DERIVATIVES AND HEDGING - Schedule of Gain (Loss) Recognized on Risk Management Contracts (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	$ (39.9)	$ (3.1)
Regulatory Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	52.8	13.5
Regulatory Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	80.3	52.7
Revenues | Vertically Integrated Utilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	(32.6)	(25.7)
Revenues | Generation & Marketing
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	(143.2)	(44.7)
Revenues | Electric Generation, Transmission and Distribution
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	3.0	1.0
Other Operation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	(0.1)
Maintenance
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	(0.1)	0.1
AEP Texas
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.1	0.4
AEP Texas | Regulatory Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.1	0.2
AEP Texas | Regulatory Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.2
AEP Texas | Revenues | Vertically Integrated Utilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
AEP Texas | Revenues | Generation & Marketing
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
AEP Texas | Revenues | Electric Generation, Transmission and Distribution
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
AEP Texas | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
AEP Texas | Other Operation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0
AEP Texas | Maintenance
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
APCo
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	42.4	14.0
APCo | Regulatory Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.1	(0.1)
APCo | Regulatory Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	39.3	13.1
APCo | Revenues | Vertically Integrated Utilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
APCo | Revenues | Generation & Marketing
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
APCo | Revenues | Electric Generation, Transmission and Distribution
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.1	0.1
APCo | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	2.9	0.9
APCo | Other Operation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0
APCo | Maintenance
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
I&M
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	(28.3)	(25.2)
I&M | Regulatory Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	(1.6)
I&M | Regulatory Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	4.3	2.2
I&M | Revenues | Vertically Integrated Utilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
I&M | Revenues | Generation & Marketing
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
I&M | Revenues | Electric Generation, Transmission and Distribution
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	(32.7)	(25.8)
I&M | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.1	0.0
I&M | Other Operation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0
I&M | Maintenance
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
OPCo
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	50.7	8.6
OPCo | Regulatory Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	47.5	8.6
OPCo | Regulatory Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	3.2	0.0
OPCo | Revenues | Vertically Integrated Utilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
OPCo | Revenues | Generation & Marketing
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
OPCo | Revenues | Electric Generation, Transmission and Distribution
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
OPCo | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
OPCo | Other Operation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0
OPCo | Maintenance
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
PSO
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	15.5	17.1
PSO | Regulatory Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	3.8	(1.2)
PSO | Regulatory Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	11.7	18.3
PSO | Revenues | Vertically Integrated Utilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
PSO | Revenues | Generation & Marketing
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
PSO | Revenues | Electric Generation, Transmission and Distribution
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
PSO | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
PSO | Other Operation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0
PSO | Maintenance
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
SWEPCo
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	15.0	19.9
SWEPCo | Regulatory Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	1.1	4.9
SWEPCo | Regulatory Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	13.9	15.0
SWEPCo | Revenues | Vertically Integrated Utilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
SWEPCo | Revenues | Generation & Marketing
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
SWEPCo | Revenues | Electric Generation, Transmission and Distribution
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
SWEPCo | Purchased Electricity, Fuel and Other Consumables Used for Electric Generation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0	0.0
SWEPCo | Other Operation
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	0.0
SWEPCo | Maintenance
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total Gain (Loss) on Risk Management Contracts	$ 0.0	$ 0.0