Fair Value (Schedule Of Carrying Values And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Long-term debt (less fair value hedges)	$ 802,448	$ 812,366
Carrying Value [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Loans and leases (including loans held for sale), net of allowance	40,915,055	40,193,374
Time deposits	2,071,688	2,130,680
Interest-bearing Deposit Liabilities, Foreign	219,899	294,391
Long-term debt (less fair value hedges)	802,448	812,366
Estimate of Fair Value Measurement [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity, fair value	636,484	552,088
Loans and leases (including loans held for sale), net of allowance	40,715,842	39,535,365
Time deposits	2,075,729	2,129,742
Foreign deposits	219,836	294,321
Long-term debt (less fair value hedges)	$ 831,621	$ 838,796

The aggregate of all foreign interest-bearing and noninterest-bearing deposit liabilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 235
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(a))
-URI http://asc.fasb.org/extlink&oid=6882215&loc=d3e537907-122884

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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No definition available.

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Fair value of investments in debt securities classified as held-to-maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-SubTopic 10
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Amount of foreign interest-bearing deposits held by the entity.

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-Publisher FASB
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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

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