Investment Securities (Schedule Of Contractual Maturities Of Investment Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investment Holdings [Line Items]
Available-for-sale securities, due within one year, amortized cost	$ 71,438
Available-for-sale securities, after one year through five years, amortized cost	2,127,299
Available-for-sale securities, after five years through ten years, amortized cost	2,388,442
Available-for-sale securities, after ten years, amortized cost	4,675,598
Available-for-sale securities, amortized cost	9,262,777	$ 3,738,281
Available-for-sale securities, due within one year, fair value	70,451
Available-for-sale securities, after one year through five years, fair value	2,106,753
Available-for-sale securities, after five years through ten years, fair value	2,323,581
Available-for-sale securities, after ten years, fair value	4,329,085
Available-for-sale securities, fair value	8,829,870	3,196,166
Held-to-maturity securities, due within one year, amortized cost	0
Held-to-maturity securities, After one year through five years, amortized cost	2
Held-to-maturity securities, after five years through ten years, amortized cost	3
Held-to-maturity securities, after ten years, amortized cost	2,295
Held to maturity, at amortized cost	2,300	2,476
Held-to-maturity securities, due within one year, fair value	0
Held-to-maturity securities, after one year through five years, fair value	2
Held-to-maturity securities, after five years through ten years, fair value	67
Held-to-maturity securities, after ten years, fair value	2,956
Held-to-maturity securities, fair value	$ 3,025	$ 3,197