Name:	fe_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesSaleOfInterestByParentPercent
Namespace Prefix:	fe_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

Deferred Tax Assets Liabilities Net Non Current Loss Carry Forward Valuation Allowances

No definition available.

Name:	fe_DeferredTaxAssetsLiabilitiesNetNonCurrentLossCarryForwardValuationAllowances
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Deferred Tax Assets Liabilities Net Non Current Loss Carry Forwards And Tax Credits

No definition available.

Name:	fe_DeferredTaxAssetsLiabilitiesNetNonCurrentLossCarryForwardsAndTaxCredits
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Provision for Income Tax.

No definition available.

Name:	fe_ProvisionForIncomeTaxLineItems
Namespace Prefix:	fe_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from employee compensation.

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

Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

Name:	us-gaap_DeferredTaxLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of deferred tax liability attributable to taxable temporary differences from the entity's basis in a discontinued operation.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 25
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482655/740-30-25-10

Name:	us-gaap_DeferredTaxLiabilitiesParentsBasisInDiscontinuedOperation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of deferred tax liability attributable to taxable temporary differences from regulatory assets and liabilities.

Name:	us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of deferred tax liability attributable to taxable temporary differences from tax deferred revenue or income classified as other.

Name:	us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.