Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 4,403	$ 4,431
Accumulated Amortization	1,683	1,621
Net Carrying Amount	2,720	2,810
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	4,041	4,066
Accumulated Amortization	1,389	1,334
Net Carrying Amount	2,652	2,732
Other
Finite-Lived Intangible Assets [Line Items]
Gross Cost	362	365
Accumulated Amortization	294	287
Net Carrying Amount	$ 68	$ 78