COMMITMENTS, GUARANTEES AND CONTINGENCIES - Schedule of Potential Amount of Future Payments (Details) $ in Millions	Mar. 31, 2025 USD ($)
Guarantor Obligations [Line Items]
Guarantor obligations	$ 1,091
JERSEY CENTRAL POWER & LIGHT COMPANY
Guarantor Obligations [Line Items]
Guarantor obligations	48
FE's Guarantees on Behalf of its Consolidated Subsidiaries
Guarantor Obligations [Line Items]
Guarantor obligations	651
FE’s Guarantees on Other Assurances
Guarantor Obligations [Line Items]
Guarantor obligations	440
Deferred compensation arrangements \| FE's Guarantees on Behalf of its Consolidated Subsidiaries
Guarantor Obligations [Line Items]
Guarantor obligations	403
Deferred compensation arrangements \| FE’s Guarantees on Other Assurances
Guarantor Obligations [Line Items]
Guarantor obligations	96
Vehicle leases \| FE's Guarantees on Behalf of its Consolidated Subsidiaries
Guarantor Obligations [Line Items]
Guarantor obligations	75
McElroy Run transfer \| FE's Guarantees on Behalf of its Consolidated Subsidiaries
Guarantor Obligations [Line Items]
Guarantor obligations	144
Other \| FE's Guarantees on Behalf of its Consolidated Subsidiaries
Guarantor Obligations [Line Items]
Guarantor obligations	29
Surety Bonds \| FE’s Guarantees on Other Assurances
Guarantor Obligations [Line Items]
Guarantor obligations	167
Surety Bonds \| FE’s Guarantees on Other Assurances \| JERSEY CENTRAL POWER & LIGHT COMPANY
Guarantor Obligations [Line Items]
Guarantor obligations	20
LOCs \| FE’s Guarantees on Other Assurances
Guarantor Obligations [Line Items]
Guarantor obligations	177
LOCs \| FE’s Guarantees on Other Assurances \| JERSEY CENTRAL POWER & LIGHT COMPANY
Guarantor Obligations [Line Items]
Guarantor obligations	$ 28