Name:	hnrg_DebtInstrumentCovenantMaximumAnnualCapitalExpendituresNextFiscalYearAndThereafter
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The maximum capital expenditures per year under the covenant of the debt instrument, for the remainder of the fiscal year.

No definition available.

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The maximum leverage ratio allowed for payment of dividends under covenant of the debt instrument.

No definition available.

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The minimum debt service coverage ratio (consolidated adjusted EBITDA / annual debt service) under the covenant of the debt instrument.

No definition available.

Name:	hnrg_DebtInstrumentCovenantMinimumDebtServiceCoverageRatio
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Represents effective percentage unhedged amount of interest rate for debt instrument.

No definition available.

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The amount of liquidity under the debt instrument.

No definition available.

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Represents ungedged portion of debt instrument.

No definition available.

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The floor percentage of variable interest rate of the debt instrument.

No definition available.

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The debt service coverage ratio (consolidated adjusted EBITDA / annual debt service).

No definition available.

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The leverage ratio.

No definition available.

Name:	hnrg_LeverageRatio
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Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

Represents the amount of notes payable for which forgiveness has been applied for.

No definition available.

Name:	hnrg_NotesPayableAmountOfForgivenessAppliedFor
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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

No definition available.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Net increase or decrease in the carrying amount of the debt instrument for the period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Subparagraph (SX 210.4-08(f))
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Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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-Section 50
-Paragraph 1D
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-Section 45
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Amount of hedged item in hedging relationship. Excludes hedged asset or liability.

No definition available.

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The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
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Period Type:	instant

Fixed interest rate related to the interest rate derivative.

No definition available.

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Nominal or face amount used to calculate payment on derivative.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-SubTopic 10
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Variable interest rate in effect as of the balance sheet date related to the interest rate derivative.

No definition available.

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

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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.

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Name:	us-gaap_LineOfCredit
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Balance Type:	credit
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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.

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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Name:	us-gaap_NotesPayable
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The cash inflow from a borrowing supported by a written promise to pay an obligation.

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Name:	us-gaap_ProceedsFromNotesPayable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Namespace Prefix:
Data Type:	na
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Data Type:	na
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Name:	srt_RangeAxis=srt_MaximumMember
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