Investment Securities - Summary of Securities with Gross Unrealized Losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses, Less than Twelve Months	$ (206)	$ (375)
Fair Value, Less than Twelve Months	11,546	10,307
Gross Unrealized Losses, Twelve Months and Over	(5,337)	(5,958)
Fair Value, Twelve Months and Over	39,443	39,724
Mortgage-backed Securities, Principally Obligations of US Federal Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses, Less than Twelve Months	(146)	(106)
Fair Value, Less than Twelve Months	8,686	5,423
Gross Unrealized Losses, Twelve Months and Over	(4,025)	(4,696)
Fair Value, Twelve Months and Over	26,763	29,619
State and Municipalities [Member]
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses, Less than Twelve Months	(60)	(269)
Fair Value, Less than Twelve Months	2,860	4,884
Gross Unrealized Losses, Twelve Months and Over	(1,301)	(1,247)
Fair Value, Twelve Months and Over	12,514	9,939
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	(11)	(15)
Fair Value, Twelve Months and Over	$ 166	$ 166