XML 49 R37.htm IDEA: XBRL DOCUMENT
v3.21.1

CHAPTER 11 PROCEEDINGS (Details) $ in Thousands |  |  | 3 Months Ended |
--- | --- | --- | --- | ---
Apr. 30, 2021 USD ($) claim | Apr. 28, 2021 USD ($) | Mar. 31, 2021 USD ($) | Nov. 13, 2020
Debt Instrument [Line Items] |  |  |  |
Debtor-in-possession financing, percentage of lenders involved |  |  |  | 95.00%
Debtor-in-possession financing, letters of credit outstanding |  |  | $ 262,500 |
Debtor-in-possession financing, amount arranged |  |  | 105,000 |
Debtor-in-possession financing, borrowings outstanding |  |  | 157,500 |
Contractual interest expense |  |  | $ 28,500 |
Subsequent Event |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Rights offering, agreed backstop amount |  | $ 50,000 |  |
Cash received by holders of an allowed general unsecured claim |  | $ 10,000 |  |
Percentage of the equity method investment received |  | 100.00% |  |
Percentage of the new common stock received |  | 4.00% |  |
Cap percentage of new common stock received |  | 96.00% |  |
Cash distribution pool |  | $ 3,000 |  |
Increase in additional cash distribution pool |  | 2,000 |  |
Number of claims | claim | 2,700 |  |  |
Claims amount | $ 13,000,000 |  |  |
Maximum | Subsequent Event |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Allowed general unsecured claims |  | 300 |  |
6.625% senior unsecured notes due 2023 | Senior Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Stated interest rate |  |  | 6.625% |
6.000% senior unsecured notes due 2024 | Senior Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Stated interest rate |  |  | 6.00% |
6.375% Senior Notes Due 2025 | Senior Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Stated interest rate |  |  | 6.375% |
6.375% senior unsecured notes due 2026 | Senior Notes |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Stated interest rate |  |  | 6.375% |
Exit Facility | Subsequent Event |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt instrument, amount |  | $ 580,000 |  |

X
- Definition Debtor-In-Possession Financing, Percentage Of Lenders Involved + References No definition available. + Details
Name: | gpor_DebtorInPossessionFinancingPercentageOfLendersInvolved
Namespace Prefix: | gpor_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Plan Of Reorganization, Allowed General Unsecured Claims + References No definition available. + Details
Name: | gpor_PlanOfReorganizationAllowedGeneralUnsecuredClaims
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Plan Of Reorganization, Cash Distribution Pool + References No definition available. + Details
Name: | gpor_PlanOfReorganizationCashDistributionPool
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Plan Of Reorganization, Holders Of An Allowed General Unsecured Claim, Cap Percentage Of New Common Stock Received + References No definition available. + Details
Name: | gpor_PlanOfReorganizationHoldersOfAnAllowedGeneralUnsecuredClaimCapPercentageOfNewCommonStockReceived
Namespace Prefix: | gpor_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Plan Of Reorganization, Holders Of An Allowed General Unsecured Claim, Cash Received + References No definition available. + Details
Name: | gpor_PlanOfReorganizationHoldersOfAnAllowedGeneralUnsecuredClaimCashReceived
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Plan Of Reorganization, Holders Of An Allowed General Unsecured Claim, Equity Method Investment Percentage Received + References No definition available. + Details
Name: | gpor_PlanOfReorganizationHoldersOfAnAllowedGeneralUnsecuredClaimEquityMethodInvestmentPercentageReceived
Namespace Prefix: | gpor_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Plan Of Reorganization, Holders Of An Allowed General Unsecured Claim, Percentage Of New Common Stock Received + References No definition available. + Details
Name: | gpor_PlanOfReorganizationHoldersOfAnAllowedGeneralUnsecuredClaimPercentageOfNewCommonStockReceived
Namespace Prefix: | gpor_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Plan Of Reorganization, Increase In Cash Distribution Pool + References No definition available. + Details
Name: | gpor_PlanOfReorganizationIncreaseInCashDistributionPool
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Plan Of Reorganization, Rights Offering, Agreed Backstop Amount + References No definition available. + Details
Name: | gpor_PlanOfReorganizationRightsOfferingAgreedBackstopAmount
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount paid to settle bankruptcy claim. + References No definition available. + Details
Name: | us-gaap_BankruptcyClaimsAmountPaidToSettleClaims
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The aggregate number of claims filed with the bankruptcy court. + References No definition available. + Details
Name: | us-gaap_BankruptcyClaimsNumberClaimsFiled
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of contractual interest expense on prepetition liabilities not included in the statement of operations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 852 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=120604989&loc=d3e56068-112765 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 852 -SubTopic 10 -Section 55 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56145-112766 + Details
Name: | us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount debtor-in-possession financing arranged (but not necessarily all borrowed). + References No definition available. + Details
Name: | us-gaap_DebtorInPossessionFinancingAmountArranged
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of debtor-in-possession borrowings outstanding. + References No definition available. + Details
Name: | us-gaap_DebtorInPossessionFinancingBorrowingsOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of letters of credit outstanding under debtor-in-possession financing arrangement. + References No definition available. + Details
Name: | us-gaap_DebtorInPossessionFinancingLettersOfCreditOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
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_DebtInstrumentAxis=gpor_A6.625SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gpor_A6.000SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gpor_A6.375SeniorNotesDue2025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gpor_A6.375SeniorNotesDue2026Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gpor_ExitFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |