Investment Securities - Summary of Fixed Maturity Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 59,539	$ 60,573
Gross Unrealized Gains	13	21
Gross Unrealized Losses	(6,514)	(6,312)
Fair Value	53,038	54,282
Mortgage-backed Securities, Principally Obligations of US Federal Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	43,804	44,653
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(5,074)	(4,791)
Fair Value	38,730	39,862
State and Municipalities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	13,550	13,733
Gross Unrealized Gains	13	21
Gross Unrealized Losses	(1,415)	(1,501)
Fair Value	12,148	12,253
Agency Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,185	2,187
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(25)	(20)
Fair Value	$ 2,160	$ 2,167