Fair Value Measurements - Summary of Fair Value of Assets and Liabilities Measured on Recurring Basis (Detail) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets:
Small Business Administration loan pools	$ 1,003	$ 1,084
Obligations of state and political subdivisions	43,892	48,482
Mortgage backed securities	48,307	54,217
Total	93,202	103,783
Fair Value, Inputs, Level 1 [Member]
Assets:
Small Business Administration loan pools	0	0
Obligations of state and political subdivisions	0	0
Mortgage backed securities	0	0
Total	0	0
Fair Value, Inputs, Level 2 [Member]
Assets:
Small Business Administration loan pools	1,003	1,084
Obligations of state and political subdivisions	43,892	48,482
Mortgage backed securities	48,307	54,217
Total	93,202	103,783
Fair Value, Inputs, Level 3 [Member]
Assets:
Small Business Administration loan pools	0	0
Obligations of state and political subdivisions	0	0
Mortgage backed securities	0	0
Total	$ 0	$ 0