Loans Receivable and Allowance for Loan Losses (Narrative) (Details)	3 Months Ended
Mar. 31, 2018 USD ($) loan property	Mar. 31, 2017 USD ($) loan	Dec. 31, 2017 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Related Allowance	$ 0		$ 0
Impaired Financing Receivable, Average Recorded Investment	1,242,000	$ 2,642,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	14,000	22,000
Foreclosed Real Estate Expense	(19,000)	572,000
Acquired Loans with Specific Evidence of Deterioration in Credit Quality, Outstanding Balance	1,411,000		1,444,000
Real Estate Acquired Through Foreclosure	1,436,000		1,661,000
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,238,000		1,247,000
Loans and Leases Receivable, Gross	775,913,000		764,335,000
Charge Offs	99,000	184,000
Commercial Rentals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross	$ 68,500,000
Commercial Rentals [Member] \| Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration Risk, Percentage	8.80%
Hospitality Lodging Industry [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross	$ 58,600,000
Hospitality Lodging Industry [Member] \| Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration Risk, Percentage	7.60%
Troubled Debt Restructured Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Related Allowance	$ 0		0
New Loans Identified as Troubled Debt Restructurings, Number of Loans \| loan	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 0	$ 55,000
Financing Receivable, Modifications, Recorded Investment	1,100,000		1,100,000
Financing Receivable, Modifications, Number of Contracts \| loan		1
Financing Receivable, Modifications, Pre-Modification Recorded Investment		$ 262,000
Residential Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Related Allowance	0		0
Impaired Financing Receivable, Average Recorded Investment	23,000	83,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	$ 0	0
Mortgage Loans on Real Estate, Number of Foreclosures \| loan	1
Mortgage Loans on Real Estate, Foreclosures	$ 0
Number Of Properties Under Foreclosure Proceedings \| property	8
Mortgage Loans in Process of Foreclosure, Amount	$ 702,000
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	23,000		23,000
Loans and Leases Receivable, Gross	232,771,000		235,759,000
Charge Offs	51,000	39,000
Proceeds from Sale of Mortgage Loans Held-for-sale	0
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Related Allowance	0		0
Impaired Financing Receivable, Average Recorded Investment	1,219,000	2,559,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	14,000	22,000
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,215,000		1,224,000
Loans and Leases Receivable, Gross	348,507,000		$ 342,934,000
Charge Offs		$ 85,000
Delaware Bancshares, Inc. Acquisition [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired Loans with Specific Evidence of Deterioration in Credit Quality, Outstanding Balance	1,397,000
Assets, Fair Value Adjustment	499,000
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Annual Loan Review threshold, amount	$ 1,500,000

Annual Loan Review Threshold, Amount

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The number of mortgage loans on real estate which were foreclosed on during the reporting period.

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No definition available.

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The number of new loans identified as troubled debt restructurings during the period.

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Number Of Properties Under Foreclosure Proceedings

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Amount of addition (reduction) to the amount at which an asset could be incurred (settled) in a current transaction between willing parties.

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The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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- Definition

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

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Number of financing receivables that have been modified by troubled debt restructurings.

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Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

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Reflects the amount of the write-down related to a troubled debt restructuring.

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Amount of expense recognized during the period for the foreclosure on real estate assets.

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of allowance for credit losses related to recorded investment.

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

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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.

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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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The amount of mortgage loans on real estate which were foreclosed on during the reporting period.

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The cash inflow from sales of loans that are secured with real estate mortgages and are held with the intention to resell in the near future.

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Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

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