Financial Instruments (Schedule Of Trading Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	$ 219,462	$ 202,257
U.S. government agency MBS and CMOs [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	62,497	87,608
U.S. government agency debt securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	14,537	13,529
RMBS [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	16	32
U.S. Treasury securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	4,139	2,466
ABS [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	100	1
SBA loans [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	57,596	4,780
Corporate bonds and redeemable preferred stock [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	49,945	43,435
Foreign government bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	232	483
Municipal bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	24,139	45,709
Certificates of deposit [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	918
Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	5,277	1,118
Equity securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investments-trading	$ 66	$ 3,096