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		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Financing Receivable, Modifications [Line Items]
Number of Loans	103	74	203	249
Recorded Investment	$ 18,504	$ 12,898	$ 26,373	$ 38,791
Unpaid Principal Balance	19,168	14,235	27,599	43,394
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	10	19	13	58
Recorded Investment	7,383	5,479	7,695	11,379
Unpaid Principal Balance	7,384	6,384	7,707	14,028
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0	7	2	17
Recorded Investment	0	3,373	1,123	9,313
Unpaid Principal Balance	0	3,488	1,260	9,596
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	3	10	4	18
Recorded Investment	5,603	1,222	6,096	5,013
Unpaid Principal Balance	5,918	1,304	6,425	5,320
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	1	3	2	9
Recorded Investment	8	227	14	2,006
Unpaid Principal Balance	8	248	14	2,084
Home Equity Port Folio Segments [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	42	16	94	74
Recorded Investment	1,428	933	3,407	4,149
Unpaid Principal Balance	1,486	985	3,593	4,554
Installment and Credit Cards [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	2	0	3	2
Recorded Investment	25	0	34	187
Unpaid Principal Balance	25	0	45	193
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	45	19	85	71
Recorded Investment	4,057	1,664	8,004	6,744
Unpaid Principal Balance	$ 4,347	$ 1,826	$ 8,555	$ 7,619