(5) Investment in Sunrise Energy (Details) - Condensed Statement of Operations (Sunrise Energy, USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
Jun. 30, 2013	Dec. 31, 2012
Sunrise Energy
(5) Investment in Sunrise Energy (Details) - Condensed Statement of Operations [Line Items]
Revenue	$ 1,691	$ 1,086
Expenses	(997)	(1,023)
Net income	$ 694	$ 63

Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

No definition available.

Name:	hnrg_SELLCRevenues
Namespace Prefix:	hnrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration