v3.26.3
Non-Derivative Fair Value Measurements (Details) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Nuclear decommissinoning fund [Abstract]    
Equity investments in unconsolidated subsidiaries $ 354 $ 285
Miscellaneous investments 152 164
Debt Securities, Available-for-sale, Unrealized Gain 2,000 1,800
Debt Securities, Available-for-sale, Unrealized Loss 81 47
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]    
Due in one year or less 3  
Due in 1 to 5 years 457  
Due in 5 to 10 years 334  
Due after 10 years 212  
Total 1,006  
Fair Value Measured on a Recurring Basis | Cost    
Nuclear decommissinoning fund [Abstract]    
Decommissioning Fund Investments 2,324 [1] 2,229 [2]
Fair Value Measured on a Recurring Basis | Cost | Cash equivalents    
Nuclear decommissinoning fund [Abstract]    
Cash equivalents 42 [1] 60 [2]
Fair Value Measured on a Recurring Basis | Cost | Commingled funds    
Nuclear decommissinoning fund [Abstract]    
Investments, Fair Value Disclosure 771 [1] 720 [2]
Fair Value Measured on a Recurring Basis | Cost | Debt securities    
Nuclear decommissinoning fund [Abstract]    
Debt securities 1,050 [1] 944 [2]
Fair Value Measured on a Recurring Basis | Cost | Equity securities    
Nuclear decommissinoning fund [Abstract]    
Equity Securities, FV-NI 461 [1] 505 [2]
Fair Value Measured on a Recurring Basis | Fair Value    
Nuclear decommissinoning fund [Abstract]    
Alternative investment 1,202 [1] 1,072 [2]
Decommissioning Fund Investments 4,219 [1] 3,940 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Cash equivalents    
Nuclear decommissinoning fund [Abstract]    
Cash equivalents 42 [1] 60 [2]
Alternative investment 0 [1] 0 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Commingled funds    
Nuclear decommissinoning fund [Abstract]    
Alternative investment 1,202 [1] 1,072 [2]
Investments, Fair Value Disclosure [1] 1,202  
Fair Value Measured on a Recurring Basis | Fair Value | Debt securities    
Nuclear decommissinoning fund [Abstract]    
Debt securities 1,006 [1] 945 [2]
Alternative investment 0 [1] 0 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Equity securities    
Nuclear decommissinoning fund [Abstract]    
Equity Securities, FV-NI 1,969 [1] 1,863 [2]
Alternative investment 0 [1] 0 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1    
Nuclear decommissinoning fund [Abstract]    
Decommissioning Fund Investments 2,010 [1] 1,921 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Cash equivalents    
Nuclear decommissinoning fund [Abstract]    
Cash equivalents 42 [1] 60 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Commingled funds    
Nuclear decommissinoning fund [Abstract]    
Alternative investment [2]   0
Investments, Fair Value Disclosure [1] 0  
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Debt securities    
Nuclear decommissinoning fund [Abstract]    
Debt securities 0 [1] 0 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Equity securities    
Nuclear decommissinoning fund [Abstract]    
Equity Securities, FV-NI 1,968 [1] 1,861 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2    
Nuclear decommissinoning fund [Abstract]    
Decommissioning Fund Investments 995 [1] 936 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Cash equivalents    
Nuclear decommissinoning fund [Abstract]    
Cash equivalents 0 [1] 0 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Commingled funds    
Nuclear decommissinoning fund [Abstract]    
Alternative investment [2]   0
Investments, Fair Value Disclosure [1] 0  
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Debt securities    
Nuclear decommissinoning fund [Abstract]    
Debt securities 994 [1] 934 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Equity securities    
Nuclear decommissinoning fund [Abstract]    
Equity Securities, FV-NI 1 [1] 2 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3    
Nuclear decommissinoning fund [Abstract]    
Decommissioning Fund Investments 12 [1] 11 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Cash equivalents    
Nuclear decommissinoning fund [Abstract]    
Cash equivalents 0 [1] 0 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Commingled funds    
Nuclear decommissinoning fund [Abstract]    
Alternative investment [2]   0
Investments, Fair Value Disclosure [1] 0  
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Debt securities    
Nuclear decommissinoning fund [Abstract]    
Debt securities 12 [1] 11 [2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Equity securities    
Nuclear decommissinoning fund [Abstract]    
Equity Securities, FV-NI $ 0 [1] $ 0 [2]
[1] Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $354 million of equity method investments and $152 million of rabbi trust assets and other miscellaneous investments.
[2] Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $285 million of equity method investments and $164 million of rabbi trust assets and other miscellaneous investments.