Loans, Loans Classified by Credit Quality Indicator (Details) (USD $)	6 Months Ended
	Jun. 30, 2012		Dec. 31, 2011		Jun. 30, 2011
Loans by categories [Abstract]
Total loans	$ 1,804,312,000		$ 1,744,828,000		$ 1,678,660,000
Unrated subject to review (in hundredths)	22.00%		28.00%
Threshold amount of commercial and construction loans and leases subject to loan review	3,000,000
Percentage of loan portfolio review coverage (in hundredths)	69.00%		65.00%
Period of full review in loan committee for loans with relatively short term, minimum	1 year
Period of full review in loan committee for loans with relatively short term, maximum	3 years
Commercial [Member]
Loans by categories [Abstract]
Total loans	441,167,000		450,411,000		450,916,000
Unrated subject to review (in hundredths)	31.00%		50.00%
Commercial mortgage [Member]
Loans by categories [Abstract]
Total loans	596,639,000		609,487,000		593,842,000
Unrated subject to review (in hundredths)	27.00%		25.00%
Construction [Member]
Loans by categories [Abstract]
Total loans	269,636,000		246,611,000		205,730,000
Unrated subject to review (in hundredths)	84.00%		79.00%
Direct lease financing [Member]
Loans by categories [Abstract]
Total loans	140,012,000		129,682,000		127,016,000
Unrated subject to review (in hundredths)	17.00%		25.00%
Residential mortgage [Member]
Loans by categories [Abstract]
Total loans	97,226,000		96,110,000		98,113,000
Unrated subject to review (in hundredths)	4.00%		3.00%
Consumer loans and others [Member]
Loans by categories [Abstract]
Total loans	211,492,000		165,397,000
Consumer [Member]
Loans by categories [Abstract]
Total loans	255,769,000		209,041,000		200,132,000
Unrated subject to review (in hundredths)	4.00%		2.00%
Unamortized loan costs [Member]
Loans by categories [Abstract]
Total loans	3,863,000		3,486,000		2,911,000
Unrated subject to review (in hundredths)	0.00%		0.00%
Pass [Member]
Loans by categories [Abstract]
Total loans	1,048,626,000		1,078,774,000
Pass [Member] | Commercial [Member]
Loans by categories [Abstract]
Total loans	303,881,000		320,287,000
Pass [Member] | Commercial mortgage [Member]
Loans by categories [Abstract]
Total loans	454,857,000		476,421,000
Pass [Member] | Construction [Member]
Loans by categories [Abstract]
Total loans	193,150,000		176,824,000
Pass [Member] | Direct lease financing [Member]
Loans by categories [Abstract]
Total loans	18,259,000		12,025,000
Pass [Member] | Residential mortgage [Member]
Loans by categories [Abstract]
Total loans	28,209,000		28,981,000
Pass [Member] | Consumer [Member]
Loans by categories [Abstract]
Total loans	50,270,000		64,236,000
Pass [Member] | Unamortized loan costs [Member]
Loans by categories [Abstract]
Total loans	0		0
Special Mention [Member]
Loans by categories [Abstract]
Total loans	27,465,000		22,664,000
Special Mention [Member] | Commercial [Member]
Loans by categories [Abstract]
Total loans	2,769,000		1,049,000
Special Mention [Member] | Commercial mortgage [Member]
Loans by categories [Abstract]
Total loans	24,696,000		21,615,000
Special Mention [Member] | Construction [Member]
Loans by categories [Abstract]
Total loans	0		0
Special Mention [Member] | Direct lease financing [Member]
Loans by categories [Abstract]
Total loans	0		0
Special Mention [Member] | Residential mortgage [Member]
Loans by categories [Abstract]
Total loans	0		0
Special Mention [Member] | Consumer [Member]
Loans by categories [Abstract]
Total loans	0		0
Special Mention [Member] | Unamortized loan costs [Member]
Loans by categories [Abstract]
Total loans	0		0
Substandard [Member]
Loans by categories [Abstract]
Total loans	35,073,000		25,910,000
Substandard [Member] | Commercial [Member]
Loans by categories [Abstract]
Total loans	10,009,000		7,696,000
Substandard [Member] | Commercial mortgage [Member]
Loans by categories [Abstract]
Total loans	10,340,000		6,867,000
Substandard [Member] | Construction [Member]
Loans by categories [Abstract]
Total loans	12,055,000		6,716,000
Substandard [Member] | Direct lease financing [Member]
Loans by categories [Abstract]
Total loans	236,000		649,000
Substandard [Member] | Residential mortgage [Member]
Loans by categories [Abstract]
Total loans	94,000		1,264,000
Substandard [Member] | Consumer [Member]
Loans by categories [Abstract]
Total loans	2,339,000		2,718,000
Substandard [Member] | Unamortized loan costs [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member] | Commercial [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member] | Commercial mortgage [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member] | Construction [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member] | Direct lease financing [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member] | Residential mortgage [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member] | Consumer [Member]
Loans by categories [Abstract]
Total loans	0		0
Doubtful [Member] | Unamortized loan costs [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member] | Commercial [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member] | Commercial mortgage [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member] | Construction [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member] | Direct lease financing [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member] | Residential mortgage [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member] | Consumer [Member]
Loans by categories [Abstract]
Total loans	0		0
Loss [Member] | Unamortized loan costs [Member]
Loans by categories [Abstract]
Total loans	0		0
Unrated [Member]
Loans by categories [Abstract]
Total loans	693,148,000	[1]	617,480,000	[1]
Unrated [Member] | Commercial [Member]
Loans by categories [Abstract]
Total loans	124,508,000	[1]	121,379,000	[1]
Unrated [Member] | Commercial mortgage [Member]
Loans by categories [Abstract]
Total loans	106,746,000	[1]	104,584,000	[1]
Unrated [Member] | Construction [Member]
Loans by categories [Abstract]
Total loans	64,431,000	[1]	63,071,000	[1]
Unrated [Member] | Direct lease financing [Member]
Loans by categories [Abstract]
Total loans	121,517,000	[1]	117,008,000	[1]
Unrated [Member] | Residential mortgage [Member]
Loans by categories [Abstract]
Total loans	68,923,000	[1]	65,865,000	[1]
Unrated [Member] | Consumer [Member]
Loans by categories [Abstract]
Total loans	203,160,000	[1]	142,087,000	[1]
Unrated [Member] | Unamortized loan costs [Member]
Loans by categories [Abstract]
Total loans	$ 3,863,000	[1]	$ 3,486,000	[1]

[1] Unrated loans consist of performing loans which did not exhibit any negative characteristics which would require the loan to be evaluated, or fell below the dollar threshold requiring review and was not one of the loans otherwise selected in ongoing portfolio evaluation. The scope of the Bank's loan review policy encompasses commercial and construction loans and leases which singly, or in aggregate forloans to related borrowers, exceed $3.0 million. The loan portfolio review coverage was approximately 69% at June 30, 2012 and approximately 65% at December 31, 2011. This review is performed by the loan review department, which is independent of the loan department and reports directly to the audit committee. All classified loans are reviewed by the independent loan review function of the Bank. Potential problem loans which are identified by either the independent loan review department or line management are also reviewed. All loans are subject to review by their relationship manager and senior loan personnel. Also, many of the Bank's loans are relatively short term, and are subject to reconsideration with a full review in loan committee between one and three years.