Allowance for Loan Losses - Balance in Allowance for Loan Losses and Recorded Investment in Loans by Impairment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	$ 1,931	$ 909
Allowance for Loan Losses, Collectively Evaluated for Impairment	18,069	17,491
Total Allowance for Loan Losses	20,000	18,400
Unaccreted Credit Component Other Loans	2,391	3,005
Loans, Individually Evaluated for Impairment	13,324	13,436
Loans, Collectively Evaluated for Impairment	3,889,005	3,638,069
Total loans	3,905,684	3,655,262
Unaccreted Credit Component Other Loans	251,559	260,577
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	3,355	3,757
Residential Properties
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	9,908	9,715
Total Allowance for Loan Losses	9,908	9,715
Unaccreted Credit Component Other Loans	229	248
Loans, Collectively Evaluated for Impairment	2,799,370	2,581,245
Total loans	2,799,370	2,581,245
Unaccreted Credit Component Other Loans	26,407	26,605
Commercial Real Estate
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	4,390	4,399
Total Allowance for Loan Losses	4,390	4,399
Unaccreted Credit Component Other Loans	1,343	1,449
Loans, Individually Evaluated for Impairment	3,982	4,037
Loans, Collectively Evaluated for Impairment	703,781	691,632
Total loans	708,458	696,748
Unaccreted Credit Component Other Loans	167,910	168,057
Commercial Real Estate \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	695	1,079
Commercial and Industrial Loans
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	1,931	909
Allowance for Loan Losses, Collectively Evaluated for Impairment	3,162	2,715
Total Allowance for Loan Losses	5,093	3,624
Unaccreted Credit Component Other Loans	789	1,204
Loans, Individually Evaluated for Impairment	9,342	9,399
Loans, Collectively Evaluated for Impairment	326,121	299,539
Total loans	337,295	310,779
Unaccreted Credit Component Other Loans	54,025	62,849
Commercial and Industrial Loans \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	1,832	1,841
Consumer Loans
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	274	267
Total Allowance for Loan Losses	274	267
Unaccreted Credit Component Other Loans	25	100
Loans, Collectively Evaluated for Impairment	29,361	29,330
Total loans	29,361	29,330
Unaccreted Credit Component Other Loans	2,686	2,899
Land
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	335	395
Total Allowance for Loan Losses	335	395
Unaccreted Credit Component Other Loans	5	4
Loans, Collectively Evaluated for Impairment	30,372	36,323
Total loans	31,200	37,160
Unaccreted Credit Component Other Loans	531	167
Land \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	$ 828	$ 837

Allowance for loan losses in unaccreted credit component other loans.

No definition available.

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- Definition

Loans and lease receivable in unaccreted credit component other loan.

+ References

No definition available.

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- Definition

Loans and leases receivable allowance impaired.

+ References

No definition available.

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- Definition

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

+ 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 (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

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

+ References

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- Definition

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

+ 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 (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

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

+ 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 (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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- Definition

Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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