v3.26.1
DERIVATIVES AND HEDGING - Schedule of Gain (Loss) Recognized on Risk Management Contracts (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts $ 195 $ 71 $ 448 $ 269
Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 8 (6) 2 (5)
Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 167 77 348 230
AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 2 0
AEP TEXAS INC. | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
AEP TEXAS INC. | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts (1) 0 1 0
APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 64 4 173 64
APPALACHIAN POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 3 0 0 0
APPALACHIAN POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 55 3 158 60
INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 8 15 (16) (7)
INDIANA MICHIGAN POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 (1) 0 (1)
INDIANA MICHIGAN POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 7 4 14 15
OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 4 6 9 6
OHIO POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 3 3 5 0
OHIO POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 3 3 6
PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 43 23 75 65
PUBLIC SERVICE COMPANY OF OKLAHOMA | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 4 (6) 1 (2)
PUBLIC SERVICE COMPANY OF OKLAHOMA | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 39 29 74 67
SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 45 38 52 69
SOUTHWESTERN ELECTRIC POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts (1) (3) (4) (2)
SOUTHWESTERN ELECTRIC POWER COMPANY | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityNoncurrent        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 46 41 56 71
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 4 1   4
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0   0
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 4 1   4
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0   0
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0   0
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0   0
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0   0
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenance        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 2   2  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenance | AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 1   1  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenance | APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 1   1  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenance | INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenance | OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 1   1  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenance | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenance | SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseOperations        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 2   2  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseOperations | AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseOperations | APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseOperations | INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseOperations | OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseOperations | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Location, Statement of Income, Balance [Axis]: us-gaap:UtilitiesOperatingExpenseOperations | SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0   0  
Vertically Integrated Utilities | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 1 12 (29) (20)
Vertically Integrated Utilities | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Vertically Integrated Utilities | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Vertically Integrated Utilities | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Vertically Integrated Utilities | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Vertically Integrated Utilities | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Vertically Integrated Utilities | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Generation & Marketing Revenues | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 11 (13) 110 60
Generation & Marketing Revenues | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Generation & Marketing Revenues | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Generation & Marketing Revenues | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Generation & Marketing Revenues | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Generation & Marketing Revenues | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Generation & Marketing Revenues | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Electric Generation, Transmission and Distribution | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Electric Generation, Transmission and Distribution | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Electric Generation, Transmission and Distribution | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 1 0 1 0
Electric Generation, Transmission and Distribution | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 1 12 (30) (21)
Electric Generation, Transmission and Distribution | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Electric Generation, Transmission and Distribution | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts 0 0 0 0
Electric Generation, Transmission and Distribution | Location, Statement of Income, Balance [Axis]: us-gaap:Revenues | SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts $ 0 $ 0 0 $ 0
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts     13  
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | AEP TEXAS INC.        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts     0  
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | APPALACHIAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts     13  
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | INDIANA MICHIGAN POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts     0  
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | OHIO POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts     0  
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts     0  
Purchased Electricity, Fuel and Other Consumables Used for Electric Generation | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization | SOUTHWESTERN ELECTRIC POWER COMPANY        
Derivative Instruments and Hedging Activities Disclosures [Line Items]        
Total Gain on Risk Management Contracts     $ 0