Retirement Benefits (Components Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Non-service Cost or Income Components	$ 184	$ 136	$ 116
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	128	134	110
Interest cost	163	152	174
Expected return on plan assets(b)	(320)	(297)	(291)
Prior service credit	0	0	(1)
Actuarial (gain) loss	25	73	60
Defined Benefit Plan, Non-service Cost or Income Components	(132)	(72)	(58)
Net periodic benefit cost (income)(d)	$ (4)	62	52
Defined Benefit Plan, Amortization of Gain (Loss)	10 years
Defined Benefit Plan, Difference Between Actual and Expected Return (Loss) on Plan Assets Amortization Period	4 years
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 20	23	19
Interest cost	34	33	39
Expected return on plan assets(b)	(85)	(80)	(80)
Prior service credit	(4)	(4)	(4)
Actuarial (gain) loss	(19)	(6)	(9)
Defined Benefit Plan, Non-service Cost or Income Components	(74)	(57)	(54)
Net periodic benefit cost (income)(d)	$ (54)	$ (34)	$ (35)
Defined Benefit Plan, Amortization of Gain (Loss)	10 years
Defined Benefit Plan, Difference Between Actual and Expected Return (Loss) on Plan Assets Amortization Period	4 years