Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 19	$ 43	$ 56	$ 133
Interest cost	125	132	371	407
Expected return on plan assets	(232)	(232)	(686)	(715)
Amortization of prior service cost	0	1	(1)	0
Recognized actuarial loss (gain)	42	43	125	127
Net periodic benefit (credit) cost	(46)	(13)	(135)	(48)
Curtailment gain (loss)			(1)	(5)
Settlement loss	1	0	2	1
Total (credit) cost	(45)	(13)	(134)	(52)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	0	1
Interest cost	1	0	3	3
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	1	1	2	3
Recognized actuarial loss (gain)	0	0	0	(1)
Net periodic benefit (credit) cost	2	2	5	6
Curtailment gain (loss)			0	0
Settlement loss	0	0	0	0
Total (credit) cost	2	2	5	6
Domestic Plan | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	26	0	79
Interest cost	66	66	198	198
Expected return on plan assets	(89)	(95)	(268)	(285)
Amortization of prior service cost	0	0	0	0
Recognized actuarial loss (gain)	9	19	28	55
Net periodic benefit (credit) cost	(14)	16	(42)	47
Domestic Plan | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	0	0	1	1
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	1	1	3	3
Recognized actuarial loss (gain)	0	0	(1)	(1)
Net periodic benefit (credit) cost	1	1	3	3
Foreign Plan | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	19	17	56	54
Interest cost	59	66	173	209
Expected return on plan assets	(143)	(137)	(418)	(430)
Amortization of prior service cost	0	1	(1)	0
Recognized actuarial loss (gain)	33	24	97	72
Net periodic benefit (credit) cost	(32)	(29)	(93)	(95)
Curtailment gain (loss)			(1)	(5)
Settlement loss	1	0	2	1
Total (credit) cost	(31)	(29)	(92)	(99)
Foreign Plan | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	0	1
Interest cost	1	0	2	2
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	0	0	(1)	0
Recognized actuarial loss (gain)	0	0	1	0
Net periodic benefit (credit) cost	1	1	2	3
Curtailment gain (loss)			0	0
Settlement loss	0	0	0	0
Total (credit) cost	$ 1	$ 1	$ 2	$ 3