Fair Value (Schedule Of Carrying Values And Estimated Fair Values Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity, fair value	$ 635,379	$ 609,547
Time deposits	2,528,735	2,593,038
Long-term debt (less fair value hedges)	2,158,701	2,273,575
Carrying Value [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity, fair value	606,279	588,981
Loans and leases (including loans held for sale), net of allowance	38,587,527	38,468,402
Time deposits	2,528,735	2,593,038
Foreign deposits	1,648,111	1,980,161
Other short-term borrowings	0	0
Long-term debt (less fair value hedges)	2,155,606	2,269,762
Estimated Fair Value [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity, fair value	635,379	609,547
Loans and leases (including loans held for sale), net of allowance	38,333,815	38,088,242
Time deposits	2,536,904	2,602,955
Foreign deposits	1,647,876	1,979,805
Other short-term borrowings	0	0
Long-term debt (less fair value hedges)	$ 2,301,239	$ 2,423,643