Basis of Presentation and Significant Accounting Policies (Details 4) (Predecessor)	12 Months Ended
Dec. 31, 2013
Predecessor
Full Cost
Discount rate for estimated present value of future net revenues from proved reserves less estimated future capital expenditures (as a percent)	10.00%
Period for calculation of unweighted arithmetic average of the price	12 months

Represents the period prior to the end of the reporting period used for calculation of unweighted arithmetic average of the price used when performing the ceiling test for capitalized cost less related deferred income taxes for oil and gas producing companies that use full cost method of accounting for investments in oil and gas producing properties.

No definition available.

Name:	epnrg_UnamortizedCostsCapitalizedLessRelatedDeferredIncomeTaxesCeilingLimitationPeriodForCalculationOfUnweightedArithmeticAveragePrice
Namespace Prefix:	epnrg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration