XML 69 R58.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Derivative Instruments - Gain (Los) On Derivative Instruments (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2016 | Jun. 30, 2015 | Jun. 30, 2016 | Jun. 30, 2015
Derivative [Line Items] |  |  |  |
Net (loss) gain on derivative instruments | $ (137,392) | $ (10,082) | $ (79,657) | $ 40,022
Gas sales |  |  |  |
Derivative [Line Items] |  |  |  |
Net (loss) gain on derivative instruments | (133,621) | (8,087) | (76,621) | 38,453
Oil and condensate sales |  |  |  |
Derivative [Line Items] |  |  |  |
Net (loss) gain on derivative instruments | (2,628) | (1,995) | (1,346) | 1,569
Natural gas liquids sales |  |  |  |
Derivative [Line Items] |  |  |  |
Net (loss) gain on derivative instruments | $ (1,143) | $ 0 | $ (1,690) | $ 0

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13(h)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 + Details
Name: | us-gaap_GainLossOnSaleOfDerivatives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_EnergyAxis=gpor_GasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnergyAxis=us-gaap_OilReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnergyAxis=us-gaap_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |