ACQUISITIONS, DISPOSITIONS AND IMPAIRMENTS (Details) $ in Millions	1 Months Ended									3 Months Ended				12 Months Ended
	Dec. 31, 2024 USD ($) MW	Sep. 30, 2024 USD ($)	Feb. 29, 2024 USD ($)	Dec. 31, 2023 USD ($)	Aug. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Jan. 31, 2022 USD ($)	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2024 USD ($) MW	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2020 property MW	Oct. 31, 2021 USD ($)	Dec. 31, 2019 partnership counterparty joint_venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges														$ 142.5	$ 85.6	$ 48.8
Loss on the Sale of the Competitive Contracted Renewables Portfolio														0.0	92.7	0.0
Other than temporary impairment														0.0	19.0	188.0
Kentucky Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges																363.0
Useful life						30 years					30 years
SOUTHWESTERN ELECTRIC POWER COMPANY
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges														$ 0.0	85.6	$ 0.0
VIU
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Wind generation MW | MW																	1,484
Enterprise value																		$ 2,850.0
Decrease in expected transaction costs											$ 28.0
Pretax reduction in investment basis						$ 335.0					335.0
VIU | Diversion Wind Energy, LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Wind generation MW | MW	201
Percentage of shares acquired	100.00%													100.00%
Property, plant and equipment, gross	$ 423.0													$ 423.0
Operating lease	20.0													20.0
Asset retirement obligations	$ 6.0													$ 6.0
VIU | Proceeds for KY Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Enterprise value												$ 2,646.0
VIU | PUBLIC SERVICE COMPANY OF OKLAHOMA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business combination, consideration transferred						146.0
VIU | SOUTHWESTERN ELECTRIC POWER COMPANY | Turk Generating Plant
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges				$ 86.0
VIU | SOUTHWESTERN ELECTRIC POWER COMPANY | Dolet Hills Power Station
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges									$ 12.0
VIU | Traverse
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Wind generation MW | MW														998
Payments to acquire facilities								$ 1,200.0
VIU | Maverick
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Wind generation MW | MW														287
VIU | Sundance
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Wind generation MW | MW														199
VIU | North Central Wind Energy Facilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | property																	3
Payments to acquire facilities														$ 2,000.0
VIU | PUBLIC SERVICE COMPANY OF OKLAHOMA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of voting interest acquired	45.50%													45.50%
VIU | SOUTHWESTERN ELECTRIC POWER COMPANY
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of voting interest acquired	54.50%													54.50%
Generation & Marketing | Disposal Group, Disposed of by Sale, Not Discontinued Operations | AEP OnSite Partners
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposal of business		$ 318.0
Generation & Marketing | Disposal Group, Disposed of by Sale, Not Discontinued Operations | New Mexico Renewable Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposal of business			$ 107.0
AEPTHCo
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Enterprise value																		$ 2,850.0
Pretax reduction in investment basis						$ 335.0					$ 335.0
AEPTHCo | Proceeds for KY Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Enterprise value												2,646.0
G&M
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on the Sale of the Competitive Contracted Renewables Portfolio															93.0
Gain (loss) on disposal of business, net of tax															$ 73.0
G&M | New Mexico Renewable Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other than temporary impairment										$ 19.0
G&M | BP Wind Energy
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other than temporary impairment												$ 2.0	$ 186.0
Ownership percentage																			50.00%
Number of tax equity partnerships acquired interests in | partnership																			2
Number of counterparties with long-term power purchase agreement | counterparty																			3
Number of non-consolidated joint ventures acquired interests in | joint_venture																			5
G&M | Proceeds of Mineral Rights Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposition of other assets													$ 116.0
G&M | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Competitive Contracted Renewables
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from disposal of business					$ 1,200.0
G&M | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Proceeds of Mineral Rights Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of acquisition							$ 120.0