Represents the number of lawsuits filed.

No definition available.

Name:	hdy_LossContingencyNumberOfLawsuitsFiled
Namespace Prefix:	hdy_
Data Type:	xbrli:integerItemType
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- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
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Balance Type:	debit
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- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of plaintiffs that have filed claims pertaining to a loss contingency.

+ References

No definition available.

+ Details

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- Definition

The estimated maximum amount of possible loss from the contingency.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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- Details

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- Details

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- Details

Name:	us-gaap_LitigationCaseAxis=hdy_ShareholderLawsuitsMember
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	us-gaap_LitigationCaseAxis=hdy_IroquoisLawsuitMember
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COMMITMENTS AND CONTINGENCIES - Litigation and Other Legal Matters (Details)	Aug. 15, 2016 USD ($)	Mar. 13, 2014 lawsuit	May 09, 2012 USD ($) plaintiff	Jun. 30, 2016 USD ($)
Settlement and Release Agreement with Tullow and Dana
LITIGATION AND OTHER LEGAL MATTERS
Settlement amount	$ 686,570
Settlement and Release Agreement with Tullow and Dana \| Subsequent event
LITIGATION AND OTHER LEGAL MATTERS
Settlement amount	$ 686,570
Shareholder Lawsuits
LITIGATION AND OTHER LEGAL MATTERS
Number of lawsuits filed \| lawsuit		2
Provision for possible loss				$ 0
Iroquois Lawsuit
LITIGATION AND OTHER LEGAL MATTERS
Provision for possible loss				$ 0
Number of plaintiffs which filed lawsuit \| plaintiff			5
Damages sought			$ 18,500,000
Maximum possible loss			$ 18,500,000