Investment Securities - Narrative (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) Investment	Mar. 31, 2022 USD ($)	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	$ 327,800		$ 429,400
Pledging requirements for credit derivatives and SWAP agreements - securities		$ 0	$ 0
Number of investments in non federal issuer representing more than 10% of shareholder's equity | Investment	0		0
Maximum investment in any single non-federal issuer representing shareholders equity	10.00%		10.00%
Fair value HTM in unrealized loss with no ACL	$ 133,147		$ 134,068
Unrealized loss included in fair value of securities HTM in unrealized loss position for which an ACL has not been recorded	18,200		20,659
Fair value AFS in unrealized loss with no ACL	278,825		266,810
Unrealized loss included in fair value of securities AFS in unrealized loss position for which an ACL has not been recorded	37,615		42,445
Fair value of securities AFS in unrealized loss position for which an ACL has been recorded, net of allowance	81,300
Unrealized loss position included in fair value of securities AFS in unrealized loss position for which an ACL has been recorded	8,900
Allowance for credit losses	1,432		1,140
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value AFS in unrealized loss with no ACL			500
Unrealized loss included in fair value of securities AFS in unrealized loss position for which an ACL has not been recorded			1
Allowance for credit losses	$ 1,432	1,275	$ 1,140	$ 929
Number of securities | Investment	39
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Accrued interest receivable	$ 1,200
Allowance for credit losses	1,400
Other Noninterest Income [Member] | Equity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Net realized gain on investment securities	$ (69)	$ 1