Loans and Allowance for Loan Losses - Credit Quality (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	$ 1,180,522	$ 1,168,797
Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	76,674	78,086
Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	3,268	6,490
Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	2,513	2,535
Non-accrual and non-performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	7,844	4,860
Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	90,299	91,971
Commercial, financial, and agricultural
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	205,657	199,022
Commercial, financial, and agricultural | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	16,305	16,288
Commercial, financial, and agricultural | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	1,258	3,249
Commercial, financial, and agricultural | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	521	532
Commercial, financial, and agricultural | Non-accrual and non-performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	3,111	982
Commercial, financial, and agricultural | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	21,195	21,051
Residential real estate | Construction
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	23,913	23,035
Residential real estate | Construction | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	601	763
Residential real estate | Construction | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	0
Residential real estate | Construction | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	0
Residential real estate | Construction | Non-accrual and non-performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	0
Residential real estate | Construction | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	601	763
Residential real estate | Mortgages
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	246,859	252,643
Residential real estate | Mortgages | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	14,902	15,280
Residential real estate | Mortgages | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	1,499	2,291
Residential real estate | Mortgages | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	1,554	1,615
Residential real estate | Mortgages | Non-accrual and non-performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	3,211	2,241
Residential real estate | Mortgages | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	21,166	21,427
Commercial real estate | Construction
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	87,497	84,998
Commercial real estate | Construction | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	7,682	8,484
Commercial real estate | Construction | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	273
Commercial real estate | Construction | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	0
Commercial real estate | Construction | Non-accrual and non-performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	408	137
Commercial real estate | Construction | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	8,090	8,894
Commercial real estate | Mortgages
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	585,900	576,635
Commercial real estate | Mortgages | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	37,184	37,271
Commercial real estate | Mortgages | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	511	677
Commercial real estate | Mortgages | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	350	352
Commercial real estate | Mortgages | Non-accrual and non-performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	1,068	1,359
Commercial real estate | Mortgages | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	39,113	39,659
Installment and other consumer
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	30,696	32,464
Installment and other consumer | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	0
Installment and other consumer | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	0
Installment and other consumer | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	88	36
Installment and other consumer | Non-accrual and non-performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	46	141
Installment and other consumer | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	$ 134	$ 177