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Commitments and Contingencies - Additional Information (Detail) (USD $) | 0 Months Ended | 12 Months Ended | 3 Months Ended | 1 Months Ended | 3 Months Ended | 48 Months Ended
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Oct. 31, 2014 | Jul. 31, 2014 | Dec. 31, 2014 Rigs | Dec. 31, 2013 | Dec. 31, 2012 | Mar. 31, 2015 | Mar. 31, 2014 | Dec. 31, 2010 | Nov. 30, 2006 Well | Jan. 31, 2007 sqkm | Dec. 31, 2008 sqkm | Nov. 01, 2010 sqkm
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Period of Charter |  |  |  |  | 2 years |  |  |  |  |  |  |
Company s share of the charter payment |  |  |  |  | 28.10%egy_PercentageOfShareInCharterPayment |  |  |  |  |  |  |
Liabilities, guarantees' fair value |  |  | $ 1,000,000 egy_GuaranteeObligationsCurrentFairValue | $ 1,100,000 egy_GuaranteeObligationsCurrentFairValue |  |  |  |  |  |  |  |
Charter fee for production up to 20,000 BOPD |  |  | 0.93 egy_CharterFeePerBarrelForProductionLevelOne | 0.25 egy_CharterFeePerBarrelForProductionLevelOne |  |  |  |  |  |  |  |
Charter fee for those bbls produced in excess of 20,000 BOPD |  |  | 2.50 egy_CharterFeePerBarrelForProductionLevelTwo |  |  |  |  |  |  |  |  |
Company's share of charter expense |  |  | 11,800,000 egy_CharterExpenses | 10,400,000 egy_CharterExpenses | 9,700,000 egy_CharterExpenses |  |  |  |  |  |  |
Number of drilling rigs contracts |  |  | 2 egy_NumberOfDrillingRigsContracts |  |  |  |  |  |  |  |  |
Drilling rig commitment period | 2016-07 |  |  |  |  |  |  |  |  |  |  |
Drilling rig cost day rate | 168,000 egy_DrillingRigDailyRate | 338,000 egy_DrillingRigDailyRate | 25,800,000 egy_DrillingRigDailyRate |  |  |  |  |  |  |  |  |
Second drilling rig contract expected well drilling period |  |  | The second drilling rig contract was signed in July 2014 for a semi-submersible rig to drill the exploration well on the Kindele prospect, a post-salt objective. The well began drilling in the first quarter of 2015. The drilling rig provides a forty-five day commitment at a day rate of approximately $338,000. The total commitment related to this rig is $15.2 million |  |  |  |  |  |  |  |  |
Second drilling rig contract commitment period |  | 45 days |  |  |  |  |  |  |  |  |  |
Rent expense, operating leases |  |  | 4,000,000 us-gaap_LeaseOperatingExpense | 4,100,000 us-gaap_LeaseOperatingExpense | 4,400,000 us-gaap_LeaseOperatingExpense |  |  |  |  |  |  |
Scenario, Forecast |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Drilling rig cost day rate |  |  |  |  |  | 15,200,000 egy_DrillingRigDailyRate / us-gaap_StatementScenarioAxis = us-gaap_ScenarioForecastMember |  |  |  |  |  |
Subsequent Exploration Phase |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of exploration wells | 4 egy_NumberOfExplorationWellsOnProject / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |  |  |
Recorded restricted cash |  |  | 20,000,000 us-gaap_RestrictedCashAndCashEquivalents / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Subsequent Exploration Phase | Well One |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Total assessment of the exploration |  |  | 10,000,000 egy_AssessmentOfExplorationOfProject / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellOneMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Assessment net to VAALCO |  |  | 5,000,000 egy_AssessmentOfExplorationNet / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellOneMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Subsequent Exploration Phase | Well Two |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Total assessment of the exploration |  |  | 10,000,000 egy_AssessmentOfExplorationOfProject / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellTwoMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Assessment net to VAALCO |  |  | 5,000,000 egy_AssessmentOfExplorationNet / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellTwoMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Subsequent Exploration Phase | Well Three |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Total assessment of the exploration |  |  | 10,000,000 egy_AssessmentOfExplorationOfProject / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellThreeMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Assessment net to VAALCO |  |  | 5,000,000 egy_AssessmentOfExplorationNet / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellThreeMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Subsequent Exploration Phase | Well Four |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Total assessment of the exploration |  |  | 10,000,000 egy_AssessmentOfExplorationOfProject / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellFourMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Assessment net to VAALCO |  |  | 5,000,000 egy_AssessmentOfExplorationNet / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_WellFourMember / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |
Gabon |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Discount |  |  | 25.00%egy_DiscountOnMarketPrice / us-gaap_StatementGeographicalAxis = country_GA |  |  |  |  |  |  |  |  |
Contractual Obligation Company Share |  |  | 3,300,000 egy_PaymentsOfContractualObligation / us-gaap_StatementGeographicalAxis = country_GA | 3,000,000 egy_PaymentsOfContractualObligation / us-gaap_StatementGeographicalAxis = country_GA | 3,700,000 egy_PaymentsOfContractualObligation / us-gaap_StatementGeographicalAxis = country_GA |  |  |  |  |  |  |
Contractual Obligation accrued amount |  |  | 2,700,000 egy_AccruedContractualObligation / us-gaap_StatementGeographicalAxis = country_GA |  |  |  |  |  |  |  |  |
Offshore Gabon |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Annual funding related to production license, term |  |  |  |  |  |  | 7 years |  |  |  |  |
Percentage of annual funding over seven years |  |  |  |  |  |  | 12.14%egy_PercentageOfAnnualFundingOverSevenYears / us-gaap_StatementGeographicalAxis = egy_OffshoreGabonMember |  |  |  |  |
Percentage of annual funding over last three years |  |  |  |  |  |  | 5.00%egy_PercentageOfAnnualFundingOverLastThreeYears / us-gaap_StatementGeographicalAxis = egy_OffshoreGabonMember |  |  |  |  |
Cash funding arrangement for abandonment of the offshore wells, platforms and facilities |  |  | 8,400,000 egy_EnvironmentalExitCostsAnticipatedCostGross / us-gaap_StatementGeographicalAxis = egy_OffshoreGabonMember |  |  |  |  |  |  |  |  |
Cash funding arrangement for abandonment of the offshore wells, platforms and facilities net |  |  | 2,300,000 us-gaap_EnvironmentalExitCostsAnticipatedCost / us-gaap_StatementGeographicalAxis = egy_OffshoreGabonMember |  |  |  |  |  |  |  |  |
Abandonment cost related to annual funding |  |  | 10,100,000 egy_AbandonmentCostRelatedToAnnualFunding / us-gaap_StatementGeographicalAxis = egy_OffshoreGabonMember |  |  |  |  |  |  |  |  |
Offshore Gabon | Scenario, Forecast |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Cash funding arrangement for abandonment of the offshore wells, platforms and facilities |  |  |  |  |  | 4,200,000 egy_EnvironmentalExitCostsAnticipatedCostGross / us-gaap_StatementGeographicalAxis = egy_OffshoreGabonMember / us-gaap_StatementScenarioAxis = us-gaap_ScenarioForecastMember |  |  |  |  |  |
Cash funding arrangement for abandonment of the offshore wells, platforms and facilities net |  |  |  |  |  | 1,200,000 us-gaap_EnvironmentalExitCostsAnticipatedCost / us-gaap_StatementGeographicalAxis = egy_OffshoreGabonMember / us-gaap_StatementScenarioAxis = us-gaap_ScenarioForecastMember |  |  |  |  |  |
Angola |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of exploration wells |  |  |  |  |  |  |  |  | 2 egy_NumberOfExplorationWellsOnProject / us-gaap_StatementGeographicalAxis = country_AO |  |  |
Cost related to drilling |  |  |  |  |  |  |  |  | 29,500,000 egy_CostRelatedToDrilling / us-gaap_StatementGeographicalAxis = country_AO |  |  |
Area under acquire property exploration rights agreement term |  |  |  | 1,400,000 egy_AreaUnderPropertyExplorationRights / us-gaap_StatementGeographicalAxis = country_AO |  |  |  |  |  |  |  |
Joint operation agreement related to third party in working interest percentage |  |  |  |  |  |  |  |  | 40.00%egy_AcquisitionOfWorkingInterestInBlock / us-gaap_StatementGeographicalAxis = country_AO |  |  |
Additional joint operation agreement related to third party in working interest percentage |  |  |  |  |  |  |  |  | 10.00%egy_AdditionalJointOperationAgreementRelatedToThirdPartyInWorkingInterestPercentage / us-gaap_StatementGeographicalAxis = country_AO |  |  |
Production license agreement term |  |  |  |  |  |  |  |  | 4 years |  |  |
Production license agreement term extended by government |  |  |  |  |  |  |  |  | 3 years |  |  |
Drilling cost to company |  |  |  |  |  |  |  |  | 14,800,000 egy_DrillingCostToCompany / us-gaap_StatementGeographicalAxis = country_AO |  |  |
Extended drilling period |  |  |  |  |  |  |  | 1 year |  |  |  |
Percentage of working interest for amounts owned |  |  |  | 40.00%egy_PercentageOfWorkingInterestForAmountsOwned / us-gaap_StatementGeographicalAxis = country_AO |  |  |  |  |  |  |  |
Exploration activities new expiry date | Nov. 30, 2017 |  |  |  |  |  |  |  |  |  |  |
Number of additional exploration wells due to exploration period extension | 2 egy_NumberOfAdditionalExplorationWells / us-gaap_StatementGeographicalAxis = country_AO |  |  |  |  |  |  |  |  |  |  |
Recorded restricted cash |  |  | 20,000,000 us-gaap_RestrictedCashAndCashEquivalents / us-gaap_StatementGeographicalAxis = country_AO |  |  |  |  |  |  |  |  |
Number of well satisfying well obligation |  |  | 1 egy_NumberOfWellSatisfyingWellObligation / us-gaap_StatementGeographicalAxis = country_AO |  |  |  |  |  |  |  |  |
Decrease in restricted cash |  |  | 5,000,000 us-gaap_DecreaseInRestrictedCash / us-gaap_StatementGeographicalAxis = country_AO |  |  |  |  |  |  |  |  |
Angola | Seismic Obligation |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Length of acquired property |  |  |  |  |  |  |  |  |  | 1,175 egy_ReprocessArea / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_SeismicObligationMember / us-gaap_StatementGeographicalAxis = country_AO | 524 egy_ReprocessArea / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_SeismicObligationMember / us-gaap_StatementGeographicalAxis = country_AO | 1,000 egy_ReprocessArea / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_SeismicObligationMember / us-gaap_StatementGeographicalAxis = country_AO
Seismic obligation cost to company |  |  |  |  |  |  |  |  |  | 3,750,000 egy_SeismicObligationCostToCompany / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_SeismicObligationMember / us-gaap_StatementGeographicalAxis = country_AO | 3,000,000 egy_SeismicObligationCostToCompany / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_SeismicObligationMember / us-gaap_StatementGeographicalAxis = country_AO |
Cost related to seismic obligation, gross |  |  |  |  |  |  |  |  |  | 7,500,000 egy_CostRelatedToSeismicObligationGross / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_SeismicObligationMember / us-gaap_StatementGeographicalAxis = country_AO | 6,000,000 egy_CostRelatedToSeismicObligationGross / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_SeismicObligationMember / us-gaap_StatementGeographicalAxis = country_AO |
Angola | Subsequent Exploration Phase | Two New Commitments |  |  |  |  |  |  |  |  |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Recorded restricted cash |  |  | $ 10,000,000 us-gaap_RestrictedCashAndCashEquivalents / us-gaap_OilAndGasDeliveryCommitmentsAndContractsAxis = egy_TwoNewCommitmentsMember / us-gaap_StatementGeographicalAxis = country_AO / us-gaap_StatementScenarioAxis = egy_SubsequentExplorationPhaseMember |  |  |  |  |  |  |  |  |

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- Definition Total anticipated costs associated with remediation, site restoration, postclosure, monitoring commitments, or other exit costs that may occur on the sale, disposal, or abandonment of a particular property resulting from unanticipated contamination of the assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 5.Y.Q4) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 5 -Section Y -Paragraph Question 4 + Details
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- Definition The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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