Condensed Parent Company Financial Statements (Condensed Statements Of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating expenses	$ 3,084	$ 3,277	$ 2,874
Operating income (loss)	943	928	795
Other (income) and deductions:
Equity earnings from consolidated subsidiaries	(61)	(51)	(62)
Interest expense	394	325	277
Other	3	6	5
Total other (income) and deductions	236	220	195
Income before income taxes	707	708	600
Income tax expense (benefit)	4	22	(74)
Net income	703	686	674
Parent Company [Member]
Operating expenses	3	9	5
Operating income (loss)	(3)	(9)	(5)
Other (income) and deductions:
Equity earnings from consolidated subsidiaries	(742)	(707)	(664)
Interest expense	34	6	1
Other	4	1	1
Total other (income) and deductions	(704)	(700)	(662)
Income before income taxes	701	691	657
Income tax expense (benefit)	(5)	2	(5)
Net income	$ 706	$ 689	$ 662