Securities - Schedule of Other Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Other Securities [Line Items]
Other securities	$ 332,123	$ 327,098
FRB and FHLB stock [Member]
Schedule of Other Securities [Line Items]
Other securities	36,222	36,222
Equity Securities With Readily Determinable Fair Values [Member]
Schedule of Other Securities [Line Items]
Other securities	53,056	64,149
Equity Securities Without Readily Determinable Fair Values [Member]
Schedule of Other Securities [Line Items]
Other securities	$ 242,845	$ 226,727