Loans - Loans Portfolio by Internal Risk Grading (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 1,219,958	$ 1,164,821	[1]
Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	219,455	208,717
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	668,760	625,218
Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	130,691	114,258
Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	538,069	510,960
Commercial real estate | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	538,069	510,960
Residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	326,879	325,855
Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	216,035	215,104
Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	110,844	110,751
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,864	5,031
Consumer | Performing
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,849	5,003
Consumer | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Total Loans	15	28
Pass | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	218,801	208,098
Pass | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	129,480	112,729
Pass | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	529,324	501,081
Pass | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	201,774	199,278
Pass | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	108,943	108,799
Special Mention | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	462	592
Special Mention | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	409	902
Special Mention | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,928	4,859
Special Mention | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	8,842	10,600
Special Mention | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,296	1,257
Substandard | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	192	27
Substandard | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	802	627
Substandard | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,817	5,020
Substandard | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,419	5,226
Substandard | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	605	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.