Loans, Allowance for Loan Losses, and Credit Quality (Details 9) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Number of Contracts	413	336
Recorded Investment	$ 59,599	$ 120,806
Unpaid Principal Balance	68,950	149,082
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	85	104
Recorded Investment	12,827	31,933
Unpaid Principal Balance	15,834	36,844
Commercial Real Estate Owner Occupied Portfolio [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	27	22
Recorded Investment	11,978	15,841
Unpaid Principal Balance	12,766	19,741
Commercial Real Estate Investor Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	25	59
Recorded Investment	12,379	42,721
Unpaid Principal Balance	13,569	54,132
Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	31	33
Recorded Investment	2,955	18,308
Unpaid Principal Balance	3,549	23,802
Home Equity Portfolio Segments [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	111	57
Recorded Investment	4,870	4,886
Unpaid Principal Balance	6,143	5,428
Installment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	13	19
Recorded Investment	298	1,004
Unpaid Principal Balance	302	1,048
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	121	42
Recorded Investment	14,292	6,113
Unpaid Principal Balance	$ 16,787	$ 8,087