Investment Securities - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Investment	Dec. 31, 2022 USD ($) Investment	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
Carrying value of securities pledged to secure public deposits and other contractual obligations	$ 464,000	$ 429,400
Number of investments in non-federal issuer representing more than 10% of shareholders' equity | Investment	0	0
Maximum investment in any single non-federal issuer representing shareholders' equity	10.00%	10.00%
Unrealized loss position, fair value	$ 128,277	$ 134,068
Unrealized loss position, accumulated loss	17,500	20,659
Fair value AFS in unrealized loss with an ACL	258,855	266,810
Available-for-sale securities in unrealized loss position, accumulated loss	35,629	42,445
Debt securities in an unrealized loss, net of allowance	83,300
Debt securities unrealized accumulated loss	8,700
Securities, available-for-sale, allowance for credit loss	731	1,140
Proceeds from Sale of Debt Securities, Available-for-sale	0	1,530	$ 4,636
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Accrued interest receivable	1,100
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value AFS in unrealized loss with an ACL	780	500
Available-for-sale securities in unrealized loss position, accumulated loss	$ 1	1
Number of securities | Investment	36
Securities, available-for-sale, allowance for credit loss	$ 731	1,140	$ 929
Equity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0	0
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Number of securities | Investment	1
Other Noninterest Income [Member] | Equity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Proceeds from sale	$ (17)	$ (198)