Investment Securities - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Accrued interest receivable	$ 227	$ 215
Investment securities	45,100	21,300
Securities received as collateral	$ 16	$ 82
Securities Available for Sale \| Government Contracts Concentration Risk \| US Treasury and Agency securities
Debt Securities, Available-for-sale [Line Items]
Percentage of portfolio	97.00%	97.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details