Retirement Benefits (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, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense	$ (1,108)	$ (996)	$ (4,675)	$ (4,179)
Other net benefit credits	(68)	(62)	(201)	(180)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense	5	7	17	18
Other net benefit credits	(67)	(62)	(198)	(180)
Net benefit credit	$ (62)	$ (55)	$ (181)	$ (162)