Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 4,874	$ 4,728
Accumulated Amortization	2,236	2,098
Net Carrying Amount	2,638	2,630
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	4,498	4,337
Accumulated Amortization	1,905	1,761
Net Carrying Amount	2,593	2,576
Other
Finite-Lived Intangible Assets [Line Items]
Gross Cost	376	391
Accumulated Amortization	331	337
Net Carrying Amount	$ 45	$ 54