Available-For-Sale And Held-To-Maturity Securities (Schedule Of Amortized Cost And Fair Values Of The Available For Sale Securities And Held To Maturity Securities) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		$ 1,641,398	$ 1,520,517
Available for sale securities, unrealized gains	[1]	1,807	7,133
Available-for-sale Securities, Gross unrealized losses	[1]	(13,298)	(14,172)
Available-for-sale securities		1,629,907	1,513,478
Held-to-maturity Securities, Amortized cost	[2]	1,855,399	1,177,565
Held-to-maturity Securities, Gross unrealized gains	[1],[2]	27,254	38,338
Held-to-maturity Securities, Gross unrealized losses	[1],[2]	(7,655)	(3,927)
Held-to-maturity securities, Estimated fair value	[2]	1,874,998	1,211,976
U S Government Corporations And Agencies Securities
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		1,700	1,613
Available for sale securities, unrealized gains	[1]	1	1
Available-for-sale Securities, Gross unrealized losses	[1]	(3)	(4)
Available-for-sale securities		1,698	1,610
U S States And Political Subdivisions
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		75,953	76,518
Available for sale securities, unrealized gains	[1]	28	20
Available-for-sale Securities, Gross unrealized losses	[1]	(1,814)	(2,137)
Available-for-sale securities		74,167	74,401
Corporate Fixed Income Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		321,017	336,210
Available for sale securities, unrealized gains	[1]	743	2,016
Available-for-sale Securities, Gross unrealized losses	[1]	(2,352)	(820)
Available-for-sale securities		319,408	337,406
Held-to-maturity Securities, Amortized cost	[2]	40,145	55,236
Held-to-maturity Securities, Gross unrealized gains	[1],[2]		4
Held-to-maturity Securities, Gross unrealized losses	[1],[2]	(396)	(1,223)
Held-to-maturity securities, Estimated fair value	[2]	39,749	54,017
Asset-Backed Securities [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		922,563	788,908
Available for sale securities, unrealized gains	[1]	774	1,321
Available-for-sale Securities, Gross unrealized losses	[1]	(7,424)	(10,155)
Available-for-sale securities		915,913	780,074
Held-to-maturity Securities, Amortized cost	[2]	496,996	177,335
Held-to-maturity Securities, Gross unrealized gains	[1],[2]	2,076	3,151
Held-to-maturity Securities, Gross unrealized losses	[1],[2]	(4,139)	(2,645)
Held-to-maturity securities, Estimated fair value	[2]	494,933	177,841
Mortgage Backed Securities | Agency Securities
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		306,309	206,982
Available for sale securities, unrealized gains	[1]	125	3,137
Available-for-sale Securities, Gross unrealized losses	[1]	(1,541)	(913)
Available-for-sale securities		304,893	209,206
Held-to-maturity Securities, Amortized cost	[2]	1,257,808	884,451
Held-to-maturity Securities, Gross unrealized gains	[1],[2]	23,346	32,926
Held-to-maturity Securities, Gross unrealized losses	[1],[2]	(3,105)	(42)
Held-to-maturity securities, Estimated fair value	[2]	1,278,049	917,335
Mortgage Backed Securities | Commercial Mortgage Backed Securities
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		11,177	107,100
Available for sale securities, unrealized gains	[1]	134	633
Available-for-sale Securities, Gross unrealized losses	[1]	(1)	(89)
Available-for-sale securities		11,310	107,644
Held-to-maturity Securities, Amortized cost	[2]	59,521	59,462
Held-to-maturity Securities, Gross unrealized gains	[1],[2]	1,832	2,257
Held-to-maturity securities, Estimated fair value	[2]	61,353	61,719
Mortgage Backed Securities | Non-Agency [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available-for-sale Securities, Amortized cost		2,679	3,186
Available for sale securities, unrealized gains	[1]	2	5
Available-for-sale Securities, Gross unrealized losses	[1]	(163)	(54)
Available-for-sale securities		2,518	3,137
Held-to-maturity Securities, Amortized cost	[2]	929	1,081
Held-to-maturity Securities, Gross unrealized losses	[1],[2]	(15)	(17)
Held-to-maturity securities, Estimated fair value	[2]	$ 914	$ 1,064

[1] Unrealized gains/(losses) related to available-for-sale securities are reported in accumulated other comprehensive income.

[2] Held-to-maturity securities are carried in the consolidated statements of financial condition at amortized cost, and the changes in the value of these securities, other than impairment charges, are not reported on the consolidated financial statements.