v3.25.2
Segment Information (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Segment Reporting Information [Line Items]        
Net Income (Loss) $ 26 $ 23 $ 68 $ 66
Natural gas 24 21 92 75
Cost of natural sold and transported 9 7 42 31
Operating and maintenance expenses 60 59 123 115
Utilities Operating Expense, Depreciation and Amortization 50 46 99 91
Interest and Debt Expense 15 15 31 28
Income Tax Expense (Benefit) 8 6 20 19
Regulated Operating Revenue, Electric, Affiliate 55 54 111 107
Total revenues        
Segment Reporting Information [Line Items]        
Net Income (Loss) 26 21 68 64
Regulated Operating Revenue 277 [1] 267 [2] 604 [3] 577 [4]
Electric Fuel and Purchased Power 103 105 209 212
Cost of natural sold and transported 9 7 42 31
Operating and maintenance expenses 60 59 123 115
Utilities Operating Expense, Depreciation and Amortization 50 46 99 91
Segment Reporting, Other Segment Item, Amount 6 7 12 16
Interest and Debt Expense 15 15 31 28
Income Tax Expense (Benefit) 8 7 20 20
All Other        
Segment Reporting Information [Line Items]        
Net Income (Loss)   2   2
Regulated Electric Segment | Total revenues        
Segment Reporting Information [Line Items]        
Regulated Operating Revenue, Electric 253 [1] 246 [2] 512 [3] 502 [4]
Net Income (Loss) 29 23 58 56
Electric Fuel and Purchased Power 103 105 209 212
Cost of natural sold and transported 0 0 0 0
Operating and maintenance expenses 52 52 106 101
Utilities Operating Expense, Depreciation and Amortization 42 39 84 76
Segment Reporting, Other Segment Item, Amount 5 7 11 15
Interest and Debt Expense 13 13 28 25
Income Tax Expense (Benefit) 9 7 16 17
Regulated Natural Gas Segment | Total revenues        
Segment Reporting Information [Line Items]        
Net Income (Loss) (3) (2) 10 8
Natural gas 24 [1] 21 [2] 92 [3] 75 [4]
Electric Fuel and Purchased Power 0 0 0 0
Cost of natural sold and transported 9 7 42 31
Operating and maintenance expenses 8 7 17 14
Utilities Operating Expense, Depreciation and Amortization 8 7 15 15
Segment Reporting, Other Segment Item, Amount 1 0 1 1
Interest and Debt Expense 2 2 3 3
Income Tax Expense (Benefit) $ (1) $ 0 $ 4 $ 3
[1] Operating revenues include $55 million of affiliate electric revenue.
[2] Operating revenues include $54 million of affiliate electric revenue.
[3] Operating revenues include $111 million of affiliate electric revenue.
[4] Operating revenues include $107 million of affiliate electric revenue.