Loans (Narrative) (Details)	3 Months Ended	6 Months Ended	12 Months Ended	18 Months Ended
	Jun. 30, 2015 USD ($) loan	Jun. 30, 2015 USD ($) loan	Dec. 31, 2014 USD ($) loan	Jun. 30, 2015 USD ($) loan	Jun. 30, 2014 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, allowance percentage	0.98%	0.98%	0.97%	0.98%
Total number of loans | loan	37	37	31	37
Total non-accrual loans	$ 13,056,000	$ 13,056,000	$ 10,263,000	$ 13,056,000
Loan portfolio	895,839,000	895,839,000	872,129,000	895,839,000	$ 846,258,000
Allowance for loan loss	$ 8,757,000	$ 8,757,000	$ 8,481,000	$ 8,757,000
Loans added to troubled debt restructuring | loan		6	15
Amount of loans added to troubled debt restructuring		$ 2,300,000	$ 12,000,000
Number of accruing loans 90 days or greater past due | loan	0	0	0	0
90 or greater days	$ 13,056,000	$ 13,056,000	$ 10,263,000	$ 13,056,000
Financing Receivable Troubled Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment income, interest		$ 249,000	$ 563,000
Loans removed from troubled debt restructuring | loan	2
Amount of loans removed from troubled debt restructuring	$ 1,600,000
Seven Troubled Debt Restructuring Loans with Reserves [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan		7
Reserve of the allowance for loan losses	447,000	$ 447,000		447,000
90 or greater days	$ 3,000,000	$ 3,000,000		$ 3,000,000
Five Troubled Debt Restructuring Loans with Reserves [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			5
Reserve of the allowance for loan losses			$ 251,000
90 or greater days			2,500,000
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, allowance percentage	80.00%	80.00%		80.00%
Loan portfolio	$ 601,270,000	$ 601,270,000	$ 561,080,000	$ 601,270,000	531,919,000
Percentage status of loan in portfolio	5.20%	5.20%	4.40%	5.20%
90 or greater days	$ 6,119,000	$ 6,119,000	$ 3,824,000	$ 6,119,000
Commercial Real Estate [Member] | Financing Receivable Troubled Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans with deferred collection of principal and interest for one year	$ 1,000,000	$ 1,000,000		$ 1,000,000
Number of accruing loans 90 days or greater past due | loan	1	1		1
90 or greater days	$ 1,000,000	$ 1,000,000		$ 1,000,000
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	63,480,000	63,480,000	73,625,000	63,480,000	77,583,000
90 or greater days	1,472,000	1,472,000	1,587,000	1,472,000
Commercial Equipment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	26,804,000	26,804,000	26,152,000	26,804,000	25,876,000
90 or greater days	387,000	387,000	286,000	387,000
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	143,662,000	143,662,000	152,837,000	143,662,000	$ 156,833,000
90 or greater days	1,158,000	1,158,000	533,000	1,158,000
Adjustable Rate Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	$ 23,400,000	$ 23,400,000		$ 23,400,000
Percentage status of loan in portfolio	2.60%	2.60%		2.60%
Four Loans Representing a Stalled Residential Development Project [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan				4
Nonaccrual loans with deferred collection of principal and interest for one year	$ 3,800,000	$ 3,800,000	3,900,000	$ 3,800,000
Nonaccrual Loans With No Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	$ 12,300,000	12,300,000	9,300,000	$ 12,300,000
Interest due to debt		898,000	$ 781,000
Increase (decrease) in loans		$ 2,800,000
Percentage status of loan in portfolio	1.46%	1.46%	1.18%	1.46%
Nonaccrual Loans With Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	$ 802,000	$ 802,000	$ 1,000,000	$ 802,000
Interest due to debt		$ 72,000	64,000
Maximum [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		20 years
Maximum [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		30 years
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit quality indicator	750,000	$ 750,000		750,000
Minimum [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		3 years
Minimum [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		10 years
Unrated [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	69,819,000	$ 69,819,000	74,955,000	69,819,000
Unrated [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	10,349,000	10,349,000	12,296,000	10,349,000
Unrated [Member] | Commercial Equipment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	8,765,000	8,765,000	7,173,000	8,765,000
Pass [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	502,595,000	502,595,000	451,256,000	502,595,000
Pass [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	48,414,000	48,414,000	53,844,000	48,414,000
Pass [Member] | Commercial Equipment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	16,840,000	16,840,000	18,517,000	16,840,000
Special Mention [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	3,078,000	3,078,000	4,383,000	3,078,000
Special Mention [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	49,000	49,000	49,000	49,000
Substandard [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	25,778,000	25,778,000	30,486,000	25,778,000
Substandard [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	4,668,000	4,668,000	7,436,000	4,668,000
Substandard [Member] | Commercial Equipment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	1,199,000	1,199,000	$ 462,000	1,199,000
Substandard [Member] | Eighteen Loans Representing Five Customer Relationships [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans	$ 10,400,000	$ 10,400,000		$ 10,400,000
Percentage status of loan in portfolio	80.00%	80.00%		80.00%
Number of loans | loan		18
Substandard [Member] | Sixteen Loans Representing Six Customer Relationships [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio			86.00%
Number of loans | loan			16
Nonaccrual loans with deferred collection of principal and interest for one year			$ 8,800,000
Doubtful [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio
Loss [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio
Loss [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio
Loss [Member] | Commercial Equipment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio
Performing Financing Receivable [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	$ 142,504,000	$ 142,504,000	$ 152,304,000	$ 142,504,000
Nonperforming Financing Receivable [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan portfolio	$ 1,158,000	$ 1,158,000	$ 533,000	$ 1,158,000