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Stock-Based Compensation (Narrative) (Details) (USD $)
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3 Months Ended | |
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Mar. 31, 2015
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Mar. 31, 2014
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| Share-based Compensation [Abstract] | ||
| Stock-based compensation expense | $ 3,500,000us-gaap_AllocatedShareBasedCompensationExpense | $ 4,300,000us-gaap_AllocatedShareBasedCompensationExpense |
| Capitalized stock-based compensation | 1,385,000gpor_CapitalizedStockBasedCompensation | 1,723,000gpor_CapitalizedStockBasedCompensation |
| Unrecognized compensation expense | $ 18,900,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized | |
| Weighted average period | 1 year 6 months 18 days | |
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- Definition
Non-cash stock based compensation capitalized. No definition available.
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- Definition
Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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