Allowance For Loan Loss Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financing Receivable Allowance For Credit Loss Additional Information [Line Items]
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	$ 4,696		$ 4,561
Financing Receivable, Collectively Evaluated for Impairment	441,952		429,127
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	36		27
Financing Receivable, Individually Evaluated for Impairment	2,361		2,066
Allowance for loan losses	4,732	$ 4,757	4,588
Loans and Leases Receivable, Gross, Carrying Amount	444,313	454,177	431,193
Commercial and Industrial Loans [Member]
Financing Receivable Allowance For Credit Loss Additional Information [Line Items]
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	694		524
Financing Receivable, Collectively Evaluated for Impairment	57,847		50,222
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	30		0
Financing Receivable, Individually Evaluated for Impairment	30		6
Allowance for loan losses	724		524
Loans and Leases Receivable, Gross, Carrying Amount	57,877	59,086	50,228
Construction And Land Development Loans [Member]
Financing Receivable Allowance For Credit Loss Additional Information [Line Items]
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	670		845
Financing Receivable, Collectively Evaluated for Impairment	35,910		45,076
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0
Financing Receivable, Individually Evaluated for Impairment	0		22
Allowance for loan losses	670		845
Loans and Leases Receivable, Gross, Carrying Amount	35,910	39,607	45,098
Commercial Real Estate Loans, Total [Member]
Financing Receivable Allowance For Credit Loss Additional Information [Line Items]
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	2,113		1,977
Financing Receivable, Collectively Evaluated for Impairment	232,014		216,701
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	6		27
Financing Receivable, Individually Evaluated for Impairment	2,331		2,038
Allowance for loan losses	2,119		2,004
Loans and Leases Receivable, Gross, Carrying Amount	234,345	239,033	218,739
Residential Real Estate Loans, Total [Member]
Financing Receivable Allowance For Credit Loss Additional Information [Line Items]
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,053		1,064
Financing Receivable, Collectively Evaluated for Impairment	106,496		108,096
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0
Financing Receivable, Individually Evaluated for Impairment	0		0
Allowance for loan losses	1,053		1,064
Loans and Leases Receivable, Gross, Carrying Amount	106,496	106,863	108,096
Consumer Installment and Revolving Loans [Member]
Financing Receivable Allowance For Credit Loss Additional Information [Line Items]
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	166		151
Financing Receivable, Collectively Evaluated for Impairment	9,685		9,032
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0
Financing Receivable, Individually Evaluated for Impairment	0		0
Allowance for loan losses	166		151
Loans and Leases Receivable, Gross, Carrying Amount	$ 9,685	$ 9,588	$ 9,032