ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Concentrations of Credit Risk and Significant Customers (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenue | AEP Subsidiaries
Concentration Risk [Line Items]
Percentage of Significant Customers Concentration Risk	80.00%	79.00%	79.00%
Revenue | AEP TEXAS INC. | NRG Energy and TXU Energy
Concentration Risk [Line Items]
Percentage of Significant Customers Concentration Risk	40.00%	41.00%	45.00%
Accounts Receivable | AEP Subsidiaries
Concentration Risk [Line Items]
Percentage of Significant Customers Concentration Risk	69.00%	60.00%	72.00%
Accounts Receivable | AEP TEXAS INC. | NRG Energy and TXU Energy
Concentration Risk [Line Items]
Percentage of Significant Customers Concentration Risk	37.00%	34.00%	42.00%