XML 104 R88.htm IDEA: XBRL DOCUMENT v3.25.0.1

FAIR VALUE MEASUREMENTS - Proceeds from the Sale of Investments in Available-for-sale Debt Securities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Sale Proceeds	$ 121	$ 38	$ 48
Realized Gains	0	0	8
Realized Losses	(15)	(3)	(13)
Interest and Dividend Income	$ 13	$ 12	$ 11

X

- Definition

Debt And Equity Securities, Realized Gain (Loss), Sales Proceeds

+ References

No definition available.

+ Details

Name:	fe_DebtAndEquitySecuritiesRealizedGainLossSalesProceeds
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Debt And Equity Securities, Realized Gains

+ References

No definition available.

+ Details

Name:	fe_DebtAndEquitySecuritiesRealizedGains
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Debt And Equity Securities, Realized Losses

+ References

No definition available.

+ Details

Name:	fe_DebtAndEquitySecuritiesRealizedLosses
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Investment Income From Trusts

+ References

No definition available.

+ Details

Name:	fe_InvestmentIncomeFromTrusts
Namespace Prefix:	fe_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_FairValueDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration