Loans Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Rollfoward of the Allowance for Loan Losses for the Quarterly Report [Roll Forward]
Allowance for Credit Losses, Beginning Balance	$ 17,012	$ 16,038	$ 15,570
Charge-offs	(1,559)	(1,270)	(1,106)
Recoveries	397	211	227
Provision	2,736	2,033	1,347
Allowance for Credit Losses, Ending Balance	18,586	17,012	16,038
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for Loan Losses - Individually Evaluated for Impairment	106	0
Allowance for Loan Losses - Collectively Evaluated for Impairment	18,480	17,012
Ending Loan Balance - Individually Evaluated for Impairment	3,683	2,079
Ending Loan Balance - Collectively Evaluated for Impairment	1,947,087	1,751,189
Commercial [Member]
Rollfoward of the Allowance for Loan Losses for the Quarterly Report [Roll Forward]
Allowance for Credit Losses, Beginning Balance	1,017	1,827	2,100
Charge-offs	(2)	(97)	(62)
Recoveries	9	23	34
Provision	849	(736)	(245)
Allowance for Credit Losses, Ending Balance	1,873	1,017	1,827
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for Loan Losses - Individually Evaluated for Impairment	94	0
Allowance for Loan Losses - Collectively Evaluated for Impairment	1,779	1,017
Ending Loan Balance - Individually Evaluated for Impairment	489	0
Ending Loan Balance - Collectively Evaluated for Impairment	128,760	105,155
Commercial Real Estate [Member]
Rollfoward of the Allowance for Loan Losses for the Quarterly Report [Roll Forward]
Allowance for Credit Losses, Beginning Balance	5,677	4,520	4,128
Charge-offs	(380)	(195)	(7)
Recoveries	0	0	0
Provision	(793)	1,352	399
Allowance for Credit Losses, Ending Balance	4,504	5,677	4,520
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for Loan Losses - Individually Evaluated for Impairment	2	0
Allowance for Loan Losses - Collectively Evaluated for Impairment	4,502	5,677
Ending Loan Balance - Individually Evaluated for Impairment	1,537	890
Ending Loan Balance - Collectively Evaluated for Impairment	442,711	430,756
Other Consumer [Member]
Rollfoward of the Allowance for Loan Losses for the Quarterly Report [Roll Forward]
Allowance for Credit Losses, Beginning Balance	6,120	5,554	5,210
Charge-offs	(1,101)	(871)	(711)
Recoveries	388	182	193
Provision	2,197	1,255	862
Allowance for Credit Losses, Ending Balance	7,604	6,120	5,554
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for Loan Losses - Individually Evaluated for Impairment	0	0
Allowance for Loan Losses - Collectively Evaluated for Impairment	7,604	6,120
Ending Loan Balance - Individually Evaluated for Impairment	95	91
Ending Loan Balance - Collectively Evaluated for Impairment	602,732	537,270
Residential Portfolio Segment [Member]
Rollfoward of the Allowance for Loan Losses for the Quarterly Report [Roll Forward]
Allowance for Credit Losses, Beginning Balance	4,198	3,790	3,369
Charge-offs	(76)	(107)	(326)
Recoveries	0	6	0
Provision	483	509	747
Allowance for Credit Losses, Ending Balance	4,605	4,198	3,790
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for Loan Losses - Individually Evaluated for Impairment	10	0
Allowance for Loan Losses - Collectively Evaluated for Impairment	4,595	4,198
Ending Loan Balance - Individually Evaluated for Impairment	1,562	1,098
Ending Loan Balance - Collectively Evaluated for Impairment	772,884	678,008
Unallocated [Member]
Rollfoward of the Allowance for Loan Losses for the Quarterly Report [Roll Forward]
Allowance for Credit Losses, Beginning Balance	0	347	763
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	0	(347)	(416)
Allowance for Credit Losses, Ending Balance	0	0	$ 347
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for Loan Losses - Individually Evaluated for Impairment	0	0
Allowance for Loan Losses - Collectively Evaluated for Impairment	0	0
Ending Loan Balance - Individually Evaluated for Impairment	0	0
Ending Loan Balance - Collectively Evaluated for Impairment	$ 0	$ 0

No definition available.

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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=66008989&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=66902209&loc=d3e3602-108585

+ Details

Name:	us-gaap_ProvisionForLoanLeaseAndOtherLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_UnallocatedFinancingReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: