Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 5,679	$ 4,817
Accumulated Amortization	(2,271)	(1,833)
Net Carrying Amount	3,408	2,984
CDI
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,563	2,600
Accumulated Amortization	(1,190)	(852)
Net Carrying Amount	1,373	1,748
Other, primarily client relationship intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,116	2,217
Accumulated Amortization	(1,081)	(981)
Net Carrying Amount	$ 2,035	$ 1,236