Loans, Allowance for Loan Losses, and Credit Quality Loans Modified in a Troubled Debt Restructuring (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Financing Receivable, Modifications [Line Items]
Number of Loans	68	89
Recorded Investment	$ 14,082	$ 12,096
Unpaid Principal Balance	18,833	15,012
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	8	22
Recorded Investment	3,446	2,844
Unpaid Principal Balance	7,218	5,315
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	4	3
Recorded Investment	5,298	2,217
Unpaid Principal Balance	5,781	2,228
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	4	5
Recorded Investment	1,643	2,035
Unpaid Principal Balance	1,676	2,087
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	5
Recorded Investment	0	1,960
Unpaid Principal Balance	0	1,980
Home Equity Port Folio Segments [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	30	28
Recorded Investment	935	1,301
Unpaid Principal Balance	1,218	1,385
Installment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1	1
Recorded Investment	10	175
Unpaid Principal Balance	20	175
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	21	25
Recorded Investment	2,750	1,564
Unpaid Principal Balance	$ 2,920	$ 1,842