v3.26.3
FAIR VALUE MEASUREMENTS - Narrative (Details) - Spent Nuclear Fuel and Decommissioning Trusts - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Adjusted cost of debt securities $ 1,900 $ 1,700
Adjusted cost of equity securities 518 540
I&M    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Adjusted cost of debt securities 1,900 1,700
Adjusted cost of equity securities $ 518 $ 540