(2) Bill and Hold (Detail) (USD $) In Millions, unless otherwise specified	19 Months Ended	24 Months Ended
Apr. 01, 2014 T	Apr. 01, 2014 T	Dec. 31, 2012
TonsOfCoalAgreedToStorePerCustomer		250,000
TonsOfCoalStored	250,000
TonsOfCoalsStoredSecondCustomer	155,000
RevenueFromBillAndHold (in Dollars)			$ 20

Maximum amount of coal stored at the mine per the agreement with the purchaser.

No definition available.

Name:	hnrg_TonsOfCoalAgreedToStorePerCustomer
Namespace Prefix:	hnrg_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration