Represents the additional shares issued from a debt conversion.

No definition available.

Name:	hnrg_DebtConversionConvertedInstrumentAdditionalShares
Namespace Prefix:	hnrg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of shares used to pay interest for the conversion of sahres.

+ References

No definition available.

+ Details

Name:	hnrg_DebtConversionConvertedInstrumentSharesUsedForInterest
Namespace Prefix:	hnrg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-3

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-5

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

+ Details

Name:	us-gaap_DebtConversionOriginalDebtAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

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-Topic 470
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-Name Accounting Standards Codification
-Section 50
-Paragraph 5
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
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-Section 40
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+ Details

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

- Definition

The cash inflow from a long-term borrowing made from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Alternate caption: Proceeds from Advances from Affiliates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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-Subparagraph (b)
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- Details

Name:	srt_CounterpartyNameAxis=srt_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=hnrg_ConversionPrice6Point254MaturityDateDecember2028Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=hnrg_ConversionPrice6Point15MaturityDateDecember2028Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_CounterpartyNameAxis=hnrg_NonaffiliatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=hnrg_ConversionPrice6Point254MaturityDateDecember2026Member
Namespace Prefix:
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Note 14 - Convertible Notes (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended			6 Months Ended
	Aug. 12, 2022	Jul. 29, 2022	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Aug. 08, 2022
Proceeds from Related Party Debt						$ 5,000	$ 0
Gain (Loss) on Extinguishment of Debt			$ (1,937)		$ 0	(2,790)	0
Debt Conversion, Original Debt, Amount						22,993	$ 0
Senior Unsecured Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage		8.00%
Senior Unsecured Convertible Notes [Member] \| Director [Member] \| Conversion Price 6 Point 254, Maturity Date December 2028 [Member]
Proceeds from Related Party Debt		$ 5,000
Debt Instrument, Convertible, Conversion Price (in dollars per share)		$ 6.254
Debt Conversion, Converted Instrument, Shares Issued (in shares)				799,488
Debt Conversion, Converted Instrument, Shares Used for Interest (in shares)				112,570
Gain (Loss) on Extinguishment of Debt						$ (600)
Senior Unsecured Convertible Notes [Member] \| Director [Member] \| Conversion Price 6 Point 15, Maturity Date December 2028 [Member]
Proceeds from Related Party Debt	$ 4,000
Debt Instrument, Interest Rate, Stated Percentage								8.00%
Debt Instrument, Convertible, Conversion Price (in dollars per share)								$ 6.254
Debt Conversion, Converted Instrument, Shares Issued (in shares)			159,898	479,693
Debt Conversion, Converted Instrument, Shares Used for Interest (in shares)				67,542
Gain (Loss) on Extinguishment of Debt			$ 200	$ (300)
Debt Conversion, Original Debt, Amount			$ 1,000	$ 3,000
Debt Conversion, Converted Instrument, Additional Shares (in shares)			25,003
Senior Unsecured Convertible Notes [Member] \| Director [Member] \| Represents conversion price of %6.15 with maturity date of December 2028, additional shares [Member].
Debt Conversion, Converted Instrument, Shares Issued (in shares)				57,564
Debt Conversion, Converted Instrument, Shares Used for Interest (in shares)			5,099			5,099
Senior Unsecured Convertible Notes [Member] \| Non-affiliated Party [Member] \| Conversion Price 6 Point 254, Maturity Date December 2026 [Member]
Proceeds from Related Party Debt	$ 10,000
Debt Instrument, Interest Rate, Stated Percentage	8.00%
Debt Instrument, Convertible, Conversion Price (in dollars per share)	$ 6.15
Debt Conversion, Converted Instrument, Shares Issued (in shares)			1,626,016	65,041
Debt Conversion, Converted Instrument, Shares Used for Interest (in shares)			224,268			224,268
Gain (Loss) on Extinguishment of Debt			$ (1,700)
Debt Conversion, Original Debt, Amount			$ 10,000
Debt Conversion, Converted Instrument, Additional Shares (in shares)			49,716