XML 41 R29.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Equity Investments (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract] |
Investments Accounted for by the Equity Method | Investments accounted for by the equity method consist of the following as of March 31, 2018 and December 31, 2017:
|  |  | Carrying value |  | (Income) loss from equity method investments
| Approximate ownership % |  | March 31, 2018 |  | December 31, 2017 |  | Three months ended March 31,
|  |  |  | 2018 |  | 2017
|  |  | (In thousands)
Investment in Tatex Thailand II, LLC | 23.5 | % |  | $ | — |  |  | $ | — |  |  | $ | (41 | ) |  | $ | (243 | )
Investment in Grizzly Oil Sands ULC | 24.9999 | % |  | 53,564 |  |  | 57,641 |  |  | 330 |  |  | 365 |
Investment in Timber Wolf Terminals LLC | 50.0 | % |  | 980 |  |  | 983 |  |  | 2 |  |  | 4 |
Investment in Windsor Midstream LLC | 22.5 | % |  | 30 |  |  | 30 |  |  | — |  |  | (311 | )
Investment in Stingray Cementing LLC(1) | — | % |  | — |  |  | — |  |  | — |  |  | 128 |
Investment in Blackhawk Midstream LLC | 48.5 | % |  | — |  |  | — |  |  | — |  |  | — |
Investment in Stingray Energy Services LLC(1) | — | % |  | — |  |  | — |  |  | — |  |  | 197 |
Investment in Sturgeon Acquisitions LLC(1) | — | % |  | — |  |  | — |  |  | — |  |  | 68 |
Investment in Mammoth Energy Services, Inc.(1) | 25.1 | % |  | 179,770 |  |  | 165,715 |  |  | (13,470 | ) |  | 2,158 |
Investment in Strike Force Midstream LLC | 25.0 | % |  | 77,350 |  |  | 77,743 |  |  | (357 | ) |  | 2,541 |
|  |  | $ | 311,694 |  |  | $ | 302,112 |  |  | $ | (13,536 | ) |  | $ | 4,907 |
(1) | On June 5, 2017, Mammoth Energy Services, Inc. ("Mammoth Energy") acquired Stingray Cementing LLC, Stingray Energy Services LLC and Sturgeon Acquisitions LLC. See below under Mammoth Energy Partners LP/Mammoth Energy Services, Inc. for information regarding these transactions.
Equity Method Investment Balance Sheet Summary | The tables below summarize financial information for the Company’s equity investments as of March 31, 2018 and December 31, 2017. Summarized balance sheet information:
| March 31, 2018 |  | December 31, 2017
| (In thousands)
Current assets | $ | 395,679 |  |  | $ | 415,032 |
Noncurrent assets | $ | 2,109,829 |  |  | $ | 1,542,090 |
Current liabilities | $ | 285,521 |  |  | $ | 261,086 |
Noncurrent liabilities | $ | 87,259 |  |  | $ | 148,839 |
Equity Method Investment Income Statement Summary | Summarized results of operations:
| Three months ended March 31,
| 2018 |  | 2017
| (In thousands)
Gross revenue | $ | 511,133 |  |  | $ | 94,478 |
Net income (loss) | $ | 64,452 |  |  | $ | (25,339 | )

X
- Definition Schedule Of Equity Method Investments, Balance Sheet Disclosures [Table Text Block] + References No definition available. + Details
Name: | gpor_ScheduleOfEquityMethodInvestmentsBalanceSheetDisclosuresTableTextBlock
Namespace Prefix: | gpor_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule Of Equity Method Investments, Income Statement Disclosures [Table Text Block] + References No definition available. + Details
Name: | gpor_ScheduleOfEquityMethodInvestmentsIncomeStatementDisclosuresTableTextBlock
Namespace Prefix: | gpor_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of equity method investments including, but not limited to, name of each investee or group of investments, percentage ownership, difference between recorded amount of an investment and the value of the underlying equity in the net assets, and summarized financial information. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration