Consolidated Statements of Capitalization - Capital Stock - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Beginning balance	$ 4,792	$ 4,216	$ 3,695
Net income	540	446	424
Equity contributions from Parent	605	580	505
Dividends to Parent	(517)	(450)	(408)
Ending balance	5,420	4,792	4,216
Common Stock [Member]
Beginning balance	$ 4,470	$ 3,890	$ 3,385
Beginning balance	10	10	10
Equity contributions from Parent	$ 605	$ 580	$ 505
Ending balance	$ 5,075	$ 4,470	$ 3,890
Ending balance	10	10	10
Retained Earnings [Member]
Beginning balance	$ 323	$ 327	$ 311
Net income	540	446	424
Dividends to Parent	(517)	(450)	(408)
Ending balance	346	323	327
Accumulated Other Comprehensive Loss [Member]
Beginning balance	(1)	(1)	(1)
Ending balance	$ (1)	$ (1)	$ (1)