FINANCING ACTIVITIES - Schedule of Interest Income Earned for Funds Loaned to Utility Money Pool (Details) - Utility - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
APPALACHIAN POWER COMPANY
Short-Term Debt [Line Items]
Interest Income Earned on Advances to the Money Pool	$ 1.6	$ 1.1	$ 2.8
INDIANA MICHIGAN POWER COMPANY
Short-Term Debt [Line Items]
Interest Income Earned on Advances to the Money Pool	0.0	2.4	0.5
OHIO POWER COMPANY
Short-Term Debt [Line Items]
Interest Income Earned on Advances to the Money Pool	3.2	0.1	0.4
PUBLIC SERVICE COMPANY OF OKLAHOMA
Short-Term Debt [Line Items]
Interest Income Earned on Advances to the Money Pool	1.0	1.5	0.3
Nonutility | AEP TEXAS INC.
Short-Term Debt [Line Items]
Interest Income Earned on Advances to the Money Pool	4.4	0.1	2.6
Nonutility | SOUTHWESTERN ELECTRIC POWER COMPANY
Short-Term Debt [Line Items]
Interest Income Earned on Advances to the Money Pool	0.2	0.2	0.2
Direct Borrowing | AEP TRANSMISSION COMPANY, LLC
Short-Term Debt [Line Items]
Interest Income Earned on Advances to the Money Pool	$ 10.5	$ 7.0	$ 1.6