Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 19	$ 46	$ 37	$ 90
Interest cost	124	138	246	275
Expected return on plan assets	(230)	(242)	(454)	(483)
Amortization of prior service cost (credit)	(1)	(1)	(1)	(1)
Recognized actuarial loss (gain)	43	42	83	84
Net periodic benefit (credit) cost	(45)	(17)	(89)	(35)
Curtailment gain (loss)	0	(5)	(1)	(5)
Settlement loss	0	1	1	1
Total (credit) cost	(45)	(21)	(89)	(39)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	1	2	3
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	0	1	1	2
Recognized actuarial loss (gain)	0	0	0	(1)
Net periodic benefit (credit) cost	1	2	3	4
Curtailment gain (loss)	0	0	0	0
Settlement loss	0	0	0	0
Total (credit) cost	1	2	3	4
Domestic Plan | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	27	0	53
Interest cost	66	66	132	132
Expected return on plan assets	(90)	(95)	(179)	(190)
Amortization of prior service cost (credit)	0	0	0	0
Recognized actuarial loss (gain)	10	18	19	36
Net periodic benefit (credit) cost	(14)	16	(28)	31
Domestic Plan | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	0	1	1
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	1	1	2	2
Recognized actuarial loss (gain)	(1)	0	(1)	(1)
Net periodic benefit (credit) cost	1	1	2	2
Foreign Plan | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	19	19	37	37
Interest cost	58	72	114	143
Expected return on plan assets	(140)	(147)	(275)	(293)
Amortization of prior service cost (credit)	(1)	(1)	(1)	(1)
Recognized actuarial loss (gain)	33	24	64	48
Net periodic benefit (credit) cost	(31)	(33)	(61)	(66)
Curtailment gain (loss)	0	(5)	(1)	(5)
Settlement loss	0	1	1	1
Total (credit) cost	(31)	(37)	(61)	(70)
Foreign Plan | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	0	1	1	2
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(1)	0	(1)	0
Recognized actuarial loss (gain)	1	0	1	0
Net periodic benefit (credit) cost	0	1	1	2
Curtailment gain (loss)	0	0	0	0
Settlement loss	0	0	0	0
Total (credit) cost	$ 0	$ 1	$ 1	$ 2