INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Effective Income Tax Rate Reconciliation [Line Items]
Tax benefit recognized from the remeasurement of excess ADIT	$ 383
Effective Income Tax Rate	(24.20%)	1.90%	(6.40%)	(11.20%)
AEPTCo
Effective Income Tax Rate Reconciliation [Line Items]
Tax benefit recognized from the remeasurement of excess ADIT	$ 256
Effective Income Tax Rate	(30.80%)	21.40%	(11.40%)	21.90%
APCo
Effective Income Tax Rate Reconciliation [Line Items]
Tax benefit recognized from the remeasurement of excess ADIT	$ 24
Effective Income Tax Rate	(14.70%)	17.90%	9.00%	12.10%
I&M
Effective Income Tax Rate Reconciliation [Line Items]
Tax benefit recognized from the remeasurement of excess ADIT	$ 38
Effective Income Tax Rate	(33.60%)	(32.30%)	(15.60%)	(37.10%)
PSO
Effective Income Tax Rate Reconciliation [Line Items]
Tax benefit recognized from the remeasurement of excess ADIT	$ 14
Effective Income Tax Rate	(90.10%)	(57.10%)	(54.60%)	(160.30%)
SWEPCo
Effective Income Tax Rate Reconciliation [Line Items]
Tax benefit recognized from the remeasurement of excess ADIT	$ 46
Effective Income Tax Rate	(100.90%)	38.90%	(64.20%)	388.20%