Available-For-Sale And Held-To-Maturity Securities (Schedule Of Amortized Cost And Fair Values Of Debt Securities By Contractual Maturity) (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Schedule Of Debt Securities At Amortized Cost And Fair Value Basis [Line Items]
Debt securities, Available-for-sale, Amortized cost, Total		$ 788,920
Debt securities, Available-for-sale, Estimated fair value, Within one year	[1]	31,290
Debt securities, Available-for-sale, Estimated fair value, After five years through ten years	[1]	115,822
Debt securities, Available-for-sale, Estimated fair value, After ten years	[1]	511,658
Debt securities, Available-for-sale, Estimated fair value, Total	[1]	787,897
Debt securities, Held-to-maturity, Amortized cost, Within one year		15,013
Debt securities, Held-to-maturity, Amortized cost, After five years through ten years		59,491
Debt securities, Held-to-maturity, Amortized cost, After ten years		1,010,744
Held-to-maturity securities, Amortized cost	[2]	1,125,426	$ 1,177,565
Held-to-maturity securities, Estimated fair value	[2]	1,148,308	$ 1,211,976
Excluding Mortgage Backed Securities
Schedule Of Debt Securities At Amortized Cost And Fair Value Basis [Line Items]
Debt securities, Available-for-sale, Amortized cost, Within one year		31,104
Debt securities, Available-for-sale, Amortized cost, After one year through three years		98,828
Debt securities, Available-for-sale, Amortized cost, After three years through five years		28,967
Debt securities, Available-for-sale, Amortized cost, After five years through ten years		115,553
Debt securities, Available-for-sale, Amortized cost, After ten years		446,966
Debt securities, Available-for-sale, Estimated fair value, Within one year		31,290
Debt securities, Available-for-sale, Estimated fair value, After one year through three years		99,728
Debt securities, Available-for-sale, Estimated fair value, After three years through five years		29,304
Debt securities, Available-for-sale, Estimated fair value, After five years through ten years		115,018
Debt securities, Available-for-sale, Estimated fair value, After ten years		445,066
Debt securities, Held-to-maturity, Amortized cost, Within one year		15,013
Debt securities, Held-to-maturity, Amortized cost, After one year through three years		40,178
Debt securities, Held-to-maturity, Amortized cost, After ten years		177,523
Debt securities, Held-to-maturity, Estimated fair value, Within one year		15,012
Debt securities, Held-to-maturity, Estimated fair value, After one year through three years		39,540
Debt securities, Held-to-maturity, Estimated fair value, After ten years		177,506
Mortgage-backed securities [Member]
Schedule Of Debt Securities At Amortized Cost And Fair Value Basis [Line Items]
Debt securities, Available-for-sale, Amortized cost, After one year through three years		94
Debt securities, Available-for-sale, Amortized cost, After five years through ten years		757
Debt securities, Available-for-sale, Amortized cost, After ten years		66,651
Debt securities, Available-for-sale, Estimated fair value, After one year through three years		95
Debt securities, Available-for-sale, Estimated fair value, After five years through ten years		804
Debt securities, Available-for-sale, Estimated fair value, After ten years		66,592
Debt securities, Held-to-maturity, Amortized cost, After five years through ten years		59,491
Debt securities, Held-to-maturity, Amortized cost, After ten years		833,221
Debt securities, Held-to-maturity, Estimated fair value, After five years through ten years		61,548
Debt securities, Held-to-maturity, Estimated fair value, After ten years		$ 854,702

[1] Due to the immaterial amount of income recognized on tax-exempt securities, yields were not calculated on a tax-equivalent basis.

[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.