Loans, Allowance for Loan Losses and Credit Quality (Details 10) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Impaired loans by loan portfolio
Related Allowance	$ 3,023	$ 3,420
Impaired Financing Receivable, Recorded Investment, Total	65,495	66,659
Impaired Financing Receivable, Unpaid Principal Balance	69,187	70,649
WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	29,077	27,297
Unpaid Principal Balance	30,513	29,689
Related Allowance
WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	36,418	39,362
Unpaid Principal Balance	38,674	40,960
Related Allowance	3,023	3,420
Commercial and Industrial [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	5,229	5,849
Unpaid Principal Balance	5,821	7,343
Related Allowance
Commercial and Industrial [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	2,544	2,726
Unpaid Principal Balance	3,301	2,851
Related Allowance	771	1,084
Commercial Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	13,869	12,999
Unpaid Principal Balance	14,536	13,698
Related Allowance
Commercial Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	17,416	20,869
Unpaid Principal Balance	17,859	21,438
Related Allowance	385	516
Commercial Construction [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	1,608
Unpaid Principal Balance	1,608
Related Allowance
Commercial Construction [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment
Unpaid Principal Balance
Related Allowance
Small Business [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	1,191	1,085
Unpaid Principal Balance	1,233	1,147
Related Allowance
Small Business [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	882	1,194
Unpaid Principal Balance	927	1,228
Related Allowance	113	353
Residential Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	2,526	2,545
Unpaid Principal Balance	2,610	2,630
Related Allowance
Residential Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	13,902	12,828
Unpaid Principal Balance	14,735	13,601
Related Allowance	1,577	1,302
Consumer - Home Equity [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	4,007	4,119
Unpaid Principal Balance	4,057	4,166
Related Allowance
Consumer - Home Equity [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	439	316
Unpaid Principal Balance	551	389
Related Allowance	58	35
Consumer - Other [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	647	700
Unpaid Principal Balance	648	705
Related Allowance
Consumer - Other [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment	1,235	1,429
Unpaid Principal Balance	1,301	1,453
Related Allowance	$ 119	$ 130