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		Dec. 31, 2015	Dec. 31, 2014
Schedule Of Debt Securities At Amortized Cost And Fair Value Basis [Line Items]
Available-for-sale Securities, debt maturities, Amortized Cost		$ 1,641,398
Available-for-sale Securities, debt maturities, within one year, Fair Value	[1]	9,724
Available-for-sale Securities, debt maturities, after five through ten years, fair value	[1]	271,760
Availably-for-sale Securities, debt maturities, after ten years, Fair Value	[1]	1,091,358
Available-for-sale Securities, debt maturities, Fair Value	[1]	1,629,907
Held-to-maturity Securities, debt maturities, after five through ten years, Amortized Cost		269,700
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost		1,545,554
Held-to-maturity Securities, Amortized cost	[2]	1,855,399	$ 1,177,565
Held-to-maturity Securities, debt maturities, Fair Value	[2]	1,874,998	$ 1,211,976
Excluding Mortgage Backed Securities
Schedule Of Debt Securities At Amortized Cost And Fair Value Basis [Line Items]
Available-for-sale Securities, debt maturities, within one year, Amortized Cost		9,710
Available-for-sale Securities, debt maturities, after one year through three years, Amortized Cost		88,249
Available-for-sale Securities, debt maturities, after three year through five years, Amortized Cost		169,684
Available-for-sale Securities, debt maturities, after five through ten years, Amortized Cost		275,252
Availably-for-sale Securities, debt maturities, after ten years, Amortized Cost		778,338
Available-for-sale Securities, debt maturities, within one year, Fair Value		9,723
Available-for-sale Securities, debt maturities, after one year through three years, Fair Value		88,426
Available-for-sale Securities, debt maturities, after three year through five years, Fair Value		168,573
Available-for-sale Securities, debt maturities, after five through ten years, fair value		271,146
Availably-for-sale Securities, debt maturities, after ten years, Fair Value		773,318
Held-to-maturity Securities, debt maturities, after one year through three years, Amortized Cost		40,145
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost		496,996
Held-to-maturity Securities, debt maturities, after one year through three years, Fair Value		39,748
Held-to-maturity Securities, debt maturities, after ten years, Fair Value		494,934
Mortgage Backed Securities
Schedule Of Debt Securities At Amortized Cost And Fair Value Basis [Line Items]
Available-for-sale Securities, debt maturities, after one year through three years, Amortized Cost		66
Available-for-sale Securities, debt maturities, after five through ten years, Amortized Cost		583
Availably-for-sale Securities, debt maturities, after ten years, Amortized Cost		319,516
Available-for-sale Securities, debt maturities, after one year through three years, Fair Value		67
Available-for-sale Securities, debt maturities, after five through ten years, fair value		614
Availably-for-sale Securities, debt maturities, after ten years, Fair Value		318,040
Held-to-maturity Securities, debt maturities, after five through ten years, Amortized Cost		269,700
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost		1,048,558
Held-to-maturity Securities, debt maturities, after five through ten years, Fair Value		269,989
Held-to-maturity Securities, debt maturities, after ten years, Fair Value		$ 1,070,327

[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.