Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Allowance for loan losses
Loans, excluding consumer finance	$ 1,041,881	$ 1,040,154
Pass
Allowance for loan losses
Loans, excluding consumer finance	1,013,214	1,004,998
Special Mention
Allowance for loan losses
Loans, excluding consumer finance	17,794	20,526
Substandard
Allowance for loan losses
Loans, excluding consumer finance	8,132	11,628
Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	2,741	3,002
Real estate - residential mortgage
Allowance for loan losses
Loans, excluding consumer finance	215,166	218,298
Real estate - residential mortgage | Pass
Allowance for loan losses
Loans, excluding consumer finance	213,523	215,712
Real estate - residential mortgage | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	873	1,715
Real estate - residential mortgage | Substandard
Allowance for loan losses
Loans, excluding consumer finance	453	595
Real estate - residential mortgage | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	317	276
Real estate - construction | Construction lending
Allowance for loan losses
Loans, excluding consumer finance	36,159	49,659
Real estate - construction | Construction lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	36,159	49,659
Real estate - construction | Consumer lot lending
Allowance for loan losses
Loans, excluding consumer finance	17,686	12,488
Real estate - construction | Consumer lot lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	17,686	12,488
Commercial, financial and agricultural | Commercial real estate lending
Allowance for loan losses
Loans, excluding consumer finance	500,325	441,903
Commercial, financial and agricultural | Commercial real estate lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	477,246	415,506
Commercial, financial and agricultural | Commercial real estate lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	15,484	15,507
Commercial, financial and agricultural | Commercial real estate lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance	7,595	10,890
Commercial, financial and agricultural | Land acquisition and development lending
Allowance for loan losses
Loans, excluding consumer finance	37,242	37,724
Commercial, financial and agricultural | Land acquisition and development lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	37,242	37,724
Commercial, financial and agricultural | Builder line lending
Allowance for loan losses
Loans, excluding consumer finance	29,748	18,194
Commercial, financial and agricultural | Builder line lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	29,748	18,194
Commercial, financial and agricultural | Commercial business lending
Allowance for loan losses
Loans, excluding consumer finance	154,509	202,394
Commercial, financial and agricultural | Commercial business lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	150,974	196,743
Commercial, financial and agricultural | Commercial business lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	1,300	3,124
Commercial, financial and agricultural | Commercial business lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance		99
Commercial, financial and agricultural | Commercial business lending | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	2,235	2,428
Equity lines
Allowance for loan losses
Loans, excluding consumer finance	42,881	48,466
Equity lines | Pass
Allowance for loan losses
Loans, excluding consumer finance	42,475	48,140
Equity lines | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	137	132
Equity lines | Substandard
Allowance for loan losses
Loans, excluding consumer finance	84	3
Equity lines | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	185	191
Consumer
Allowance for loan losses
Loans, excluding consumer finance	8,165	11,028
Consumer | Pass
Allowance for loan losses
Loans, excluding consumer finance	8,161	10,832
Consumer | Special Mention
Allowance for loan losses
Loans, excluding consumer finance		48
Consumer | Substandard
Allowance for loan losses
Loans, excluding consumer finance		41
Consumer | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	$ 4	$ 107