XML 69 R58.htm IDEA: XBRL DOCUMENT
v3.20.2

DERIVATIVE INSTRUMENTS (Schedule of Derivative Instruments) (Details) | 9 Months Ended
--- | ---
Sep. 30, 2020 MMBTU $ / MMBTU $ / bbl bbl
NYMEX Henry Hub - Remaining 2020 |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 500,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU | 2.69
NYMEX WTI - Remaining 2020 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 3,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl | 35.49
Mont Belvieu C3 - Remaining 2020 |
Derivative [Line Items] |
Daily Volume (Bbls/day) | bbl | 1,500
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl | 20.27
NYMEX Henry Hub - 2022 | Short | Call Option |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 628,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU | 2.90
NYMEX Henry Hub - 2023 | Short | Call Option |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 628,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU | 2.90
NYMEX Henry Hub - 2021 |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 250,000
Weighted average floor price (in usd per MMBtu) | $ / MMBTU | 2.46
Weighted average ceiling price (in usd per MMBtu) | $ / bbl | 2.81
Transco Zone 4 - Remaining 2020 | Long |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 60,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU | (0.05)
Fixed Spread - Remaining 2020 | Long |
Derivative [Line Items] |
Daily Volume (MMBtu/day) | MMBTU | 10,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU | (0.54)

X
- Definition The average cap rate on a group of price risk derivatives such as caps or collars. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract. + References No definition available. + Details
Name: | us-gaap_DerivativeAverageCapPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition The average floor rate on a group of price risk derivatives such as floors or collars. A payment or receipt is triggered if the market rate falls below the floor rate on the contract. + References No definition available. + Details
Name: | us-gaap_DerivativeAverageFloorPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

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 Nominal energy measure used to calculate payments on a derivative instrument. + References No definition available. + Details
Name: | us-gaap_DerivativeNonmonetaryNotionalAmountEnergyMeasure
Namespace Prefix: | us-gaap_
Data Type: | num:energyItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal volume used to calculate payments on a derivative instrument. + References No definition available. + Details
Name: | us-gaap_DerivativeNonmonetaryNotionalAmountVolume
Namespace Prefix: | us-gaap_
Data Type: | num:volumeItemType
Balance Type: | na
Period Type: | duration

X
- Definition Average fixed price related to the group of price risk swap derivatives. + References No definition available. + Details
Name: | us-gaap_DerivativeSwapTypeAverageFixedPrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_NYMEXHenryHubRemaining2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_NYMEXWTIRemaining2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_MontBelvieuC3Remaining2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_NYMEXHenryHub2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_OptionIndexedToIssuersEquityEquityAxis=us-gaap_CallOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_NYMEXHenryHub2023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_NYMEXHenryHub2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_TranscoZone4Remaining2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_FixedSpreadRemaining2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |