Fair Value (Schedule Of Carrying Values And Estimated Fair Values Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity, fair value	$ 734,292	$ 674,741
Time deposits	2,810,431	2,962,931
Other short-term borrowings	0	5,409
Long-term debt (less fair value hedges)	2,173,176	2,337,113
Carrying Value [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity, fair value	783,371	756,909
Loans and leases (including loans held for sale), net of allowance	37,538,652	37,020,811
Time deposits	2,810,431	2,962,931
Foreign deposits	1,514,270	1,804,060
Other short-term borrowings	0	5,409
Long-term debt (less fair value hedges)	2,166,932	2,329,323
Estimated Fair Value [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity, fair value	734,292	674,741
Loans and leases (including loans held for sale), net of allowance	37,419,383	37,024,198
Time deposits	2,825,093	2,988,714
Foreign deposits	1,513,920	1,803,625
Other short-term borrowings	0	5,421
Long-term debt (less fair value hedges)	$ 2,405,548	$ 2,636,422