Represents the number of senior executives of the entity covered under employment agreement.

No definition available.

Name:	epm_LossContingencyNumberOfSeniorExecutivesUnderAgreement
Namespace Prefix:	epm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period of benefits, includes payment of base pay and certain medical and disability benefits, after the termination from employment.

+ References

No definition available.

+ Details

Name:	epm_LossContingencyPeriodOfBenefitsToEmployeeAfterTermination
Namespace Prefix:	epm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transactions, Percentage of Overriding Royalty Interest with Suspended Payments

+ References

No definition available.

+ Details

Name:	epm_RelatedPartyTransactionsPercentageofOverridingRoyaltyInterestwithSuspendedPayments
Namespace Prefix:	epm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 9

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

+ Details

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41499-112717

+ Details

Name:	us-gaap_OperatingLeasesRentExpenseNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_CounterpartyNameAxis=epm_DenburyResourcesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_EmploymentContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
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Commitments and Contingencies - Narrative (Details) (USD $)	3 Months Ended		6 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Nov. 01, 2014	Jan. 26, 2015
Commitments and Contingencies
Rent Expense	$ 43,776us-gaap_OperatingLeasesRentExpenseNet	$ 44,759us-gaap_OperatingLeasesRentExpenseNet	$ 87,551us-gaap_OperatingLeasesRentExpenseNet	$ 86,667us-gaap_OperatingLeasesRentExpenseNet
Employment Contracts
Commitments and Contingencies
Number of employment agreements			2
Estimated obligation of employment contract	$ 473,000		$ 473,000
Employment Contracts \| Low end of the range
Commitments and Contingencies
Benefit period			6 months
Employment Contracts \| High end of the range
Commitments and Contingencies
Benefit period			1 year
Denbury Resources, Inc
Commitments and Contingencies
Suspended payments related to overriding royalty interest, percentage					2.89155%
Subsequent Event \| Denbury Resources, Inc
Commitments and Contingencies
Suspended payments related to overriding royalty interest, percentage						2.89155%