DERIVATIVES AND HEDGING - Schedule of Location and Fair Value of Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Derivative [Line Items]
Total Assets	$ 1,317.5	$ 1,039.1
Total Liabilities	993.8	780.4
Total MTM Derivative Contract Net Assets (Liabilities) Recognized	323.7	258.7
Current Risk Management Assets
Derivative [Line Items]
Total Assets	742.7	479.1
Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	574.8	560.0
Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	540.4	351.7
Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	453.4	428.7
AEP Texas
Derivative [Line Items]
Total Assets	0.0	0.0
Total Liabilities	0.2	0.3
Total MTM Derivative Contract Net Assets (Liabilities) Recognized	(0.2)	(0.3)
AEP Texas | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
AEP Texas | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
AEP Texas | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.2	0.3
AEP Texas | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
APCo
Derivative [Line Items]
Total Assets	34.9	42.2
Total Liabilities	6.4	7.4
Total MTM Derivative Contract Net Assets (Liabilities) Recognized	28.5	34.8
APCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	30.9	40.2
APCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	4.0	2.0
APCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	5.6	6.6
APCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.8	0.8
I&M
Derivative [Line Items]
Total Assets	12.2	29.7
Total Liabilities	29.5	12.6
Total MTM Derivative Contract Net Assets (Liabilities) Recognized	(17.3)	17.1
I&M | Current Risk Management Assets
Derivative [Line Items]
Total Assets	12.2	28.5
I&M | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	1.2
I&M | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	29.5	10.5
I&M | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	2.1
OPCo
Derivative [Line Items]
Total Assets	0.0
Total Liabilities	51.3	47.7
Total MTM Derivative Contract Net Assets (Liabilities) Recognized	(51.3)	(47.7)
OPCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
OPCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
OPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	5.2	7.5
OPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	46.1	40.2
PSO
Derivative [Line Items]
Total Assets	36.4	23.9
Total Liabilities	3.3	7.8
Total MTM Derivative Contract Net Assets (Liabilities) Recognized	33.1	16.1
PSO | Current Risk Management Assets
Derivative [Line Items]
Total Assets	34.6	22.3
PSO | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	1.8	1.6
PSO | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	1.2	7.6
PSO | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	2.1	0.2
SWEPCo
Derivative [Line Items]
Total Assets	18.8	19.1
Total Liabilities	1.4	3.4
Total MTM Derivative Contract Net Assets (Liabilities) Recognized	17.4	15.7
SWEPCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	18.3	19.1
SWEPCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.5	0.0
SWEPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.5	3.4
SWEPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.9	0.0
Commodity | Not Designated as Hedging Instrument | Current Risk Management Assets
Derivative [Line Items]
Total Assets	649.0	425.0
Commodity | Not Designated as Hedging Instrument | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	490.8	475.4
Commodity | Not Designated as Hedging Instrument | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	493.6	304.1
Commodity | Not Designated as Hedging Instrument | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	410.8	390.7
Commodity | Not Designated as Hedging Instrument | AEP Texas | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Not Designated as Hedging Instrument | AEP Texas | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Not Designated as Hedging Instrument | AEP Texas | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.2	0.3
Commodity | Not Designated as Hedging Instrument | AEP Texas | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Not Designated as Hedging Instrument | APCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	30.9	40.2
Commodity | Not Designated as Hedging Instrument | APCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	4.0	2.0
Commodity | Not Designated as Hedging Instrument | APCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	5.6	6.6
Commodity | Not Designated as Hedging Instrument | APCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.8	0.8
Commodity | Not Designated as Hedging Instrument | I&M | Current Risk Management Assets
Derivative [Line Items]
Total Assets	12.2	28.5
Commodity | Not Designated as Hedging Instrument | I&M | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	1.2
Commodity | Not Designated as Hedging Instrument | I&M | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	29.5	10.5
Commodity | Not Designated as Hedging Instrument | I&M | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	2.1
Commodity | Not Designated as Hedging Instrument | OPCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Not Designated as Hedging Instrument | OPCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Not Designated as Hedging Instrument | OPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	5.2	7.5
Commodity | Not Designated as Hedging Instrument | OPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	46.1	40.2
Commodity | Not Designated as Hedging Instrument | PSO | Current Risk Management Assets
Derivative [Line Items]
Total Assets	34.6	22.3
Commodity | Not Designated as Hedging Instrument | PSO | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	1.8	1.6
Commodity | Not Designated as Hedging Instrument | PSO | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	1.2	7.6
Commodity | Not Designated as Hedging Instrument | PSO | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	2.1	0.2
Commodity | Not Designated as Hedging Instrument | SWEPCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	18.3	19.1
Commodity | Not Designated as Hedging Instrument | SWEPCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.5	0.0
Commodity | Not Designated as Hedging Instrument | SWEPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.5	3.4
Commodity | Not Designated as Hedging Instrument | SWEPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.9	0.0
Commodity | Designated as Hedging Instrument | Current Risk Management Assets
Derivative [Line Items]
Total Assets	93.7	54.1
Commodity | Designated as Hedging Instrument | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	84.0	84.6
Commodity | Designated as Hedging Instrument | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	9.6	11.3
Commodity | Designated as Hedging Instrument | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	11.4	2.7
Commodity | Designated as Hedging Instrument | AEP Texas | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | AEP Texas | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | AEP Texas | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | AEP Texas | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | APCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | APCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | APCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | APCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | I&M | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | I&M | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | I&M | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | I&M | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | OPCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | OPCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | OPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | OPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | PSO | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | PSO | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | PSO | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | PSO | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | SWEPCo | Current Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | SWEPCo | Long-term Risk Management Assets
Derivative [Line Items]
Total Assets	0.0	0.0
Commodity | Designated as Hedging Instrument | SWEPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Commodity | Designated as Hedging Instrument | SWEPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	37.2	36.3
Interest Rate (USD) | Designated as Hedging Instrument | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	31.2	35.3
Interest Rate (USD) | Designated as Hedging Instrument | AEP Texas | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | AEP Texas | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | APCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | APCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | I&M | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | I&M | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | OPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | OPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | PSO | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | PSO | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | SWEPCo | Current Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	0.0	0.0
Interest Rate (USD) | Designated as Hedging Instrument | SWEPCo | Long-term Risk Management Liabilities
Derivative [Line Items]
Total Liabilities	$ 0.0	$ 0.0