Loans and Allowance for Loan Losses - Summary of Loans by Major Class (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans and Allowance for Loan Losses
Total loans held for investment	$ 1,180,522	$ 1,168,797
Commercial, financial, and agricultural
Loans and Allowance for Loan Losses
Total loans held for investment	205,657	199,022
Residential real estate | Construction
Loans and Allowance for Loan Losses
Total loans held for investment	23,913	23,035
Residential real estate | Mortgages
Loans and Allowance for Loan Losses
Total loans held for investment	246,859	252,643
Commercial real estate | Construction
Loans and Allowance for Loan Losses
Total loans held for investment	87,497	84,998
Commercial real estate | Mortgages
Loans and Allowance for Loan Losses
Total loans held for investment	585,900	576,635
Installment and other consumer
Loans and Allowance for Loan Losses
Total loans held for investment	$ 30,696	$ 32,464