Allowance for Loan Losses (Details 5) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Collateral value securing non-accrual loans
Non-accrual Loans principal balance	$ 14,356	$ 80,760
Non-accrual loans collateral value	21,811	96,353
Commercial and industrial loans [Member]
Collateral value securing non-accrual loans
Non-accrual Loans principal balance	5,963	16,867
Non-accrual loans collateral value	4,400
Commercial real estate mortgages [Member]
Collateral value securing non-accrual loans
Non-accrual Loans principal balance	5,893	45,344
Non-accrual loans collateral value	13,650	68,067
Real estate construction loans [Member]
Collateral value securing non-accrual loans
Non-accrual Loans principal balance	1,334	6,978
Non-accrual loans collateral value	2,300	6,715
Residential mortgages (1st and 2nd liens) [Member]
Collateral value securing non-accrual loans
Non-accrual Loans principal balance	1,031	7,028
Non-accrual loans collateral value	1,326	14,133
Home equity loans [Member]
Collateral value securing non-accrual loans
Non-accrual Loans principal balance		3,897
Non-accrual loans collateral value		7,438
Consumer and other loans [Member]
Collateral value securing non-accrual loans
Non-accrual Loans principal balance	135	646
Non-accrual loans collateral value	$ 135