v3.26.1
Segment Information (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]          
Electric $ 2,740 $ 2,878 $ 5,716 $ 5,713  
Natural gas 365 396 1,395 1,451  
Revenues Including Intersegment Revenues 3,110 3,280 7,120 7,175  
Electric fuel and purchased power 678 918 1,697 1,938  
Cost of natural gas sold and transported 93 134 613 647  
Operating and maintenance expenses 691 675 1,366 1,361  
Utilities Operating Expense, Depreciation and Amortization 662 722 1,430 1,450  
Other income, net 37 68 59 75  
Interest and Debt Expense 398 322 770 631  
Income tax benefit (60) (60) (107) (121)  
Net income 586 444 1,142 927  
Equity Method Investments $ 321   $ 321   $ 285
Number Of Reportable Segments, Disclosed By Definition, Flag true   true    
Operating Segments          
Segment Reporting [Line Items]          
Regulated Operating Revenue $ 3,105 3,274 $ 7,111 7,164  
Electric fuel and purchased power 678 918 1,697 1,938  
Cost of natural gas sold and transported 93 134 613 647  
Operating and maintenance expenses 678 660 1,342 1,333  
Utilities Operating Expense, Depreciation and Amortization 657 719 1,420 1,443  
Other income, net 163 183 349 411  
Interest and Debt Expense 300 244 584 478  
Income tax benefit (64) (52) (89) (86)  
Net income 605 474 1,204 1,011  
Intersegment Eliminations          
Segment Reporting [Line Items]          
Regulated Operating Revenue 5 6 9 11  
All Other          
Segment Reporting [Line Items]          
Net income (19) (30) (62) (84)  
Equity Method Investments 252   252   204
Regulated Electric Segment          
Segment Reporting [Line Items]          
Revenues Including Intersegment Revenues 2,741 2,878 5,717 5,713  
Regulated Electric Segment | Operating Segments          
Segment Reporting [Line Items]          
Electric 2,740 2,878 5,716 5,713  
Electric fuel and purchased power 678 918 1,697 1,938  
Cost of natural gas sold and transported 0 0 0 0  
Operating and maintenance expenses 572 554 1,130 1,122  
Utilities Operating Expense, Depreciation and Amortization 546 617 1,199 1,243  
Other income, net 140 156 284 327  
Interest and Debt Expense 265 213 515 417  
Income tax benefit (58) (48) (135) (143)  
Net income 598 468 1,027 809  
Regulated Electric Segment | Intersegment Eliminations          
Segment Reporting [Line Items]          
Electric 1 0 1 0  
Regulated Natural Gas Segment          
Segment Reporting [Line Items]          
Revenues Including Intersegment Revenues 369 402 1,403 1,462  
Equity Method Investments 69   69   $ 81
Regulated Natural Gas Segment | Operating Segments          
Segment Reporting [Line Items]          
Natural gas 365 396 1,395 1,451  
Electric fuel and purchased power 0 0 0 0  
Cost of natural gas sold and transported 93 134 613 647  
Operating and maintenance expenses 106 106 212 211  
Utilities Operating Expense, Depreciation and Amortization 111 102 221 200  
Other income, net 23 27 65 84  
Interest and Debt Expense 35 31 69 61  
Income tax benefit (6) (4) 46 57  
Net income 7 6 177 202  
Regulated Natural Gas Segment | Intersegment Eliminations          
Segment Reporting [Line Items]          
Natural gas $ 4 $ 6 $ 8 $ 11