Loans - Past Due (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	$ 4,582	$ 5,438
90 Days Plus Past Due and Still Accruing	1,061	587
Non- Accrual Loans	2,428	2,965
Current	1,215,376	1,159,383
Total Loans	1,219,958	1,164,821	[1]
Commercial
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	213	69
90 Days Plus Past Due and Still Accruing		0
Non- Accrual Loans	47	19
Current	219,242	208,648
Total Loans	219,455	208,717
Commercial real estate
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Loans	668,760	625,218
Commercial real estate | Construction and land development
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	306	136
90 Days Plus Past Due and Still Accruing	61	0
Non- Accrual Loans	68	64
Current	130,385	114,122
Total Loans	130,691	114,258
Commercial real estate | Real estate
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	1,140	1,239
90 Days Plus Past Due and Still Accruing	276	339
Non- Accrual Loans	769	773
Current	536,929	509,721
Total Loans	538,069	510,960
Residential
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Loans	326,879	325,855
Residential | Real estate
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	2,540	3,447
90 Days Plus Past Due and Still Accruing	724	248
Non- Accrual Loans	1,327	1,802
Current	213,495	211,657
Total Loans	216,035	215,104
Residential | Home equity
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	368	518
90 Days Plus Past Due and Still Accruing	0	0
Non- Accrual Loans	207	289
Current	110,476	110,233
Total Loans	110,844	110,751
Consumer
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	15	29
90 Days Plus Past Due and Still Accruing	0	0
Non- Accrual Loans	10	18
Current	4,849	5,002
Total Loans	4,864	5,031
30- 59 Days Past Due
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	615	1,625
30- 59 Days Past Due | Commercial
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	27	50
30- 59 Days Past Due | Commercial real estate | Construction and land development
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	0	60
30- 59 Days Past Due | Commercial real estate | Real estate
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	95	0
30- 59 Days Past Due | Residential | Real estate
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	330	1,280
30- 59 Days Past Due | Residential | Home equity
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	161	229
30- 59 Days Past Due | Consumer
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	2	6
60-89 Days Past Due
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	478	261
60-89 Days Past Due | Commercial
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	139	0
60-89 Days Past Due | Commercial real estate | Construction and land development
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	177	12
60-89 Days Past Due | Commercial real estate | Real estate
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	0	127
60-89 Days Past Due | Residential | Real estate
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	159	117
60-89 Days Past Due | Residential | Home equity
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	0	0
60-89 Days Past Due | Consumer
Analysis by portfolio segment of the entity's past due loans [Abstract]
Total Past Due	$ 3	$ 5

[1] Derived from audited consolidated financial statements.