Loans and Allowance for Loan Losses - Schedule of Categories of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Total gross loans	$ 450,034	$ 443,491
Less allowance for loan losses	(4,807)	(5,113)	$ (2,708)	$ (2,231)
Total loans	445,227	438,378
Commercial loans
Accounts Notes And Loans Receivable [Line Items]
Total gross loans	99,728	103,277
Less allowance for loan losses	(1,221)	(1,397)	(1,055)	(568)
Commercial real estate
Accounts Notes And Loans Receivable [Line Items]
Total gross loans	254,577	246,167
Less allowance for loan losses	(1,820)	(1,821)	(781)	(792)
Residential real estate
Accounts Notes And Loans Receivable [Line Items]
Total gross loans	88,114	85,789
Less allowance for loan losses	(1,381)	(1,471)	$ (567)	$ (572)
Installment loans
Accounts Notes And Loans Receivable [Line Items]
Total gross loans	$ 7,615	$ 8,258