Condensed Parent Company Financial Statements (Condensed Statements Of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating expenses	$ 3,277	$ 2,874	$ 2,676
Operating income (loss)	928	795	740
Other (income) and deductions:
Equity earnings from consolidated subsidiaries	(51)	(62)	(61)
Interest expense	325	277	275
Other	6	5	14
Total other (income) and deductions	220	195	173
Income before income taxes	708	600	567
Income tax benefit	22	(74)	(57)
Net income	686	674	624
Parent Company [Member]
Operating expenses	9	5	7
Operating income (loss)	(9)	(5)	(7)
Other (income) and deductions:
Equity earnings from consolidated subsidiaries	(707)	(664)	(625)
Interest expense	6	1	2
Other	(1)	(1)	(4)
Total other (income) and deductions	(700)	(662)	(619)
Income before income taxes	691	657	612
Income tax benefit	2	(5)	(4)
Net income	$ 689	$ 662	$ 616