Loans (Summary of TDRs) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Schedule of corporation's TDRs
Total TDRs	$ 100,764	$ 103,111	$ 101,824
Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	76,615	78,823	77,511
Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	24,149	24,288	24,313
Substandard Nonaccrual [Member]
Schedule of corporation's TDRs
Total TDRs	32,514	35,933	37,343
Substandard Nonaccrual [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	29,368	32,682	32,917
Substandard Nonaccrual [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	3,146	3,251	4,426
Nonperforming Financial Instruments [Member]
Schedule of corporation's TDRs
Total TDRs	18,364	19,368	18,500
Nonperforming Financial Instruments [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	15,351	16,297	15,810
Nonperforming Financial Instruments [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	3,013	3,071	2,690
Performing Financial Instruments [Member]
Schedule of corporation's TDRs
Total TDRs	49,886	47,810	45,981
Performing Financial Instruments [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	31,896	29,844	28,784
Performing Financial Instruments [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	$ 17,990	$ 17,966	$ 17,197