Name:	hdy_AdditionalConsiderationGrossExpenditureCapWellExplorationDrilling
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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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Represents the minimum depth for ultra deepwater.

No definition available.

Name:	hdy_MinimumUltraDeepWaterDepths
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Represents the number of exploration wells drilled.

No definition available.

Name:	hdy_NumberOfExplorationWellsDrilled
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Data Type:	xbrli:integerItemType
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Amount of receivable if extension well is not drilled under oil and gas properties arrangement.

No definition available.

Name:	hdy_OilAndGasPropertiesAmountReceivableIfExtensionWellNotDrilled
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Data Type:	xbrli:monetaryItemType
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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
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The amount of mutually acceptable security as per PSC oil and gas properties arrangement.

No definition available.

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

No definition available.

Name:	hdy_OilAndGasPropertiesOwnershipInterest
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Data Type:	num:percentItemType
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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
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Data Type:	num:percentItemType
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Represents the maximum period of time over which current available liquidity could be exhausted.

No definition available.

Name:	hdy_OverduePeriodOfCurrentObligations
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- References

No definition available.

Name:	hdy_StatusOfBusinessAbstract
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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
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Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

No definition available.

Name:	us-gaap_LitigationSettlementAmount
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

The cash inflow associated with the sale, maturity and collection of all investments such as debt, security and so forth during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585

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Namespace Prefix:
Data Type:	na
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Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=hdy_GuineaConcessionMember
Namespace Prefix:
Data Type:	na
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