DERIVATIVES AND HEDGING - Schedule of Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Assets:
Gross Amounts Recognized	$ 1,317.5	$ 1,039.1
Derivative Asset, Current	309.4	210.4
Long-term Risk Management Assets, Net	246.5	289.1
Total Assets	555.9	499.5
Liabilities:
Gross Amounts Recognized	993.8	780.4
Current Risk Management Liabilities, Net	132.6	100.0
Long-term Risk Management Liabilities, Net	198.3	224.4
Total Liabilities	330.9	324.4
Total MTM Derivative Contract Net Assets (Liabilities)	225.0	175.1
Current Risk Management Assets
Assets:
Gross Amounts Recognized	742.7	479.1
Gross Amounts Offset	(433.3)	(268.7)
Long-term Risk Management Assets
Assets:
Gross Amounts Recognized	574.8	560.0
Gross Amounts Offset	(328.3)	(270.9)
Current Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	540.4	351.7
Gross Amounts Offset	(407.8)	(251.7)
Long-term Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	453.4	428.7
Gross Amounts Offset	(255.1)	(204.3)
AEP Texas
Assets:
Gross Amounts Recognized	0.0	0.0
Derivative Asset, Current	0.0	0.0
Long-term Risk Management Assets, Net	0.0	0.0
Total Assets	0.0	0.0
Liabilities:
Gross Amounts Recognized	0.2	0.3
Current Risk Management Liabilities, Net	0.0	0.0
Long-term Risk Management Liabilities, Net	0.0	0.0
Total Liabilities	0.0	0.0
Total MTM Derivative Contract Net Assets (Liabilities)	0.0	0.0
AEP Texas | Current Risk Management Assets
Assets:
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
AEP Texas | Long-term Risk Management Assets
Assets:
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
AEP Texas | Current Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	0.2	0.3
Gross Amounts Offset	(0.2)	(0.3)
AEP Texas | Long-term Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
APCo
Assets:
Gross Amounts Recognized	34.9	42.2
Derivative Asset, Current	28.3	35.7
Long-term Risk Management Assets, Net	3.2	1.4
Total Assets	31.5	37.1
Liabilities:
Gross Amounts Recognized	6.4	7.4
Current Risk Management Liabilities, Net	2.9	2.0
Long-term Risk Management Liabilities, Net	0.0	0.2
Total Liabilities	2.9	2.2
Total MTM Derivative Contract Net Assets (Liabilities)	28.6	34.9
APCo | Current Risk Management Assets
Assets:
Gross Amounts Recognized	30.9	40.2
Gross Amounts Offset	(2.6)	(4.5)
APCo | Long-term Risk Management Assets
Assets:
Gross Amounts Recognized	4.0	2.0
Gross Amounts Offset	(0.8)	(0.6)
APCo | Current Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	5.6	6.6
Gross Amounts Offset	(2.7)	(4.6)
APCo | Long-term Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	0.8	0.8
Gross Amounts Offset	(0.8)	(0.6)
I&M
Assets:
Gross Amounts Recognized	12.2	29.7
Derivative Asset, Current	3.9	18.4
Long-term Risk Management Assets, Net	0.0	0.0
Total Assets	3.9	18.4
Liabilities:
Gross Amounts Recognized	29.5	12.6
Current Risk Management Liabilities, Net	3.2	0.3
Long-term Risk Management Liabilities, Net	0.0	0.4
Total Liabilities	3.2	0.7
Total MTM Derivative Contract Net Assets (Liabilities)	0.7	17.7
I&M | Current Risk Management Assets
Assets:
Gross Amounts Recognized	12.2	28.5
Gross Amounts Offset	(8.3)	(10.1)
I&M | Long-term Risk Management Assets
Assets:
Gross Amounts Recognized	0.0	1.2
Gross Amounts Offset	0.0	(1.2)
I&M | Current Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	29.5	10.5
Gross Amounts Offset	(26.3)	(10.2)
I&M | Long-term Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	0.0	2.1
Gross Amounts Offset	0.0	(1.7)
OPCo
Assets:
Gross Amounts Recognized	0.0
Derivative Asset, Current	0.0	0.0
Long-term Risk Management Assets, Net	0.0	0.0
Total Assets	0.0	0.0
Liabilities:
Gross Amounts Recognized	51.3	47.7
Current Risk Management Liabilities, Net	5.1	7.3
Long-term Risk Management Liabilities, Net	46.1	40.2
Total Liabilities	51.2	47.5
Total MTM Derivative Contract Net Assets (Liabilities)	(51.2)	(47.5)
OPCo | Current Risk Management Assets
Assets:
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
OPCo | Long-term Risk Management Assets
Assets:
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
OPCo | Current Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	5.2	7.5
Gross Amounts Offset	(0.1)	(0.2)
OPCo | Long-term Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	46.1	40.2
Gross Amounts Offset	0.0	0.0
PSO
Assets:
Gross Amounts Recognized	36.4	23.9
Derivative Asset, Current	33.8	20.6
Long-term Risk Management Assets, Net	0.4	1.4
Total Assets	34.2	22.0
Liabilities:
Gross Amounts Recognized	3.3	7.8
Current Risk Management Liabilities, Net	0.4	5.8
Long-term Risk Management Liabilities, Net	0.7	0.0
Total Liabilities	1.1	5.8
Total MTM Derivative Contract Net Assets (Liabilities)	33.1	16.2
PSO | Current Risk Management Assets
Assets:
Gross Amounts Recognized	34.6	22.3
Gross Amounts Offset	(0.8)	(1.7)
PSO | Long-term Risk Management Assets
Assets:
Gross Amounts Recognized	1.8	1.6
Gross Amounts Offset	(1.4)	(0.2)
PSO | Current Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	1.2	7.6
Gross Amounts Offset	(0.8)	(1.8)
PSO | Long-term Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	2.1	0.2
Gross Amounts Offset	(1.4)	(0.2)
SWEPCo
Assets:
Gross Amounts Recognized	18.8	19.1
Derivative Asset, Current	17.9	18.1
Long-term Risk Management Assets, Net	0.0	0.0
Total Assets	17.9	18.1
Liabilities:
Gross Amounts Recognized	1.4	3.4
Current Risk Management Liabilities, Net	0.0	2.3
Long-term Risk Management Liabilities, Net	0.4	0.0
Total Liabilities	0.4	2.3
Total MTM Derivative Contract Net Assets (Liabilities)	17.5	15.8
SWEPCo | Current Risk Management Assets
Assets:
Gross Amounts Recognized	18.3	19.1
Gross Amounts Offset	(0.4)	(1.0)
SWEPCo | Long-term Risk Management Assets
Assets:
Gross Amounts Recognized	0.5	0.0
Gross Amounts Offset	(0.5)	0.0
SWEPCo | Current Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	0.5	3.4
Gross Amounts Offset	(0.5)	(1.1)
SWEPCo | Long-term Risk Management Liabilities
Liabilities:
Gross Amounts Recognized	0.9	0.0
Gross Amounts Offset	$ (0.5)	$ 0.0