2.4.0.84080 - Disclosure - Stock-Based Incentive Plan (Details)truefalsefalse1false USDtruefalse$D2013_StockOptionsAndIncentiveWarrantsMemberhttp://www.sec.gov/CIK0001006655duration2012-07-01T00:00:002013-06-30T00:00:00falsefalseStock Options and Incentive Warrantsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldiepm_StockOptionsAndIncentiveWarrantsMemberus-gaap_AwardTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDtruefalse$D2012_StockOptionsAndIncentiveWarrantsMemberhttp://www.sec.gov/CIK0001006655duration2011-07-01T00:00:002012-06-30T00:00:00falsefalseStock Options and Incentive Warrantsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldiepm_StockOptionsAndIncentiveWarrantsMemberus-gaap_AwardTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDtruefalse$D2011_StockOptionsAndIncentiveWarrantsMemberhttp://www.sec.gov/CIK0001006655duration2010-07-01T00:00:002011-06-30T00:00:00falsefalseStock Options and Incentive Warrantsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldiepm_StockOptionsAndIncentiveWarrantsMemberus-gaap_AwardTypeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false truefalseD2013_StockOptionsMemberhttp://www.sec.gov/CIK0001006655duration2012-07-01T00:00:002013-06-30T00:00:00falsefalseStock Optionsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_StockOptionsMemberus-gaap_AwardTypeAxisexplicitMemberSharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli05false truefalseD2012_StockOptionsMemberhttp://www.sec.gov/CIK0001006655duration2011-07-01T00:00:002012-06-30T00:00:00falsefalseStock Optionsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_StockOptionsMemberus-gaap_AwardTypeAxisexplicitMemberSharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli06false truefalseD2011_StockOptionsMemberhttp://www.sec.gov/CIK0001006655duration2010-07-01T00:00:002011-06-30T00:00:00falsefalseStock Optionsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_StockOptionsMemberus-gaap_AwardTypeAxisexplicitMemberSharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli07false truefalseI2013_NaturalGasSystemsInc2003StockPlanMemberhttp://www.sec.gov/CIK0001006655instant2013-06-30T00:00:000001-01-01T00:00:00falsefalse2003 Stock Planus-gaap_PlanNameAxisxbrldihttp://xbrl.org/2006/xbrldiepm_NaturalGasSystemsInc2003StockPlanMemberus-gaap_PlanNameAxisexplicitMemberSharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli08false truefalseD2012Q4_124M_StockOptionsMember_NaturalGasSystemsInc2003StockPlanMemberhttp://www.sec.gov/CIK0001006655duration2003-08-25T00:00:002013-06-30T00:00:00falsefalse2003 Stock Planus-gaap_PlanNameAxisxbrldihttp://xbrl.org/2006/xbrldiepm_NaturalGasSystemsInc2003StockPlanMemberus-gaap_PlanNameAxisexplicitMemberfalsefalseStock Optionsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_StockOptionsMemberus-gaap_AwardTypeAxisexplicitMemberSharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli09false truefalseI2013_EvolutionPetroleumCorporationAmendedAndRestated2004StockPlanMemberhttp://www.sec.gov/CIK0001006655instant2013-06-30T00:00:000001-01-01T00:00:00falsefalse2004 Stock Planus-gaap_PlanNameAxisxbrldihttp://xbrl.org/2006/xbrldiepm_EvolutionPetroleumCorporationAmendedAndRestated2004StockPlanMemberus-gaap_PlanNameAxisexplicitMemberSharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli010false truefalseI2013_WarrantMember_BoardOfDirectorsAuthorizedGrantsOutsideOfStockPlansMemberhttp://www.sec.gov/CIK0001006655instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseBoard of Directors Authorized, Outside of EMP Stock Plansus-gaap_PlanNameAxisxbrldihttp://xbrl.org/2006/xbrldiepm_BoardOfDirectorsAuthorizedGrantsOutsideOfStockPlansMemberus-gaap_PlanNameAxisexplicitMemberfalsefalseIncentive Warrantsus-gaap_AwardTypeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_WarrantMemberus-gaap_AwardTypeAxisexplicitMemberSharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli01true 3us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Stock-Based Incentive Plan2false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGrossus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8truefalsefalse600000600000falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesGross number of share options (or share units) granted during the period.No definition available.false1Number of shares granted under the Plan3false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9truefalsefalse65000006500000falsefalsefalse10falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Number of shares of common stock authorized for issuance under plan4false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7truefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9truefalsefalse800914800914falsefalsefalse10falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false1Number of shares remaining available for grant under plan5false 4us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRightsus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalsepositiveLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10truefalsefalse10375001037500falsefalsefalsexbrli:sharesItemTypesharesThe specified number of securities that each class of warrants or rights outstanding give the holder the right but not the obligation to purchase from the issuer at a specific price, on or before a certain date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(2)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 2 -Article 4 false1Number of Incentive Warrants issued (in shares)6false 4us-gaap_AllocatedShareBasedCompensationExpenseus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse2627426274USD$falsetruefalse2truefalsefalse327776327776USD$falsetruefalse3truefalsefalse715027715027USD$falsetruefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse6falsefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryRepresents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph 64 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.F) -URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph g(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section F false2Non-cash stock-based compensation expense7false 4epm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAndIncentiveWarrantsGrantsInPeriodGrossepm_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse00falsefalsefalse5truefalsefalse00falsefalsefalse6truefalsefalse00falsefalsefalse7falsefalsefalse00falsefalsefalse8falsefalsefalse00falsefalsefalse9falsefalsefalse00falsefalsefalse10falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesGross number of share options (or share units) and Incentive Warrants granted during the period.No definition available.false1Granted (in shares)falseStock-Based Incentive Plan (Details) (USD $)NoRoundingNoRoundingUnKnownUnKnowntruefalsefalseSheethttp://www.evolutionpetroleum.com/role/DisclosureStockBasedIncentivePlanDetails107