XML 146 R128.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Regulatory Matters - Reliability and FERC Matters (Details) $ in Millions |  |  |  |  |  |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | ---
Feb. 20, 2017 | Feb. 17, 2017 USD ($) Natural_gas_plant | Jan. 19, 2017 | Jan. 18, 2017 USD ($) Natural_gas_plant MW | Aug. 24, 2016 USD ($) | Aug. 24, 2012 USD ($) | Apr. 30, 2007 kv | Dec. 31, 2016 USD ($) entity MW
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Regional enforcement entities | entity |  |  |  |  |  |  |  | 8
FERC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Power threshold for cost methodology (in KW) | kv |  |  |  |  |  |  | 500 |
Denied recovery charges of exit fees | $ |  |  |  |  |  |  |  | $ 78.8
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% |  |
ROE granted for RTO's (percent) |  |  |  |  |  | 0.50% |  |
Remaining recovery period of regulatory assets |  |  |  |  |  | 5 years |  |
Settled Litigation | California Claims Matters | FERC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Settlement amount | $ |  |  |  |  | $ 3.6 |  |  |
Purchase Agreement with Aspen Generating, LLC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Plant generation capacity (in MW's) |  |  |  |  |  |  |  | 1,572
Subsequent Event | PATH | FERC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Base ROE (percent) | 10.40% |  | 8.11% |  |  |  |  |
Subsequent Event | Purchase Agreement with Aspen Generating, LLC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Cash purchase price | $ |  | $ 925.0 |  | $ 925.0 |  |  |  |
Plant generation capacity (in MW's) |  |  |  | 1,572 |  |  |  |
Subsequent Event | Purchase Agreement with Aspen Generating, LLC | AE Supply |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Number of gas generating plants | Natural_gas_plant |  | 4 |  | 4 |  |  |  |
Springdale Generating Facility Units 1-5 | Subsequent Event | Purchase Agreement with Aspen Generating, LLC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Plant generation capacity (in MW's) |  |  |  | 638 |  |  |  |
Chamberburg Generating Facility Units 12-13 | Subsequent Event | Purchase Agreement with Aspen Generating, LLC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Plant generation capacity (in MW's) |  |  |  | 88 |  |  |  |
Gans Generating Facility Units 8-9 | Subsequent Event | Purchase Agreement with Aspen Generating, LLC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Plant generation capacity (in MW's) |  |  |  | 88 |  |  |  |
Hunlock Creek | Subsequent Event | Purchase Agreement with Aspen Generating, LLC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Plant generation capacity (in MW's) |  |  |  | 45 |  |  |  |
Bath County Hydro | Subsequent Event | Purchase Agreement with Aspen Generating, LLC |  |  |  |  |  |  |  |
Regulatory Matters [Line Items] |  |  |  |  |  |  |  |
Plant generation capacity (in MW's) |  |  |  | 713 |  |  |  |

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 Disposal Group, Including Discontinued Operation, Number of Gas Generating Plants + References No definition available. + Details
Name: | fe_DisposalGroupIncludingDiscontinuedOperationNumberofGasGeneratingPlants
Namespace Prefix: | fe_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Plant Capacity + References No definition available. + Details
Name: | fe_PlantCapacity
Namespace Prefix: | fe_
Data Type: | num:powerItemType
Balance Type: | na
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 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 judgment or settlement awarded to (against) the entity in respect of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow associated with the amount received from the sale of a business segment or subsidiary or sale of an entity that is related to it but not strictly controlled during the period (for example, an unconsolidated subsidiary, affiliate, joint venture or equity method investment). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3179-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 + Details
Name: | us-gaap_ProceedsFromDivestitureOfBusinessesAndInterestsInAffiliates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_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: |

X
- Details
Name: | us-gaap_LitigationStatusAxis=us-gaap_SettledLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=fe_CaliforniaClaimsMattersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=fe_PurchaseAgreementwithAspenGeneratingLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_PublicUtilityAxis=fe_SpringdaleGeneratingFacilityUnits15Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=fe_ChamberburgGeneratingFacilityUnits1213Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=fe_GansGeneratingFacilityUnits89Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=fe_HunlockCreekMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=fe_BathCountyHydroMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |