COMMITMENTS AND CONTINGENCIES (Details)	Jun. 30, 2012
JDZ 5 [Member]
Loss Contingencies [Line Items]
Working interest awarded in mining concessions (in hundredths)	15.00%
JDZ 6 [Member]
Loss Contingencies [Line Items]
Working interest awarded in mining concessions (in hundredths)	15.00%

The percentage of working interest awarded in mining concessions.

No definition available.

Name:	erhe_WorkingInterestAwardedInMiningConcessions
Namespace Prefix:	erhe_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant