Loans Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	$ 19,057	$ 17,216	$ 18,586	$ 17,012
Charge-offs	(264)	(305)	(634)	(575)
Recoveries	218	109	313	225
Provision	629	422	1,375	780
Allowance for Loan Losses, Ending Balance	19,640	17,442	19,640	17,442
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	185	146	185	146	$ 106
Allowance for loan losses - Loans Collectively Evaluated for Impairment	19,455	17,296	19,455	17,296	18,480
Ending Loan Balance - Individually Evaluated for Impairment	2,492	2,859	2,492	2,859	3,683
Ending Loan Balance - Collectively Evaluated for Impairment	2,055,370	1,875,773	2,055,370	1,875,773	1,947,087
Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	1,119	939	1,873	1,017
Charge-offs	0	(23)	(16)	(39)
Recoveries	0	5	0	12
Provision	(175)	4	(913)	(65)
Allowance for Loan Losses, Ending Balance	944	925	944	925
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	88	112	88	112	94
Allowance for loan losses - Loans Collectively Evaluated for Impairment	856	813	856	813	1,779
Ending Loan Balance - Individually Evaluated for Impairment	489	503	489	503	489
Ending Loan Balance - Collectively Evaluated for Impairment	118,392	125,756	118,392	125,756	128,760
Commercial Real Estate Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	5,412	5,449	4,504	5,677
Charge-offs	0	0	0	0
Recoveries	3	0	12	0
Provision	423	(466)	1,322	(694)
Allowance for Loan Losses, Ending Balance	5,838	4,983	5,838	4,983
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	44	0	44	0	2
Allowance for loan losses - Loans Collectively Evaluated for Impairment	5,794	4,983	5,794	4,983	4,502
Ending Loan Balance - Individually Evaluated for Impairment	813	1,178	813	1,178	1,537
Ending Loan Balance - Collectively Evaluated for Impairment	463,580	440,631	463,580	440,631	442,711
Consumer Loans Financing
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	8,019	6,702	7,604	6,120
Charge-offs	(248)	(277)	(595)	(530)
Recoveries	215	104	301	213
Provision	351	776	1,027	1,502
Allowance for Loan Losses, Ending Balance	8,337	7,305	8,337	7,305
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	8,337	7,305	8,337	7,305	7,604
Ending Loan Balance - Individually Evaluated for Impairment	110	88	110	88	95
Ending Loan Balance - Collectively Evaluated for Impairment	661,798	578,666	661,798	578,666	602,732
Residential
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Loan Losses, Beginning Balance	4,507	4,126	4,605	4,198
Charge-offs	(16)	(5)	(23)	(6)
Recoveries	0	0	0	0
Provision	30	108	(61)	37
Allowance for Loan Losses, Ending Balance	4,521	4,229	4,521	4,229
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses - Loans Individually Evaluated for Impairment	53	34	53	34	10
Allowance for loan losses - Loans Collectively Evaluated for Impairment	4,468	4,195	4,468	4,195	4,595
Ending Loan Balance - Individually Evaluated for Impairment	1,080	1,090	1,080	1,090	1,562
Ending Loan Balance - Collectively Evaluated for Impairment	$ 811,600	$ 730,720	$ 811,600	$ 730,720	$ 772,884

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A valuation allowance for financing receivables that are expected to be uncollectible.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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Amount of direct write-downs of financing receivables charged against the allowance.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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