STATEMENTS OF INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues [Abstract]
Operating revenue	$ 2,465	$ 1,870	$ 1,826
Operating expenses
Electric fuel and purchased power	1,432	835	875
Operating and maintenance expenses	271	275	285
Demand side management program expenses	17	16	17
Depreciation and amortization	300	295	230
Taxes (other than income taxes)	79	90	72
Total operating expenses	2,099	1,511	1,479
Operating income	366	359	347
Other income (expense), net	1	(2)	2
Allowance for funds used during construction — equity	4	33	27
Interest charges and financing costs
Interest Expense	114	119	99
Allowance for funds used during construction — debt	(2)	(14)	(12)
Total interest charges and financing costs	112	105	87
Income before income taxes	259	285	289
Income taxes	(59)	(10)	26
Net income	$ 318	$ 295	$ 263