Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 18	$ 44
Interest cost	122	137
Expected return on plan assets	(224)	(241)
Amortization of prior service cost	0	0
Recognized actuarial loss (gain)	40	42
Net periodic benefit (credit) cost	(44)	(18)
Curtailment gain	(1)	0
Settlement loss	1	0
Total (credit) cost	(44)	(18)
U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	26
Interest cost	66	66
Expected return on plan assets	(89)	(95)
Amortization of prior service cost	0	0
Recognized actuarial loss (gain)	9	18
Net periodic benefit (credit) cost	(14)	15
Non-U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	18	18
Interest cost	56	71
Expected return on plan assets	(135)	(146)
Recognized actuarial loss (gain)	31	24
Net periodic benefit (credit) cost	(30)	(33)
Curtailment gain	(1)	0
Settlement loss	1	0
Total (credit) cost	(30)	(33)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	1	2
Expected return on plan assets	0	0
Amortization of prior service cost	1	1
Recognized actuarial loss (gain)	0	(1)
Net periodic benefit (credit) cost	2	2
Curtailment gain	0	0
Settlement loss	0	0
Total (credit) cost	2	2
U.S. Postretirement 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 cost	1	1
Recognized actuarial loss (gain)	0	(1)
Net periodic benefit (credit) cost	1	1
Foreign Postretirement Benefit Plan, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	1	1
Expected return on plan assets	0	0
Recognized actuarial loss (gain)	0	0
Net periodic benefit (credit) cost	1	1
Curtailment gain	0	0
Settlement loss	0	0
Total (credit) cost	$ 1	$ 1