Employee Retirement Benefits (Components Of Net Periodic Benefit Cost As Well As Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Income For Qualified Plan And SERP) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Service cost	$ 6	$ 9	$ 10
Interest cost	13	10	10
Expected return on plan assets	(21)	(22)	(21)
Amortization of actuarial (gain) loss and prior service cost	(2)	0	6
Other	(6)	(3)	1
Net periodic benefit cost	(10)	(6)	6
Current year actuarial (gain) loss	(2)	(12)	(62)
Amortization of actuarial loss	8	3	(7)
Current year prior service cost	0	0	1
Total recognized in other comprehensive (income) loss	6	(9)	(68)
Total recognized in net periodic benefit cost and other comprehensive income	$ (4)	$ (15)	$ (62)