Securities - Amortized Cost and Fair Value of Securities with Gross Unrealized Gains and Losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 439,259	$ 433,962
Gross Unrealized Gains	83	3,032
Gross Unrealized Losses	(39,655)	(7,063)
Fair Value	399,687	429,931
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	105,435	90,775
Gross Unrealized Losses	(8,335)	(1,598)
Fair Value	97,100	89,177
U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	155,489	159,673
Gross Unrealized Gains		695
Gross Unrealized Losses	(13,977)	(3,482)
Fair Value	141,512	156,886
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	105,994	118,550
Gross Unrealized Gains		839
Gross Unrealized Losses	(12,013)	(1,462)
Fair Value	93,981	117,927
State and Local Governments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	72,341	64,964
Gross Unrealized Gains	83	1,498
Gross Unrealized Losses	(5,330)	(521)
Fair Value	$ 67,094	$ 65,941