SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - (Government Assistance) (Details) - USD ($)			3 Months Ended		6 Months Ended
	Jan. 11, 2024	Oct. 18, 2022	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
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			$ 22,000,000		$ 31,000,000
Maximum disbursement	$ 1,100,000,000
Civil Nuclear Credit Program \| Income Statement Location [Axis]: us-gaap:CostOfGoodsAndServicesSold
Public Utility, Property, Plant and Equipment [Line Items]
Disbursement				$ 16,000,000		$ 57,000,000
Civil Nuclear Credit Program \| Income Statement Location [Axis]: us-gaap:UtilitiesOperatingExpenseMaintenanceAndOperations
Public Utility, Property, Plant and Equipment [Line Items]
Disbursement				$ 60,000,000		$ 100,000,000
Senate Bill 846 \| Utility
Public Utility, Property, Plant and Equipment [Line Items]
Debt instrument, face amount		1,100,000,000
Maximum \| Senate Bill 846 \| Utility
Public Utility, Property, Plant and Equipment [Line Items]
Debt instrument, face amount		$ 1,400,000,000