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, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense	$ (1,170)	$ (1,108)	$ (5,004)	$ (4,675)
Other net benefit credits	(52)	(68)	(143)	(201)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense	8	5	21	17
Other net benefit credits	(52)	(67)	(143)	(198)
Net benefit credit	$ (44)	$ (62)	$ (122)	$ (181)