(4) Equity Investment in Sunrise Energy (Details) - Condensed Balance Sheet - Sunrise (Equity Investmentin SELLC [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014
Equity Investmentin SELLC [Member]
(4) Equity Investment in Sunrise Energy (Details) - Condensed Balance Sheet - Sunrise [Line Items]
Current assets	$ 3,319
Oil and gas properties, net	6,796
	10,115
Total liabilities	803
Members' capital	9,312
	$ 10,115

Name:	hnrg_EquityInvestmentinSunriseEnergyDetailsCondensedBalanceSheetSunriseLineItems
Namespace Prefix:	hnrg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

No definition available.

+ Details

Name:	hnrg_SELLCCurrentAssets
Namespace Prefix:	hnrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

No definition available.

+ Details

Name:	hnrg_SELLCMembersCapital
Namespace Prefix:	hnrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Net amount of capitalized costs relating to oil and gas producing activities.

+ References

No definition available.

+ Details

Name:	hnrg_SELLCOilAndGasPropertiesNet
Namespace Prefix:	hnrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

No definition available.

+ Details

Name:	hnrg_SELLCTotalAssets
Namespace Prefix:	hnrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

+ References

No definition available.

+ Details

Name:	hnrg_SELLCTotalLiabilities
Namespace Prefix:	hnrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of liabilities and partners' capital, including the portion of equity attributable to noncontrolling interests, if any.

+ References

No definition available.

+ Details

Name:	hnrg_SELLCTotalLibilitiesAndEquity
Namespace Prefix:	hnrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant