Available for Sale Securities - Summary of Gross Unrealized Losses on Securities Available-for-sale and Fair Values (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 21,297	$ 30,114
Unrealized Loss	(280)	(1,786)
Fair Value	81,465	83,955
Unrealized Loss	(15,510)	(13,961)
Fair Value	102,762	114,069
Unrealized Loss	(15,790)	(15,747)
U.S. Treasury notes [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	0
Unrealized Loss	0	0
Fair Value	7,142	26,627
Unrealized Loss	(1,093)	(2,970)
Fair Value	7,142	26,627
Unrealized Loss	(1,093)	(2,970)
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value	339	5,088
Unrealized Loss	(1)	(396)
Fair Value	15,572	12,145
Unrealized Loss	(3,938)	(3,333)
Fair Value	15,911	17,233
Unrealized Loss	(3,939)	(3,729)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value	20,958	19,084
Unrealized Loss	(279)	(1,310)
Fair Value	55,857	45,183
Unrealized Loss	(10,425)	(7,658)
Fair Value	76,815	64,267
Unrealized Loss	(10,704)	(8,968)
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	4,517
Unrealized Loss	0	(46)
Fair Value	1,928	0
Unrealized Loss	(25)	0
Fair Value	1,928	4,517
Unrealized Loss	(25)	(46)
Certificates of Deposit [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	1,425
Unrealized Loss	0	(34)
Fair Value	966	0
Unrealized Loss	(29)	0
Fair Value	966	1,425
Unrealized Loss	$ (29)	$ (34)