Loans and Leases (Loans and leases not covered by share agreements (in text)) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	$ 2,835,802	$ 2,825,170
Financing Receivable, Recorded Investment, 30 to 89 Days Past Due, Percentage	0.29%
Nonpass
Financing Receivable, Recorded Investment [Line Items]
Percent of nonaccrual loans	15.00%	15.00%
Loans and leases receivable	276,875	279,847
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Percent of loans	53.00%	50.00%
Substandard
Financing Receivable, Recorded Investment [Line Items]
Percent of loans	47.00%	50.00%
Performing Troubled Debt Restructured Loan | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable	$ 13,000