Represents the current ratio (as defined in the Exit Credit Agreement).

No definition available.

Name:	hk_CurrentRatio
Namespace Prefix:	hk_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of consecutive semi-annual redeterminations between which the entity and the lenders, each of whom have the right to a specified number of interim unscheduled redeterminations of the borrowing base under the credit facility.

+ References

No definition available.

+ Details

Name:	hk_LineOfCreditFacilityBorrowingBaseNumberOfConsecutiveSemiAnnualRedeterminationsBetweenWhichInterimUnscheduledRedeterminationIsAvailable
Namespace Prefix:	hk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of interim unscheduled redeterminations of borrowing base available to the entity and the lender under the credit facility.

+ References

No definition available.

+ Details

Name:	hk_LineOfCreditFacilityBorrowingBaseNumberOfInterimUnscheduledRedeterminationAvailable
Namespace Prefix:	hk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the total net debt to EBITDA ratio (as defined in the Senior Credit Agreement).

+ References

No definition available.

+ Details

Name:	hk_TotalNetDebtToEbitdaRatio
Namespace Prefix:	hk_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the Total net debt to EBITDA ratio when major portion of assets sold.

+ References

No definition available.

+ Details

Name:	hk_TotalNetDebtToEbitdaRatioWhenMaterialPortionOfAssetsSold
Namespace Prefix:	hk_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hk_SeniorRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hk_FifthAmendmentToSeniorCreditAgreementMember
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Data Type:	na
Balance Type:
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- Details

Name:	hk_ReportingPeriodCovenantAxis=hk_QuarterEndingSeptember302018Member
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Data Type:	na
Balance Type:
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- Details

Name:	hk_ReportingPeriodCovenantAxis=hk_QuartersEndingDecember312018Member
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	hk_ReportingPeriodCovenantAxis=hk_QuarterEndingMarch312019AndAnyFiscalQuaterThereafterMember
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- Details

Name:	us-gaap_LongtermDebtTypeAxis=hk_FourthAmendmentToSeniorCreditAgreementMember
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- Details

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LONG-TERM DEBT - Senior Facility (Details) $ in Millions	Jul. 12, 2018	Sep. 07, 2017 USD ($) item	Nov. 07, 2018	Sep. 30, 2018 USD ($)	May 01, 2018 USD ($)	Feb. 02, 2018
Senior revolving credit facility
Current and long-term debt
Maximum borrowing capacity		$ 1,000.0
Current borrowing capacity				$ 200.0
Number of interim unscheduled redeterminations of borrowing base to which the company and lender each have the right \| item		1
Number of consecutive semi-annual redeterminations between which the company and the lenders each have the right to one interim unscheduled redetermination of borrowing base \| item		2
Amount outstanding				55.0
Letters of credit outstanding				1.6
Borrowing capacity available				$ 143.4
Senior revolving credit facility \| Minimum
Current and long-term debt
Current Ratio		1.00
Senior revolving credit facility \| ABR - based \| Minimum
Current and long-term debt
Applicable margin (as a percent)		1.25%
Senior revolving credit facility \| ABR - based \| Maximum
Current and long-term debt
Applicable margin (as a percent)		2.25%
Senior revolving credit facility \| LIBOR \| Minimum
Current and long-term debt
Applicable margin (as a percent)		2.25%
Senior revolving credit facility \| LIBOR \| Maximum
Current and long-term debt
Applicable margin (as a percent)		3.25%
Fifth Amendment to Senior Credit Agreement \| Fiscal quarter ending September 30, 2018
Current and long-term debt
Total Net Debt to EBITDA ratio			4.75
Fifth Amendment to Senior Credit Agreement \| Fiscal quarter ending December 31, 2018
Current and long-term debt
Total Net Debt to EBITDA ratio			4.25
Fifth Amendment to Senior Credit Agreement \| Fiscal quarter ending March 31, 2019 and any fiscal quarter thereafter
Current and long-term debt
Total Net Debt to EBITDA ratio			4.0
Fourth Amendment to the Senior Credit Agreement
Current and long-term debt
Total Net Debt to EBITDA when major portion of assets sold	4.0
Fourth Amendment to the Senior Credit Agreement \| Fiscal quarter ending September 30, 2018
Current and long-term debt
Total Net Debt to EBITDA ratio	4.75
Fourth Amendment to the Senior Credit Agreement \| Fiscal quarters ending December 31, 2018, March 31, 2019 and June 30, 2019
Current and long-term debt
Total Net Debt to EBITDA ratio	5.0
Fourth Amendment to the Senior Credit Agreement \| Fiscal quarter ending September 30, 2019
Current and long-term debt
Total Net Debt to EBITDA ratio	4.25
Fourth Amendment to the Senior Credit Agreement \| Fiscal quarter ending December 31, 2019 and any fiscal quarter thereafter
Current and long-term debt
Total Net Debt to EBITDA ratio	4.0
Third Amendment to the Senior Credit Agreement
Current and long-term debt
Maximum borrowing capacity					$ 1,000.0
Second Amendment to Senior Credit Agreement \| Fiscal quarter ending June 30, 2018
Current and long-term debt
Total Net Debt to EBITDA ratio						4.50
Second Amendment to Senior Credit Agreement \| Fiscal quarter after June 30, 2018
Current and long-term debt
Total Net Debt to EBITDA ratio						4.00