Loans and Allowance for Loan Losses (Details 7) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	$ 1,094,195	$ 1,068,432
Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	53,632	71,786
Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	2,189	4,121
Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	3,940	4,684
Non-accrual
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	6,311	5,672
Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	66,072	86,263
Commercial Financial And Agricultural
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	200,628	192,238
Commercial Financial And Agricultural | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	7,378	9,868
Commercial Financial And Agricultural | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	94	658
Commercial Financial And Agricultural | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	458	500
Commercial Financial And Agricultural | Non-accrual
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	2,429	2,507
Commercial Financial And Agricultural | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	10,359	13,533
Residential Real Estate | Construction
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	28,285	26,492
Residential Real Estate | Construction | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	598	1,459
Residential Real Estate | Construction | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	462
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
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	598	1,921
Residential Real Estate | Mortgage
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	246,415	246,754
Residential Real Estate | Mortgage | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	8,584	9,978
Residential Real Estate | Mortgage | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	1,371	2,262
Residential Real Estate | Mortgage | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	2,410	3,116
Residential Real Estate | Mortgage | Non-accrual
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	2,775	1,956
Residential Real Estate | Mortgage | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	15,140	17,312
Commercial Real Estate | Construction
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	106,406	98,340
Commercial Real Estate | Construction | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	3,581	1,284
Commercial Real Estate | Construction | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	0	0
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
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	169	97
Commercial Real Estate | Construction | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	3,750	1,381
Commercial Real Estate | Mortgage
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	479,571	472,455
Commercial Real Estate | Mortgage | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	33,482	49,197
Commercial Real Estate | Mortgage | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	718	723
Commercial Real Estate | Mortgage | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	1,053	1,068
Commercial Real Estate | Mortgage | Non-accrual
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	653	936
Commercial Real Estate | Mortgage | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	35,906	51,924
Installment and Other Consumer
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	32,890	32,153
Installment and Other Consumer | Watch
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	9	0
Installment and Other Consumer | Substandard
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	6	16
Installment and Other Consumer | Performing TDRs
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	19	0
Installment and Other Consumer | Non-accrual
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	285	176
Installment and Other Consumer | Total
Credit quality of the loan portfolio using internal rating system reflecting management's risk assessment
Financing receivable	$ 319	$ 192