Available-For-Sale And Held-To-Maturity Securities (Schedule Of Gross Unrealized Losses And The Estimated Fair Value By Length Of Time In A Loss Position) (Details) $ in Thousands	Sep. 30, 2021 USD ($)
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	$ (10,460)
Available-for-sale Securities, Estimated fair value, Less than 12 months	917,360
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(293)
Available-for-sale Securities, Estimated fair value, 12 months or more	51,476
Available-for-sale Securities, Gross unrealized losses, Total	(10,753)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	968,836
Agency Mortgage Backed Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(6,142)
Available-for-sale Securities, Estimated fair value, Less than 12 months	618,905
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(2)
Available-for-sale Securities, Estimated fair value, 12 months or more	332
Available-for-sale Securities, Gross unrealized losses, Total	(6,144)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	619,237
Corporate Fixed Income Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(2,673)
Available-for-sale Securities, Estimated fair value, Less than 12 months	181,665
Available-for-sale Securities, Gross unrealized losses, Total	(2,673)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	181,665
Asset-Backed Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Gross unrealized losses, Less than 12 months	(1,645)
Available-for-sale Securities, Estimated fair value, Less than 12 months	116,790
Available-for-sale Securities, Gross unrealized losses, 12 months or more	(291)
Available-for-sale Securities, Estimated fair value, 12 months or more	51,144
Available-for-sale Securities, Gross unrealized losses, Total	(1,936)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 167,934

Schedule of available for sale and held to maturity securities.

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This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

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This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
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