(Net Periodic Pension Expense For Qualified And Nonqualified U.S. Defined Benefit Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Settlement loss				$ 424
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 85	$ 68	$ 153
Interest cost	393	440	467
Expected return on plan assets	(668)	(631)	(765)
Actuarial loss (gain)	202	200	337
Amortization of prior service cost	20	16	16
Curtailment loss (gain)	0	0	0
Settlement loss	0	0	424
Net periodic pension expense	32	93	632
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	5	5
Interest cost	6	8	8
Expected return on plan assets	(8)	(10)	(11)
Actuarial loss (gain)	2	2	2
Amortization of prior service cost	0	0	0
Curtailment loss (gain)	(1)	(1)	0
Settlement loss	1	2	0
Net periodic pension expense	$ 5	$ 6	$ 4