XML 16 R39.htm IDEA: XBRL DOCUMENT v2.4.0.6

(11) Gain on Sale (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
North Dakota Lease Play Gain on Sale	$ 10.7

X

- Definition

North Dakota Lease Play Gain on Sale 2011

+ References

No definition available.

+ Details

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