XML 108 R92.htm IDEA: XBRL DOCUMENT
v3.25.0.1

CAPITALIZATION - Narrative (Details) $ / shares in Units, $ in Millions |  |  |  | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 25, 2024 USD ($) | May 04, 2023 USD ($) tradingDay | May 01, 2023 | Dec. 31, 2024 USD ($) subsidiary $ / shares shares | Dec. 31, 2023 USD ($) shares | Dec. 31, 2022 shares | Dec. 05, 2024 USD ($) | Sep. 30, 2024 | Sep. 05, 2024 USD ($) | Apr. 30, 2023 | Jun. 30, 2013 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
FERC-defined equity to total capitalization ratio |  |  |  | 35.00% |  |  |  |  |  |  |
Preference shares outstanding (in shares) | shares |  |  |  | 0 | 0 |  |  |  |  |  |
Preferred shares, outstanding (in shares) | shares |  |  |  | 0 | 0 |  |  |  |  |  |
Number of subsidiaries that issued environmental control bonds | subsidiary |  |  |  | 2 |  |  |  |  |  |  |
Environmental control bonds outstanding |  |  |  | $ 188 | $ 218 |  |  |  |  |  |
Principal default amount specified in debt covenants |  |  |  | $ 100 |  |  |  |  |  |  |
4.00%, $1,500 Million Notes Maturity 2026 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of debt |  | $ 1,480 |  |  |  |  |  |  |  |  |
2026 Convertible Notes |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument, convertible, conversion ratio |  |  |  | 0.021362 |  |  |  |  |  |  |
Phase In Recovery Bonds |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt and other long-term obligations |  |  |  | $ 175 | $ 191 |  |  |  |  |  |
Unsecured Debt | 2026 Convertible Notes |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Issuance interest rate |  |  |  |  |  |  |  |  |  | 4.00% |
Registered Shareholders, Directors and Employees of Subsidiaries |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Consolidated tax benefit allocation (in shares) | shares |  |  |  | 3,000,000 | 2,000,000 | 2,000,000 |  |  |  |  |
FET | Senior Notes | 5.15%, 300 Million Notes Maturing 2026 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of loan |  |  |  |  |  |  |  |  | $ 400 |  |
FET | Promissory Notes | 4.55% Unsecured Senior Notes Maturing 2031 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of loan |  |  |  |  |  |  |  |  | $ 400 |  |
Issuance interest rate |  |  |  |  |  |  |  | 4.55% |  |  |
FET | Promissory Notes | 5.15%, 300 Million Notes Maturing 2026 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Issuance interest rate |  |  |  |  |  |  |  | 5.00% |  |  |
AGC |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
FERC-defined equity to total capitalization ratio |  |  |  | 45.00% |  |  |  |  |  |  |
JCP&L | Promissory Notes | 5.10% Unsecured Senior Notes Maturing 2035 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of loan |  |  |  |  |  |  | $ 700 |  |  |  |
Effective shelf registration, effective period |  |  |  | 60 days |  |  |  |  |  |  |
Interest accrual rate for the first 90 days |  |  |  | 0.25% |  |  |  |  |  |  |
Additional interest accrual rate for subsequent 90 days |  |  |  | 0.25% |  |  |  |  |  |  |
Additional interest accrual maximum rate per year |  |  |  | 0.50% |  |  |  |  |  |  |
Issuance interest rate |  |  |  | 5.10% |  |  |  |  |  |  |
FE | Promissory Notes | 4.00%, $1,500 Million Notes Maturity 2026 |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of loan |  | $ 1,500 |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold trading days | tradingDay |  | 20 |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold consecutive trading days | tradingDay |  | 30 |  |  |  |  |  |  |  |  |
Debt instrument, convertible, threshold percentage of stock price trigger |  | 130.00% |  |  |  |  |  |  |  |  |
Debt instrument, convertible, business days | tradingDay |  | 5 |  |  |  |  |  |  |  |  |
Threshold trading days measurement period | tradingDay |  | 10 |  |  |  |  |  |  |  |  |
Debt instrument, measurement period percentage |  | 98.00% |  |  |  |  |  |  |  |  |
Debt instrument, conversation price (in dollars per share) | $ / shares |  |  |  | $ 46.81 |  |  |  |  |  |  |
Debt instrument convertible premium |  |  | 0.20 |  |  |  |  |  |  |  |
Repurchase price, percentage |  |  | 1 |  |  |  |  |  |  |  |
Ohio Funding Companies | Phase In Recovery Bonds |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Face amount of loan |  |  |  |  |  |  |  |  |  |  | $ 445
Brookfield II | FET |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gain (loss) from disposal of discontinued operation | $ 7,000 |  |  |  |  |  |  |  |  |  |

X
- Definition Debt Instrument, Additional Interest Accrual, Maximum Rate Per Year + References No definition available. + Details
Name: | fe_DebtInstrumentAdditionalInterestAccrualMaximumRatePerYear
Namespace Prefix: | fe_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Additional Interest Accrual, Rate For First Ninety Days + References No definition available. + Details
Name: | fe_DebtInstrumentAdditionalInterestAccrualRateForFirstNinetyDays
Namespace Prefix: | fe_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Additional Interest Accrual, Rate For Subsequent Ninety Days + References No definition available. + Details
Name: | fe_DebtInstrumentAdditionalInterestAccrualRateForSubsequentNinetyDays
Namespace Prefix: | fe_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Convertible, Business Days + References No definition available. + Details
Name: | fe_DebtInstrumentConvertibleBusinessDays
Namespace Prefix: | fe_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument Convertible, Conversion Price, Premium + References No definition available. + Details
Name: | fe_DebtInstrumentConvertibleConversionPricePremium
Namespace Prefix: | fe_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Convertible, Repurchase Price, Percentage Of Principal Amount + References No definition available. + Details
Name: | fe_DebtInstrumentConvertibleRepurchasePricePercentageOfPrincipalAmount
Namespace Prefix: | fe_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Debt Instrument, Convertible, Threshold Trading Days, Measurement Period + References No definition available. + Details
Name: | fe_DebtInstrumentConvertibleThresholdTradingDaysMeasurementPeriod
Namespace Prefix: | fe_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Measurement Period Percentage + References No definition available. + Details
Name: | fe_DebtInstrumentMeasurementPeriodPercentage
Namespace Prefix: | fe_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective Shelf Registration, Effective Period + References No definition available. + Details
Name: | fe_EffectiveShelfRegistrationEffectivePeriod
Namespace Prefix: | fe_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum Equity To Total Capitalization Ratio To Be Maintained For Payment Of Capital Dividend + References No definition available. + Details
Name: | fe_MinimumEquityToTotalCapitalizationRatioToBeMaintainedForPaymentOfCapitalDividend
Namespace Prefix: | fe_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Subsidiaries That Issued Environmental Control Bonds + References No definition available. + Details
Name: | fe_NumberOfSubsidiariesThatIssuedEnvironmentalControlBonds
Namespace Prefix: | fe_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Preference Stock Shares Outstanding. + References No definition available. + Details
Name: | fe_PreferenceStockSharesOutstanding
Namespace Prefix: | fe_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Principal Default Amount Specified In Debt Covenants. + References No definition available. + Details
Name: | fe_PrincipalDefaultAmountSpecifiedInDebtCovenants
Namespace Prefix: | fe_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The price per share of the conversion feature embedded in the debt instrument. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-5 + Details
Name: | us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(a)(5)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-3 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-7 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-6 + Details
Name: | us-gaap_DebtInstrumentConvertibleConversionRatio1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentConvertibleThresholdTradingDays
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482900/835-30-50-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482925/835-30-45-2 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(a)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types: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 Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(f)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69E -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69E Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69F -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69F Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 11: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1E -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1E -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1E -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1F -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1F -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1F -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1F -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1I -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I Reference 26: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482925/835-30-45-2 Reference 27: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482900/835-30-50-1 + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of tax expense (benefit) on gain (loss) not previously recognized resulting from the disposal of a discontinued operation. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482659/740-20-45-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5C -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483499/205-20-50-5C Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147483475/205-20-45-3B Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483499/205-20-50-1 + Details
Name: | us-gaap_DiscontinuedOperationTaxEffectOfIncomeLossFromDisposalOfDiscontinuedOperation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-4 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represents the current and noncurrent portions of a debt security issued by a state, certain agencies or authorities, a local government, or development corporation to finance the construction of air- or water-pollution control facilities or sewage or solid waste disposal facilities pursuant to federal law. The bonds are backed by the credit of the beneficiary of the financing rather than the credit of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(20)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 + Details
Name: | us-gaap_LongtermPollutionControlBondCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.6-05(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(16)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 14 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-14 + Details
Name: | us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan. + References No definition available. + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesEmployeeBenefitPlan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fe_A4001500MillionNotesMaturity2026Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fe_A2026ConvertibleNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fe_PhaseInRecoveryBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=fe_RegisteredShareholdersDirectorsAndEmployeesOfSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fe_A5.00UnsecuredSeniorNotesMaturing2035Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fe_A4.55UnsecuredSeniorNotesMaturing2030Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fe_A5.10UnsecuredSeniorNotesMaturing2035Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | srt_CounterpartyNameAxis=fe_NorthAmericanTransmissionCompanyIILLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |