Loans Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	$ 19,640	$ 17,442	$ 18,586	$ 17,012
Charge-offs	(325)	(622)	(960)	(1,197)
Recoveries	102	75	416	300
Provision	586	800	1,961	1,580
Allowance for Loan Losses, Ending Balance	20,003	17,695	20,003	17,695
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	177	138	177	138	$ 106
Allowance for loan losses - Loans Collectively Evaluated for Impairment	19,826	17,557	19,826	17,557	18,480
Ending Loan Balance - Individually Evaluated for Impairment	3,423	3,275	3,423	3,275	3,683
Ending Loan Balance - Collectively Evaluated for Impairment	2,122,677	1,905,524	2,122,677	1,905,524	1,947,087
Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	944	925	1,873	1,017
Charge-offs	0	0	(16)	(2)
Recoveries	0	1	1	8
Provision	99	(46)	(815)	(143)
Allowance for Loan Losses, Ending Balance	1,043	880	1,043	880
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	84	104	84	104	94
Allowance for loan losses - Loans Collectively Evaluated for Impairment	959	776	959	776	1,779
Ending Loan Balance - Individually Evaluated for Impairment	489	489	489	489	489
Ending Loan Balance - Collectively Evaluated for Impairment	126,623	124,871	126,623	124,871	128,760
Commercial Real Estate Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	5,838	4,983	4,504	5,677
Charge-offs	0	(342)	0	(342)
Recoveries	0	0	12	0
Provision	81	446	1,403	(248)
Allowance for Loan Losses, Ending Balance	5,919	5,087	5,919	5,087
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	45	0	45	0	2
Allowance for loan losses - Loans Collectively Evaluated for Impairment	5,874	5,087	5,874	5,087	4,502
Ending Loan Balance - Individually Evaluated for Impairment	812	1,543	812	1,543	1,537
Ending Loan Balance - Collectively Evaluated for Impairment	469,310	439,172	469,310	439,172	442,711
Consumer Loans Financing
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	8,337	7,305	7,604	6,120
Charge-offs	(300)	(280)	(895)	(847)
Recoveries	102	74	403	292
Provision	551	509	1,578	2,043
Allowance for Loan Losses, Ending Balance	8,690	7,608	8,690	7,608
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	0	0	0	0	0
Allowance for loan losses - Loans Collectively Evaluated for Impairment	8,690	7,608	8,690	7,608	7,604
Ending Loan Balance - Individually Evaluated for Impairment	109	104	109	104	95
Ending Loan Balance - Collectively Evaluated for Impairment	694,079	591,925	694,079	591,925	602,732
Residential
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	4,521	4,229	4,605	4,198
Charge-offs	(25)	0	(49)	(6)
Recoveries	0	0	0	0
Provision	(145)	(109)	(205)	(72)
Allowance for Loan Losses, Ending Balance	4,351	4,120	4,351	4,120
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	48	34	48	34	10
Allowance for loan losses - Loans Collectively Evaluated for Impairment	4,303	4,086	4,303	4,086	4,595
Ending Loan Balance - Individually Evaluated for Impairment	2,013	1,139	2,013	1,139	1,562
Ending Loan Balance - Collectively Evaluated for Impairment	$ 832,665	$ 749,556	$ 832,665	$ 749,556	$ 772,884