Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost Combined U.S. and Significant Non-U.S. Plans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 10	$ 8
Interest cost	85	106
Expected return on plan assets	(208)	(210)
Amortization of prior service (credit) cost	0	0
Recognized actuarial loss (credit)	52	40
Net periodic benefit credit	(61)	(56)
Total (credit) cost	(61)	(56)
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Interest cost	46	53
Expected return on plan assets	(82)	(86)
Recognized actuarial loss (credit)	23	18
Net periodic benefit credit	(13)	(15)
Pension Benefits | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	10	8
Interest cost	39	53
Expected return on plan assets	(126)	(124)
Amortization of prior service (credit) cost	0	0
Recognized actuarial loss (credit)	29	22
Net periodic benefit credit	(48)	(41)
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	0	1
Expected return on plan assets	0	0
Amortization of prior service (credit) cost	(1)	(1)
Recognized actuarial loss (credit)	1	0
Net periodic benefit credit	0	0
Total (credit) cost	0	0
Post-retirement Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Interest cost	0	0
Expected return on plan assets	0	0
Recognized actuarial loss (credit)	0	0
Net periodic benefit credit	0	0
Post-retirement Benefits | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	0	1
Expected return on plan assets	0	0
Amortization of prior service (credit) cost	(1)	(1)
Recognized actuarial loss (credit)	1	0
Net periodic benefit credit	$ 0	$ 0