Loans and Allowance for Loan Losses - Summary of Recorded Investment in Loans Impairment Method and Activity in Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Reserves:
Loan losses, Reserves	$ 16,178	$ 13,773	$ 11,420
Loans evaluated for impairment:
Loans, Individually evaluated for impairment	6,586	2,575	3,950
Loans, Collectively evaluated for impairment	1,374,632	1,246,184	1,192,256
Total loans, net of deferred loan fees	1,381,218	1,249,074	1,196,522
Loans Acquired with Deteriorated Credit Quality
Loans evaluated for impairment:
Loans acquired		315	316
Specific Reserves
Reserves:
Loan losses, Reserves	43
General Reserves
Reserves:
Loan losses, Reserves	16,135	13,773	11,420
Real Estate
Reserves:
Loan losses, Reserves	12,125	9,309	7,672
Loans evaluated for impairment:
Loans, Individually evaluated for impairment	4,080	2,420	2,580
Loans, Collectively evaluated for impairment	989,915	834,152	819,654
Total loans, net of deferred loan fees	993,995	836,887	822,550
Real Estate \| Loans Acquired with Deteriorated Credit Quality
Loans evaluated for impairment:
Loans acquired		315	316
Real Estate \| Specific Reserves
Reserves:
Loan losses, Reserves	43
Real Estate \| General Reserves
Reserves:
Loan losses, Reserves	12,082	9,309	7,672
Commercial
Reserves:
Loan losses, Reserves	4,053	4,044	3,362
Loans evaluated for impairment:
Loans, Individually evaluated for impairment	2,506	155	1,370
Loans, Collectively evaluated for impairment	384,717	412,032	372,602
Total loans, net of deferred loan fees	387,223	412,187	373,972
Commercial \| General Reserves
Reserves:
Loan losses, Reserves	$ 4,053	4,044	3,362
Unallocated
Reserves:
Loan losses, Reserves		420	386
Unallocated \| General Reserves
Reserves:
Loan losses, Reserves		$ 420	$ 386

Allowance for loan and lease losses reserves.

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Amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings.

+ References

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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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The balance of financing receivables that were individually evaluated for impairment.

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

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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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.

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-Topic 210
-SubTopic 10
-Section S99
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