Premises and Equipment - Components of Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 23,920	$ 22,042
Accumulated depreciation	10,054	9,409
Premises and equipment, net	13,866	12,633
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	2,550	2,550
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	14,420	12,664
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	6,621	6,499
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 329	$ 329