Loans (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012		Sep. 30, 2012		Dec. 31, 2011		Sep. 30, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on fair value of loans	$ 156,000
Major classifications of loans [Abstract]
Total loans, gross	1,852,324,000		1,852,324,000		1,741,342,000
Unamortized loan costs	4,668,000		4,668,000		3,486,000
Total loans, net of deferred loan costs	1,856,992,000		1,856,992,000		1,744,828,000		1,715,648,000
Supplemental loan data
Total supplemental loans	1,852,324,000		1,852,324,000		1,741,342,000
Number of loans identified as impaired			30
Balance of impaired loans	29,200,000		29,200,000		17,600,000
Balance of impaired loans related to specific reserve	20,200,000		20,200,000		14,500,000
Number of troubled debt restructured loans	8		8		2
Specific reserve	10,900,000		10,900,000		5,900,000
Balance of impaired loans without specific reserve	9,000,000		9,000,000
Troubled debt restructured loans	8,300,000		8,300,000
Troubled debt restructured loans, specific reserve	4,200,000		4,200,000
Interest income lost on impaired loans	631,000
Interest income on impaired loans			65,000
Commercial [Member]
Major classifications of loans [Abstract]
Total loans, gross	453,444,000		453,444,000		450,411,000
Total loans, net of deferred loan costs	453,444,000		453,444,000		450,411,000		461,679,000
Supplemental loan data
Total supplemental loans	453,444,000		453,444,000		450,411,000
Balance of impaired loans	7,654,000		7,654,000		6,450,000
Balance of impaired loans related to specific reserve	3,435,000		3,435,000		5,550,000
Specific reserve	1,885,000		1,885,000		2,724,000
Balance of impaired loans without specific reserve	4,219,000		4,219,000		900,000
Commercial mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans available-for-sale	7,900,000		7,900,000
Major classifications of loans [Abstract]
Total loans, gross	614,410,000	[1]	614,410,000	[1]	609,487,000	[1]
Total loans, net of deferred loan costs	614,410,000		614,410,000		609,487,000		577,237,000
Supplemental loan data
Total supplemental loans	614,410,000	[1]	614,410,000	[1]	609,487,000	[1]
Amount of owner occupied loans	157,200,000		157,200,000		137,900,000
Percentage of owner occupied loans (in hundredths)	25.60%		25.60%		22.60%
Balance of impaired loans	11,324,000		11,324,000		3,672,000
Balance of impaired loans related to specific reserve	7,742,000		7,742,000		3,672,000
Specific reserve	4,028,000		4,028,000		712,000
Balance of impaired loans without specific reserve	3,582,000		3,582,000		0
Construction [Member]
Major classifications of loans [Abstract]
Total loans, gross	263,726,000		263,726,000		246,611,000
Total loans, net of deferred loan costs	263,726,000		263,726,000		246,611,000		242,806,000
Supplemental loan data
Total supplemental loans	263,726,000		263,726,000		246,611,000
Balance of impaired loans	9,162,000		9,162,000		4,949,000
Balance of impaired loans related to specific reserve	8,886,000		8,886,000		4,949,000
Specific reserve	4,899,000		4,899,000		2,296,000
Balance of impaired loans without specific reserve	276,000		276,000		0
Total commercial loans [Member]
Major classifications of loans [Abstract]
Total loans, gross	1,331,580,000		1,331,580,000		1,306,509,000
Supplemental loan data
Total supplemental loans	1,331,580,000		1,331,580,000		1,306,509,000
Direct lease financing [Member]
Major classifications of loans [Abstract]
Total loans, gross	146,728,000		146,728,000		129,682,000
Total loans, net of deferred loan costs	146,728,000		146,728,000		129,682,000		129,400,000
Supplemental loan data
Total supplemental loans	146,728,000		146,728,000		129,682,000
Residential mortgage [Member]
Major classifications of loans [Abstract]
Total loans, gross	97,589,000		97,589,000		96,110,000
Total loans, net of deferred loan costs	97,589,000		97,589,000		96,110,000		96,139,000
Supplemental loan data
Total supplemental loans	97,589,000		97,589,000		96,110,000
Balance of impaired loans	93,000		93,000		1,264,000
Balance of impaired loans related to specific reserve	93,000		93,000		0
Specific reserve	71,000		71,000		0
Balance of impaired loans without specific reserve	0		0		1,264,000
Consumer loans and others [Member]
Major classifications of loans [Abstract]
Total loans, gross	276,427,000		276,427,000		209,041,000
Total loans, net of deferred loan costs	232,150,000		232,150,000		165,397,000
Supplemental loan data
Total supplemental loans	276,427,000		276,427,000		209,041,000
Construction 1-4 family [Member]
Major classifications of loans [Abstract]
Total loans, gross	71,599,000		71,599,000		85,189,000
Supplemental loan data
Total supplemental loans	71,599,000		71,599,000		85,189,000
Commercial construction, acquisition and development [Member]
Major classifications of loans [Abstract]
Total loans, gross	192,127,000		192,127,000		161,422,000
Supplemental loan data
Total supplemental loans	$ 192,127,000		$ 192,127,000		$ 161,422,000

[1] At September 30, 2012, our owner occupied loans amounted to $157.2 million, or 25.6% of commercial mortgages as compared to $137.9 million, or 22.6% at December 31, 2011.