XML 90 R76.htm IDEA: XBRL DOCUMENT
v3.21.2

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands | 1 Months Ended | 2 Months Ended | 3 Months Ended | 5 Months Ended | 6 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Jun. 30, 2021 | May 17, 2021 | Jun. 30, 2020 | May 17, 2021 | Jun. 30, 2020 | Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | $ 6,500 |  |  |  |  |
Contingent consideration, gain (loss) due to change in value | 1,100 | $ 1,100 | $ (3,200) | $ 1,100 | $ (3,000) |
Contingent consideration, settlements | 600 |  |  | $ 200 | $ 300 |
Level 3 |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | 6,500 |  |  |  |  | $ 6,200
Prepaid Expenses and Other Current Assets |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | 500 |  |  |  |  |
Other Noncurrent Assets |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | $ 6,000 |  |  |  |  |

X
- Definition Contingent Consideration, Asset, Fair Value + References No definition available. + Details
Name: | gpor_ContingentConsiderationAssetFairValue
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Contingent Consideration, Asset, Settlements + References No definition available. + Details
Name: | gpor_ContingentConsiderationAssetSettlements
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Contingent Consideration, Change In Amount, Asset + References No definition available. + Details
Name: | gpor_ContingentConsiderationChangeInAmountAsset
Namespace Prefix: | gpor_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |