Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost Amounts Recorded in Consolidated Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	$ (467)	$ (541)	$ (2,085)	$ (2,140)
Other net benefit (credits) cost	(69)	(63)	(203)	(194)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	10	8	28	25
Other net benefit (credits) cost	(69)	(63)	(203)	(194)
Total (credit) cost	(59)	(55)	(175)	(169)
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	0	1	0	1
Other net benefit (credits) cost	0	0	0	0
Total (credit) cost	$ 0	$ 1	$ 0	$ 1