FINANCING ACTIVITIES - Schedule of Fees Paid to AEP Credit for Customer Accounts Receivable Sold (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	$ 5,962.1	$ 5,470.1	$ 16,432.6	$ 15,212.7
APCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,049.4	1,028.8	3,155.9	3,038.5
I&M
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	805.3	735.1	2,284.3	2,018.8
OPCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,048.8	989.0	2,946.9	2,889.3
PSO
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	693.0	615.6	1,554.6	1,463.8
SWEPCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	721.5	638.9	1,814.2	1,555.0
Servicing Contracts | APCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	3.7	4.0	10.9	12.1
Servicing Contracts | I&M
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	4.2	4.1	11.2	12.0
Servicing Contracts | OPCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	7.4	7.5	22.3	22.3
Servicing Contracts | PSO
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	4.0	4.1	9.7	10.9
Servicing Contracts | SWEPCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	$ 4.1	$ 4.4	$ 11.9	$ 13.5