ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Depreciation and Amortization (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	$ 3,148.6	$ 2,927.5	$ 3,072.8
Amortization of Certain Securitized Assets	91.3	91.9	93.3
Amortization of Regulatory Assets and Liabilities	50.0	71.0	36.7
Depreciation and Amortization	3,289.9	3,090.4	3,202.8
AEP Texas
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	405.9	380.0	363.5
Amortization of Certain Securitized Assets	91.3	91.9	93.3
Amortization of Regulatory Assets and Liabilities	(3.7)	(3.4)	(4.4)
Depreciation and Amortization	493.5	468.5	452.4
AEPTCo
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	430.9	393.8	346.2
Amortization of Certain Securitized Assets	0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities	0.0	0.0	0.0
Depreciation and Amortization	430.9	393.8	346.2
APCo
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	600.4	571.1	576.1
Amortization of Certain Securitized Assets	0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities	2.0	0.8	(0.2)
Depreciation and Amortization	602.4	571.9	575.9
I&M
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	456.2	439.8	511.9
Amortization of Certain Securitized Assets	0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities	24.9	30.2	15.3
Depreciation and Amortization	481.1	470.0	527.2
OPCo
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	386.0	315.8	293.1
Amortization of Certain Securitized Assets	0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities	0.0	0.4	1.2
Depreciation and Amortization	386.0	316.2	294.3
PSO
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	263.1	240.3	226.2
Amortization of Certain Securitized Assets	0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities	9.1	15.2	3.9
Depreciation and Amortization	272.2	255.5	230.1
SWEPCo
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and Amortization of Property, Plant and Equipment	375.4	323.4	319.3
Amortization of Certain Securitized Assets	0.0	0.0	0.0
Amortization of Regulatory Assets and Liabilities	13.9	19.4	5.5
Depreciation and Amortization	$ 389.3	$ 342.8	$ 324.8