Available-For-Sale And Held-To-Maturity Securities (Schedule Of Amortized Cost Of Held-To-Maturity Securities By Credit Quality Indicator) (Details) - USD ($) $ in Thousands		Jun. 30, 2024	Dec. 31, 2023
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity securities, at amortized cost	[1]	$ 6,059,267	$ 5,888,798
Asset-Backed Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity securities, at amortized cost	[2]	6,059,267
Asset-Backed Securities [Member] | AAA [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity securities, at amortized cost		1,584,129
Asset-Backed Securities [Member] | AA [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity securities, at amortized cost		4,468,981
Asset-Backed Securities [Member] | A [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity securities, at amortized cost		5,000
Asset-Backed Securities [Member] | C [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity securities, at amortized cost		$ 1,157

[1] 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.

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