Investment Securities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021 USD ($) Investment	Dec. 31, 2020 USD ($) Investment	Dec. 31, 2019 USD ($)
Debt Securities, Available-for-sale [Line Items]
Carrying value of securities pledged to secure public deposits and other contractual obligations	$ 281,700,000	$ 249,600,000
Pledging requirements for credit derivatives and SWAP agreements - securities	$ 23,000,000	$ 32,600,000
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	$ 89,837,000	$ 0
Unrealized loss position, accumulated loss	984,000	0
Fair value AFS in unrealized loss with an ACL	179,992,000	18,253,000
Available-for-sale securities in unrealized loss position, accumulated loss	2,300,000	78,000
Debt securities in an unrealized loss, net of allowance	66,200,000
Debt securities unrealized accumulated loss	1,700,000
Securities, available-for-sale, allowance for credit loss	929,000	869,000
Proceeds from Sale of Debt Securities, Available-for-sale	4,636,000	66,421,000	$ 26,494,000
Accrued interest receivable	11,900,000
Equity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Proceeds from Sale of Debt Securities, Available-for-sale	0	0
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value AFS in unrealized loss with an ACL	779,000
Available-for-sale securities in unrealized loss position, accumulated loss	$ 1,000
Number of securities | Investment	22
Securities, available-for-sale, allowance for credit loss	$ 929,000	869,000	$ 0
Held-to-maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Accrued interest receivable	414,000
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Accrued interest receivable	593,000
Other Noninterest Income [Member] | Equity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Proceeds from sale	$ 161,000	$ (186,000)