FINANCING ACTIVITIES - Schedule of Short-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Short-Term Debt [Line Items]
Short-term – Securitized Debt of Receivables	$ 900.0	$ 900.0
Interest Rate	4.56%	4.73%
Commercial Paper	$ 250.0	$ 1,618.3
Total Short-term Debt	1,157.7	2,523.8
SWEPCo
Short-Term Debt [Line Items]
Notes Payable	7.7	5.5
Total Short-term Debt	$ 7.7	$ 5.5
Commercial Paper
Short-Term Debt [Line Items]
Weighted-Average Interest Rate	4.30%	4.70%
Notes Payable | SWEPCo
Short-Term Debt [Line Items]
Weighted-Average Interest Rate	6.50%	6.69%