Name:	hdy_AdditionalConsiderationGrossExpenditureCapAppraisalWell
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The gross expenditure cap related to future costs associated with the drilling of an exploration well to be paid on behalf of the entity as additional consideration in the sale of an investment.

No definition available.

Name:	hdy_AdditionalConsiderationGrossExpenditureCapWellExplorationDrilling
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The number of days after the rig contracted to drill an exploration well moves off the well location in which additional consideration in the sale of an investment is to be paid on behalf of the entity.

No definition available.

Name:	hdy_AdditionalConsiderationPaymentPeriod
Namespace Prefix:	hdy_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the contract area of oil and gas properties, held by the entity currently.

No definition available.

Name:	hdy_CurrentContractArea
Namespace Prefix:	hdy_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

Represents the depth, below seabed which is required to be drilled, of an exploration well.

No definition available.

Name:	hdy_ExplorationWellsRequiredToBeDrilledDepthBelowSeabed
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Data Type:	num:lengthItemType
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Period Type:	duration

Represents the estimated amount of expenditure which is required to be incurred on exploration wells.

No definition available.

Name:	hdy_ExplorationWellsRequiredToBeDrilledEstimatedExpenditureAggregate
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the estimated amount of expenditure which is required to be incurred on each of the exploration wells.

No definition available.

Name:	hdy_ExplorationWellsRequiredToBeDrilledEstimatedExpenditureOnEachWell
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents minimum depth to be reached to satisfy work requirement.

No definition available.

Name:	hdy_MinimumDepthToBeReachedToSatisfyWorkRequirement
Namespace Prefix:	hdy_
Data Type:	num:lengthItemType
Balance Type:	na
Period Type:	duration

Represents the required expenditure on acquisition of 3D seismic.

No definition available.

Name:	hdy_OilAndGasProperties3DSeismicRequiredToBeAcquiredEstimatedExpenditure
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Agreed amount in training budget as per PSC oil and gas properties arrangement.

No definition available.

Name:	hdy_OilAndGasPropertiesAgreedAmountInTrainingBudget
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of receivable if extension well is not drilled under oil and gas properties arrangement.

No definition available.

Name:	hdy_OilAndGasPropertiesAmountReceivableIfExtensionWellNotDrilled
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	hdy_OilAndGasPropertiesAndProjectsLineItems
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Data Type:	xbrli:stringItemType
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Period Type:	duration

Represents the annual surface tax, per square kilometer on retained concession acreage, which is required to be paid.

No definition available.

Name:	hdy_OilAndGasPropertiesAnnualSurfaceTaxRequiredToBePaid
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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

Represents the amount of annual training budget which is required to be established for oil industry personnel of regulatory authority.

No definition available.

Name:	hdy_OilAndGasPropertiesAnnualTrainingBudgetRequiredToBeEstablished
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the contract area of oil and gas properties as percentage of original contract area, retained by the entity.

No definition available.

Name:	hdy_OilAndGasPropertiesAreaRetainedAsPercentageOfOriginalContractArea
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the area of oil and gas properties to be relinquished, by the entity, as percentage of retained contract area.

No definition available.

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the increase (decrease) in the property balance resulting from capitalized cost adjustment.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the contract area of oil and gas properties, retained by the entity.

No definition available.

Name:	hdy_OilAndGasPropertiesContractAreaRetained
Namespace Prefix:	hdy_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

Represents the daily production of oil and gas barrels per day.

No definition available.

Name:	hdy_OilAndGasPropertiesDailyProductionBarrelsPerDay
Namespace Prefix:	hdy_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Estimated amount of unused portion of training program under oil and gas properties arrangement.

No definition available.

Name:	hdy_OilAndGasPropertiesEstimatedAmountOfUnusedPortionOfTrainingProgram
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Estimated amount to limit the cost recovery to share of expenditures as per PSC oil and gas properties arrangement.

No definition available.

Name:	hdy_OilAndGasPropertiesEstimatedAmountToLimitCostRecoveryToShareOfExpenditures
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Extension period for second exploration, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	hdy_OilAndGasPropertiesExtensionPeriodForSecondExploration
Namespace Prefix:	hdy_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the share of entity in net revenue, during the first production, after recovery cost of operations.

No definition available.

Name:	hdy_OilAndGasPropertiesFirstProductionInterestInNetRevenuesAfterRecoveryCostOfOperationsPercentage
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the share of regulatory authority in net revenue, during the first production, after recovery cost of operations.

No definition available.

Name:	hdy_OilAndGasPropertiesFirstProductionInterestOfRegulatoryAuthorityInNetRevenuesAfterRecoveryCostOfOperationsPercentage
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the share of entity in net revenue, after recovery cost of operations.

No definition available.

Name:	hdy_OilAndGasPropertiesInterestInNetRevenuesAfterRecoveryCostOfOperationsPercentage
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the share of regulatory authority in net revenue, after recovery cost of operations.

No definition available.

Name:	hdy_OilAndGasPropertiesInterestOfRegulatoryAuthorityInNetRevenuesAfterRecoveryCostOfOperationsPercentage
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The amount of mutually acceptable security as per PSC oil and gas properties arrangement.

No definition available.

Name:	hdy_OilAndGasPropertiesMutuallyAcceptableSecurity
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Notice period for termination, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	hdy_OilAndGasPropertiesNoticePeriodForTermination
Namespace Prefix:	hdy_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the number of exploratory well in extension period under oil and gas properties arrangement.

No definition available.

Name:	hdy_OilAndGasPropertiesNumberOfExploratoryWellInExtensionPeriod
Namespace Prefix:	hdy_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The percentage interest in the investment of an oil and gas property.

No definition available.

Name:	hdy_OilAndGasPropertiesOwnershipInterest
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the interest of the entity sold in the investment in oil and gas properties managed by the entity.

No definition available.

Name:	hdy_OilAndGasPropertiesOwnershipInterestSold
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the percentage of aggregate revenue from production after royalty payment which will be split between regulatory authority and the entity.

No definition available.

Name:	hdy_OilAndGasPropertiesPercentageOfAggregateRevenueAfterRoyaltyPayment
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the relinquishment of contract area of oil and gas properties, retained by the entity, as percentage of original contract area.

No definition available.

Name:	hdy_OilAndGasPropertiesRelinquishmentOfAreaRetainedAsPercentageOfOriginalContractArea
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the period by which exploration period may be extended to allow the completion of the appraisal of any discovery made.

No definition available.

Name:	hdy_OilAndGasPropertiesRenewalOfExplorationPeriodForAppraisalOfDiscoveryMade
Namespace Prefix:	hdy_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the period by which exploration period may be extended to allow the completion of a well in process.

No definition available.

Name:	hdy_OilAndGasPropertiesRenewalOfExplorationPeriodForCompletionOfWellInProcess
Namespace Prefix:	hdy_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the royalty interest to be paid to regulatory authority, as percentage of aggregate revenue from production.

No definition available.

Name:	hdy_OilAndGasPropertiesRoyaltyToBePaidAsPercentageOfAggregateRevenue
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the share of regulatory authority in cost and profit oil.

No definition available.

Name:	hdy_OilAndGasPropertiesShareOfCostAndProfitOilByRegulatoryAuthority
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the area of 3D seismic which is required to be acquired.

No definition available.

Name:	hdy_OilAndGasPropertiesSquareKilometersOf3DSeismicRequiredToBeAcquired
Namespace Prefix:	hdy_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

Represents the working interest of regulatory authority in oil and gas properties.

No definition available.

Name:	hdy_OilAndGasPropertiesWorkingInterestOfRegulatoryAuthority
Namespace Prefix:	hdy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the amount of unproved properties written-off during the period subject to the Full-Cost Ceiling Test.

No definition available.

Name:	hdy_OilAndGasPropertySubjectToFullCostCeilingTestUnprovedPropertiesWriteOff
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations, inclusive of transaction cost.

No definition available.

Name:	hdy_ProceedsFromSaleOfOilAndGasPropertyAndEquipmentGross
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the threshold gross expenditure cap related to future costs associated with well to be paid by the entity in the sale of an investment.

No definition available.

Name:	hdy_ThresholdGrossExpenditureCapForDeterminationOfBearingPortionOfShareOfCost
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the transaction costs on sale of interest in unevaluated oil and gas property and equipment.

No definition available.

Name:	hdy_TransactionCostsOnSaleOfInterestInUnevaluatedOilAndGasPropertyAndEquipment
Namespace Prefix:	hdy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The sum of the capitalized costs incurred, as of the balance sheet date, of unproved properties excluded from amortization including acquisition costs, exploration costs, development costs, and production costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10.(c)(7)(ii))
-URI http://asc.fasb.org/extlink&oid=50486907&loc=d3e511914-122862

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_CapitalizedCostsOilAndGasProducingActivitiesNetAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Capitalized costs of unproved properties incurred for any combination mineral interests acquisitions and other costs not previously disclosed within this table.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Properties
-URI http://asc.fasb.org/extlink&oid=21914647

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=51678428&loc=d3e61901-109447

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-Glossary Unproved Properties
-URI http://asc.fasb.org/extlink&oid=6527831

Name:	us-gaap_CapitalizedCostsUnprovedProperties
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Data Type:	xbrli:monetaryItemType
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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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=51719941&loc=d3e2921-110230

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Section 35
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=28370743&loc=d3e66150-109466

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Name:	us-gaap_ImpairmentOfOilAndGasProperties
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=51678428&loc=d3e61831-109447

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10.(a)(2))
-URI http://asc.fasb.org/extlink&oid=50486907&loc=d3e511914-122862

Name:	us-gaap_ProvedDevelopedAndUndevelopedReservesNet
Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=hdy_GuineaConcessionMember
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Name:	us-gaap_CounterpartyNameAxis=hdy_TullowGuineaLtdMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_CounterpartyNameAxis=hdy_DanaPetroleumEAndPLimitedMember
Namespace Prefix:
Data Type:	na
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Name:	dei_LegalEntityAxis=hdy_DanaPetroleumEAndPLimitedMember
Namespace Prefix:
Data Type:	na
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Name:	dei_LegalEntityAxis=hdy_TullowGuineaLtdMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementScenarioAxis=hdy_RangeOfDailyProductionFrom0To2000BarrelsPerDayMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementScenarioAxis=hdy_RangeOfDailyProductionFrom2001To5000BarrelsPerDayMember
Namespace Prefix:
Data Type:	na
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Namespace Prefix:
Data Type:	na
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