Investment Securities (Schedule Of Unrealized Loss On Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Securities Available-for-Sale, Less than 12 months, Fair value	$ 3,164	$ 237,613
Securities Available-for-Sale, Less than 12 months, Unrealized losses	79	1,106
Securities Available-for-Sale, 12 months or longer, Fair value	21,057	171,805
Securities Available-for-Sale, 12 months or longer, Unrealized losses	127	5,117
Securities Available-for-Sale, Fair value, Total	24,221	409,418
Securities Available-for-Sale, Unrealized losses, Total	206	6,223
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Less than 12 months, Fair value	3,164
Securities Available-for-Sale, Less than 12 months, Unrealized losses	79
Securities Available-for-Sale, Fair value, Total	3,164
Securities Available-for-Sale, Unrealized losses, Total	79
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Securities Available-for-Sale, Less than 12 months, Fair value		237,613
Securities Available-for-Sale, Less than 12 months, Unrealized losses		1,106
Securities Available-for-Sale, 12 months or longer, Fair value	21,057	171,805
Securities Available-for-Sale, 12 months or longer, Unrealized losses	127	5,117
Securities Available-for-Sale, Fair value, Total	21,057	409,418
Securities Available-for-Sale, Unrealized losses, Total	$ 127	$ 6,223

Amount of 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 more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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