RATE MATTERS - SWEPCo Rate Matters (Details) - 2025 Texas Base Rate Case - SOUTHWESTERN ELECTRIC POWER COMPANY - USD ($) $ in Millions	1 Months Ended
	Mar. 31, 2026	Oct. 31, 2025
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)		$ 164
Requested return on equity		10.75%
Requested debt capital structure		48.00%
Requested equity capital structure		52.00%
Requested net annual increase		$ 95
Approved annual base rate increase	$ 26
Approved return on equity	9.60%
Minimum
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)	$ (36)
Requested return on equity	9.25%
Maximum
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)	$ (64)
Requested return on equity	9.44%
Pirkey Plant
Public Utilities, General Disclosures [Line Items]
Regulatory asset, requested to recovery amount		$ 21