Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	$ (541)	$ (535)	$ (2,140)	$ (1,985)
Other net benefit (credits) cost	(63)	(62)	(194)	(185)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	8	19	25	56
Interest cost	114	125	349	371
Expected return on plan assets	(213)	(232)	(652)	(686)
Amortization of prior service (credit) cost	0	0	(1)	(1)
Recognized actuarial loss	36	42	110	125
Net periodic benefit (credit) cost	(55)	(46)	(169)	(135)
Curtailment loss (credit)			0	(1)
Settlement loss	0	1	0	2
Compensation and benefits expense (Operating income)	8	19	25	56
Other net benefit (credits) cost	(63)	(64)	(194)	(190)
Total (credit) cost	(55)	(45)	(169)	(134)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	1	0
Interest cost	0	1	2	3
Expected return on plan assets	0	0	0	0
Amortization of prior service (credit) cost	(1)	1	(3)	2
Recognized actuarial loss	1	0	1	0
Net periodic benefit (credit) cost	1	2	1	5
Curtailment loss (credit)			0	0
Settlement loss	0	0	0	0
Compensation and benefits expense (Operating income)	1	0	1	0
Other net benefit (credits) cost	0	2	0	5
Total (credit) cost	1	2	1	5
United States | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	58	66	176	198
Expected return on plan assets	(89)	(89)	(268)	(268)
Amortization of prior service (credit) cost	0	0	0	0
Recognized actuarial loss	14	9	41	28
Net periodic benefit (credit) cost	(17)	(14)	(51)	(42)
United States | 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 (credit) cost	0	1	(1)	3
Recognized actuarial loss	0	0	0	(1)
Net periodic benefit (credit) cost	0	1	0	3
Foreign Plan | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	8	19	25	56
Interest cost	56	59	173	173
Expected return on plan assets	(124)	(143)	(384)	(418)
Amortization of prior service (credit) cost	0	0	(1)	(1)
Recognized actuarial loss	22	33	69	97
Net periodic benefit (credit) cost	(38)	(32)	(118)	(93)
Curtailment loss (credit)			0	(1)
Settlement loss	0	1	0	2
Total (credit) cost	(38)	(31)	(118)	(92)
Foreign Plan | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	1	0
Interest cost	0	1	1	2
Expected return on plan assets	0	0	0	0
Amortization of prior service (credit) cost	(1)	0	(2)	(1)
Recognized actuarial loss	1	0	1	1
Net periodic benefit (credit) cost	1	1	1	2
Curtailment loss (credit)			0	0
Settlement loss	0	0	0	0
Total (credit) cost	$ 1	$ 1	$ 1	$ 2