Guarantees, Commitments And Contingencies (Schedule Of Guarantees Issued) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Guarantor Obligations [Line Items]
Unused Commitments to Extend Credit	$ 18,273,714	$ 17,169,785
Commercial letters of credit	60,320	18,447
Total Unfunded Lending Commitments	19,300,754	18,066,629
Financial Guarantee [Member]
Guarantor Obligations [Line Items]
Letters Of Credit Standby	771,269	661,554
Performance Guarantee [Member]
Guarantor Obligations [Line Items]
Letters Of Credit Standby	$ 195,451	$ 216,843