2.4.0.8090300 - Disclosure - OIL AND GAS CONCESSIONS (Details)truefalsefalse1false USDfalsefalse$c20130630http://www.sec.gov/CIK0000799235instant2013-06-30T00:00:000001-01-01T00:00:00U002Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$c20120930http://www.sec.gov/CIK0000799235instant2012-09-30T00:00:000001-01-01T00:00:00U002Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 4erhe_AnalysisOfCostOfOilAndGasConcessionsAbstracterhe_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Analysis of cost of oil and gas concessions [Abstract]2false 5erhe_OilAndGasConcessionFeeserhe_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1045701110457011USD$falsetruefalse2truefalsefalse1004630310046303USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount, as of the balance sheet date, of concession fees paid or incurred in connection with land exploration and development projects.No definition available.false2Oil and gas concessions3false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3false USDtruefalse$c20130630_StatementGeographicalAxis_DrstpConcessionMemberhttp://www.sec.gov/CIK0000799235instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseDRSTP Concession [Member]us-gaap_StatementGeographicalAxisxbrldihttp://xbrl.org/2006/xbrldierhe_DrstpConcessionMemberus-gaap_StatementGeographicalAxisexplicitMemberU002Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0DRSTP Concession [Member]4true 4erhe_AnalysisOfCostOfOilAndGasConcessionsAbstracterhe_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Analysis of cost of oil and gas concessions [Abstract]5false 5erhe_OilAndGasConcessionFeeserhe_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse28395002839500USD$falsefalsefalse2truefalsefalse28395002839500USD$falsefalsefalsexbrli:monetaryItemTypemonetaryAmount, as of the balance sheet date, of concession fees paid or incurred in connection with land exploration and development projects.No definition available.false2Oil and gas concessions6false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse5false USDtruefalse$c20130630_StatementGeographicalAxis_ChadConcessionMemberhttp://www.sec.gov/CIK0000799235instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseChad Concession [Member]us-gaap_StatementGeographicalAxisxbrldihttp://xbrl.org/2006/xbrldierhe_ChadConcessionMemberus-gaap_StatementGeographicalAxisexplicitMemberU002Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Chad Concession [Member]7true 4erhe_AnalysisOfCostOfOilAndGasConcessionsAbstracterhe_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Analysis of cost of oil and gas concessions [Abstract]8false 5erhe_OilAndGasConcessionFeeserhe_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse69697396969739USD$falsefalsefalse2truefalsefalse68006006800600USD$falsefalsefalsexbrli:monetaryItemTypemonetaryAmount, as of the balance sheet date, of concession fees paid or incurred in connection with land exploration and development projects.No definition available.false2Oil and gas concessions9false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse7false USDtruefalse$c20130630_StatementGeographicalAxis_KenyaConcessionMemberhttp://www.sec.gov/CIK0000799235instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseKenya Concession [Member]us-gaap_StatementGeographicalAxisxbrldihttp://xbrl.org/2006/xbrldierhe_KenyaConcessionMemberus-gaap_StatementGeographicalAxisexplicitMemberU002Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Kenya Concession [Member]10true 4erhe_AnalysisOfCostOfOilAndGasConcessionsAbstracterhe_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Analysis of cost of oil and gas concessions [Abstract]11false 5erhe_OilAndGasConcessionFeeserhe_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse576142576142USD$falsefalsefalse2truefalsefalse326073326073USD$falsefalsefalsexbrli:monetaryItemTypemonetaryAmount, as of the balance sheet date, of concession fees paid or incurred in connection with land exploration and development projects.No definition available.false2Oil and gas concessions12false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse9false USDtruefalse$c20130630_StatementGeographicalAxis_PendingConcessionsInOtherAfricanCountriesMemberhttp://www.sec.gov/CIK0000799235instant2013-06-30T00:00:000001-01-01T00:00:00falsefalsePending Concessions in Other African Countries [Member]us-gaap_StatementGeographicalAxisxbrldihttp://xbrl.org/2006/xbrldierhe_PendingConcessionsInOtherAfricanCountriesMemberus-gaap_StatementGeographicalAxisexplicitMemberU002Standardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Pending Concessions in Other African Countries [Member]13true 4erhe_AnalysisOfCostOfOilAndGasConcessionsAbstracterhe_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Analysis of cost of oil and gas concessions [Abstract]14false 5erhe_OilAndGasConcessionFeeserhe_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse7163071630USD$falsetruefalse2truefalsefalse8013080130USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount, as of the balance sheet date, of concession fees paid or incurred in connection with land exploration and development projects.No definition available.false2Oil and gas concessionsfalseOIL AND GAS CONCESSIONS (Details) (USD $)NoRoundingUnKnownUnKnownUnKnowntruefalsefalseSheethttp://erhc.com/role/OilAndGasConcessionsDetails214