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, 2022		Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, debt maturities, within one year, Amortized Cost		$ 16,047		$ 36,671
Available-for-sale Securities, debt maturities, after one year through three years, Amortized Cost		185,012		217,606
Available-for-sale Securities, debt maturities, after three year through five years, Amortized Cost		123,696		192,271
Available-for-sale Securities, debt maturities, after five year through ten years, Amortized Cost		442,055		455,429
Available-for-sale Securities, debt maturities, after ten years, Amortized Cost		1,096,409		1,202,536
Available-for-sale Securities, Amortized cost		1,863,219		2,104,513
Available-for-sale Securities, debt maturities, within one year, Fair Value		15,877	[1]	36,899
Available-for-sale Securities, debt maturities, after one year through three years, Fair Value		178,776		222,942
Available-for-sale Securities, debt maturities, after three year through five years, Fair Value		108,707		196,380
Available-for-sale Securities, debt maturities, after five year through ten years, fair value		380,362	[1]	455,848
Availably-for-sale Securities, debt maturities, after ten years, Fair Value		952,319	[1]	1,201,824
Available-for-sale Securities, debt maturities, Fair Value		1,636,041	[1]	2,113,893
Held-to-maturity Securities, debt maturities, after three through five years, Amortized Cost		0		2,825
Held-to-maturity Securities, debt maturities, after five through ten years, Amortized Cost		2,413,239		2,282,162
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost		3,577,212		3,063,571
Held-to-maturity Securities, Amortized cost	[2]	5,990,451		5,348,558
Held-to-maturity Securities, debt maturities, after three through five years, Fair Value		0		2,825
Held-to-maturity Securities, debt maturities, after five through ten years, Fair Value		2,323,608		2,278,597
Held-to-maturity Securities, debt maturities, after ten years, Fair Value		3,414,810		3,062,059
Held-to-maturity Securities, debt maturities, Fair Value	[2]	$ 5,738,418		$ 5,343,481

[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.