Allowance for Loan Losses - Balance in Allowance for Loan Losses and Recorded Investment in Loans by Impairment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	$ 909
Allowance for Loan Losses, Collectively Evaluated for Impairment	17,491	$ 15,400
Total Allowance for Loan Losses	18,400	15,400
Unaccreted Credit Component Other Loans	3,005	432
Loans, Individually Evaluated for Impairment	13,436	8,994
Loans, Collectively Evaluated for Impairment	3,600,909	2,539,649
Total loans	3,655,262	2,552,016
Unaccreted Credit Component Other Loans	260,577	59,037
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	3,757	3,373
Residential Properties
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	9,715	6,669
Total Allowance for Loan Losses	9,715	6,669
Unaccreted Credit Component Other Loans	248	128
Loans, Individually Evaluated for Impairment		6,093
Loans, Collectively Evaluated for Impairment	2,581,245	1,774,796
Total loans	2,581,245	1,780,889
Unaccreted Credit Component Other Loans	26,605	12,373
Commercial Real Estate
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	4,399	2,983
Total Allowance for Loan Losses	4,399	2,983
Unaccreted Credit Component Other Loans	1,449	136
Loans, Individually Evaluated for Impairment	4,037	2,148
Loans, Collectively Evaluated for Impairment	691,632	474,634
Total loans	696,748	476,959
Unaccreted Credit Component Other Loans	168,057	24,796
Commercial Real Estate \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	1,079	177
Commercial and Industrial Loans
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	909
Allowance for Loan Losses, Collectively Evaluated for Impairment	2,715	5,227
Total Allowance for Loan Losses	3,624	5,227
Unaccreted Credit Component Other Loans	1,204	147
Loans, Individually Evaluated for Impairment	9,399	753
Loans, Collectively Evaluated for Impairment	299,539	233,992
Total loans	310,779	237,941
Unaccreted Credit Component Other Loans	62,849	20,165
Commercial and Industrial Loans \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	1,841	3,196
Consumer Loans
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	267	288
Total Allowance for Loan Losses	267	288
Unaccreted Credit Component Other Loans	100	19
Loans, Collectively Evaluated for Impairment	29,330	32,127
Total loans	29,330	32,127
Unaccreted Credit Component Other Loans	2,899	1,266
Land
Financing Receivable Impaired [Line Items]
Allowance for Loan Losses, Collectively Evaluated for Impairment	395	233
Total Allowance for Loan Losses	395	233
Unaccreted Credit Component Other Loans	4	2
Loans, Collectively Evaluated for Impairment	837	24,100
Total loans	37,160	24,100
Unaccreted Credit Component Other Loans	167	$ 437
Land \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable Impaired [Line Items]
Loans, Purchased Impaired	$ 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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