XML 145 R126.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Regulatory Matters - Reliability and FERC Matters (Details) $ in Millions |  |  |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 20, 2017 USD ($) | Oct. 13, 2017 | Mar. 10, 2017 | Feb. 20, 2017 | Jan. 19, 2017 | Jun. 15, 2016 kv | Aug. 04, 2014 | Aug. 24, 2012 USD ($) | Dec. 31, 2017 USD ($) | Sep. 30, 2017 USD ($) | Sep. 30, 2017 | Dec. 31, 2017 USD ($) entity | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($)
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regional enforcement entities | entity |  |  |  |  |  |  |  |  |  |  |  | 8 |  |
Impairment of assets and related charges (Note 2) |  |  |  |  |  |  |  |  |  |  |  | $ 2,406.0 | $ 10,665.0 | $ 42.0
FERC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Power threshold for cost methodology (in KW) | kv |  |  |  |  |  | 500 |  |  |  |  |  |  |  |
Denied recovery charges of exit fees |  |  |  |  |  |  |  |  | $ 78.8 |  |  | $ 78.8 |  |
Ohio Companies | FERC | Unit Power Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of proposed purchase power agreement |  |  |  |  |  |  | 8 years |  |  |  |  |  |  |
MAIT |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment of assets and related charges (Note 2) |  |  |  |  |  |  |  |  |  | $ 13.0 |  |  |  |
MAIT | FERC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Approved ROE |  | 10.30% |  |  |  |  |  |  |  |  | 11.00% |  |  |
Approved capital structure |  | 60.00% |  |  |  |  |  |  |  |  |  |  |  |
JCP&L | FERC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment of assets and related charges (Note 2) |  |  |  |  |  |  |  |  | $ 28.0 |  |  |  |  |
Approved suspension period |  |  | 5 months |  |  |  |  |  |  |  |  |  |  |
JCP&L | FERC | Network Integration Transmission Service |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Annual revenue requirement | $ 135.0 |  |  |  |  |  |  |  |  |  |  |  |  |
JCP&L | FERC | PJM Tariff |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Annual revenue requirement | $ 20.0 |  |  |  |  |  |  |  |  |  |  |  |  |
PATH-Allegheny | FERC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost recovery PP&E reclassified to Regulatory Assets |  |  |  |  |  |  |  | $ 62.0 |  |  |  |  |  |
Path-WV | FERC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost recovery PP&E reclassified to Regulatory Assets |  |  |  |  |  |  |  | $ 59.0 |  |  |  |  |  |
PATH | FERC |  |  |  |  |  |  |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cost recovery proposed ROE (percent) |  |  |  |  |  |  |  | 10.90% |  |  |  |  |  |
Base ROE (percent) |  |  |  | 10.40% | 8.11% |  |  | 10.40% |  |  |  |  |  |
ROE granted for RTO's (percent) |  |  |  |  |  |  |  | 0.50% |  |  |  |  |  |
Remaining recovery period of regulatory assets |  |  |  |  |  |  |  | 5 years |  |  |  |  |  |

X
- Definition Base Return On Equity + References No definition available. + Details
Name: | fe_BaseReturnOnEquity
Namespace Prefix: | fe_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Denied Recovery Charges of Exit Fees + References No definition available. + Details
Name: | fe_DeniedRecoveryChargesOfExitFees
Namespace Prefix: | fe_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Power Threshold For Cost Methodology + References No definition available. + Details
Name: | fe_PowerThresholdForCostMethodology
Namespace Prefix: | fe_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition Proposed Purchase Power Agreement, Term + References No definition available. + Details
Name: | fe_ProposedPurchasePowerAgreementTerm
Namespace Prefix: | fe_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Rate Matters, Approved Suspension Period + References No definition available. + Details
Name: | fe_PublicUtilitiesRateMattersApprovedSuspensionPeriod
Namespace Prefix: | fe_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Settlement Agreement, Annual Revenue Requirement + References No definition available. + Details
Name: | fe_PublicUtilitiesSettlementAgreementAnnualRevenueRequirement
Namespace Prefix: | fe_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reclassifications of Plant, Property and Equipment, Net to Regulatory Assets + References No definition available. + Details
Name: | fe_ReclassificationsOfPlantPropertyAndEquipmentNetToRegulatoryAssets
Namespace Prefix: | fe_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Regional Enforcement Entities + References No definition available. + Details
Name: | fe_RegionalEnforcementEntities
Namespace Prefix: | fe_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Regulatory Asset, Cost Recovery, Proposed Return on Equity + References No definition available. + Details
Name: | fe_RegulatoryAssetCostRecoveryProposedReturnOnEquity
Namespace Prefix: | fe_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Regulatory matters. + References No definition available. + Details
Name: | fe_RegulatoryMattersLineItems
Namespace Prefix: | fe_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Remaining Recovery Period of Regulatory Assets + References No definition available. + Details
Name: | fe_RemainingRecoveryPeriodOfRegulatoryAssets
Namespace Prefix: | fe_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Return on equity granted for RTO participation. + References No definition available. + Details
Name: | fe_ReturnOnEquityGrantedForRegionalTransmissionOrganizationParticipation
Namespace Prefix: | fe_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of public utility's approved equity to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedEquityCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's approved return on equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=fe_FercMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fe_CEIOEandTEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=fe_UnitPowerAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fe_MidAtlanticInterstateTransmissionLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fe_JcpAndLMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=fe_NetworkIntegrationTransmissionServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=fe_PJMTariffMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fe_PathAlleghenyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fe_PathWvMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fe_PathMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |