Loans - Loans Portfolio by Internal Risk Grading (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 1,360,063	$ 1,357,476	[1]
Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	289,301	285,972
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	752,892	753,040
Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	93,759	97,240
Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	659,133	655,800
Commercial real estate | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	659,133	655,800
Residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	312,644	313,371
Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	212,665	209,438
Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	99,979	103,933
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,226	5,093
Consumer | Performing
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,224	5,093
Consumer | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2	0
Pass | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	285,940	285,092
Pass | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	91,200	93,000
Pass | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	651,835	647,519
Pass | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	207,747	204,261
Pass | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	99,640	103,541
Special Mention | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,768	154
Special Mention | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	1,840
Special Mention | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,911	4,403
Special Mention | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,152	1,685
Special Mention | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Substandard | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,593	726
Substandard | Commercial real estate | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,559	2,400
Substandard | Commercial real estate | Other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,387	3,878
Substandard | Residential | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,766	3,492
Substandard | Residential | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total Loans	339	392
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.