Entity Central Index Key Document Document and Entity Information [Abstract] Document Document And Entity Information [Abstract] Document Document And Entity Information [Abstract] Document Information [Table] Document Information [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Entity Information [Line Items] Entity Information [Line Items] 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 Current Fiscal Year End Date Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Well Known Seasoned Issuer Entity Current Reporting Status Entity Current Reporting Status Entity Voluntary Filers Entity Voluntary Filers Entity Filer Category Entity Filer Category Entity Public Float Entity Public Float Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Statement Of Financial Position [Abstract] Statement Of Financial Position [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] ASSETS Assets [Abstract] Cash and Cash Equivalents Cash And Cash Equivalents At Carrying Value Accounts Receivable: Accounts Receivable Net Current [Abstract] Oil and gas sales Accounts Receivable Net Current Joint interest operations Oil And Gas Joint Interest Billing Receivables Current Marketable Securities Marketable Securities Current Assets of Discontinued Operations Assets Of Disposal Group Including Discontinued Operation Current Derivative Financial Instruments Derivative Assets Current Other Current Assets Other Assets Current Total current assets Assets Current Property and Equipment: Property Plant And Equipment Net [Abstract] Unevaluated oil and gas properties Unproved Oil And Gas Property Successful Effort Method Oil and gas properties, successful efforts method Proved Oil And Gas Property Successful Effort Method Other Property Plant And Equipment Other Accumulated depreciation, depletion and amortization Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Net property and equipment Property Plant And Equipment Net Assets of Discontinued Operations Assets Of Disposal Group Including Discontinued Operation Noncurrent Other Assets Other Assets Noncurrent Total Assets Assets LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities And Stockholders Equity [Abstract] Accounts Payable Accounts Payable Current Deferred Income Taxes Payable Deferred Tax Liabilities Current Current Income Taxes Payable Accrued Income Taxes Current Accrued Expenses Accrued Liabilities Current Liabilities of Discontinued Operations Liabilities Of Disposal Group Including Discontinued Operation Current Total current liabilities Liabilities Current Long-term Debt Long Term Debt Noncurrent Deferred Income Taxes Payable Deferred Tax Liabilities Noncurrent Reserve for Future Abandonment Costs Asset Retirement Obligations Noncurrent Other Non-Current Liabilities Other Liabilities Noncurrent Total liabilities Liabilities Commitments and Contingencies Commitments And Contingencies Stockholders’ Equity: Stockholders Equity [Abstract] Common stock—$0.50 par, 75,000,000 shares authorized, 48,408,734 and 47,680,516 shares issued and outstanding at December 31, 2012 and 2013, respectively Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated other comprehensive income Accumulated Other Comprehensive Income Loss Net Of Tax Retained earnings Retained Earnings Accumulated Deficit Total stockholders’ equity Stockholders Equity Total liabilities and stockholders' equity Liabilities And Stockholders Equity 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 Common stock, shares outstanding Common Stock Shares Outstanding Gain on sale of oil and gas property. Production and severance taxes operating expense. Exploration expense including unproved impairments and exploratory dry hole costs. Loss on sale of oil and gas property. Income Statement [Abstract] Income Statement [Abstract] Oil sales Oil And Condensate Revenue Natural gas sales Natural Gas Production Revenue Total oil and gas sales Oil And Gas Sales Revenue Gain on sale of oil and gas properties Gain On Sale Of Oil And Gas Property Total revenues Revenues Operating expenses: Operating Expenses [Abstract] Production taxes Production And Severance Taxes Operating Expense Gathering and transportation Gas Gathering Transportation Marketing And Processing Costs Lease operating Lease Operating Expense Exploration Exploration Expense Including Unproved Impairments And Exploratory Dry Hole Costs Depreciation, depletion and amortization Depreciation Depletion And Amortization General and administrative, net General And Administrative Expense Impairment of oil and gas properties Impairment Of Oil And Gas Properties Loss on sale of oil and gas properties Loss On Sale Of Oil And Gas Property Total operating expenses Operating Expenses Operating loss Operating Income Loss Other income (expenses): Nonoperating Income Expense [Abstract] Gain on sale of marketable securities Marketable Securities Gain Loss Gains (losses) from derivative financial instruments Gain Loss On Sale Of Commodity Contracts Loss on early extinguishment of debt Gains Losses On Extinguishment Of Debt Other income Interest And Other Income Interest expense Interest Expense Total other income (expenses) Nonoperating Income Expense Loss from continuing operations before income taxes Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments Benefit from income taxes Income Tax Expense Benefit Loss from continuing operations Income Loss From Continuing Operations Income from discontinued operations Income Loss From Discontinued Operations Net Of Tax Net income (loss) Net Income Loss Net income (loss) per share: Earnings Per Share [Abstract] Loss from continuing operations, Basic Income Loss From Continuing Operations Per Basic Share Income from discontinued operations, Basic Income Loss From Discontinued Operations Net Of Tax Per Basic Share Net income (loss), Basic Earnings Per Share Basic Loss from continuing operations, Diluted Income Loss From Continuing Operations Per Diluted Share Income from discontinued operations, Diluted Income Loss From Discontinued Operations Net Of Tax Per Diluted Share Net income (loss), Diluted Earnings Per Share Diluted Dividends per common share Common Stock Dividends Per Share Declared Weighted average shares outstanding: Weighted Average Number Of Shares Outstanding [Abstract] Basic Weighted Average Number Of Shares Outstanding Basic Diluted Weighted Average Number Of Diluted Shares Outstanding Statement Of Partners Capital [Abstract] Statement Of Partners Capital [Abstract] Net income (loss) Unrealized hedging gains, net of provision for (benefit from) income taxes of $161, $(161) and $— Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax Net change in unrealized gains on marketable securities, net of benefit from income taxes of $6,543, $8,487 and $2,380 Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax Other comprehensive loss Other Comprehensive Income Loss Net Of Tax Comprehensive income (loss) Comprehensive Income Net Of Tax Other comprehensive income unrealized hedging gains losses net of tax tax amount. Other comprehensive unrealized gain on marketable securities net of tax tax. Unrealized hedging gains, income tax provision (benefit) Other Comprehensive Income Unrealized Hedging Gains Losses Net Of Tax Tax Amount Net change in unrealized gains on marketable securities, income tax benefit Other Comprehensive Income Net Unrealized Gains Losses Tax Value of stock issued during the period as a result of any share-based compensation plan other than an employee stock ownership plan (ESOP) and share-based compensation cost during the period with respect to the award, which will be recognized in income. Statement Of Stockholders Equity [Abstract] Statement Of Stockholders Equity [Abstract] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid In Capital [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income [Member] Beginning Balance Beginning Balance, Shares Shares Issued Stock-based compensation Stock Based Compensation Stock-based compensation, Shares Stock Issued During Period Shares Share Based Compensation Tax withholdings related to stock grants Adjustments Related To Tax Withholding For Share Based Compensation Tax withholdings related to stock grants, Shares Shares Paid For Tax Withholding For Share Based Compensation Excess income taxes from stock-based compensation Adjustments To Additional Paid In Capital Tax Effect From Share Based Compensation Repurchases of common stock Stock Repurchased And Retired During Period Value Repurchases of common stock, Shares Stock Repurchased And Retired During Period Shares Dividends paid Dividends Other comprehensive loss Ending Balance Ending Balance, Shares Gains and losses from sales of oil and gas properties, other assets, and marketable securities. Dry hole costs and lease hold impairments. Payment To Acquire Property Plant And Equipment, Discontinued Operations. Proceeds from Sale of Oil and Gas Property and Equipment, Discontinued Operations. Tax benefit cost from share based compensation financing activities. Statement Of Cash Flows [Abstract] Statement Of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Income from discontinued operations Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Gain on sale of assets Gain Loss On Sale Of Assets Deferred income taxes Deferred Income Tax Expense Benefit Dry hole costs and leasehold impairments Dry Hole Costs And Lease Hold Impairments (Gains) losses on derivative financial instruments Cash settlements of derivative financial instruments Derivative Cash Received On Hedge Loss on early extinguishment of debt Debt issuance cost and discount amortization Amortization Of Financing Costs And Discounts Stock-based compensation Share Based Compensation Excess income taxes from stock-based compensation Decrease (increase) in accounts receivable Increase Decrease In Accounts Receivable Decrease (increase) in other current assets Increase Decrease In Other Operating Assets Increase (decrease) in accounts payable and accrued expenses Increase Decrease In Accounts Payable And Accrued Liabilities Net cash provided by continuing operations Net Cash Provided By Used In Operating Activities Continuing Operations Net cash provided by (used for) discontinued operations Cash Provided By Used In Operating Activities Discontinued Operations 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] Capital expenditures Payments To Acquire Property Plant And Equipment Proceeds from sales of oil and gas properties Proceeds From Sale Of Other Investments Proceeds from sales of marketable securities Proceeds From Sale Of Available For Sale Securities Equity Investing activities of continuing operations Net Cash Provided By Used In Investing Activities Continuing Operations Cash flow from investing activities of discontinued operations: Net Cash Provided By Used In Discontinued Operations [Abstract] Capital expenditures Payment To Acquire Property Plant And Equipment Discontinued Operations Proceeds from sale of oil and gas properties Proceeds From Sale Of Oil And Gas Property And Equipment Discontinued Operations Investing activities of discontinued operations Cash Provided By Used In Investing Activities Discontinued Operations Net cash used for 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 Proceeds From Issuance Of Long Term Debt Principal payments on debt Repayments Of Long Term Debt Costs related to early extinguishment of debt Payments Of Debt Extinguishment Costs Debt issuance costs Payments Of Debt Issuance Costs Tax withholding related to stock grants Payments Related To Tax Withholding For Share Based Compensation Repurchases of common stock Payments For Repurchase Of Common Stock Excess income taxes from stock-based compensation Tax Benefit Cost From Share Based Compensation Financing Activities Dividends paid Payments Of Dividends Net cash provided by (used for) 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 the year Cash and cash equivalents, end of the year Text Block [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Acquisitions and Dispositions of Oil and Gas Properties Property Plant And Equipment Disclosure [Text Block] Oil and Gas Producing Activities Oil And Gas Exploration And Production Industries Disclosures [Text Block] Long-term Debt Long Term Debt [Text Block] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Stockholders' Equity Stockholders Equity Note Disclosure [Text Block] Stock-based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Retirement Plan Pension And Other Postretirement Benefits Disclosure [Text Block] Income Taxes Income Tax Disclosure [Text Block] Derivative Financial Instruments and Hedging Activities Derivative Instruments And Hedging Activities Disclosure [Text Block] Supplementary Quarterly Financial Data (Unaudited) Quarterly Financial Information [Text Block] Oil and gas reserves information text block. Oil and Gas Reserves Information (Unaudited) Oil And Gas Reserves Information [Text Block] Basis of presentation and principles of consolidation. Basis of Presentation and Principles of Consolidation Basis Of Presentation And Principles Of Consolidation Policy [Text Block] Divestitures Policy [Text Block] Discontinued West Texas Operations Divestitures Policy [Text Block] Reclassifications Prior Period Reclassification Adjustment Description Use of Estimates in the Preparation of Financial Statements Use Of Estimates Concentration of credit risk and accounts receivable. Concentration Of Credit Risk And Accounts Receivable Concentration Of Credit Risk And Accounts Receivable Policy [Text Block] Marketable Securities Marketable Securities Policy Fair Value Measurements Fair Value Of Financial Instruments Policy Property and Equipment Property Plant And Equipment Policy [Text Block] Other Assets Policy Text Block. Other Assets Other Assets Policy [Text Block] Accrued expenses. Accrued Expenses Accrued Expenses Policy [Text Block] Reserve for Future Abandonment Costs Asset Retirement Obligations Policy Stock-Based Compensation Share Based Compensation Option And Incentive Plans Policy Segment Reporting Segment Reporting Policy Policy [Text Block] Derivative Financial Instruments and Hedging Activities Derivatives Policy [Text Block] Major Purchasers Policy Text Block Major Purchasers Major Purchasers Policy [Text Block] Revenue Recognition and Gas Balancing Revenue Recognition Policy [Text Block]