(4) Investment in Savoy (Details) - Condensed Statement of Operations (Equity Investment in Savoy, USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
Jun. 30, 2013	Dec. 31, 2012
Equity Investment in Savoy
(4) Investment in Savoy (Details) - Condensed Statement of Operations [Line Items]
Revenue	$ 18,373	$ 17,261
Expenses	(12,946)	(11,719)
Net income	$ 5,427	$ 5,542

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