Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Cash and due from banks	$ 2,201	$ 723
Interest bearing deposits with the FRB	5,686	13,700
Interest bearing deposits with other institutions	5,773	3,025
Securities purchased under agreements to resell	607	227
Other short-term investment securities	352	0
Cash and cash equivalents	$ 14,619	$ 17,675