Summary of Significant Accounting Policies - Summary of Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Accounting Policies [Abstract]
Due from the FRB	$ 3,308,089		$ 1,756,245
Cash and due from banks	431,527	$ 500,682	360,242
Cash and cash equivalents at end of period	$ 3,739,616		$ 2,116,487