Retirement Benefits (Components Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Non-service Cost or Income Components	$ 136	$ 116	$ 90
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	134	110	88
Interest cost	152	174	187
Expected return on plan assets	(297)	(291)	(276)
Prior service credit	0	(1)	(1)
Actuarial (gain) loss	73	60	25
Defined Benefit Plan, Non-service Cost or Income Components	(72)	(58)	(65)
Net periodic benefit cost (income)	62	52	23
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	23	19	18
Interest cost	33	39	43
Expected return on plan assets	(80)	(80)	(77)
Prior service credit	(4)	(4)	(5)
Actuarial (gain) loss	(6)	(9)	(15)
Defined Benefit Plan, Non-service Cost or Income Components	(57)	(54)	(54)
Net periodic benefit cost (income)	$ (34)	$ (35)	$ (36)