Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	$ (691)	$ (701)	$ (1,599)	$ (1,450)
Other net benefit credits	(65)	(63)	(131)	(123)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	19	17	37
Interest cost	117	124	235	246
Expected return on plan assets	(218)	(230)	(439)	(454)
Amortization of prior service cost	(1)	(1)	(1)	(1)
Recognized actuarial loss	37	43	74	83
Net periodic benefit (credit) cost	(58)	(45)	(114)	(89)
Curtailment loss (credit)			0	(1)
Settlement loss			0	1
Compensation and benefits expense (Operating income)	(7)	(19)	(17)	(37)
Other net benefit credits	(65)	(64)	(131)	(126)
Total (credit) cost	(58)	(45)	(114)	(89)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	1	2	2
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(1)	0	(2)	1
Recognized actuarial loss	0	0	0	0
Net periodic benefit (credit) cost	0	1	0	3
Curtailment loss (credit)			0	0
Settlement loss			0	0
Compensation and benefits expense (Operating income)	0	0	0	0
Other net benefit credits	0	1	0	3
Total (credit) cost	0	1	0	3
Domestic Plan | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	59	66	118	132
Expected return on plan assets	(90)	(90)	(179)	(179)
Amortization of prior service cost	0	0	0	0
Recognized actuarial loss	14	10	27	19
Net periodic benefit (credit) cost	(17)	(14)	(34)	(28)
Domestic Plan | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	1	1	1	1
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(1)	1	(1)	2
Recognized actuarial loss	0	(1)	0	(1)
Net periodic benefit (credit) cost	0	1	0	2
Foreign Plan | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	19	17	37
Interest cost	58	58	117	114
Expected return on plan assets	(128)	(140)	(260)	(275)
Amortization of prior service cost	(1)	(1)	(1)	(1)
Recognized actuarial loss	23	33	47	64
Net periodic benefit (credit) cost	(41)	(31)	(80)	(61)
Curtailment loss (credit)			0	(1)
Settlement loss			0	1
Total (credit) cost			(80)	(61)
Foreign 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	0	(1)	(1)	(1)
Recognized actuarial loss	0	1	0	1
Net periodic benefit (credit) cost	$ 0	$ 0	0	1
Curtailment loss (credit)			0	0
Settlement loss			0	0
Total (credit) cost			$ 0	$ 1