Financial Instruments (Schedule Of Trading Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	$ 375,745	$ 307,852
U.S. government agency MBS and CMOs [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	218,767	196,146
U.S. government agency debt securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	4,791	14,680
RMBS [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	14	15
U.S. Treasury securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	6,065	11,105
ABS [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	1	100
SBA loans [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	26,073	27,634
Corporate bonds and redeemable preferred stock [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	31,877	38,503
Foreign government bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	626	844
Municipal bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	25,121	13,737
Certificates of deposit [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	3,575	841
Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	55,780	3,686
Equity securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	99	$ 561
Residential transition loans [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	$ 2,956