REGULATORY MATTERS - Pennsylvania and West Virginia (Details) $ in Thousands											3 Months Ended	9 Months Ended
	Aug. 31, 2023 USD ($)	Aug. 30, 2023 USD ($)	Aug. 22, 2023 USD ($)	May 31, 2023 USD ($)	Jan. 13, 2023 USD ($)	Aug. 25, 2022 USD ($) MW	May 01, 2022 USD ($)	Mar. 17, 2022	Nov. 22, 2021 site MW	Jan. 16, 2020 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 proposal	Dec. 31, 2022 USD ($)
FERC | Regulated Transmission
Regulatory Matters [Line Items]
Pre-tax impairment of regulatory asset													$ 25,000
Transmission Related Vegetation Management Programs | FERC | FE
Regulatory Matters [Line Items]
Customer refund											$ 45,000
Customer refund, net											34,000
Capital assets											195,000
Operating expense											90,000
Operating expense, net											67,000
Reduction in operating expense											$ 160,000
Pennsylvania | PPUC | Pennsylvania Companies
Regulatory Matters [Line Items]
Recovery period		5 years
Public utilities, settlement amount		$ 650
Pennsylvania | DSP June 2019- May 2023
Regulatory Matters [Line Items]
Number of RFP's | proposal												2
RFP term												2 years
Pennsylvania | EE&C Phase IV | PPUC | ME
Regulatory Matters [Line Items]
Demand reduction targets												2.90%
Energy consumption reduction targets												3.10%
Pennsylvania | EE&C Phase IV | PPUC | PN
Regulatory Matters [Line Items]
Demand reduction targets												3.30%
Energy consumption reduction targets												3.00%
Pennsylvania | EE&C Phase IV | PPUC | Penn
Regulatory Matters [Line Items]
Demand reduction targets												2.00%
Energy consumption reduction targets												2.70%
Pennsylvania | EE&C Phase IV | PPUC | WP
Regulatory Matters [Line Items]
Demand reduction targets												2.50%
Energy consumption reduction targets												2.40%
Pennsylvania | New LTIIPs | PPUC | Pennsylvania Companies
Regulatory Matters [Line Items]
Recovery period										5 years
Amount of requested rate increase										$ 572,000
West Virginia | WVPSC | MP and PE
Regulatory Matters [Line Items]
Amount of requested rate increase	$ 17,000			$ 207,000
Requested amount of annual depreciation expense				$ 76,000	$ 76,000
Increase in annual amount of depreciation expense			$ 33,000
Recovery period for expenditures for cost recovery program	2 years
West Virginia | WVPSC | MP and PE | Solar Generation Project
Regulatory Matters [Line Items]
Plant capacity (in MW's) | MW									50
Percent of subscriptions required prior to commencement of construction								85.00%
Number of proposed solar sites | site									3
Number of solar sites | site									5
Expected cost of the program							$ 110,000
Number of approved solar sites | site									3
West Virginia | ENEC | WVPSC | MP and PE
Regulatory Matters [Line Items]
Amount of requested rate increase	$ 167,500					$ 183,800
Under recovered amount, percent	9.90%					12.20%
Supplemental requested decrease	$ 267,000					$ 145,000
Approved amount of annual increase						$ 92,000
Approved ROE	4.00%					4.00%
Public utilities, requested under recovery, not recovered, amount	$ 75,600
Plant capacity (in MW's) | MW						1,200
Public utilities, deferred requested rate Increase amount	$ 92,000
Three month period | Pennsylvania | DSP June 2019- May 2023
Regulatory Matters [Line Items]
Term of energy contract												3 months
Twelve month period | Pennsylvania | DSP June 2019- May 2023
Regulatory Matters [Line Items]
Term of energy contract												12 months
Twenty-four month period | Pennsylvania | DSP June 2019- May 2023
Regulatory Matters [Line Items]
Term of energy contract												24 months