Segment Reporting (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Operating revenue		$ 1,939	$ 2,152	$ 2,426
Electric fuel and purchased power		588	910	1,157
Operating and maintenance expenses		313	279	317
Utilities Operating Expense, Depreciation and Amortization		455	368	388
Other income (expense), net		12	2	0
Interest and Debt Expense		153	136	141
Total income tax benefit		(57)	(45)	(53)
Net Income (Loss) Attributable to Parent		394	384	349
Total revenues | Regulated Electric Segment
Segment Reporting Information [Line Items]
Operating revenue		1,939	2,152	2,426
Electric fuel and purchased power		588	910	1,157
Operating and maintenance expenses		313	279	317
Utilities Operating Expense, Depreciation and Amortization		455	368	388
Other income (expense), net	[1]	93	120	127
Interest and Debt Expense		153	136	141
Total income tax benefit		(57)	(45)	(53)
Net Income (Loss) Attributable to Parent		$ 394	$ 384	$ 349

[1] Other segment expenses, net, for 2023 additionally includes workforce reduction expenses