Loans (Details 4) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Recorded Investment , With related allowance recorded	$ 22,466	$ 31,944
Unpaid Principal Balance, With related allowance recorded	27,316	39,284
Related Allowance		11
Residential real estate - Closed-end first mortgages
Financing Receivable, Impaired [Line Items]
Recorded Investment , With no related allowance recorded	7,628	7,919
Unpaid Principal Balance, With no related allowance recorded	8,079	8,465
Recorded Investment , With related allowance recorded	7,628	7,919
Unpaid Principal Balance, With related allowance recorded	8,079	8,465
Related Allowance
Commercial real estate - Owner occupied
Financing Receivable, Impaired [Line Items]
Recorded Investment , With no related allowance recorded	78	369
Unpaid Principal Balance, With no related allowance recorded	78	376
Recorded Investment , With related allowance recorded	78	369
Unpaid Principal Balance, With related allowance recorded	78	376
Related Allowance
Commercial real estate - Non owner occupied
Financing Receivable, Impaired [Line Items]
Recorded Investment , With no related allowance recorded	13,855	15,208
Unpaid Principal Balance, With no related allowance recorded	16,730	17,584
Recorded Investment , With related allowance recorded	13,855	16,347
Unpaid Principal Balance, With related allowance recorded	16,730	18,723
Related Allowance		11
Land and construction
Financing Receivable, Impaired [Line Items]
Recorded Investment , With no related allowance recorded	905	7,241
Unpaid Principal Balance, With no related allowance recorded	2,429	11,652
Recorded Investment , With related allowance recorded	905	7,241
Unpaid Principal Balance, With related allowance recorded	2,429	11,652
Related Allowance
Consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment , With no related allowance recorded		68
Unpaid Principal Balance, With no related allowance recorded		68
Recorded Investment , With related allowance recorded		68
Unpaid Principal Balance, With related allowance recorded		68
Related Allowance
Commercial real estate - Non owner occupied recorded allowance
Financing Receivable, Impaired [Line Items]
Recorded Investment , With related allowance recorded		1,139
Unpaid Principal Balance, With related allowance recorded		1,139
Related Allowance		$ 11