FINANCING ACTIVITIES - Schedule of Utility Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits (Details) - Utility $ in Millions	3 Months Ended
	Mar. 31, 2025 USD ($)
AEP Texas
Short-Term Debt [Line Items]
Maximum Borrowings	$ 468.4
Maximum Loans	0.0
Average Borrowings	252.7
Average Loans	0.0
Authorized Short-term Borrowing Limit	600.0
AEP Texas | Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(144.4)
AEPTCo
Short-Term Debt [Line Items]
Maximum Borrowings	403.6
Maximum Loans	13.8
Average Borrowings	211.8
Average Loans	9.6
Authorized Short-term Borrowing Limit	820.0
AEPTCo | Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(276.1)
APCo
Short-Term Debt [Line Items]
Maximum Borrowings	210.1
Maximum Loans	24.2
Average Borrowings	103.4
Average Loans	18.3
Authorized Short-term Borrowing Limit	750.0
APCo | Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(48.5)
I&M
Short-Term Debt [Line Items]
Maximum Borrowings	141.9
Maximum Loans	0.0
Average Borrowings	88.2
Average Loans	0.0
Authorized Short-term Borrowing Limit	500.0
I&M | Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(83.7)
OPCo
Short-Term Debt [Line Items]
Maximum Borrowings	29.9
Maximum Loans	165.9
Average Borrowings	19.5
Average Loans	87.1
Authorized Short-term Borrowing Limit	600.0
OPCo | Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(9.7)
PSO
Short-Term Debt [Line Items]
Maximum Borrowings	91.5
Maximum Loans	232.0
Average Borrowings	91.5
Average Loans	154.8
Authorized Short-term Borrowing Limit	750.0
PSO | Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	(91.5)
SWEPCo
Short-Term Debt [Line Items]
Maximum Borrowings	406.8
Maximum Loans	0.0
Average Borrowings	337.3
Average Loans	0.0
Authorized Short-term Borrowing Limit	750.0
SWEPCo | Related Party
Short-Term Debt [Line Items]
Net Loans to (Borrowings from)	$ (399.8)