The amount prepaid for the long-term purchase agreement.

No definition available.

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- Definition

Represents the term of long-term purchase agreement.

+ References

No definition available.

+ Details

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- Definition

The amount of energy to be used under the long-term agreement, in Megawatts Per Hour.

+ References

No definition available.

+ Details

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- Definition

The amount prepaid for the short-term purchase agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

The amount of energy to be used under the short-term agreement, in Megawatts Per Hour.

+ References

No definition available.

+ Details

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Namespace Prefix:	hnrg_
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- Definition

The cash outflow to settle a bank borrowing during the year.

+ References

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hnrg_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
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SUBSEQUENT EVENTS (Details) $ in Thousands		3 Months Ended	9 Months Ended
SUBSEQUENT EVENTS (Details) $ in Thousands	Oct. 23, 2024 USD ($) MWh	Jun. 30, 2024 USD ($) MWh	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
SUBSEQUENT EVENTS
Payments on bank debt			$ 86,500	$ 56,463
Hoosier
SUBSEQUENT EVENTS
Long Term Purchase Agreement, Prepaid Contract Amount		$ 45,000
Long Term Purchase Commitment, Total Usage of Power, Megawatt Per Hour (Megawatt-Hour) \| MWh		1,302,480
Subsequent Events
SUBSEQUENT EVENTS
Power contract term (in months)	19 months
Subsequent Events \| Hoosier
SUBSEQUENT EVENTS
Long-term purchase agreement prepaid contract amount	$ 60,000
Long-term purchase commitment total usage of power, megawatt per hour \| MWh	1,918,275
Subsequent Events \| Revolving credit
SUBSEQUENT EVENTS
Repayment of revolving credit	$ 34,000
Subsequent Events \| Term Loan \| Revolving credit
SUBSEQUENT EVENTS
Payments on bank debt	$ 20,000