Basis Swap Contracts Two Thousand Thirteen Short Index Basis Swap Contracts [Member] Two Thousand Thirteen Short Index Basis Swap Contracts Two Thousand Twelve Fourth Quarter Long Index Basis Swap Contracts [Member] [Member] [Member] Two Thousand Twelve Fourth Quarter Long Index Basis Swap Contracts [Member] [Member] [Member] Two Thousand Twelve Fourth Quarter Long Index Basis Swap Contracts [Member] [Member] [Member] Two Thousand Thirteen Long Index Basis Swap Contracts [Member] Two Thousand Thirteen Long Index Basis Swap Contracts [Member] Two Thousand Thirteen Long Index Basis Swap Contracts [Member] Basic Long Index Swaps [Member] Basic Long Index Swaps [Member] Basic Long Index Swaps Member. Basic Index Swaps [Member] Basic Index Swaps [Member] Basic Index Swaps Member. Basic Short Index Swaps [Member] Basic Short Index Swaps [Member] Basic Short Index Swaps Member. Average Daily Index Swaps Volume Average Daily Index Swaps Volume Average Daily Index Swaps Volume. Price Differential Average Daily Index Swaps Price Differential Average Daily Index Swaps Price Differential. NGI-So Cal Border Monthly price differential to NYMEX HH NGI-So Cal Border Monthly Price Differential to NYMEX HH NGI-So Cal Border Monthly Price Differential to NYMEX HH. Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract] Incentive Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Acquisitions and Divestitures [Abstract] Acquisitions and Divestitures [Abstract] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Groups, Including Discontinued Operations, Name [Domain] Disposal Groups, Including Discontinued Operations, Name [Domain] Pioneer South Africa [Member] Pioneer South Africa [Member] Pioneer South Africa [Member] Pioneer Tunisia [Member] Pioneer Tunisia [Member] Pioneer Tunisia [Member] BOEMRE [Member] BOEMRE [Member] BOEMRE [Member] 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] Business Combination, Consideration Transferred Business Combination, Consideration Transferred Proceeds from divestiture of interest in consolidated subsidiaries Proceeds from Divestiture of Interest in Consolidated Subsidiaries Liabilities Assumed by Buyer [Line Items] Liabilities Assumed by Buyer [Line Items] Liabilities Assumed by Buyer [Line Items] Gains Losses On Sales Of Assets Discontinued Operations Gains Losses On Sales Of Assets Discontinued Operations The net gain or loss from discontinued operations resulting from the sale, transfer, termination, or other disposition of assets during the period are included in gains (losses) on the disposition of assets in nonoperating income (expense) from discontinued operations. Reconciliation of earnings attributable to common stockholders, basic and diluted Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block] Reconciliation Of Basic To Diluted Weighted Average Common Shares Outstanding Schedule of Weighted Average Number of Shares [Table Text Block] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Adjustments for Error Corrections [Axis] Adjustments for Error Corrections [Axis] Adjustments for Error Correction [Domain] Adjustments for Error Correction [Domain] Decrease in Current Deferred Tax Assets, Revision of Unrealized Current Derivative Gains, Net [Member] Decrease in Current Deferred Tax Assets, Revision of Unrealized Current Derivative Gains, Net [Member] Decrease in Current Deferred Tax Assets, Revision of Unrealized Current Derivative Gains, Net [Member] Increase in Current Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member] Increase in Current Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member] Increase in Current Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member] Decrease in Noncurrent Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member] Decrease in Noncurrent Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member] Decrease in Noncurrent Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Restatement Adjustment [Member] Restatement Adjustment [Member] Error Corrections and Prior Period Adjustments Restatement [Line Items] Error Corrections and Prior Period Adjustments Restatement [Line Items] Adjustment to deferred income taxes due to revision of unrealized current derivative gains, net Quantifying Misstatement in Current Year Financial Statements, Amount Net Income (Loss) Per Share Earnings Per Share [Text Block] Organization And Nature Of Operations [Abstract] Organization and Nature of Operations [Abstract] Organization And Nature Of Operations Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Income Statement [Abstract] Revenues and other income: Revenues [Abstract] Oil and gas Oil and Gas Revenue Interest and other Other Nonoperating Income Derivative gains (losses), net Gain (Loss) on Derivative Instruments, Net, Pretax Gain (loss) on disposition of assets, net Gains (Losses) on Sales of Assets Total revenues and other income Total revenues and other income Total revenues and income from equity affiliates and other income. 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 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 Hurricane activity, net Loss from Catastrophes Other Other Nonoperating Expense Costs and expenses, Total Costs and Expenses Income (loss) from continuing operations before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax benefit (provision) Income Tax Expense (Benefit) Income (loss) from continuing operations Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Income (loss) from discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net income (loss) Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net income (loss) attributable to common stockholders Net Income (Loss) Attributable to Parent Basic earnings per share: Earnings Per Share, Basic [Abstract] Income (loss) from continuing operations attributable to common stockholders Income (Loss) from Continuing Operations, Per Basic Share Income (loss) from discontinued operations attributable to common stockholders Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share Net income (loss) attributable to common stockholders Earnings Per Share, Basic Diluted earnings per share: Earnings Per Share, Diluted [Abstract] Income (loss) from continuing operations attributable to common stockholders Income (Loss) from Continuing Operations, Per Diluted Share Income (loss) from discontinued operations attributable to common stockholders Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share Net income (loss) attributable to common stockholders Earnings Per Share, Diluted Weighted average shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Diluted Dividends declared per share Common Stock, Dividends, Per Share, Declared Amounts attributable to common stockholders: Income Amounts Attributable to Parent, Disclosures [Abstract] Income (loss) from continuing operations Income (Loss) from Continuing Operations Attributable to Parent Income (loss) from discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Net income (loss) Other Expense [Abstract] Other Expense [Abstract] Other Expense Other Operating Expenses Text Block Other Operating Expenses [Text Block] 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] Statement, Operating Activities Segment [Axis] Statement, Operating Activities Segment [Axis] Segment, Operating Activities [Domain] Segment, Operating Activities [Domain] Continuing Operations [Member] Segment, Continuing Operations [Member] Discontinued Operations [Member] Segment, Discontinued 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 discontinued operations, net of tax, attributable to parent Income (loss) as reported Participating basic earnings Participating Securities, Distributed and Undistributed Earnings Basic income attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Reallocation of participating earnings Dilutive Securities, Effect on Basic Earnings Per Share Diluted income attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Diluted Asset Retirement Obligation [Abstract] Schedule of asset retirement obligations Schedule of Asset Retirement Obligations [Table Text Block] Natural Gasoline contract, price per barrel [Member] Natural Gasoline contract, price per barrel [Member] Natural Gasoline contract, price per barrel [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] Gas contracts, in MMBTU [Member] Gas contracts, in MMBTU [Member] Gas 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Contracts [Member] Two Thousand Fifteen Swap Contracts [Member] 2012 - Rollfactor Swap Contracts [Member] Two Thousand Twelve Rollfactor Swap Contracts [Member] Two Thousand Twelve Rollfactor Swap Contracts [Member] Two Thousand Fifteen Rollfactor Swap Contracts [Member] Two Thousand Fifteen Rollfactor Swap Contracts [Member] Two Thousand Fifteen Rollfactor Swap Contracts [Member] 2013 Rollfactor Swap Contracts [Member] Two Thousand Thirteen Rollfactor Swap Contracts [Member] Two Thousand Thirteen Rollfactor Swap Contracts [Member] 2014 Rollfactor Swap Contracts [Member] Two Thousand Fourteen Rollfactor Swap Contracts [Member] Two Thousand Fourteen Rollfactor Swap Contracts [Member] 2012 Basis Swap Contracts [Member] Two Thousand Twelve Basis Swap Contracts [Member] Two Thousand Twelve Basis Swap Contracts [Member] 2014 Basis Swap Contracts [Member] Two Thousand Fourteen Basis Swap Contracts [Member] 2014 - Basis Swap Contracts 2015 Basis Swap Contracts [Member] Two Thousand Fifteen Basis Swap Contracts [Member] Two Thousand Fifteen Basis Swap Contracts [Member] Derivative, by Nature [Axis] Derivative, by Nature [Axis] Derivative, Name [Domain] Derivative, Name [Domain] Ceiling [Member] Ceiling [Member] Ceiling [Member] Floor [Member] Floor [Member] Floor [Member] Short Put [Member] Short Put [Member] Short Put [Member] Trading Activity, Gains and Losses, Net [Line Items] Trading Activity, Gains and Losses, Net [Line Items] Average Daily Gas Production Derivatives Volume (MMBTU) Average Daily Gas Production Derivatives Volume Average Daily Gas Production Derivatives Volume Average Daily NGL Production Derivative Barrels Per Day Average Daily NGL Production Derivative Barrels Per Day Average Daily NGL Production Derivative Barrels Per Day Derivative, Swap Type, Average Fixed Price Derivative, Swap Type, Average Fixed Price Average daily oil production derivative barrels per day Average daily oil production derivative barrels per day Average Daily Oil Production 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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 Other property and equipment, net Property, Plant and Equipment, Other, Gross Other assets: Other Assets, Noncurrent [Abstract] Investment in unconsolidated affiliate Equity Method Investments Derivatives Derivative Assets, Noncurrent Other, net of allowance for doubtful accounts of $655 and $340 as of June 30, 2012 and December 31, 2011, respectively 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, 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11,264,936 at June 30, 2012 and December 31, 2011, respectively Treasury Stock, Value Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss - net deferred hedge losses, net of tax Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Total equity attributable to common stockholders Stockholders' Equity Attributable to Parent Noncontrolling interests in consolidating subsidiaries Stockholders' Equity Attributable to Noncontrolling Interest Total equity Commitments and contingencies Commitments and Contingencies Liabilities and Stockholders' Equity, Total Liabilities and Equity 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] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Restricted Stock [Member] Restricted Stock Equity Awards Memeber [Member] Restricted Stock Equity Awards Memeber [Member] Pioneer Southwest Ltip Restricted Units [Member] Pioneer Southwest Ltip Restricted Units [Member] Pioneer Southwest LTIP Restricted Units [Member] Performance Units [Member] Performance Units [Member] Performance Units [Member] Restricted Stock Liability Awards [Member] Restricted Stock Liability Awards [Member] Restricted Stock Liability Awards [Member] Pioneer Southwest Ltip Phantom Units [Member] Pioneer Southwest Ltip Phantom Units [Member] Pioneer Southwest LTIP Phantom Units [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Allocated Share-based Compensation Expense Allocated Share-based Compensation Expense Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Share Based Compensation Arrangement By Share Based Payment Award Liability Share Based Compensation Arrangement By Share Based Payment Award Liability Share Based Compensation Arrangement By Share Based Payment Award Liability Amount Of Liabilities Attributable To Liability Awards Included In Accounts Payable Amount Of Liabilities Attributable To Liability Awards Included In Accounts Payable Amount Of Liabilities Attributable To Liability Awards Included In Accounts Payable Restricted Stock Awards Unvested Shares At Balance Sheet Date Restricted Stock Awards Unvested Shares At Balance Sheet Date The number of unvested restricted stock shares not reflected in balance sheet Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures 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, Options, Forfeitures in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Postretirement benefit obligation revaluation Defined Benefit Plan, Benefit Obligation Beginning asset retirement obligations Asset Retirement Obligation Liabilities assumed in acquisitions Asset Retirement Obligation, Liabilities Incurred New wells placed on production Assets Retirement Obligations on New Assets Placed in Production Assets Retirement Obligations on New Assets Placed in Production Changes in estimates Asset Retirement Obligation, Revision of Estimate Asset Retirement Obligation Liabilities Reclassified Asset Retirement Obligation Liabilities Reclassified Asset Retirement Obligation Liabilities Reclassified 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 Accretion of discount from discontinued operations 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 Ending asset retirement obligations Asset retirement obligations, current portions Asset Retirement Obligation, Current Oil and gas Oil And Gas Revenue From Discontinued Operations Aggregate revenue during the period related to discontinued oil and gas business activities. Interest and other Other Nonoperating Income From Discontinued Operations The aggregate amount of other income amounts resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income recognized for the period from discontinued operations. Such amounts may include: (a) dividends, (b) interest on securities, (c) profits on securities (net of losses), and (d) miscellaneous other income items. Gain (loss) on disposition of assets, net Total revenues and other income from discontinued operations Total Revenues And Other Income From Discontinued Operations Total revenues and income from equity affiliates and other income from discontinued operations. Oil and gas production Oil And Gas Production Expense From Discontinued Operations Discontinued operations costs incurred to operate and maintain an entities' wells and related equipment and facilities, including depreciation and applicable operating costs of support equipment and facilities and other costs of operating and maintaining those wells and related equipment and facilities. Production and ad valorem taxes Taxes Excluding Income and Excise Taxes from Discontinued Operations Taxes Excluding Income and Excise Taxes from Discontinued Operations Depletion, depreciation and amortization Depreciation Depletion And Amortization From Discontinued Operations The aggregate expense recognized in the current period from discontinued operations that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. Impairment of oil and gas properties Impairment of Oil and Gas Properties from Discontinued Operations Impairment of Oil and Gas Properties from Discontinued Operations Exploration and abandonments Exploration Abandonment And Impairment Expense From Discontinued Operations The discontinued operations adjustment to expense previously capitalized costs of drilling exploratory wells when proved reserves are not found or when the entity obtains information that raises substantial doubt about the economic or operational viability of the project. General and administrative General And Administrative Expense From Discontinued Operations The aggregate total of discontinued operations expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line. Accretion of discount on asset retirement obligations Asset Retirement Obligation Accretion Expense From Discontinued Operations Accretion expense related to asset retirement obligations from discontinued operations. Interest Interest expense discontinued operations Interest expense discontinued operations Other Other Nonoperating Expense From Discontinued Operations Any other expense items resulting from secondary business-related activities, excluding those considered part of the normal operations of the business that have not been previously categorized from discontinued operations. Total costs and expenses from discontinued operations Costs And Expenses From Discontinued Operations Total costs of sales and operating expenses for the period from discontinued operations. Income from discontinued operations before income taxes Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Current tax provision Discontinued Operation Current Tax Effect Of Discontinued Operation Discontinued Operation Current Tax Effect Of Discontinued Operation Deferred tax provision Discontinued Operation Deferred Tax Effect Of Discontinued Operation Discontinued Operation Deferred Tax Effect Of Discontinued Operation Income from discontinued operations Trade, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Other, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Noncurrent 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 Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Exploratory Costs [Abstract] Exploratory Costs [Abstract] Capitalized exploratory well and project activity Capitalized Exploratory Well and Project Activity [Table Text Block] Capitalized Exploratory Well and Project Activity [Table Text Block] Aging of 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] Transportation commitment charges Transportation Commitment Loss Transportation Commitment Loss Above market drilling rig rates Idle Rig Expense Expenses from idle and terminate rigs. Terminated drilling rig contract charges Terminated Drilling Rig Expense Terminated Drilling Rig Expense Inventory valuation charges Tangible Asset Impairment Charges Other Other General Expense Premier Silica acquisition costs Business Combination, Acquisition Related Costs Contingency and environmental accrual adjustments Change In Accrual For Legal And Environmental Contingencies Change in Accrual for Legal and Environmental Contingencies. Loss on extinguishment of debt Gains (Losses) on Extinguishment of Debt Total other expense Asset Retirement Obligations Asset Retirement Obligation Disclosure [Text Block] Fair Value, Assets Measured on Recurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Trading Securities [Member] Trading Assets, Excluding Debt and Equity Securities [Member] Commodity Derivatives [Member] Commodity [Member] Deferred Compensation Plan Assets [Member] Deferred Compensation Plan Assets [Member] Deferred Compensation Plan Assets [Member] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Axis] Fair Value, Hierarchy [Axis] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Domain] Fair Value, Measurements, 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] 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] Assets, (Fair Value, Total) Fair Value Assets Measured On Recurring Basis Assets Total Fair Value Assets Measured On Recurring Basis Assets Total Liabilities, (Fair Value, Total) Fair Value Liabilities Measured On Recurring Basis Liabilities Total Fair Value Liabilities Measured On Recurring Basis Liabilities Total Recurring Measurements, (Fair Value, Total) Recurring Measurements, (Fair Value, Total) Recurring Measurements, (Fair Value, Total). Interest and Other Income [Abstract] Equity interest in income of unconsolidated affiliate Income (Loss) from Equity Method Investments Alaskan Petroleum Production Tax credits and refunds Income Tax Credits and Adjustments Third-party income from vertical integration services Third-party income from vertical integration services Third-party income from vertical integration services (b) Other income Other Income Deferred compensation plan income Deferred Compensation Plan Income Deferred Compensation Plan Income Interest income Other Interest and Dividend Income Total interest and other income Schedule of accumulated postretirement benefit obligations Schedule of Changes in Accumulated Postemployment Benefit Obligations [Table Text Block] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Distributions Made to Member or Limited Partner by Distribution Type [Axis] Distributions Made to Member or Limited Partner by Distribution Type [Axis] Distribution Type [Domain] Distribution Type [Domain] Cash Distribution [Member] Cash Distribution [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Distribution Made to Member or Limited Partner, Distributions Declared, Per Unit Distribution Made to Member or Limited Partner, Distributions Declared, Per Unit Distribution Made to Member or Limited Partner, Cash Distributions Declared Distribution Made to Member or Limited Partner, Cash Distributions Declared Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule of components of other expense Schedule of Components of Other Expense Text Block Schedule of Components of Other Expense Text Block Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] 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] 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 Deferred Income Tax Expense (Benefit) Gain (loss) on disposition of assets, net Discontinued operations Adjustment Income Loss From Discontinued Operations Net Of Tax Aggregate non-cash (income) loss and investing and financing cash flows from a disposal group. Amortization of Financing Costs and Discounts Amortization of Financing Costs and Discounts Derivative related activity Unrealized Gain Loss On Derivative Instruments Aggregate net unrealized 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. Amortization of deferred revenue Deferred Revenue Amortization Deferred revenue recognized but not to be included in current operations cash flows. Other noncash items Other Noncash Income (Expense) 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 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 Proceeds from Sale of Productive Assets Payments for acquisition, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Investment in unconsolidated subsidiary Payments to Acquire Interest in Subsidiaries and Affiliates 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 Principal payments on long-term debt Repayments of Long-term Debt Distributions to noncontrolling interests Payments of Distributions to Affiliates Payments of other liabilities Borrowings Payments of Other Liabilities Borrowings and payments of other liabilities Exercise of long-term incentive plan stock options Proceeds from Stock Options Exercised Purchases of treasury stock Payments for Repurchase of Common Stock Excess tax benefits from share-based payment arrangements Excess Tax Benefit (Tax Deficiency) from Share-based Compensation, Financing Activities Payment 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 Fair Value Measurements Fair Value Disclosures [Text Block] Presentation Consolidation, Policy [Policy Text Block] Derivatives And Hedging Derivatives, Policy [Policy Text Block] Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Impairment Of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Schedule of oil derivative contracts volume and weighted average price Schedule of Oil Derivative Contracts volume and weighted average price [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 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] Schedule of marketing and basis transfer derivative contracts Schedule Of Marketing And Basis Transfer Derivative Contracts TextBlock Schedule Of Marketing And Basis Transfer Derivative Contracts TextBlock. Schedule of derivative instruments Schedule of Derivative Instruments [Table Text Block] Schedule of derivative obligations under terminated hedge arrangements Schedule of Derivative Obligations Under Terminated Hedge Arrangements [Text Block] Schedule of Derivative Obligations Under Terminated Hedge Arrangements [Text Block] Schedule of derivative assets and liabilities by counterparty Schedule of Derivative Assets and Liabilities by Counterparty [Table Text Block] Schedule of Derivative Assets and Liabilities by Counterparty [Table Text Block] Schedule of Subsidiary or Equity Method Investee [Table] Schedule of Subsidiary or Equity Method Investee [Table] Subsidiary or Equity Method Investee [Line Items] Subsidiary or Equity Method Investee [Line Items] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Fair Value, Disclosure Item Amounts [Domain] Fair Value, Disclosure Item Amounts [Domain] Carrying Value [Member] Carrying Value [Member] Carrying Value [Member] Fair Value [Member] Fair Value [Member] Fair Value [Member] Long-term Debt Element Interest And Other Income Other Income and Other Expense Disclosure [Text Block] Current Income Tax Expense (Benefit) Current Income Tax Expense (Benefit) Deferred income tax (provision) benefit Income tax (provision) benefit U.S. federal Effective Income Tax Rate, Continuing Operations Income loss before income taxes, including noncontrolling interest Income loss before income taxes, including noncontrolling interest Income loss before income taxes, including noncontrolling interest Components of discontinued operations Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block] Discontinued operations assets and liabilities included in assets and liabilities held-for-sale 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 (provisions) benefits attributable to income from continuing operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Pretax noncash impairment charges Management oil price outlook (BBL) Management oil price outlook Management oil price outlook Management gas price outlook (MCF) Management gas price outlook Management gas price outlook Discount rate used in impairment calculation discount rate used in impairment calculation discount rate used in impairment calculation 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] Raton Shale Field [Member] Raton Shale Field [Member] Raton Shale Field [Member] Impaired Long-Lived Assets Held and Used [Line Items] Impaired Long-Lived Assets Held and Used [Line Items] Carrying value of asset group Carrying value of asset group Carrying value of asset group Gain (loss) on sale of assets [Table] Gain (loss) on sale of assets [Table] Gain (loss) on sale of assets [Table] ALASKA Alaska [Member] Alaska [Member] Eagle Ford Shale [Member] Eagle Ford Shale [Member] Eagle Ford Shale [Member] Gain Loss on Sale of Assets [Line Items] Gain Loss on Sale of Assets [Line Items] Gain Loss on Sale of Assets [Line Items] Proceeds from Sale of Productive Assets Sale of interest in an unproved oil and gas property Proceeds from Sale of Oil and Gas Property and Equipment Gain (loss) on disposition of assets in continuing operations Gain (Loss) on Disposition of Assets Business acquisition, cost of acquired entity, purchase price Business Acquisition, Cost of Acquired Entity, Purchase Price Business acquisition, purchase price allocation, assets acquired Business Acquisition, Purchase Price Allocation, Assets Acquired Business acquisition, purchase price allocation, property, plant and equipment Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment Business acquisition, purchase price allocation, liabilities assumed Business Acquisition, Purchase Price Allocation, Liabilities Assumed Business acquisition, purchase price allocation, deferred taxes asset (liability), net, noncurrent Business Acquisition, Purchase Price Allocation, Deferred Taxes Asset (Liability), Net, Noncurrent Business combination, acquisition related costs Acquisition and Divestitures Acquisition and Divestitures [Text Block] Acquisition and Divestitures text block Current assets (excluding cash and cash equivalents) Assets of Disposal Group, Including Discontinued Operation, Current Property, plant and equipment Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net Goodwill Disposal Group, Including Discontinued Operation, Goodwill Deferred tax assets Disposal Group, Including Discontinued Operation, Deferred Tax Assets Other assets, net Disposal Group, Including Discontinued Operation, Other Assets Total assets Current liabilities Liabilities of Disposal Group, Including Discontinued Operation, Current Deferred revenue Discontinued Operations, Deferred Revenue Discontinued Operations, Deferred Revenue Other liabilities Disposal Group, Including Discontinued Operation, Other Liabilities Total liabilities Disposal Group, Including Discontinued Operation, Classified Balance Sheet Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Classified Balance Sheet Disclosures [Abstract] Components of interest and other income Interest and Other Income [Table Text Block] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement and Other Comprehensive Income Location [Domain] Income Statement Location [Domain] Interest Expense [Member] Interest Expense [Member] Derivative Gains, Net [Member] Derivative Gains Losses [Member] Derivative gains (losses) [Member] Oil And Gas revenue [Member] Oil And Gas Revenue [Member] Oil and gas revenue Total derivatives, Liability Amount of Gain/(Loss) Reclassified from AOCI into Earnings Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax Exploratory Costs Oil and Gas Exploration and Production Industries Disclosures [Text Block] Natural gasoline contract, in barrels [Member] Natural gasoline contract, in barrels [Member] Natural gasoline contract, in barrels [Member] 2015 Gas Derivatives [Member] [Member] 2015 Gas Derivatives [Member] [Member] 2015 Gas Derivatives [Member] [Member] 2014 Gas Derivatives [Member] 2014 Gas Derivatives [Member] 2014 Gas Derivatives [Member] Rollfactor Swap Contracts [Member] Rollfactor Swap Contracts [Member] Rollfactor Swap Contracts [Member] 2013 Diesel Swaps [Member] 2013 Diesel Swaps [Member] 2013 Diesel Swaps [Member] 2012 Interest Rate Derivatives [Member] 2012 Interest Rate Derivatives [Member] 2012 Interest Rate Derivatives [Member] NGL Swap [Member] Ngl Swaps [Member] NGL Swaps NGL Collar Contracts With Short Put [Member] Ngl Collar Contracts With Short Puts [Member] NGL Collar Contracts with Short Puts 2015 Gas Collars with Short Puts Derivatives [Member] 2015 Gas Collars with Short Puts Derivatives [Member] 2015 Gas Collars with Short Puts Derivatives [Member] Schedule of Trading Securities and Other Trading Assets [Line Items] Schedule of Trading Securities and Other Trading Assets [Line Items] NYMEX swap multiple, second nearby month Swap Multiple Second Nearby Month Swap Multiple Second Nearby Month NYMEX swap multiple, third nearby month Swap Multiple Third Nearby Month Swap Multiple Third Nearby Month Terminated Derivatives Proceeds Terminated Derivatives Proceeds Terminated Derivatives Proceeds Derivative Nonmonetary Notional Volume per Day (BBL) Derivative Nonmonetary Notional Volume Per Day Derivative Nonmonetary Notional Volume Per Day Derivative, Fixed Interest Rate Derivative, Fixed 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 Net deferred losses from hedging in AOCI Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Oil and Gas Commodity Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax, Oil and Gas Commodity Net deferred gains or losses associated to net deferred tax benefits Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax Deferred Tax Provisions Net deferred gains or losses associated to net deferred tax provisions Derivative Instruments Loss From Discontinued Interest Rate Hedges In Aoci Derivative Instruments Loss From Discontinued Interest Rate Hedges In Accumulated Other Comprehensive Income DerivativeInstrumentsLossFromDiscontinuedInterestRateHedgesInAoci Average Daily Gas Production Derivatives Price Per MMBtu Average Daily Gas Production Derivatives Price Per MMBtu Average Daily Gas Production Derivatives Price Per MMBtu 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 Exploratory well costs charged to exploration expense Capitalized Exploratory Well Cost, Charged to Expense Ending capitalized exploratory costs Capitalized exploratory costs that have been suspended, One year or less Capitalized Exploratory Well Costs that Have Been Capitalized for Period of One Year or Less Capitalized exploratory costs that have been suspended, More than one year Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year Number of projects with exploratory costs that have been suspended for a period greater than one year Projects that have Exploratory Well Costs that have been Capitalized for Period Greater than One Year, Number of Projects Statement of Other Comprehensive Income [Abstract] Net income (loss) Net hedge (gains) losses included in continuing operations Income tax (benefit) provision Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Other comprehensive activity Other Comprehensive Income (Loss), Net of Tax Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive (income) loss attributable to the noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income (loss) attributable to common stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Commitments and Contingencies Disclosure [Abstract] Commitments And Contingencies Commitments and Contingencies Disclosure [Text Block]