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ORGANIZATION AND BASIS OF PRESENTATION (Details) individual in Millions, customer in Millions, $ in Millions				3 Months Ended			6 Months Ended
	Jul. 16, 2025 USD ($)	Mar. 24, 2025 employee	Feb. 26, 2025 USD ($) substation transmission_project mi kV	Jun. 30, 2025 USD ($) individual transmissionCenter mi MW	Mar. 31, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) customer individual transmissionCenter mi MW	Jun. 30, 2024 USD ($)	Feb. 21, 2025	Dec. 31, 2024 USD ($)
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				$ 406.0		$ 163.0	$ 946.0	$ 565.0
Capitalized cost of equity				24.0		13.0	46.0	26.0
Capitalized interest				18.0		16.0	34.0	33.0
Equity method investment earnings, net (Note 1)				0.0		22.0	0.0	43.0
Revision of Prior Period, Adjustment
Regulatory Asset [Line Items]
Net increase to income before income taxes				21.0
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
Other Sundry Investments
Regulatory Asset [Line Items]
Equity method investments				85.0			85.0			$ 84.0
Global Holding
Regulatory Asset [Line Items]
Equity method investments				47.5			47.5			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 \| 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
Valley Link \| PJM 2024 RTEP Window 1 \| PJM
Regulatory Asset [Line Items]
Transmission solutions to the reliability issues			$ 3,000.0
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				$ 88.0		78.0	$ 153.0	66.0
Capitalized cost of equity				7.0		1.0	13.0	2.0
Capitalized interest				3.0		5.0	6.0	11.0
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 \| Organizational Changes
Regulatory Asset [Line Items]
Restructuring charges					$ 5.0
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 2024 RTEP Window 1 \| PJM
Regulatory Asset [Line Items]
Transmission solutions to the reliability issues			$ 1,020.0
FEV \| Global Holding
Regulatory Asset [Line Items]
Equity method investments				$ 47.5			$ 47.5
Investment ownership percentage				33.33%			33.33%
FEV \| Global Holding \| Subsequent Event
Regulatory Asset [Line Items]
Ownership percentage sold	0.3333
Proceeds from investments sold	$ 47.5
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		$ 42.0