Fair Value (Schedule Of Carrying Values And Estimated Fair Values Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
HTM investment securities	$ 655,768	$ 729,974
Time deposits	3,107,815	3,413,550
Other short-term borrowings	6,608	70,273
Long-term debt (less fair value hedges)	2,326,659	1,954,462
Carrying Value [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
HTM investment securities	740,738	807,804
Loans and leases (including loans held for sale), net of allowance	36,465,718	36,296,284
Time deposits	3,107,815	3,413,550
Foreign deposits	1,398,749	1,575,361
Other short-term borrowings	6,608	70,273
Long-term debt (less fair value hedges)	2,318,092	1,943,618
Estimated Fair Value [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
HTM investment securities	655,768	729,974
Loans and leases (including loans held for sale), net of allowance	36,624,062	36,006,619
Time deposits	3,137,538	3,444,189
Foreign deposits	1,398,296	1,574,271
Other short-term borrowings	6,636	70,387
Long-term debt (less fair value hedges)	$ 2,652,991	$ 2,225,078