XML 59 R47.htm IDEA: XBRL DOCUMENT
v3.21.1

Commitments, Guarantees and Contingencies - Potential Collateral Obligations (Details) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2021 USD ($)
Guarantor Obligations [Line Items] |
Guarantor obligations | $ 342
Percent of face amount of debt | 100.00%
Curing period | 30 days
Upon Further Downgrade |
Guarantor Obligations [Line Items] |
Guarantor obligations | $ 28
Surety Bond (Collateralized Amount) |
Guarantor Obligations [Line Items] |
Guarantor obligations | $ 314
Percent of face amount of debt | 60.00%
Capped portion of surety bond obligations | $ 39
Utilities and FET |
Guarantor Obligations [Line Items] |
Guarantor obligations | 84
Utilities and FET | Upon Further Downgrade |
Guarantor Obligations [Line Items] |
Guarantor obligations | 28
Utilities and FET | Surety Bond (Collateralized Amount) |
Guarantor Obligations [Line Items] |
Guarantor obligations | 56
FirstEnergy |
Guarantor Obligations [Line Items] |
Guarantor obligations | 258
FirstEnergy | Upon Further Downgrade |
Guarantor Obligations [Line Items] |
Guarantor obligations | 0
FirstEnergy | Surety Bond (Collateralized Amount) |
Guarantor Obligations [Line Items] |
Guarantor obligations | $ 258

X
- Definition Guarantor Obligations, Capped Portion of Surety Bond Obligations + References No definition available. + Details
Name: | fe_GuarantorObligationsCappedPortionOfSuretyBondObligations
Namespace Prefix: | fe_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Guarantor Obligations, Curing Period + References No definition available. + Details
Name: | fe_GuarantorObligationsCuringPeriod
Namespace Prefix: | fe_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Guarantor Obligations, Maximum Contractual Obligations, Percent of Face Amount of Debt + References No definition available. + Details
Name: | fe_GuarantorObligationsMaximumContractualObligationsPercentOfFaceAmountOfDebt
Namespace Prefix: | fe_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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_GuaranteeObligationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=fe_UponFurtherDowngradeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_SuretyBondMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=fe_RegulatedDistributionandRegulatedTransmissionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |