XML 32 R76.htm IDEA: XBRL DOCUMENT
v3.2.0.727

Concentrations of Credit Risk - Schedule of Credit Risk (Details) - Net revenue - Major Customers | 12 Months Ended
--- | ---
Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2013
Concentrations of Credit Risk |  |  |
Percent of Total Revenue | 100.00% | 100.00% | 100.00%
Plains Marketing L.P. (includes Delhi production) |  |  |
Concentrations of Credit Risk |  |  |
Percent of Total Revenue | 99.00% | 96.00% | 90.00%
Enterprise Crude Oil LLC |  |  |
Concentrations of Credit Risk |  |  |
Percent of Total Revenue | 0.00% | 2.00% | 4.00%
Flint Hills |  |  |
Concentrations of Credit Risk |  |  |
Percent of Total Revenue | 0.00% | 1.00% | 2.00%
ETC Texas Pipeline, LTD. |  |  |
Concentrations of Credit Risk |  |  |
Percent of Total Revenue | 0.00% | 1.00% | 0.00%
All others |  |  |
Concentrations of Credit Risk |  |  |
Percent of Total Revenue | 1.00% | 0.00% | 4.00%

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ConcentrationRiskLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=epm_PlainsMarketingLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=epm_EnterpriseCrudeOilLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=epm_FlintHillsResourcesLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=epm_ETCTexasPipelineLTDMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=epm_AllOtherImmaterialCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |