Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Allowance for loan losses
Loans, excluding consumer finance	$ 776,049	$ 765,966
Loans	1,075,641	1,062,120
Pass
Allowance for loan losses
Loans, excluding consumer finance	756,244	744,812
Special Mention
Allowance for loan losses
Loans, excluding consumer finance	16,281	17,851
Substandard
Allowance for loan losses
Loans, excluding consumer finance	1,910	1,802
Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	1,614	1,501
Real estate - residential mortgage
Allowance for loan losses
Loans, excluding consumer finance	183,697	184,901
Loans	183,697	184,901
Real estate - residential mortgage | Pass
Allowance for loan losses
Loans, excluding consumer finance	179,808	180,232
Real estate - residential mortgage | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	2,210	2,832
Real estate - residential mortgage | Substandard
Allowance for loan losses
Loans, excluding consumer finance	978	1,243
Real estate - residential mortgage | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	701	594
Real estate - construction
Allowance for loan losses
Loans	65,588	54,461
Real estate - construction | Construction Lending
Allowance for loan losses
Loans, excluding consumer finance	53,319	42,051
Real estate - construction | Construction Lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	53,319	42,051
Real estate - construction | Consumer lot lending
Allowance for loan losses
Loans, excluding consumer finance	12,269	12,410
Real estate - construction | Consumer lot lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	12,269	12,410
Commercial, financial and agricultural
Allowance for loan losses
Loans	459,820	455,935
Commercial, financial and agricultural | Commercial real estate lending
Allowance for loan losses
Loans, excluding consumer finance	303,080	310,833
Commercial, financial and agricultural | Commercial real estate lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	299,627	306,578
Commercial, financial and agricultural | Commercial real estate lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	3,008	3,801
Commercial, financial and agricultural | Commercial real estate lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance	445	454
Commercial, financial and agricultural | Land acquisition and development lending
Allowance for loan losses
Loans, excluding consumer finance	45,245	43,404
Commercial, financial and agricultural | Land acquisition and development lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	35,151	33,156
Commercial, financial and agricultural | Land acquisition and development lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	10,094	10,248
Commercial, financial and agricultural | Builder line lending
Allowance for loan losses
Loans, excluding consumer finance	29,180	31,201
Commercial, financial and agricultural | Builder line lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	28,743	31,201
Commercial, financial and agricultural | Builder line lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance	437
Commercial, financial and agricultural | Commercial business lending
Allowance for loan losses
Loans, excluding consumer finance	82,315	70,497
Commercial, financial and agricultural | Commercial business lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	81,735	69,897
Commercial, financial and agricultural | Commercial business lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	551	576
Commercial, financial and agricultural | Commercial business lending | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	29	24
Equity lines
Allowance for loan losses
Loans, excluding consumer finance	54,111	55,660
Loans	54,111	55,660
Equity lines | Pass
Allowance for loan losses
Loans, excluding consumer finance	52,895	54,289
Equity lines | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	409	389
Equity lines | Substandard
Allowance for loan losses
Loans, excluding consumer finance	47	99
Equity lines | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	760	883
Consumer
Allowance for loan losses
Loans, excluding consumer finance	12,833	15,009
Loans	12,833	15,009
Consumer | Pass
Allowance for loan losses
Loans, excluding consumer finance	12,697	14,998
Consumer | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	9	5
Consumer | Substandard
Allowance for loan losses
Loans, excluding consumer finance	3	$ 6
Consumer | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	$ 124