Commitments, Guarantees, And Contingent Liabilities (Schedule Of Guarantees Issued) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Unused Commitments to Extend Credit		$ 18,113,233	$ 17,169,785
Commercial Letters Of Credit		38,964	18,447
Total Unfunded Lending Commitments		19,145,265	18,066,629
Financial [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Standby letters of credit		798,476	661,554
Performance [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Standby letters of credit		194,592	$ 216,843
Minimum [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Litigation Settlement, Amount	$ 37,500
Loss Contingency, Estimate of Possible Loss		0
Maximum [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Litigation Settlement, Amount	$ 37,750
Loss Contingency, Estimate of Possible Loss		$ 10,000