Loans (Summary of TDRs) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Schedule of corporation's TDRs
Total nonperforming TDRs	$ 49,638	$ 48,566	$ 43,926
Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	32,342	29,665	19,779
Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	17,296	18,901	24,147
Performing [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	30,723	31,369	27,177
Performing [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	17,755	15,789	8,521
Performing [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	12,968	15,580	18,656
Nonperforming [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	18,915	17,197	16,749
Nonperforming [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	14,587	13,876	11,258
Nonperforming [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total nonperforming TDRs	$ 4,328	$ 3,321	$ 5,491