Loans and Allowance for Loan Losses (Details 9) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	$ 16,100	$ 15,444	$ 15,523	$ 14,855
Provision for loan losses	400	500	1,300	1,500
Loan charge-offs	(556)	(399)	(1,159)	(962)
Loan recoveries	196	34	476	186
Net loan charge-offs	(360)	(365)	(683)	(776)
Balance, end of period	$ 16,140	$ 15,579	$ 16,140	$ 15,579
Net charge-offs to average loans (annualized)	0.09%	0.11%	0.06%	0.08%
Allowance for loan losses to gross loans	1.00%	1.17%
Allowance for loan losses to nonperforming loans	270.53%	278.05%
Commercial [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period			$ 9,937
Balance, end of period	$ 10,640		10,640
Commercial [Member] | Owner occupied RE [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	2,699	$ 2,964	2,534	$ 2,843
Provision for loan losses	71	(141)	236	(20)
Loan charge-offs
Loan recoveries
Net loan charge-offs
Balance, end of period	2,770	2,823	2,770	2,823
Commercial [Member] | Non-owner occupied RE [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	3,581	2,981	3,230	2,778
Provision for loan losses	379	634	857	1,257
Loan charge-offs			(234)	(433)
Loan recoveries	25	1	132	14
Net loan charge-offs	25	1	(102)	(419)
Balance, end of period	3,985	3,616	3,985	3,616
Commercial [Member] | Business [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	3,849	3,857	3,848	4,123
Provision for loan losses	(17)	213	(31)	31
Loan charge-offs	(536)	(388)	(655)	(518)
Loan recoveries	89	31	223	77
Net loan charge-offs	(447)	(357)	(432)	(441)
Balance, end of period	3,385	3,713	3,385	3,713
Commercial [Member] | Construction [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	544	350	325	295
Provision for loan losses	(44)	(122)	175	(67)
Loan charge-offs
Loan recoveries
Net loan charge-offs
Balance, end of period	500	228	500	228
Consumer [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period			5,586
Balance, end of period	5,500		5,500
Consumer [Member] | Other [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	268	295	281	309
Provision for loan losses	22	(1)	41	(14)
Loan charge-offs	(20)	(11)	(54)	(11)
Loan recoveries	1	1	3
Net loan charge-offs	(19)	(10)	(51)	(11)
Balance, end of period	271	284	271	284
Consumer [Member] | Real Estate [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	3,446	3,061	3,495	2,780
Provision for loan losses	89	160	114	359
Loan charge-offs			(76)
Loan recoveries	1	1	3	83
Net loan charge-offs	1	1	(73)	83
Balance, end of period	3,536	3,222	3,536	3,222
Consumer [Member] | Home equity [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	1,431	1,608	1,600	1,475
Provision for loan losses	(93)	(196)	(157)	(75)
Loan charge-offs			(140)
Loan recoveries	80		115	12
Net loan charge-offs	80		(25)	12
Balance, end of period	1,418	1,412	1,418	1,412
Consumer [Member] | Construction [Member]
Financing Receivable, Allowance For Credit Losses [Roll Forward]
Balance, beginning of period	282	328	210	252
Provision for loan losses	(7)	(47)	65	29
Loan charge-offs
Loan recoveries
Net loan charge-offs
Balance, end of period	$ 275	$ 281	$ 275	$ 281