DERIVATIVES AND HEDGING - Schedule of Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Total Assets
Gross Amounts Recognized	$ 1,039.1	$ 1,167.4
Current Risk Management Assets	210.4	217.5
Long-term Risk Management Assets	289.1	321.2
Total Risk Management Assets	499.5	538.7
Total Liabilities
Gross Amounts Recognized	780.4	1,083.4
Current Risk Management Liabilities	100.0	229.6
Long-term Risk Management Liabilities	224.4	241.8
Total Risk Management Liabilities	324.4	471.4
Total MTM Derivative Contract Net Assets (Liabilities)	175.1	67.3
Prepaid Expenses and Other Current Assets
Total Assets
Gross Amounts Recognized	479.1	611.8
Gross Amounts Offset	(268.7)	(394.3)
Other Noncurrent Assets
Total Assets
Gross Amounts Recognized	560.0	555.6
Gross Amounts Offset	(270.9)	(234.4)
Other Current Liabilities
Total Liabilities
Gross Amounts Recognized	351.7	646.7
Gross Amounts Offset	(251.7)	(417.1)
Other Noncurrent Liabilities
Total Liabilities
Gross Amounts Recognized	428.7	436.7
Gross Amounts Offset	(204.3)	(194.9)
AEP Texas
Total Assets
Gross Amounts Recognized	0.0	0.0
Current Risk Management Assets	0.0	0.0
Long-term Risk Management Assets	0.0	0.0
Total Risk Management Assets	0.0	0.0
Total Liabilities
Gross Amounts Recognized	0.3	2.9
Current Risk Management Liabilities	0.0	2.7
Long-term Risk Management Liabilities	0.0	0.0
Total Risk Management Liabilities	0.0	2.7
Total MTM Derivative Contract Net Assets (Liabilities)	0.0	(2.7)
AEP Texas | Prepaid Expenses and Other Current Assets
Total Assets
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
AEP Texas | Other Noncurrent Assets
Total Assets
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
AEP Texas | Other Current Liabilities
Total Liabilities
Gross Amounts Recognized	0.3	2.9
Gross Amounts Offset	(0.3)	(0.2)
AEP Texas | Other Noncurrent Liabilities
Total Liabilities
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
APCo
Total Assets
Gross Amounts Recognized	42.2	24.9
Current Risk Management Assets	35.7	22.4
Long-term Risk Management Assets	1.4	0.0
Total Risk Management Assets	37.1	22.4
Total Liabilities
Gross Amounts Recognized	7.4	25.4
Current Risk Management Liabilities	2.0	15.9
Long-term Risk Management Liabilities	0.2	6.6
Total Risk Management Liabilities	2.2	22.5
Total MTM Derivative Contract Net Assets (Liabilities)	34.9	(0.1)
APCo | Prepaid Expenses and Other Current Assets
Total Assets
Gross Amounts Recognized	40.2	24.6
Gross Amounts Offset	(4.5)	(2.2)
APCo | Other Noncurrent Assets
Total Assets
Gross Amounts Recognized	2.0	0.3
Gross Amounts Offset	(0.6)	(0.3)
APCo | Other Current Liabilities
Total Liabilities
Gross Amounts Recognized	6.6	18.5
Gross Amounts Offset	(4.6)	(2.6)
APCo | Other Noncurrent Liabilities
Total Liabilities
Gross Amounts Recognized	0.8	6.9
Gross Amounts Offset	(0.6)	(0.3)
I&M
Total Assets
Gross Amounts Recognized	29.7	42.1
Current Risk Management Assets	18.4	27.8
Long-term Risk Management Assets	0.0	11.8
Total Risk Management Assets	18.4	39.6
Total Liabilities
Gross Amounts Recognized	12.6	5.6
Current Risk Management Liabilities	0.3	2.0
Long-term Risk Management Liabilities	0.4	0.0
Total Risk Management Liabilities	0.7	2.0
Total MTM Derivative Contract Net Assets (Liabilities)	17.7	37.6
I&M | Prepaid Expenses and Other Current Assets
Total Assets
Gross Amounts Recognized	28.5	30.1
Gross Amounts Offset	(10.1)	(2.3)
I&M | Other Noncurrent Assets
Total Assets
Gross Amounts Recognized	1.2	12.0
Gross Amounts Offset	(1.2)	(0.2)
I&M | Other Current Liabilities
Total Liabilities
Gross Amounts Recognized	10.5	5.4
Gross Amounts Offset	(10.2)	(3.4)
I&M | Other Noncurrent Liabilities
Total Liabilities
Gross Amounts Recognized	2.1	0.2
Gross Amounts Offset	(1.7)	(0.2)
OPCo
Total Assets
Gross Amounts Recognized	0.0	0.0
Current Risk Management Assets	0.0	0.0
Long-term Risk Management Assets	0.0	0.0
Total Risk Management Assets	0.0	0.0
Total Liabilities
Gross Amounts Recognized	47.7	50.8
Current Risk Management Liabilities	7.3	6.8
Long-term Risk Management Liabilities	40.2	43.9
Total Risk Management Liabilities	47.5	50.7
Total MTM Derivative Contract Net Assets (Liabilities)	(47.5)	(50.7)
OPCo | Prepaid Expenses and Other Current Assets
Total Assets
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
OPCo | Other Noncurrent Assets
Total Assets
Gross Amounts Recognized	0.0	0.0
Gross Amounts Offset	0.0	0.0
OPCo | Other Current Liabilities
Total Liabilities
Gross Amounts Recognized	7.5	6.9
Gross Amounts Offset	(0.2)	(0.1)
OPCo | Other Noncurrent Liabilities
Total Liabilities
Gross Amounts Recognized	40.2	43.9
Gross Amounts Offset	0.0	0.0
PSO
Total Assets
Gross Amounts Recognized	23.9	19.7
Current Risk Management Assets	20.6	19.0
Long-term Risk Management Assets	1.4	0.0
Total Risk Management Assets	22.0	19.0
Total Liabilities
Gross Amounts Recognized	7.8	30.7
Current Risk Management Liabilities	5.8	28.9
Long-term Risk Management Liabilities	0.0	1.0
Total Risk Management Liabilities	5.8	29.9
Total MTM Derivative Contract Net Assets (Liabilities)	16.2	(10.9)
PSO | Prepaid Expenses and Other Current Assets
Total Assets
Gross Amounts Recognized	22.3	19.7
Gross Amounts Offset	(1.7)	(0.7)
PSO | Other Noncurrent Assets
Total Assets
Gross Amounts Recognized	1.6	0.0
Gross Amounts Offset	(0.2)	0.0
PSO | Other Current Liabilities
Total Liabilities
Gross Amounts Recognized	7.6	29.7
Gross Amounts Offset	(1.8)	(0.8)
PSO | Other Noncurrent Liabilities
Total Liabilities
Gross Amounts Recognized	0.2	1.0
Gross Amounts Offset	(0.2)	0.0
SWEPCo
Total Assets
Gross Amounts Recognized	19.1	12.5
Current Risk Management Assets	18.1	11.6
Long-term Risk Management Assets	0.0	0.0
Total Risk Management Assets	18.1	11.6
Total Liabilities
Gross Amounts Recognized	3.4	16.6
Current Risk Management Liabilities	2.3	14.4
Long-term Risk Management Liabilities	0.0	1.2
Total Risk Management Liabilities	2.3	15.6
Total MTM Derivative Contract Net Assets (Liabilities)	15.8	(4.0)
SWEPCo | Prepaid Expenses and Other Current Assets
Total Assets
Gross Amounts Recognized	19.1	12.0
Gross Amounts Offset	(1.0)	(0.4)
SWEPCo | Other Noncurrent Assets
Total Assets
Gross Amounts Recognized	0.0	0.5
Gross Amounts Offset	0.0	(0.5)
SWEPCo | Other Current Liabilities
Total Liabilities
Gross Amounts Recognized	3.4	14.9
Gross Amounts Offset	(1.1)	(0.5)
SWEPCo | Other Noncurrent Liabilities
Total Liabilities
Gross Amounts Recognized	0.0	1.7
Gross Amounts Offset	$ 0.0	$ (0.5)