FINANCING ACTIVITIES - Schedule of Nonutility Money Pool Activity (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
AEP Texas
Short-Term Debt [Line Items]
Advances to Affiliates	$ 425.3	$ 7.2
Nonutility | AEP Texas
Short-Term Debt [Line Items]
Maximum Loans	7.2
Average Loans	7.1
Nonutility | AEP Texas | Related Party
Short-Term Debt [Line Items]
Advances to Affiliates	7.2
Nonutility | SWEPCo
Short-Term Debt [Line Items]
Maximum Loans	2.4
Average Loans	2.1
Nonutility | SWEPCo | Related Party
Short-Term Debt [Line Items]
Advances to Affiliates	$ 0.0