Stockholders' Equity Common Stock Rollforward (Details) |
12 Months Ended | ||||
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Nov. 01, 2017
shares
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Dec. 31, 2017
shares
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Dec. 31, 2016
shares
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Dec. 31, 2015
shares
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Oct. 31, 2017
shares
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| Increase (Decrease) in Common Stock Outstanding [Roll Forward] | |||||
| Common shares outstanding at beginning of period (in shares) | 173,826,163 | 176,953,403 | 183,197,960 | ||
| Number of shares of common stock issued during period (in shares) | 26,950 | 30,301 | 34,913 | ||
| Number of shares of restricted common stock issued during period (in shares) | 643,474 | 852,459 | 552,680 | ||
| Number of shares of common stock repurchased during period (in shares) | (4,010,000) | (6,832,150) | |||
| Common shares outstanding at end of period (in shares) | 174,496,587 | 173,826,163 | 176,953,403 | ||
| Reverse stock split, conversion ratio | 0.50 | ||||
| Common shares authorized (in shares) | 450,000,000 | 450,000,000 | 450,000,000 | 900,000,000 | |
| Number of nonvested restricted common shares outstanding (in shares) | 1,284,010 | 1,319,712 | 1,145,305 | ||
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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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 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 number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Number of new stock issued during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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