Allowance for Loan Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	$ 4,965	$ 4,528	$ 4,643	$ 4,289
Financing Receivable, Allowance for Credit Losses, Charge-offs	(489)	(8)	(573)	(468)
Financing Receivable, Allowance for Credit Losses, Recoveries	194	58	500	1,357
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	(295)	50	(73)	889
Provision for loan losses	0	0	100	(600)
Financing Receivable, Allowance for Credit Losses	4,670	4,578	4,670	4,578
Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	677	506	540	523
Financing Receivable, Allowance for Credit Losses, Charge-offs	(449)	0	(449)	(83)
Financing Receivable, Allowance for Credit Losses, Recoveries	39	3	45	26
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	(410)	3	(404)	(57)
Provision for loan losses	237	6	368	49
Financing Receivable, Allowance for Credit Losses	504	515	504	515
Construction And Land Development Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	874	744	812	669
Financing Receivable, Allowance for Credit Losses, Charge-offs	0	0	0	0
Financing Receivable, Allowance for Credit Losses, Recoveries	133	5	347	1,207
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	133	5	347	1,207
Provision for loan losses	(156)	(76)	(308)	(1,203)
Financing Receivable, Allowance for Credit Losses	851	673	851	673
Commercial Real Estate Loans, Total [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	2,121	2,092	2,071	1,879
Financing Receivable, Allowance for Credit Losses, Charge-offs	0	0	0	(194)
Financing Receivable, Allowance for Credit Losses, Recoveries	0	0	0	0
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	0	0	0	(194)
Provision for loan losses	(60)	140	(10)	547
Financing Receivable, Allowance for Credit Losses	2,061	2,232	2,061	2,232
Residential Real Estate Loans, Total [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	1,119	1,061	1,107	1,059
Financing Receivable, Allowance for Credit Losses, Charge-offs	(30)	(7)	(108)	(162)
Financing Receivable, Allowance for Credit Losses, Recoveries	20	49	97	115
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	(10)	42	(11)	(47)
Provision for loan losses	(32)	(83)	(19)	8
Financing Receivable, Allowance for Credit Losses	1,077	1,020	1,077	1,020
Consumer Installment and Revolving Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	174	125	113	159
Financing Receivable, Allowance for Credit Losses, Charge-offs	(10)	(1)	(16)	(29)
Financing Receivable, Allowance for Credit Losses, Recoveries	2	1	11	9
Financing Receivable Allowance For Credit Losses Net Chargeoffs Recoveries	(8)	0	(5)	(20)
Provision for loan losses	11	13	69	(1)
Financing Receivable, Allowance for Credit Losses	$ 177	$ 138	$ 177	$ 138