Commodity Risk Management Activities - Commodity Derivative Contracts (Details)	3 Months Ended
Mar. 31, 2021 USD ($) MMBTU $ / MMBTU
Risk Management Activities
Fair Value \| $	$ 401,141
2021 Contracts \| Basis swap
Risk Management Activities
Volume (Mmbtu) \| MMBTU	305,000
Basis Differential	(1.10)
Fair Value \| $	$ (27,181)
2021 Contracts \| Two-way costless collar
Risk Management Activities
Volume (Mmbtu) \| MMBTU	2,755,000
Ceiling Price	3.27
Floor Price	2.78
Fair Value \| $	$ 411,801
2022 Contracts \| Two-way costless collar
Risk Management Activities
Volume (Mmbtu) \| MMBTU	900,000
Ceiling Price	3.34
Floor Price	2.80
Fair Value \| $	$ 16,521

Represents the derivative basis differential price.

No definition available.

Name:	epsn_DerivativeBasisDifferentialPrice
Namespace Prefix:	epsn_
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Period Type:	instant

- Definition

The cap rate on a price risk derivative such as a cap or collar. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeCapPrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611

+ Details

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

- Definition

Floor rate on a price risk derivative such as a floor or a collar. A payment or receipt is triggered if the market rate falls below the floor rate on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFloorPrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
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Period Type:	instant

- Definition

Nominal energy measure used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeNonmonetaryNotionalAmountEnergyMeasure
Namespace Prefix:	us-gaap_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- 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

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Data Type:	xbrli:stringItemType
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- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=epsn_SwapAndCollarContract2021Member
Namespace Prefix:
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- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_BasisSwapMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=epsn_TwoWayCostlessCollarMember
Namespace Prefix:
Data Type:	na
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- Details

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