XML 46 R35.htm IDEA: XBRL DOCUMENT
v3.21.1

Organization and Accounting Policies (Narrative) (Details) |  |  | 3 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jun. 20, 2026 | Feb. 25, 2021 USD ($) | Mar. 31, 2021 USD ($) / $ | Mar. 31, 2020 USD ($) | Feb. 24, 2021 | Dec. 31, 2020 / $
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Impairment of proved crude oil and natural gas properties |  |  | $ 0 | $ 30,625,000 |  |
Receivable balance, gross, noncurrent |  |  | $ 8,800,000 |  |  |
Exchange rate | / $ |  |  | 559.3 |  |  | 534.8
Transfers between levels |  |  | $ 0 | 0 |  |
Bargain purchase gain |  |  | 7,651,000 |  |  |
Sasol Gabon S.A. [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Bargain purchase gain |  | $ 7,700,000 | 7,700,000 |  |  |
Bargain purchase gain, net of tax |  | 5,500,000 | $ 5,500,000 |  |  |
Bargain purchase gain, income tax benefit |  | $ 2,200,000 |  | 2,200,000 |  |
Office and Miscellaneous Equipment [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Estimated useful life of assets |  |  | 5 years |  |  |
Leasehold Improvements [Member] | Minimum [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Estimated useful life of assets |  |  | 5 years |  |  |
Leasehold Improvements [Member] | Maximum [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Estimated useful life of assets |  |  | 7 years |  |  |
Consortium [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Receivable balance, gross, noncurrent |  |  | $ 12,900,000 |  |  |
Prior Production Sharing Contract, Through September 17, 2018 [Member] | Government Of Gabon [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Monthly royalty rate, based on production at the published price |  |  | 13.00% |  |  |
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Government Of Gabon [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Monthly royalty rate, based on production at the published price |  |  | 13.00% |  |  |
Etame Marine Block [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Impairment of proved crude oil and natural gas properties |  |  |  | $ 30,600,000 |  |
Working interest ownership, percentage |  | 58.80% |  |  | 31.10% |
Etame Marine Block [Member] | Sasol Gabon S.A. [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Increase (decrease) in working interest ownership percentage |  | 27.80% |  |  |  |
Etame Marine Block [Member] | Prior Production Sharing Contract, Through September 17, 2018 [Member] | Consortium [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Working interest ownership, percentage |  |  | 7.50% |  |  |
Etame Marine Block [Member] | Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Government Of Gabon [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Working interest ownership, percentage |  |  | 7.50% |  |  |
Etame Marine Block [Member] | Scenario, Forecast [Member] | Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Increase (decrease) in working interest ownership percentage | (1.60%) |  |  |  |  |
Etame Marine Block [Member] | Scenario, Forecast [Member] | Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Government Of Gabon [Member] |  |  |  |  |  |
Organization And Accounting Policies [Line Items] |  |  |  |  |  |
Increase (decrease) in working interest ownership percentage | 2.50% |  |  |  |  |
Working interest ownership, percentage | 10.00% |  |  |  |  |

X
- Definition Business Combination, Bargain Purchase Gain, Recognized Amount, Net Of Tax + References No definition available. + Details
Name: | egy_BusinessCombinationBargainPurchaseGainRecognizedAmountNetOfTax
Namespace Prefix: | egy_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Business Combination, Bargain Purchase Gain, Recognized Amount, Tax Expense Benefit + References No definition available. + Details
Name: | egy_BusinessCombinationBargainPurchaseGainRecognizedAmountTaxExpenseBenefit
Namespace Prefix: | egy_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Increase (Decrease) In Working Interest Ownership Percentage + References No definition available. + Details
Name: | egy_IncreaseDecreaseInWorkingInterestOwnershipPercentage
Namespace Prefix: | egy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Monthly Royalty Rate, Based On Production At The Published Price + References No definition available. + Details
Name: | egy_MonthlyRoyaltyRateBasedOnProductionAtPublishedPrice
Namespace Prefix: | egy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Organization And Accounting Policies [Line Items] + References No definition available. + Details
Name: | egy_OrganizationAndAccountingPoliciesLineItems
Namespace Prefix: | egy_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Working Interest Ownership, Percentage + References No definition available. + Details
Name: | egy_WorkingInterestOwnershipPercentage
Namespace Prefix: | egy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as noncurrent. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522 + Details
Name: | us-gaap_AccountsReceivableGrossNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6571-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (f)(1) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6387-128476 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 25 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6396-128476 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6527-128477 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 25 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6393-128476 + Details
Name: | us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy. + References No definition available. + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6897108&loc=SL6897125-166521 + Details
Name: | us-gaap_ForeignCurrencyExchangeRateTranslation1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2921-110230 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 360 -Section 35 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=66906256&loc=d3e66150-109466 + Details
Name: | us-gaap_ImpairmentOfOilAndGasProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=egy_SasolGabonS.a.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_OfficeEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LeaseholdImprovementsMember
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_RelatedPartyTransactionsByRelatedPartyAxis=egy_VaalcoEnergyInc.AndOtherEtameMarinBlockOwnersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=egy_PriorProductionSharingContractThroughSeptember172018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=egy_GovernmentOfGabonMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=egy_ProductionSharingContractSeptember172018ThroughSeptember162028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=egy_EtameMarineBlockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |