Schedule of changes in noncontrolling interests Non-redeemable and Redeemable Noncontrolling Interest [Table Text Block] Tabular disclosure of non-redeemable and redeemable noncontrolling interest. COSTS Costs and Other Deductions [Abstract] No definition available Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] LAWSUITS, CLAIMS, COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Related Party [Axis] Related Party [Axis] Noncontrolling Interest [Table] Noncontrolling Interest [Table] Total right-of-use assets Leases, Right-of-Use Asset Leases, Right-of-Use Asset PENSION AND POSTRETIREMENT BENEFIT PLANS Retirement Benefits [Text Block] Production costs Production Costs, Period Cost Inventory Write-down Inventory Write-down Condensed Income Statement [Table] Condensed Income Statement [Table] Other current assets, net Other Current Assets [Member] Net Fair Value Presented in the Balance Sheet Derivative Asset Liabilities and Equity [Abstract] Liabilities and Equity [Abstract] Statistical Measurement [Domain] Statistical Measurement [Domain] Second Lien Notes (Second Priority Lien) Senior Lien [Member] Distributions to noncontrolling interest holders Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Applicable margin on Alternate Base Rate loans Debt Instrument, Adjustable Base Rate [Member] Represents alternate base rate DERIVATIVES Derivative Instruments and Hedging Activities Disclosure [Text Block] Current Fiscal Year End Date Current Fiscal Year End Date Term Loan Term Loan [Member] Term Loan Member COMPENSATION PLANS Compensation and Employee Benefit Plans [Text Block] OPERATING (LOSS) INCOME Operating Income (Loss) Entity Address, Postal Zip Code Entity Address, Postal Zip Code Total current liabilities Total current liabilities Liabilities, Current Variable Rate [Domain] Variable Rate [Domain] Variable Rate [Axis] Variable Rate [Axis] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Assets [Abstract] Assets [Abstract] Schedule of condensed cash flow statement Condensed Cash Flow Statement [Table Text Block] Entity Shell Company Entity Shell Company Cover [Abstract] Cover [Abstract] Accounts payable Accounts Payable, Current Document Type Document Type Derivative assets Derivative Asset, Current Accumulated deficit Retained Earnings (Accumulated Deficit) Operating lease, net Operating Lease, Right-of-Use Asset Repayments of 2014 Revolving Credit Facility Repayments of Lines of Credit Offsetting Assets [Table] Offsetting Assets [Table] Upfront fees on commitment Debtor In Possession Financing upfront Fees On commitment Debtor In Possession Financing upfront Fees On commitment Net gain on early extinguishment of debt Net gain on early extinguishment of debt Pre-tax gain on extinguishment of debt, net of a reduction in deferred issuance costs Gain (Loss) on Extinguishment of Debt BSP JV Benefit Street Partners [Member] Represents Benefit Street Partners (BSP). Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] Taxes paid Income Taxes Paid EQUITY Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Debt instrument, repurchased face amount Debt Instrument, Repurchased Face Amount1 Face (par) amount of the original debt instrument that was repurchased during the period. Unrecovered capital costs Unrecovered Capital Costs Unrecovered Capital Costs Current portion of deferred gain and issuance costs, net Deferred Gain (Loss) and Issuance Costs, Net, Current Deferred Gain (Loss) and Issuance Costs, Net, Current Gain (loss) from interest-rate risk Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Preferred stock (20 million shares authorized at $0.01 par value) no shares outstanding at June 30, 2020 and December 31, 2019 Preferred Stock, Value, Issued Document Quarterly Report Document Quarterly Report Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Other comprehensive income: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] OTHER LONG-TERM LIABILITIES Other long-term liabilities Other Liabilities, Noncurrent Other Payments for (Proceeds from) Other Investing Activities Contributions deferred till December 2020 Defined Benefit Plan, Plan Assets, Contributions By Employer, Amount Deferred Defined Benefit Plan, Plan Assets, Contributions By Employer, Amount Deferred OTHER INFORMATION OTHER INFORMATION [Text Block] The entire disclosure for Other information. Share-based compensation, net APIC, Share-based Payment Arrangement, Increase for Cost Recognition Inventories Total Inventory, Net Oil and natural gas sales Revenue from Contract with Customer, Excluding Assessed Tax Line of credit minimum liquidity over rolling amount Line Of Credit Minimum Liquidity Over Rolling Amount Line Of Credit Minimum Liquidity Over Rolling Amount Debtor-in-Possession Revolving Facility Debtor-in-Possession Revolving Facility [Member] Debtor-in-Possession Revolving Facility Member Schedule of net deferred gain and issuance costs Schedule of Deferred Gain and Issuance Costs [Table Text Block] Schedule of Deferred Gain and Issuance Costs [Table Text Block] Entity File Number Entity File Number Settlement loss Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Postretirement and Other Benefit Plans Disclosure Defined Benefit Plan Disclosure [Line Items] Statement [Line Items] Statement [Line Items] Alpine JV Alpine JV [Member] Alpine JV [Member] Class of Stock [Domain] Class of Stock [Domain] NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS Net Income (Loss) Attributable to Noncontrolling Interest [Abstract] One month LIBOR One Month Libor [Member] Represents one month LIBOR. Derivatives Derivative Instruments and Hedging Activities Disclosures [Line Items] Document Fiscal Period Focus Document Fiscal Period Focus Accrued interest Interest Payable, Current Statement [Table] Statement [Table] Interest cost Defined Benefit Plan, Interest Cost Statistical Measurement [Axis] Statistical Measurement [Axis] Credit Facility [Axis] Credit Facility [Axis] Deferred gain Debt Instrument Unamortized Premium On Exchange Of Debt The amount of debt premium that was originally recognized on exchange of the instrument that has yet to be amortized. Interest not paid Debt Instrument, Interest Not Paid Debt Instrument, Interest Not Paid 5.5% Notes Due 2021 5.5% Senior Notes due 2021 Senior Notes550 Percent Due2021 [Member] Represents the senior notes payable that bear an interest rate of 5.50 percent and will mature in 2021. Other expenses, net Other Operating Income (Expense), Net Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Letters of credit outstanding Debtor-in-Possession Financing, Letters of Credit Outstanding Aggregate claims held by creditors, percent Debtor Reorganization Items Debtor In Possession Facility, Aggregate Claims Held By Creditors, Percent Debtor Reorganization Items Debtor In Possession Facility, Aggregate Claims Held By Creditors, Percent Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Marketing, trading and other Marketing, Trading, and Other [Member] Marketing, Trading, and Other Debtor reorganization items, equity offering amount Debtor Reorganization Items, Equity Offering Amount Debtor Reorganization Items, Equity Offering Amount Prepaid expenses Prepaid Expense, Current Asset retirement obligations Asset Retirement Obligation, Current Issuance of common stock Proceeds from Issuance of Common Stock Debt Instrument, Redemption, Period One Debt Instrument, Redemption, Period One [Member] Schedule of calculation of basic and diluted EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of asset impairments Details of Impairment of Long-Lived Assets Held and Used by Asset [Table Text Block] LEASES Lessee, Finance Leases [Text Block] Amendment Flag Amendment Flag Other Other Accrued Liabilities, Current Net cash provided by operating activities Net cash (used in) provided by operating activities Net Cash Provided by (Used in) Operating Activities Distributions paid to noncontrolling interest holders Payments of Ordinary Dividends, Noncontrolling Interest Related Party [Domain] Related Party [Domain] Series B Preferred Stock Series B Preferred Stock [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Total derivatives Other Noncurrent Liabilities [Member] Net derivative (gain) loss from commodity contracts Derivative, Gain (Loss) on Derivative, Net Fair Value Measurement [Domain] Fair Value Measurement [Domain] Debt Instrument, Redemption, Period Three Debt Instrument, Redemption, Period Three [Member] Other Current Assets Other Assets [Abstract] Senior Notes (Unsecured) Senior Notes [Member] Local Phone Number Local Phone Number Repurchase value of the principal amounts Early Repayment of Senior Debt Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Dilutive effect of potentially dilutive securities (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Initial investment commitment in joint venture, period Initial Investment Commitment In Joint Venture, Period Initial Investment Commitment In Joint Venture, Period CASH FLOW FROM FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Changes in capital investment accruals Increase Decrease In Capital Investment Accrual Represents the information pertaining to changes in capital investment accruals General and administrative expenses Selling, General and Administrative Expense Entity Current Reporting Status Entity Current Reporting Status Number of drilling rigs released Operating Lease, Right-Of-Use Asset, Number Of Drilling Rigs Released Operating Lease, Right-Of-Use Asset, Number Of Drilling Rigs Released OTHER ASSETS Other assets Other Assets, Noncurrent JOINT VENTURES Equity Method Investments and Joint Ventures Disclosure [Text Block] NGLs Propane [Member] Issuance of common stock Stock Issued During Period, Value, New Issues TOTAL ASSETS Assets Accrued Liabilities Accrued Liabilities [Abstract] Schedule of accrued liabilities Schedule of Accrued Liabilities [Table Text Block] Schedule of supplemental balance sheet information related to operating leases Lease Operating Balance Sheet Presentation And Other Information [Table Text Block] The tabular disclosure of the presentation of the operating lease balance sheet accounts and other information. Subsequent Event Type [Axis] Subsequent Event Type [Axis] Entity Small Business Entity Small Business MEZZANINE EQUITY Redeemable Noncontrolling Interest, Equity, Carrying Amount [Abstract] Line of credit minimum liquidity over amount Line Of Credit Minimum Liquidity Over Amount Line Of Credit Minimum Liquidity Over Amount Depreciation, depletion and amortization Depreciation, Depletion and Amortization Entity Filer Category Entity Filer Category Percentage of common interest held by ECR Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Product and Service [Axis] Product and Service [Axis] Net amounts due from joint interest partners Due from Joint Ventures Asset divestitures Proceeds from Sale of Productive Assets Entity Address, City or Town Entity Address, City or Town Retirement Plan Type [Axis] Retirement Plan Type [Axis] Indebtedness in excess Accounts Receivable from Securitization Unproved properties Impairment of Oil and Gas Properties, Unproved Properties Impairment of Oil and Gas Properties, Unproved Properties Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Natural gas Natural Gas, Production [Member] Document Fiscal Year Focus Document Fiscal Year Focus Gross Amounts Offset in the Balance Sheet Derivative Liability, Fair Value, Gross Asset DEFERRED GAIN AND ISSUANCE COSTS, NET Deferred gain and issuance costs, net Deferred Gain (Loss) and Issuance Costs, Net, Noncurrent Deferred Gain (Loss) and Issuance Costs, Net, Noncurrent Debt Instrument [Axis] Debt Instrument [Axis] Contributions from noncontrolling interest holders, net Contributions from noncontrolling interest holders, net Noncontrolling Interest, Increase from Sale of Parent Equity Interest Additional Paid-in Capital Additional Paid-in Capital [Member] Initial investment commitment in joint venture Initial Investment Commitment In Joint Venture Initial Investment Commitment In Joint Venture Disaggregation of revenue Disaggregation of Revenue [Line Items] Changes in operating assets and liabilities, net Increase (Decrease) in Operating Capital Net Fair Value Presented in the Balance Sheet Derivative Liability Investments in consolidated subsidiaries Investments in and Advances to Affiliates, Amount of Equity Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Dry hole expenses Results of Operations, Dry Hole Costs Other Other Receivables Schedule of other current assets, net Schedule of Other Current Assets [Table Text Block] Common stock, outstanding shares (in shares) Common Stock, Shares, Outstanding Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Other revenue Other Operating Income 2014 Revolving Credit Facility Revolving Credit Facility [Member] (LOSS) INCOME BEFORE INCOME TAXES Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Adjustments to reconcile net loss to net cash provided by operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Other Other Asset Impairment Charges Subsequent Event Subsequent Event [Member] Aggregate letters of credit issued Letters of Credit Outstanding, Amount Common stock, authorized shares (in shares) Common Stock, Shares Authorized Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] Number of drilling rigs remaining Operating Lease, Right-Of-Use Asset, Number Of Drilling Rigs Operating Lease, Right-Of-Use Asset, Number Of Drilling Rigs Document Period End Date Document Period End Date Decrease in accrued employee-related costs Increase (Decrease) in Employee Related Liabilities Entity Registrant Name Entity Registrant Name Gross Amounts Recognized at Fair Value Estimate of Fair Value Measurement [Member] Income Statement [Abstract] Income Statement [Abstract] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] 2020 Senior Notes payment Repayments of Senior Debt Operating lease Operating Lease, Liability, Noncurrent Outstanding principal held by lenders, percent Debtor Reorganization Items Debtor In Possession Facility, Outstanding Principal Held By Lenders, Percent Debtor Reorganization Items Debtor In Possession Facility, Outstanding Principal Held By Lenders, Percent Issuance costs and original issue discounts Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net CURRENT ASSETS Assets, Current [Abstract] Partnership contribution Proceeds from Partnership Contribution Debt repurchases Repayments of Subordinated Debt Ares JV Ares Joint Venture [Member] Represents Ares joint venture (Ares JV). Exploration expense Exploration Expense Consolidated Entities [Axis] Consolidated Entities [Axis] Proved oil and natural gas properties Impairment of Oil and Gas Properties, Proved Properties Impairment of Oil and Gas Properties, Proved Properties Commitment fees Debtor-in-Possession Financing, Fee on Unused Borrowings Comprehensive (loss) income attributable to common stock Comprehensive Income (Loss), Net of Tax, Attributable to Parent Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Debtor in possession financing, borrowings outstanding Debtor-in-Possession Financing, Borrowings Outstanding Amortization of deferred gain Amortization Of Deferred Gains And Debt Issuance Cost The amount of amortization of deferred gains and deferred debt issuance costs. Interest-rate Contract Interest Rate Cap [Member] Capital investments Payments to Acquire Property, Plant, and Equipment Consolidation Items [Domain] Consolidation Items [Domain] Combined Non-Guarantor Subsidiaries Non-Guarantor Subsidiaries [Member] Entity Tax Identification Number Entity Tax Identification Number DEBT Long-term Debt [Text Block] Net derivative (loss) gain from commodity contracts Net derivative gain (loss) from commodity contracts Gain (Loss) on Derivative Instruments, Net, Pretax Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] NET (LOSS) INCOME Net (loss) income Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Schedule of disaggregated revenue Disaggregation of Revenue [Table Text Block] Trading Symbol Trading Symbol Mezzanine Equity - Redeemable Noncontrolling Interests Mezzanine Equity Redeemable Noncontrolling Interest [Member] This element represents mezzanine equity redeemable noncontrolling interest. Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Schedule of inventories Schedule of Inventory, Current [Table Text Block] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Legal Entity [Axis] Legal Entity [Axis] Oil Oil and Condensate [Member] Shares canceled for taxes Payment, Tax Withholding, Share-based Payment Arrangement Alternative Base Rate Alternative Base Rate [Member] Alternative Base Rate Member Entity [Domain] Entity [Domain] Net deferred gain and issuance costs Deferred Gain (Loss) and Issuance Costs, Net Carrying value as of the balance sheet of the deferred gain (loss) and issuance costs, net. Acquisitions Purchase of Assets, Net The cash outflows related to purchasing assets other than capital expenditures, including assets acquired as the result of a merger. Total Debt Long-term Debt Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] LEASES Lessee, Operating Leases [Text Block] Mezzanine equity Net income (loss) attributable to noncontrolling interests Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Redeemable Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Common Class C Common Class C [Member] Lease liability Lease, Liability, Current Lease, Liability, Current Service cost Defined Benefit Plan, Service Cost Non-current asset retirement obligation Asset Retirement Obligations, Noncurrent Cash restricted for capital investments and distributions to a joint venture (JV) partner Restricted Cash and Cash Equivalents City Area Code City Area Code Equity Components [Axis] Equity Components [Axis] Title of 12(b) Security Title of 12(b) Security 2016 Credit Agreement (Shared First Priority Lien) Secured First Lien Second Out Credit Agreement [Member] Represents information pertaining to Secured First Lien Second Out Credit Agreement which is entered into by entity in 2016. Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Minimum Minimum [Member] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Consolidated Entities [Domain] Consolidated Entities [Domain] Total property, plant and equipment, net Total property, plant and equipment, net Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Operating lease Operating Lease, Liability, Current Grace period Debt Instrument, Grace Period Debt Instrument, Grace Period Net income attributable to noncontrolling interests Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] Recognized actuarial loss Defined Benefit Plan, Amortization of Gain (Loss) Total Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Schedule of derivative instruments in statement of financial position, fair value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Senior Debtor In Possession Senior Debtor In Possession [Member] Senior Debtor In Possession Member REVENUES Revenues [Abstract] CASH FLOW FROM OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities [Abstract] Commodity Contracts Commodity Contract [Member] Number of wells to be drilled Number Of Wells Agreed For Drilling Number Of Wells Agreed For Drilling Percentage of debt hedged by price risk derivatives Percentage Of Debt Hedged By Price Risk Derivatives Percentage Of Debt Hedged By Price Risk Derivatives Additional paid-in capital Additional Paid in Capital, Common Stock Total lease liabilities Total Lease Liability Total Lease Liability Subsequent Event Type [Domain] Subsequent Event Type [Domain] Business Acquisition [Line Items] Business Acquisition [Line Items] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Redeemable Noncontrolling Interest, by Legal Entity [Table] Redeemable Noncontrolling Interest, by Legal Entity [Table] Asset impairments Total Asset Impairment Charges Eliminations Intersegment Eliminations [Member] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Retirement Plan Type [Domain] Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Consolidation Items [Axis] Consolidation Items [Axis] Debtor-in-possession financing, amount arranged Debtor-in-Possession Financing, Amount Arranged Outstanding interest rate on borrowings Debtor-in-Possession Financing, Interest Rate on Borrowings Outstanding Accrued liabilities Accrued Liabilities [Member] Trade receivables Accounts Receivable, after Allowance for Credit Loss, Current Finished goods Inventory, Finished Goods, Gross Percentage of common interest held by CRC Noncontrolling Interest, Ownership Percentage by Parent Shared First Priority Lien Shared First Priority Lien [Member] Shared First Priority Lien [Member] Other Information [Table] Other Information [Table] Other Information [Table] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period Two Debt Instrument, Redemption, Period Two [Member] Materials and supplies Other Inventory, Supplies, Gross Cash Cash Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Combined Guarantor Subsidiaries Guarantor Subsidiaries [Member] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Gross Amounts Recognized at Fair Value Derivative Asset, Fair Value, Gross Asset Percentage of holding assets by subsidiaries in consolidated assets Percentage Of Holding Assets By subsidiaries In Consolidated Assets Percentage of total consolidated assets under financing agreement by subsidiary. NON-OPERATING (LOSS) INCOME Nonoperating Income (Expense) [Abstract] Contributions from noncontrolling interest holders, net Temporary Equity, Increase From Contributions The amount of increase in temporary equity due to contributions. Other current assets, net Other current assets, net Other Assets, Current Net periodic benefit costs: Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Interest rate to be in place to receive payment Derivative, Cap Interest Rate 2017 Credit Agreement (Shared First Priority Lien) Secured First Lien Second Out Credit Agreement2017 [Member] Represents information pertaining to Secured First Lien Second Out Credit Agreement which is entered into by entity in 2017. Entity Central Index Key Entity Central Index Key Entity Emerging Growth Company Entity Emerging Growth Company Credit Facility [Domain] Credit Facility [Domain] ACCOUNTING AND DISCLOSURE CHANGES Accounting Standards Update and Change in Accounting Principle [Text Block] Weighted-average common shares outstanding — diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Derivative Contract [Domain] Derivative Contract [Domain] Letters of Credit Letter of Credit [Member] Basic (in dollars per share) Earnings Per Share, Basic Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Accrued taxes other than on income Accrual for Taxes Other than Income Taxes, Current Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] Amounts due to (from) affiliates Due to Affiliate, Noncurrent OGCI OGCI [Member] OGCI [Member] Net cash provided by (used in) financing activities Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Contributions from noncontrolling interest holders, net Proceeds from Noncontrolling Interests New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Accounting Standards Update and Change in Accounting Principle [Abstract] Electricity Sale Of Electricity [Member] This member represents electricity sales. Balance Sheet Location [Axis] Balance Sheet Location [Axis] Common stock (200 million shares authorized at $0.01 par value) outstanding shares (June 30, 2020 - 49,453,297 and December 31, 2019 - 49,175,843) Common Stock, Value, Issued Fair Value of Derivatives Offsetting Assets [Line Items] Current portion of long-term debt Less: Current Portion of Long-Term Debt Long-term Debt, Current Maturities Retirement Benefits [Abstract] Retirement Benefits [Abstract] 5% Senior Notes due 2020 Senior Notes500 Percent Due2020 [Member] Represents the senior notes payable that bear an interest rate of 5.00 percent and will mature in 2020. Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Equity attributable to noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Inventory Disclosure [Abstract] Inventory Disclosure [Abstract] CASH FLOW FROM INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] LONG-TERM DEBT Total Long-Term Debt Long-term Debt, Excluding Current Maturities Gross Amounts Offset in the Balance Sheet Derivative Asset, Fair Value, Gross Liability Debt instrument Debt Debt Instrument [Line Items] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Total equity attributable to common stock Stockholders' Equity Attributable to Parent Redemption period, extended Redemption Period, Extended The option to extension additional period of redemption. Other revenue: Revenue Not from Contract with Customer, Other TOTAL LIABILITIES AND EQUITY Liabilities and Equity Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax INCOME TAXES Income Tax Disclosure [Text Block] Total derivatives Derivative Assets (Liabilities), at Fair Value, Net Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Accrued employee-related costs Employee-related Liabilities, Current 6% Senior Notes due 2024 Senior Notes600 Percent Due2024 [Member] Represents the senior notes payable that bear an interest rate of 6.00 percent and will mature in 2024. Total costs Total costs Costs and Other Deductions Total costs of sales, operating expenses, and other operating expenses for the period. Value of interests Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Share Value, Amount Equity Attributable to Common Stock Parent Parent [Member] Other assets Other Assets [Member] Weighted-average anti-dilutive shares Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] Other non-cash charges to income, net Other Noncash Income (Expense) Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Equity Component [Domain] Equity Component [Domain] Dividends paid Payments of Dividends Entity Address, Address Line One Entity Address, Address Line One Equity Attributable to Noncontrolling Interest Mezzanine Equity - Redeemable Noncontrolling Interests Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward] Reportable Legal Entities Reportable Legal Entities [Member] NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK Net Income (Loss) Attributable to Parent Entity Address, State or Province Entity Address, State or Province Finance lease Finance Lease, Liability, Noncurrent Applicable margin on LIBOR loans LIBOR London Interbank Offered Rate (LIBOR) [Member] INVENTORIES Inventory Disclosure [Text Block] Leases [Abstract] Leases [Abstract] BASIS OF PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Taxes other than on income Taxes, Miscellaneous Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Total current assets Total current assets Assets, Current Other Information [Line Items] Other Information [Line Items] [Line Items] for Other Information [Table] Net (loss) income attributable to common stock per share Earnings Per Share [Abstract] Earnings Per Share [Abstract] CONDENSED CONSOLIDATING FINANCIAL INFORMATION Condensed Financial Information of Parent Company Only Disclosure [Text Block] Increase in accrued taxes other than income Increase (Decrease) in Property and Other Taxes Payable PROPERTY, PLANT AND EQUIPMENT Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Elk Hills Carbon JV Elk Hills Carbon [Member] Elk Hills Carbon [Member] Debtor reorganization Items Debtor In possession facility, principal amount Debtor Reorganization Items Debtor In Possession Facility, Principal Amount Debtor Reorganization Items Debtor In Possession Facility, Principal Amount OTHER INFORMATION OTHER INFORMATION Other Information abstract Entity Interactive Data Current Entity Interactive Data Current Crude Oil Hedge Positions Energy Related Derivative [Member] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Reclassification of realized losses on pension and postretirement benefits to income Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Accumulated depreciation, depletion and amortization Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Maximum redemption period Period of Make Whole Payment and Maximum Redemption Period The period of make whole payment and maximum redemption period. Employer contributions to pension plan Defined Benefit Plan, Plan Assets, Contributions by Employer Oil and natural gas, price per barrel Oil and Gas, Average Sale Price Products and Services [Domain] Product and Service [Domain] 2014 Revolving Credit Facility (Shared First Priority Lien) Secured Debt [Member] Line of credit facility remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Junior Debtor-in-Possession Facility Junior Debtor-in-Possession Facility [Member] Junior Debtor-in-Possession Facility Member Interest and debt expense, net Interest And Debt Expense, Net Interest And Debt Expense, Net Debt instrument, interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Common Class A Common Class A [Member] Diluted EPS calculation Earnings Per Share, Diluted [Abstract] Increase in cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Equity Net income (loss) attributable to noncontrolling interests Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Nonredeemable Non-operating (loss) income Nonoperating Income (Expense) Finance lease, net Finance Lease, Right-of-Use Asset, after Accumulated Amortization Derivative, amount of hedged item Derivative, Amount of Hedged Item Decrease in other accrued liabilities Increase (Decrease) in Other Accrued Liabilities Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Weighted-average common shares outstanding — basic (in shares) Weighted Average Number of Shares Outstanding, Basic Interest rate added to variable rate basis Debt Instrument, Basis Spread on Variable Rate Potential reduction in debt Potential Reduction in Debt Potential Reduction in Debt Condensed Financial Information Disclosure [Abstract] Condensed Financial Information Disclosure [Abstract] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] Net Fair Value Presented in the Balance Sheet Reported Value Measurement [Member] REVENUE RECOGNITION Revenue from Contract with Customer [Text Block] Interest paid, net of capitalized amounts Interest Paid, Excluding Capitalized Interest, Operating Activities Schedule of condensed income statement Condensed Income Statement [Table Text Block] Total equity Beginning balance Ending balance Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Estimated fair value of long-term debt Long-term Debt, Fair Value Total revenues Total revenues Revenues Class of Stock [Axis] Class of Stock [Axis] Income tax Income Tax Expense (Benefit) Cash—beginning of period Cash—end of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Number of trading days Number Of Trading Days Number Of Trading Days Redeemable Noncontrolling Interests Temporary Equity [Line Items] Accrued liabilities Accrued liabilities Accrued Liabilities, Current Diluted (in dollars per share) Earnings Per Share, Diluted Finance lease Finance Lease, Liability, Current Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] ECR Ecr Corporate Holdings [Member] This member represents ECR corporate holdings Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Noncontrolling Interest Noncontrolling Interest [Line Items] Debt carrying value Long-term Debt, Gross Schedule of long-term debt Schedule of Long-term Debt Instruments [Table Text Block] Gross Amounts Recognized at Fair Value Derivative Liability, Fair Value, Gross Liability Net loss Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest Distributions to noncontrolling interest holders Noncontrolling Interest, Decrease from Distributions to Redeemable Noncontrolling Interest Holders Decrease in redeemable noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders. Maximum Maximum [Member] Preferred stock, authorized shares (in shares) Preferred Stock, Shares Authorized Equity Attributable to Noncontrolling Interests Equity Attributable to Noncontrolling Interest Noncontrolling Interest [Member] Accumulated Deficit Retained Earnings [Member] Preferred stock, outstanding shares (in shares) Preferred Stock, Shares Outstanding Measurement Basis [Axis] Measurement Basis [Axis] Finance Lease, Liability, Current, Statement of Financial Position [Extensible List] Finance Lease, Liability, Current, Statement of Financial Position [Extensible List] Effective tax rate Effective Income Tax Rate Reconciliation, Percent Schedule of components of the net periodic benefit costs Schedule of Net Benefit Costs [Table Text Block] Net cash used in investing activities Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Allowance for credit loss Accounts Receivable, Allowance for Credit Loss Net proceeds from settled commodity derivatives Proceeds (Payments) on Derivative Settlements to Reconcile Net Income Loss to Cash provided by Used in Operating Activities The net proceeds (payments) on derivative settlements, which increase (reduce) net income and are thus added (deducted) when calculating cash provided by or used in operating activities. Other non-operating expenses Other Nonoperating Expense Document Transition Report Document Transition Report Debt Repurchases of debt Long-term Debt, Unclassified [Abstract] Postretirement Benefit Other Postretirement Benefits Plan [Member] Schedule of condensed balance sheet Condensed Balance Sheet [Table Text Block] Threshold through consecutive days Threshold Through Consecutive Days Threshold Through Consecutive Days Pension Benefit Pension Plan [Member] EARNINGS PER SHARE Earnings Per Share [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Redeemable noncontrolling interests Beginning balance Ending balance Mezzanine equity Redeemable Noncontrolling Interest, Equity, Carrying Amount CURRENT LIABILITIES Liabilities, Current [Abstract] Accrued interest Debt Instrument, Increase, Accrued Interest ASSET IMPAIRMENTS Asset Impairment Charges [Text Block] Proceeds from 2014 Revolving Credit Facility Proceeds from Lines of Credit Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Basic EPS calculation Earnings Per Share, Basic [Abstract]