RATE MATTERS - 2025 Ohio Base Rate Case (Details) - OPCo - USD ($) $ in Millions	1 Months Ended
	Oct. 29, 2025	May 31, 2025
2025 Ohio Base Rate Case
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)		$ 97
Requested return on equity		10.90%
Requested debt capital structure		49.10%
Requested equity capital structure		50.90%
2025 Ohio Base Rate Case | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Recommended exclusion of investments from rate base	$ 59
Recommended exclusion of capitalized incentives	55
Recommended reduction in employee related expenses	23
2025 Ohio Base Rate Case | Minimum | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)	$ (12)
Requested return on equity	9.33%
2025 Ohio Base Rate Case | Maximum | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)	$ (28)
Requested return on equity	9.84%
Annual Rider Revenue Requirements
Public Utilities, General Disclosures [Line Items]
Requested annual base rate increase (decrease)		$ 308