XML 122 R102.htm IDEA: XBRL DOCUMENT
v3.20.4

Subsequent Events (Details) | 2 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 01, 2021 MMBTU $ / MMBTU | Dec. 31, 2020 MMBTU $ / MMBTU
Tetco M2 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU |  | 60,000
Weighted average price of derivative swap (usd per MMBtu or Bbls) |  | (0.67)
Rex Zone 3 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU |  | 35,000
Weighted average price of derivative swap (usd per MMBtu or Bbls) |  | (0.21)
Subsequent Event | NYMEX WTI |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU | 2,250 |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | 53.07 |
Subsequent Event | Mont Belvieu C3 Swap - 2021 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU | 3,100 |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | 27.80 |
Subsequent Event | Mont Belvieu C3 Swap - 2022 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU | 1,000 |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | 27.30 |
Subsequent Event | Tetco M2 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU | 36,443 |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | (0.61) |
Subsequent Event | Rex Zone 3 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU | 94,505 |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | (0.22) |
Subsequent Event | NYMEX Henry Hub - 2021 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU | 210,000 |
Subsequent Event | NYMEX Henry Hub - 2021 | Minimum |  |
Subsequent Event [Line Items] |  |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | 2.67 |
Subsequent Event | NYMEX Henry Hub - 2021 | Maximum |  |
Subsequent Event [Line Items] |  |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | 3.15 |
Subsequent Event | NYMEX Henry Hub - 2022 |  |
Subsequent Event [Line Items] |  |
Daily Volume (MMBtu/day) | MMBTU | 340,000 |
Subsequent Event | NYMEX Henry Hub - 2022 | Minimum |  |
Subsequent Event [Line Items] |  |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | 2.82 |
Subsequent Event | NYMEX Henry Hub - 2022 | Maximum |  |
Subsequent Event [Line Items] |  |
Weighted average price of derivative swap (usd per MMBtu or Bbls) | 3.40 |

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 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
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_BasisSwapTetcoM2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_BasisSwapRexZone3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_NYMEXHenryHubSwap2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_MontBelvieuC3Swap2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=gpor_MontBelvieuC3Swap2022Member
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: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
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: |