Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Allowance for loan losses
Loans, excluding consumer finance	$ 774,795	$ 765,966
Loans	1,088,538	1,062,120
Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	759,920	744,812
Special Mention [Member]
Allowance for loan losses
Loans, excluding consumer finance	12,017	17,851
Substandard [Member]
Allowance for loan losses
Loans, excluding consumer finance	1,874	1,802
Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	984	1,501
Real estate - residential mortgage
Allowance for loan losses
Loans, excluding consumer finance	179,960	184,901
Loans	179,960	184,901
Real estate - residential mortgage | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	176,844	180,232
Real estate - residential mortgage | Special Mention [Member]
Allowance for loan losses
Loans, excluding consumer finance	1,313	2,832
Real estate - residential mortgage | Substandard [Member]
Allowance for loan losses
Loans, excluding consumer finance	1,240	1,243
Real estate - residential mortgage | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	563	594
Real estate - construction
Allowance for loan losses
Loans	62,554	54,461
Real estate - construction | Construction lending
Allowance for loan losses
Loans, excluding consumer finance	48,164	42,051
Real estate - construction | Construction lending | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	48,164	42,051
Real estate - construction | Consumer lot lending
Allowance for loan losses
Loans, excluding consumer finance	14,390	12,410
Real estate - construction | Consumer lot lending | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	14,390	12,410
Commercial, financial and agricultural
Allowance for loan losses
Loans	466,349	455,935
Commercial, financial and agricultural | Commercial real estate lending
Allowance for loan losses
Loans, excluding consumer finance	312,384	310,833
Commercial, financial and agricultural | Commercial real estate lending | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	311,126	306,578
Commercial, financial and agricultural | Commercial real estate lending | Special Mention [Member]
Allowance for loan losses
Loans, excluding consumer finance	867	3,801
Commercial, financial and agricultural | Commercial real estate lending | Substandard [Member]
Allowance for loan losses
Loans, excluding consumer finance	391	454
Commercial, financial and agricultural | Land acquisition and development lending
Allowance for loan losses
Loans, excluding consumer finance	41,241	43,404
Commercial, financial and agricultural | Land acquisition and development lending | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	32,017	33,156
Commercial, financial and agricultural | Land acquisition and development lending | Special Mention [Member]
Allowance for loan losses
Loans, excluding consumer finance	9,224	10,248
Commercial, financial and agricultural | Builder line lending
Allowance for loan losses
Loans, excluding consumer finance	29,606	31,201
Commercial, financial and agricultural | Builder line lending | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	29,606	31,201
Commercial, financial and agricultural | Commercial business lending
Allowance for loan losses
Loans, excluding consumer finance	83,118	70,497
Commercial, financial and agricultural | Commercial business lending | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	82,673	69,897
Commercial, financial and agricultural | Commercial business lending | Special Mention [Member]
Allowance for loan losses
Loans, excluding consumer finance	376	576
Commercial, financial and agricultural | Commercial business lending | Substandard [Member]
Allowance for loan losses
Loans, excluding consumer finance	69
Commercial, financial and agricultural | Commercial business lending | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance		24
Equity lines
Allowance for loan losses
Loans, excluding consumer finance	52,411	55,660
Loans	52,411	55,660
Equity lines | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	51,699	54,289
Equity lines | Special Mention [Member]
Allowance for loan losses
Loans, excluding consumer finance	237	389
Equity lines | Substandard [Member]
Allowance for loan losses
Loans, excluding consumer finance	173	99
Equity lines | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	302	883
Consumer
Allowance for loan losses
Loans, excluding consumer finance	13,521	15,009
Loans	13,521	15,009
Consumer | Pass [Member]
Allowance for loan losses
Loans, excluding consumer finance	13,401	14,998
Consumer | Special Mention [Member]
Allowance for loan losses
Loans, excluding consumer finance		5
Consumer | Substandard [Member]
Allowance for loan losses
Loans, excluding consumer finance	1	$ 6
Consumer | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	$ 119