Benefit Plans (Schedule of Components of Net Periodic Pension Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 39	$ 64	$ 68
Interest cost	333	206	184
Expected return on plan assets	(485)	(493)	(522)
Amortization:
Net loss (gain)	4	96	131
Prior service cost (credit)	6	6	5
Net periodic benefit cost (income)	(103)	(121)	(134)
Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	15	23	20
Interest cost	65	41	38
Expected return on plan assets	(8)	(13)	(14)
Amortization:
Net loss (gain)	(2)	18	22
Prior service cost (credit)	(40)	(45)	(46)
Net periodic benefit cost (income)	$ 30	$ 24	$ 20