RATE MATTERS - PSO Rate Matters (Details) - PUBLIC SERVICE COMPANY OF OKLAHOMA $ in Millions	1 Months Ended
	Jan. 31, 2026 USD ($)	Oct. 31, 2024 USD ($)	Jan. 31, 2024 USD ($) MW
2024 Oklahoma Base Rate Case
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)			$ 218
Requested return on equity			10.80%
Requested debt capital structure			48.90%
Requested equity capital structure			51.10%
Net Maximum Capacity (MWs) | MW			155
Public utilities, net annual revenue increase		$ 120
Settlement agreement return on common equity		9.50%
Settlement agreement debt capital structure		48.90%
Settlement agreement equity capital structure		51.10%
Interim annual base rate increase		$ 120
2026 Oklahoma Base Rate Case | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)	$ 299
Requested return on equity	10.50%
Requested debt capital structure	50.10%
Requested equity capital structure	49.90%