v3.26.1
Segment Information - MEC (Details)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
segment
operatingSegment
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Segment Reporting [Line Items]          
Number of reportable segments | operatingSegment     8    
Revenues $ 6,686 $ 6,394 $ 13,358 $ 12,760  
Cost of sales 1,376 1,434 3,046 2,965  
Operating income 1,278 1,004 2,736 2,387  
Interest expense (791) (709) (1,537) (1,395)  
Interest and dividend income 67 63 121 125  
Income tax expense (benefit) (333) (357) (763) (756)  
Other segment items (65) (80) (256) (162)  
Net income (loss) attributable to parent 891 702 2,005 1,889  
Capital expenditures 2,531 2,445 4,949 4,573  
Assets 154,029   $ 154,029   $ 148,327
MEC          
Segment Reporting [Line Items]          
Number of reportable segments | segment     2    
Revenues 872 860 $ 2,012 1,874  
Cost of sales 196 211 680 580  
Operations and maintenance 231 235 451 462  
Depreciation and amortization 282 255 559 562  
Property and other taxes 42 44 90 88  
Operating income 121 115 232 182  
Interest expense (106) (100) (211) (201)  
Interest and dividend income 6 7 12 14  
Income tax expense (benefit) (193) (178) (409) (414)  
Other segment items 49 45 69 68  
Net income (loss) attributable to parent 263 245 511 477  
Capital expenditures 470 335 888 740  
Assets 28,083   28,083   27,643
MEC | Other          
Segment Reporting [Line Items]          
Revenues 1 1 4 3  
Cost of sales 0 1 0 1  
Operations and maintenance 0 0 0 1  
Depreciation and amortization 0 0 0 0  
Property and other taxes 0 0 0 0  
Operating income 1 0 4 1  
Interest expense 0 0 0 0  
Interest and dividend income 0 0 0 0  
Income tax expense (benefit) 0 2 1 2  
Other segment items (1) (1) (1) (2)  
Net income (loss) attributable to parent 0 (3) 2 (3)  
Capital expenditures 0 1 0 1  
Assets 1   1   3
MEC | Electric | Operating segments          
Segment Reporting [Line Items]          
Revenues 760 743 1,507 1,410  
Cost of sales 146 153 340 277  
Operations and maintenance 185 201 366 394  
Depreciation and amortization 264 238 523 528  
Property and other taxes 38 41 81 81  
Operating income 127 110 197 130  
Interest expense (98) (93) (194) (186)  
Interest and dividend income 6 7 11 13  
Income tax expense (benefit) (190) (180) (414) (426)  
Other segment items 42 41 65 64  
Net income (loss) attributable to parent 267 245 493 447  
Capital expenditures 441 309 835 683  
Assets 25,980   25,980   25,495
MEC | Natural Gas | Operating segments          
Segment Reporting [Line Items]          
Revenues 111 116 501 461  
Cost of sales 50 57 340 302  
Operations and maintenance 46 34 85 67  
Depreciation and amortization 18 17 36 34  
Property and other taxes 4 3 9 7  
Operating income (7) 5 31 51  
Interest expense (8) (7) (17) (15)  
Interest and dividend income 0 0 1 1  
Income tax expense (benefit) (3) 0 4 10  
Other segment items 8 5 5 6  
Net income (loss) attributable to parent (4) 3 16 33  
Capital expenditures 29 $ 25 53 $ 56  
Assets $ 2,102   $ 2,102   $ 2,145