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Period Type:

ORGANIZATION AND BASIS OF PRESENTATION - Narrative (Details) individual in Millions, customer in Millions, $ in Millions				3 Months Ended			9 Months Ended
	Jul. 16, 2025 USD ($)	Mar. 24, 2025 employee	Feb. 26, 2025 USD ($) substation transmission_project mi kV	Sep. 30, 2025 USD ($) individual transmissionCenter mi MW	Mar. 31, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) customer individual transmissionCenter mi MW	Sep. 30, 2024 USD ($)	Jul. 31, 2025	Feb. 21, 2025	Dec. 31, 2024 USD ($)
Regulatory Asset [Line Items]
Number of customers \| customer							6.0
Number of regional transmission centers \| transmissionCenter				2			2
Net increase to income before income taxes				$ 610.0		$ 560.0	$ 1,556.0	$ 1,125.0
Capitalized cost of equity				30.0		16.0	76.0	42.0
Capitalized interest				21.0		19.0	55.0	52.0
Equity method investment earnings, net (Note 1)				0.0		21.0	0.0	64.0
Organizational Changes
Regulatory Asset [Line Items]
Expected number of employees reassigned \| employee		200
Percentage of employees reduced from workforce		3.00%
Restructuring charges					$ 26.0
Revision of Prior Period, Adjustment
Regulatory Asset [Line Items]
Net increase to income before income taxes				21.0
Other Sundry Investments
Regulatory Asset [Line Items]
Equity method investments				38.0			38.0				$ 84.0
Global Holding
Regulatory Asset [Line Items]
Equity method investments											45.0
Valley Link
Regulatory Asset [Line Items]
Equity method investments				0.0			0.0				0.0
Valley Link \| PJM
Regulatory Asset [Line Items]
Number of transmission projects \| transmission_project			2
Valley Link \| PJM \| PJM 2024 RTEP Window 1
Regulatory Asset [Line Items]
Transmission solutions to the reliability issues			$ 3,000.0
Valley Link \| PJM \| Putnam County, West Virginia to Frederick, Maryland
Regulatory Asset [Line Items]
Service area \| mi			260
Transmission line electrical potential (in kV) \| kV			765
Number of substations \| substation			2
Valley Link \| PJM \| Campbell County, Virginia and Fauquier County, Virginia
Regulatory Asset [Line Items]
Service area \| mi			155
Transmission line electrical potential (in kV) \| kV			765
Path Wv \| Variable Interest Entity, Not Primary Beneficiary
Regulatory Asset [Line Items]
Equity method investments				$ 17.0			$ 17.0				17.0
Variable interest entities percentage of high voltage transmission line project owned By variable interest entity one in joint venture party one				100.00%			100.00%
Variable interest entities percentage of high voltage transmission line project owned by variable interest entity one in joint venture party two				50.00%			50.00%
VEPCO and Transource Energy, LLC \| Valley Link
Regulatory Asset [Line Items]
Equity method investments			$ 3,000.0
JERSEY CENTRAL POWER & LIGHT COMPANY
Regulatory Asset [Line Items]
Number of customers \| customer							1.2
Transmission services available area populations \| individual				2.8			2.8
Net increase to income before income taxes				$ 160.0		150.0	$ 313.0	216.0
Capitalized cost of equity				8.0		1.0	21.0	3.0
Capitalized interest				4.0		5.0	10.0	16.0
JERSEY CENTRAL POWER & LIGHT COMPANY \| Organizational Changes
Regulatory Asset [Line Items]
Restructuring charges					$ 5.0
JERSEY CENTRAL POWER & LIGHT COMPANY \| Revision of Prior Period, Adjustment
Regulatory Asset [Line Items]
Net increase to income before income taxes				4.0
JERSEY CENTRAL POWER & LIGHT COMPANY \| Other Sundry Investments
Regulatory Asset [Line Items]
Equity method investments				$ 0.0			$ 0.0				$ 0.0
Brookfield \| FET \| North American Transmission Company II LLC
Regulatory Asset [Line Items]
Equity method investment, ownership percentage				49.90%			49.90%
FET \| Valley Link
Regulatory Asset [Line Items]
Equity method investment, ownership percentage										34.00%
FET \| Valley Link \| PJM \| PJM 2024 RTEP Window 1
Regulatory Asset [Line Items]
Transmission solutions to the reliability issues			$ 1,000.0
FEV \| Global Holding
Regulatory Asset [Line Items]
Equity method investments				$ 47.5			$ 47.5
Investment ownership percentage	33.33%								33.33%
Ownership percentage sold	0.3333
Proceeds from investments sold	$ 47.5
FEV \| Global Holding \| Variable Interest Entity, Not Primary Beneficiary
Regulatory Asset [Line Items]
Proceeds from dividends received								60.0
Dominion HV \| Valley Link
Regulatory Asset [Line Items]
Equity method investment, ownership percentage										30.00%
Transource \| Valley Link
Regulatory Asset [Line Items]
Equity method investment, ownership percentage										36.00%
Regulated Transmission
Regulatory Asset [Line Items]
Service area \| mi				24,000			24,000
Integrated Segment
Regulatory Asset [Line Items]
Number of customers \| customer							2.0
Plant capacity (in MW's) \| MW				3,610			3,610
Corporate and Other \| FEV \| Global Holding \| Other Nonoperating Income (Expense)
Regulatory Asset [Line Items]
Equity method investment earnings, net (Note 1)						$ 21.0		$ 63.0