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Income Taxes (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Components of the provision for income taxes |  |  |
Federal | $ 2,932 | $ 0 | $ 0
State | 1,539 | 1,571 | 868
Deferred portion of income tax expense (benefit) | (448,643) | (276,722) | 397,780
Income tax expense (benefit) | $ (444,172) | $ (275,151) | $ 398,648
Effective tax rate (as a percent) | 37.00% | 38.10% | 37.40%
Deferred Income Taxes [Abstract] |  |  |
Deferred Tax Liabilities, Oil and Gas Properties | $ 518,394 | $ 854,029 |
Deferred Tax Liabilities, Derivative asset | 0 | 179,543 |
Deferred Tax Liabilities, Other | 7,733 | 1,233 |
Deferred Tax Liabilities | 526,127 | 1,034,805 |
Deferred Tax Assets, Federal and State Tax Net Operating Loss Carryforwards | 151,343 | 244,942 |
Deferred Tax Assets, Derivative Instruments | 31,349 | 0 |
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost | 10,083 | 14,529 |
Deferred Tax Assets, Tax Credit Carryforwards | 12,448 | 6,952 |
Deferred Tax Assets, Other Liabilities | 10,567 | 20,497 |
Deferred Tax Assets, Gross | 215,790 | 286,920 |
Deferred Tax Assets, Valuation Allowance | (5,335) | (10,394) |
Deferred Tax Assets, Net | 210,455 | 276,526 |
Deferred Tax Liabilities, Net | 315,672 | 758,279 |
Unrecognized Tax Benefits, Exercise of Stock Awards | 126,700 |  |
Tax Credit Recorded for IRS R&D Settlement |  | 2,000 |
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] |  |  |
Unrecognized Tax Benefits, Beginning Balance | 2,782 | 1,582 | $ 2,358
Unrecognized Tax Benefits, Additions For Tax Positions Of Prior Years | 9 | 1,200 | 140
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities | (2,345) | 0 | (916)
Unrecognized Tax Benefits, Ending Balance | 446 | 2,782 | $ 1,582
State and Local Jurisdiction [Member] |  |  |
Deferred Income Taxes [Abstract] |  |  |
Income Taxes Receivable, Current | 0 | 65 |
Taxes Payable, Current | 1,181 | 0 |
Operating Loss Carryforwards | 184,600 |  |
General Business Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member] |  |  |
Deferred Income Taxes [Abstract] |  |  |
Tax Credit Carryforward, Amount | 528 |  |
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member] |  |  |
Deferred Income Taxes [Abstract] |  |  |
Income Taxes Receivable, Current | 644 | $ 5,378 |
Operating Loss Carryforwards | 540,200 |  |
Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member] | Domestic Tax Authority [Member] |  |  |
Deferred Income Taxes [Abstract] |  |  |
Tax Credit Carryforward, Amount | 7,200 |  |
Internal Revenue Service (IRS) [Member] | Alternative Minimum Tax Credit Carryforward [Member] | Domestic Tax Authority [Member] |  |  |
Deferred Income Taxes [Abstract] |  |  |
Tax Credit Carryforward, Amount | $ 5,600 |  |

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- Definition Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19,20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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