Document and Entity Information Statement [Table] Statement [Line Items] Statement Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Consolidated Balance Sheets Assets [Abstract] Assets Assets, Current [Abstract] CURRENT ASSETS Cash Cash-end of year Cash-beginning of year Cash Accounts Receivable, Net, Current Trade receivables Inventory, Net Inventories Total Other Assets, Current Other current assets, net Other current assets Assets, Current Total current assets Total current assets Property, Plant and Equipment, Gross PROPERTY, PLANT AND EQUIPMENT Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated depreciation, depletion and amortization Property, Plant and Equipment, Net Total property, plant, equipment, net Total property, plant, equipment, net Other Assets, Noncurrent OTHER ASSETS Other assets Assets TOTAL ASSETS Liabilities and Equity [Abstract] Liabilities and Stockholders' Equity Liabilities, Current [Abstract] CURRENT LIABILITIES Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. Debt Instrument Carrying Amount Current Less Current Maturities of Long-Term Debt Current maturities of long-term debt Accounts Payable, Current Accounts payable Accrued Liabilities, Current Accrued liabilities Accrued liabilities Liabilities, Current Total current liabilities Total current liabilities Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt, classified as noncurrent. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. Debt Instrument Carrying Amount Noncurrent Long-Term Debt - Principal Amount LONG-TERM DEBT - PRINCIPAL AMOUNT Carrying value as of the balance sheet of the deferred gain (loss) and issuance costs, net. Deferred Gain (Loss) and Issuance Costs, Net DEFERRED GAIN AND ISSUANCE COSTS, NET Deferred gain and issuance costs, net Deferred gain and issuance costs, net Other Liabilities, Noncurrent OTHER LONG-TERM LIABILITIES Other long-term liabilities Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] EQUITY Preferred Stock, Value, Issued Preferred stock (20 million shares authorized at $0.01 par value) no shares outstanding at December 31, 2017 or 2016 Common Stock, Value, Issued Common stock (200 million shares authorized at $0.01 par value) outstanding shares (2017 - 42,901,946 shares and 2016 - 42,542,637 shares) Additional Paid in Capital, Common Stock Additional paid-in capital Retained Earnings (Accumulated Deficit) Accumulated deficit Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Stockholders' Equity Attributable to Parent Total equity attributable to common stock Stockholders' Equity Attributable to Noncontrolling Interest Noncontrolling interest Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance Balance Total equity Liabilities and Equity TOTAL LIABILITIES AND EQUITY Preferred Stock, Shares Authorized Preferred stock, authorized shares Preferred Stock, Par or Stated Value Per Share Preferred stock, par value (in dollars per share) Preferred Stock, Shares Outstanding Preferred stock, outstanding shares Common Stock, Shares Authorized Common stock, authorized shares Common Stock, Par or Stated Value Per Share Common stock, par value (in dollars per share) Common Stock, Shares, Outstanding Balance at the end of the year (in shares) Balance at the beginning of the year (in shares) Common stock, outstanding shares Consolidated Statements of Operations Revenues [Abstract] REVENUES AND OTHER REVENUES Oil and Gas Sales Revenue Oil and gas net sales Gain (Loss) on Derivative Instruments, Net, Pretax Net derivative losses (gains) Net derivative (losses) gains Other Operating Income Other revenue Revenues Total revenues and other Total revenues and other Costs and Other Deductions [Abstract] COSTS AND OTHER Production Costs, Period Cost Production costs Selling, General and Administrative Expense General and administrative expenses Depreciation, Depletion and Amortization Depreciation, depletion and amortization Asset Impairment Charges Asset impairments Taxes, Miscellaneous Taxes other than on income Exploration Expense Exploration expense Other Operating Income (Expense), Net Other expenses, net Total costs of sales, operating expenses, and nonoperating expenses for the period. Costs and Other Deductions Total costs and other Total costs and other Operating Income (Loss) OPERATING INCOME (LOSS) Nonoperating Income (Expense) [Abstract] NON-OPERATING (LOSS) INCOME Pre-tax interest expense Interest and debt expense, net Gain (Loss) on Repurchase of Debt Instrument Net gains on early extinguishment of debt Net gains on early extinguishment of debt Pre-tax deferred gain on early extinguishment of debt Gain (Loss) on Disposition of Assets Gains on asset divestitures Gains on asset divestitures Other Nonoperating Expense Other non-operating expense Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (loss) before income taxes (LOSS) INCOME BEFORE INCOME TAXES Income Tax Expense (Benefit) Income tax benefit Total tax expense (benefit) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net (loss) income NET (LOSS) INCOME Net income (loss) Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to noncontrolling interest Less: net income attributable to noncontrolling interest Net Income (Loss) Attributable to Parent NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK Net (loss) income attributable to common stock EARNINGS PER SHARE Net (loss) income attributable to common stock per share Earnings Per Share, Basic and Diluted Basic and diluted (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Dividends per common share (in dollars per share) Consolidated Statements of Comprehensive Income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive (loss) income items: Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Pension and postretirement losses Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Net of Tax Reclassification to income of realized losses on pension and postretirement Other Comprehensive Income (Loss), Net of Tax Total other comprehensive income, net of tax Other comprehensive income, net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive (loss) income attributable to common stock Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Pension and postretirement losses, tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Reclassification to income of realized losses (gains) on derivatives, tax Consolidated Statements of Equity Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Parent [Member] Equity Attributable to Common Stock Additional Paid In Capital [Member] Additional Paid-in Capital Retained Earnings [Member] Accumulated Deficit Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive (Loss) Income Noncontrolling Interest [Member] Noncontrolling Interest Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (decrease) in Equity Common stock issuances Noncontrolling Interest, Increase from Sale of Parent Equity Interest Contribution from noncontrolling interest, net Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Distributions paid to noncontrolling interest holders Dividends, Common Stock, Cash Dividends on common stock Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Share-based compensation, net Consolidated Statements of Cash Flows Net Cash Provided by (Used in) Operating Activities [Abstract] CASH FLOW FROM OPERATING ACTIVITIES Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income (loss) to net cash provided by operating activities: Deferred Income Tax Expense (Benefit) Deferred income tax benefit Deferred Total tax expense (benefit) The net receipt (payment) on derivative settlements, which reduce or increase net income and are thus added back or deducted when calculating cash provided by or used in operating activities. Receipt Payment On Derivative Settlements, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Net (payments) proceeds on settled derivatives The amount of amortization of deferred gains. Amortization of Deferred Gains Amortization of deferred gain Other Noncash Income Tax Expense Other non-cash tax provision Other Noncash Income (Expense) Other non-cash charges to income, net Results of Operations, Dry Hole Costs Dry hole expenses Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities, net: Increase (Decrease) in Receivables (Increase) decrease in trade receivables Increase (Decrease) in Inventories Decrease in inventories Increase (Decrease) in Other Current Assets (Increase) decrease in other current assets Increase (Decrease) in Accounts Payable and Accrued Liabilities Decrease in accounts payable and accrued liabilities Net Cash Provided by (Used in) Operating Activities Net cash (used) provided by operating activities Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] CASH FLOW FROM INVESTING ACTIVITIES Payments to Acquire Property, Plant, and Equipment Capital investments Amount used to fund capital investments Represents the information pertaining to changes in capital investment accruals Increase Decrease In Capital Investment Accrual Changes in capital investment accruals Proceeds from Sale of Productive Assets Asset divestitures The cash outflows related to purchasing assets other than capital expenditures, including assets acquired as the result of a merger. Purchase of Assets, Net Acquisitions and other Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] CASH FLOW FROM FINANCING ACTIVITIES Proceeds from Lines of Credit Proceeds from 2014 Revolving Credit Facility Repayments of Lines of Credit Repayments of 2014 Revolving Credit Facility Proceeds used to repay 2014 revolving credit facility Proceeds from Issuance of Senior Long-term Debt Proceeds from 2016 Credit Agreement Proceeds from Issuance of Long-term Debt Proceeds from 2017 Term Loan Repayments of Senior Debt Payments on 2014 Term Loan Repayments of Subordinated Debt Debt repurchases Payments of Debt Restructuring Costs Debt transaction costs Proceeds from Noncontrolling Interests Contribution from noncontrolling interest, net Net proceeds from the transaction Payments of Ordinary Dividends, Noncontrolling Interest Distributions paid to noncontrolling interest holders Proceeds from Stock Plans Employee stock purchases and other Payments of Shares Cancelled for Taxes Shares canceled for taxes Proceeds from Issuance of Common Stock Issuance of common stock Payments of Ordinary Dividends, Common Stock Cash dividends paid Net Cash Provided by (Used in) Financing Activities Net cash provided (used) by financing activities Net cash provided (used) by financing activities Cash and Cash Equivalents, Period Increase (Decrease) Increase (decrease) in cash and cash equivalents Increase (decrease) in cash No definition available. THE SPIN-OFF, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND OTHER Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] THE SPIN-OFF, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND OTHER ACCOUNTING AND DISCLOSURE CHANGES New Accounting Pronouncements and Changes in Accounting Principles [Text Block] ACCOUNTING AND DISCLOSURE CHANGES No definition available. ACQUISITIONS AND DIVESTITURES Mergers, Acquisitions and Dispositions Disclosures [Text Block] ACQUISITIONS AND DIVESTITURES PROPERTY, PLANT AND EQUIPMENT Property, Plant and Equipment Disclosure [Text Block] PROPERTY, PLANT AND EQUIPMENT DEBT Long-term Debt [Text Block] DEBT LEASE COMMITMENTS Leases of Lessee Disclosure [Text Block] LEASE COMMITMENTS LAWSUITS, CLAIMS, COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] LAWSUITS, CLAIMS, COMMITMENTS AND CONTINGENCIES DERIVATIVES Derivative Instruments and Hedging Activities Disclosure [Text Block] DERIVATIVES INCOME TAXES Income Taxes Income Tax Disclosure [Text Block] INCOME TAXES STOCK COMPENSATION Disclosure of Compensation Related Costs, Share-based Payments [Text Block] STOCK COMPENSATION EQUITY Stockholders' Equity Note Disclosure [Text Block] EQUITY Earnings Per Share [Text Block] EARNINGS PER SHARE PENSION AND POSTRETIREMENT BENEFIT PLANS Pension and Other Postretirement Benefits Disclosure [Text Block] PENSION AND POSTRETIREMENT BENEFIT PLANS SUBSEQUENT EVENT Subsequent Events [Text Block] SUBSEQUENT EVENT No definition available. CONDENSED CONSOLIDATING FINANCIAL INFORMATION Condensed Financial Statements [Text Block] CONDENSED CONSOLIDATING FINANCIAL INFORMATION SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS Basis of Accounting, Policy [Policy Text Block] Basis of Presentation Use of Estimates, Policy [Policy Text Block] Risks and Uncertainties Major Customers, Policy [Policy Text Block] Concentration of Customers Property, Plant and Equipment, Policy [Policy Text Block] Property, Plant and Equipment Asset Retirement Obligations, Policy [Policy Text Block] Asset Retirement Obligations Pension and Other Postretirement Plans, Policy [Policy Text Block] Pension and Postretirement Benefit Plans Fair Value Measurement, Policy [Policy Text Block] Fair Value Measurements Revenue Recognition, Policy [Policy Text Block] Revenue Recognition Inventory, Policy [Policy Text Block] Inventories Derivatives, Policy [Policy Text Block] Derivative Instruments Compensation Related Costs, Policy [Policy Text Block] Stock-Based Incentive Plans Earnings Per Share, Policy [Policy Text Block] Earnings Per Share Commitments and Contingencies, Policy [Policy Text Block] Other Loss Contingencies Income Tax, Policy [Policy Text Block] Income Taxes Disclosure of accounting policy for production sharing type contracts. Production Sharing Type Contracts [Policy Text Block] Production Sharing Type Contracts Schedule of Change in Asset Retirement Obligation [Table Text Block] Summary of the activity of the asset retirement obligation Schedule of Inventory, Current [Table Text Block] Schedule of Inventories Schedule of Other Current Assets [Table Text Block] Schedule of other current assets Schedule of Accrued Liabilities [Table Text Block] Schedule of accrued liabilities Capitalized Exploratory Well Costs, Roll Forward [Table Text Block] Summary of the activity of capitalized exploratory well costs Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Debt instrument Debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Debt The tabular disclosure of debt instruments financial performance covenants. Debt Instrument, Financial Performance Covenants [Table Text Block] Schedule of financial performance covenants