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Accounts Receivable - Related Parties | 12 Months Ended
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Dec. 31, 2014
Receivables [Abstract] |
Accounts Receivable - Related Parties | ACCOUNTS RECEIVABLE—RELATED PARTIES Included in the accompanying consolidated balance sheets as of December 31, 2014 and 2013 are amounts receivable from related parties of the Company. At December 31, 2013, these receivables totaled $2.6 million. At December 31, 2014, the amount of related party receivables was immaterial.

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- Definition Accounts receivable, related parties [Text Block] + References No definition available. + Details
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Namespace Prefix: | gpor_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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- Details
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Period Type: | duration