Employee Retirement Benefits (Benefit Obligation Activity Using An Actuarial Measurement Date For Qualified Plan And SERP) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in projected benefit obligation:
Benefit obligation, January 1	$ 282	$ 362
Service cost	6	9	$ 10
Interest cost	13	10	10
Actuarial loss (gain)	10	(70)
Benefits paid	(48)	(29)
Projected benefit obligation, December 31	263	282	362
Change in plan assets:
Fair value of plan assets, January 1	332	397
Actual return on plan assets	33	(36)
Benefits paid	(48)	(29)
Fair value of plan assets, December 31	317	332	$ 397
Funded status:
Funded status, December 31	54	50
Accumulated benefit obligation	$ 247	$ 264