Retirement Plans (Reconciliation of The Change In AOCL For Defined-Benefit Retirement Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Amortization of:
Change in AOCL, pretax	$ (241)	$ (2,365)	$ 453
Pension Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial gain	(61)	(1,684)
Prior service (credit) cost	(5)	(3)
Amortization of:
Net actuarial (loss) gain from prior years	(171)	(352)
Prior service credit (cost)	20	20
Settlement/curtailment/other	(3)	(77)
Change in AOCL, pretax	(220)	(2,096)
Other  Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial gain	(39)	(265)
Prior service (credit) cost	2	(4)
Amortization of:
Net actuarial (loss) gain from prior years	16	0
Prior service credit (cost)	(1)	0
Settlement/curtailment/other	1	0
Change in AOCL, pretax	$ (21)	$ (269)