Loans Receivable and Credit Quality Loan footnote text disclosures (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Deferred Income	$ (3,800,000)	$ (3,200,000)
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	2,675,000	32,000
Financing Receivable, Modifications, Recorded Investment	62,800,000	55,300,000
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Time to obtain new appraisal on impaired loans	12
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Time to obtain new appraisal on impaired loans	18
Accruing Troubled Debt Restructured Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 26,700,000	$ 27,400,000