COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($) item
Purchase commitments related to equipment
Remaining period in 2019	$ 7,997
Total	7,997
Drilling rig commitments
Obligations under drilling rig commitments
Remaining period in 2019	1,321
Total	1,321
Non-cancelable termination penalties	1,100
Drilling rig commitments	1,300
Rig termination commitments
Obligations under rig termination and stacking fees commitments
2020	3,000
Total	$ 3,000
Gathering, transportation and sales \| West Texas
Purchase commitments related to equipment
Number of long-term crude oil sales contracts to which the entity is committed \| item	3
Number of long-term natural gas sales contracts to which the entity is committed \| item	10
Gathering, transportation and sales \| West Texas \| Minimum
Purchase commitments related to equipment
Period of commitment for production from the date of first production	1 year
Gathering, transportation and sales \| West Texas \| Maximum
Purchase commitments related to equipment
Period of commitment for production from the date of first production	20 years

Represents the number of long-term crude oil sales contracts to which the entity is committed.

No definition available.

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

- Definition

Represents the number of long-term natural gas sales contracts to which the entity is committed.

+ References

No definition available.

+ Details

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

- Definition

Represents the period of commitment for production from the date of first production.

+ References

No definition available.

+ Details

Name:	hk_ContractualObligationPeriodOfCommitmentForProductionFromTheDateOfFirstProduction
Namespace Prefix:	hk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the obligation amount of commitment related to drilling rigs. There are two separate trigger dates that must be met.

+ References

No definition available.

+ Details

Name:	hk_DrillingRigRelatedCommitmentAmount
Namespace Prefix:	hk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of termination penalties on non-cancelable purchase commitments in lieu of paying the remaining drilling commitments.

+ References

No definition available.

+ Details

Name:	hk_NonCancelableTerminationPenalties
Namespace Prefix:	hk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation maturing in the remainder of the fiscal year following the latest fiscal year ended.

+ References

No definition available.

+ Details

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

- Definition

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

+ Details

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

- Definition

Minimum amount of other commitment maturing in the second fiscal year following the latest fiscal year for commitments not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in this taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Minimum amount of purchase arrangement maturing in the remainder of the fiscal year following the latest fiscal year ended. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

+ References

No definition available.

+ Details

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

- Details

Name:	hk_ContractualObligationAxis=hk_DrillingRigCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	hk_ContractualObligationAxis=hk_RigTerminationCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	hk_ContractualObligationAxis=hk_GatheringTransportationAndSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=hk_WestTexasMember
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_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: