Premises and Equipment, Net - Cost and Accumulated Depreciation of Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Premises and equipment	$ 33,326	$ 33,411
Accumulated depreciation	(16,797)	(15,919)
Premises and equipment, net	16,529	17,492
Land [Member]
Property Plant And Equipment [Line Items]
Premises and equipment	4,246	4,254
Buildings and Improvements [Member]
Property Plant And Equipment [Line Items]
Premises and equipment	22,807	22,709
Furniture and Equipment [Member]
Property Plant And Equipment [Line Items]
Premises and equipment	6,178	6,410
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Premises and equipment	$ 95	$ 38