FINANCING ACTIVITIES - Schedule of Proceeds on Sale of Receivables to AEP Credit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
APPALACHIAN POWER COMPANY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of receivables to AEP Credit	$ 1,953.7	$ 1,819.8	$ 1,552.9
INDIANA MICHIGAN POWER COMPANY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of receivables to AEP Credit	2,105.3	2,054.8	2,045.6
OHIO POWER COMPANY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of receivables to AEP Credit	3,197.8	3,339.3	3,101.3
PUBLIC SERVICE COMPANY OF OKLAHOMA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of receivables to AEP Credit	1,781.3	1,944.5	1,809.5
SOUTHWESTERN ELECTRIC POWER COMPANY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale of receivables to AEP Credit	$ 1,838.1	$ 1,866.4	$ 1,858.4