Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 7,239	$ 7,126
Accumulated Amortization	2,503	2,306
Net Carrying Amount	4,736	4,820
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	6,752	6,650
Accumulated Amortization	2,139	1,961
Net Carrying Amount	4,613	4,689
Other
Finite-Lived Intangible Assets [Line Items]
Gross Cost	487	476
Accumulated Amortization	364	345
Net Carrying Amount	$ 123	$ 131