Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2018 |
Dec. 31, 2017 |
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| Statement of Financial Position [Abstract] | ||
| Capitalized costs of oil and natural gas properties excluded from amortization | $ 2,971,119 | $ 2,912,974 |
| Preferred stock, par value (in usd per share) | $ 0.01 | $ 0.01 |
| Preferred stock, shares authorized (in shares) | 5,000,000 | 5,000,000 |
| Preferred stock dividend rate, percent | 12.00% | 12.00% |
| Redeemable preferred stock, shares authorized (in shares) | 30,000 | 30,000 |
| Preferred stock Series A, issued (in shares) | 0 | 0 |
| Preferred stock Series A, outstanding (in shares) | 0 | 0 |
| Common stock, par value (in usd per share) | $ 0.01 | $ 0.01 |
| Common stock, shares authorized (in shares) | 200,000,000 | 200,000,000 |
| Common stock, shares, issued (in shares) | 173,523,487 | 183,105,910 |
| Common stock, shares, outstanding (in shares) | 173,523,487 | 183,105,910 |
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- Definition The sum of the capitalized costs incurred, as of the balance sheet date, of unproved properties excluded from amortization including acquisition costs, exploration costs, development costs, and production costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Face amount or stated value per share of common stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The percentage rate used to calculate dividend payments on preferred stock. No definition available.
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- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition The maximum number of securities classified as temporary equity that are permitted to be issued by an entity's charter and bylaws. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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