SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Government Assistance (Details) - USD ($)			3 Months Ended		9 Months Ended
	Jan. 11, 2024	Oct. 18, 2022	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Performance-Based Disbursement
Public Utility, Property, Plant and Equipment [Line Items]
Disbursement		$ 7
Maximum disbursement		300,000,000
Civil Nuclear Credit Program
Public Utility, Property, Plant and Equipment [Line Items]
Disbursement			$ 34,000,000	$ 71,000,000	$ 134,000,000	$ 370,000,000
Maximum disbursement	$ 1,100,000,000
Civil Nuclear Credit Program, Incurred Fuel Costs
Public Utility, Property, Plant and Equipment [Line Items]
Disbursement					$ 57,000,000
Government Assistance, Statement of Income or Comprehensive Income [Extensible Enumeration]					Cost of Product and Service Sold
Senate Bill 846
Public Utility, Property, Plant and Equipment [Line Items]
Debt instrument, face amount		1,400,000,000
Utility | Senate Bill 846
Public Utility, Property, Plant and Equipment [Line Items]
Debt instrument, face amount		$ 1,100,000,000