Loans, Allowance for Loan Losses, and Credit Quality (Details 10) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Commercial and industrial
Troubled Debt Restructurings Subsequent Default [Line Items]
Number of Contracts	7
Recorded Investment	$ 865
Commercial real estate - owner occupied
Troubled Debt Restructurings Subsequent Default [Line Items]
Number of Contracts	0
Recorded Investment	0
Commercial real estate - investor
Troubled Debt Restructurings Subsequent Default [Line Items]
Number of Contracts	4
Recorded Investment	1,302
Real estate construction
Troubled Debt Restructurings Subsequent Default [Line Items]
Number of Contracts	1
Recorded Investment	18
Home Equity
Troubled Debt Restructurings Subsequent Default [Line Items]
Number of Contracts	2
Recorded Investment	60
Installment
Troubled Debt Restructurings Subsequent Default [Line Items]
Number of Contracts	0
Recorded Investment	0
Residential Mortgage
Troubled Debt Restructurings Subsequent Default [Line Items]
Number of Contracts	0
Recorded Investment	$ 0