Loans - Loans Portfolio by Internal Risk Grading (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 1,288,693	$ 1,164,821	[1]
Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	236,418	208,717
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	722,415	625,218
Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	132,322	114,258
Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	590,093	510,960
Commercial real estate | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	590,093	510,960
Residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	324,885	325,855
Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	211,305	215,104
Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	113,580	110,751
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,975	5,031
Consumer | Performing
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,965	5,003
Consumer | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Total Loans	10	28
Pass | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	235,653	208,098
Pass | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	128,538	112,729
Pass | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	580,241	501,081
Pass | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	198,350	199,278
Pass | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	111,640	108,799
Special Mention | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	367	592
Special Mention | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,072	902
Special Mention | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,126	4,859
Special Mention | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	8,771	10,600
Special Mention | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,339	1,257
Substandard | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	398	27
Substandard | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,712	627
Substandard | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,726	5,020
Substandard | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,184	5,226
Substandard | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	601	695
Doubtful | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Doubtful | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Doubtful | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Doubtful | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Doubtful | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 0	$ 0

[1] Derived from audited consolidated financial statements.