Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 4,330	$ 4,353
Accumulated Amortization	1,878	1,816
Net Carrying Amount	2,452	2,537
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	3,969	3,993
Accumulated Amortization	1,561	1,508
Net Carrying Amount	2,408	2,485
Other
Finite-Lived Intangible Assets [Line Items]
Gross Cost	361	360
Accumulated Amortization	317	308
Net Carrying Amount	$ 44	$ 52