Investment Securities (Schedule Of Fair Value And Unrealized Losses Of Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Investment Holdings [Line Items]
Available-for-sale securities, less than 12 months, fair value	$ 9,803	$ 1,259,524
Available-for-sale securities, less than 12 months, unrealized losses	28	14,548
Available-for-sale securities, 12 months or longer, fair value	243,318	343,189
Available-for-sale securities, 12 months or longer, unrealized losses	2,262	9,614
Available-for-sale securities, fair value	253,121	1,602,713
Available-for-sale securities, unrealized losses	2,290	24,162
Obligations Of States And Political Subdivisions
Investment Holdings [Line Items]
Available-for-sale securities, less than 12 months, fair value	0	2,530
Available-for-sale securities, less than 12 months, unrealized losses	0	83
Available-for-sale securities, 12 months or longer, fair value	2,029	8,208
Available-for-sale securities, 12 months or longer, unrealized losses	271	539
Available-for-sale securities, fair value	2,029	10,738
Available-for-sale securities, unrealized losses	271	622
Residential Mortgage-Backed Securities And Collateralized Mortgage Obligations
Investment Holdings [Line Items]
Available-for-sale securities, less than 12 months, fair value	9,803	1,256,994
Available-for-sale securities, less than 12 months, unrealized losses	28	14,465
Available-for-sale securities, 12 months or longer, fair value	241,289	334,981
Available-for-sale securities, 12 months or longer, unrealized losses	1,991	9,075
Available-for-sale securities, fair value	251,092	1,591,975
Available-for-sale securities, unrealized losses	$ 2,019	$ 23,540

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 320
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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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