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
	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	$ (1,070)	$ (938)
Other net benefit (credits) cost	(64)	(64)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	8	8
Other net benefit (credits) cost	(64)	(64)
Total (credit) cost	(56)	(56)
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	0	0
Other net benefit (credits) cost	0	0
Total (credit) cost	$ 0	$ 0