Investment Securities - Summary of Securities with Gross Unrealized Losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses, Less than Twelve Months	$ (100)	$ (282)
Fair Value, Less than Twelve Months	5,118	10,636
Gross Unrealized Losses, Twelve Months and Over	(6,313)	(6,030)
Fair Value, Twelve Months and Over	48,182	43,509
Mortgage-backed Securities, Principally Obligations of US Federal Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses, Less than Twelve Months	(30)	(78)
Fair Value, Less than Twelve Months	1,988	5,797
Gross Unrealized Losses, Twelve Months and Over	(4,733)	(4,714)
Fair Value, Twelve Months and Over	36,024	33,971
State and Municipalities [Member]
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses, Less than Twelve Months	(70)	(204)
Fair Value, Less than Twelve Months	3,130	4,839
Gross Unrealized Losses, Twelve Months and Over	(1,550)	(1,296)
Fair Value, Twelve Months and Over	10,005	7,371
Agency Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses, Less than Twelve Months	0	0
Fair Value, Less than Twelve Months	0	0
Gross Unrealized Losses, Twelve Months and Over	(30)	(20)
Fair Value, Twelve Months and Over	$ 2,153	$ 2,167