Investment Securities (Schedule Of Contractual Maturities Of Investment Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Investment Holdings [Line Items]
Available-for-sale securities, due within one year, amortized cost	$ 46,775
Available-for-sale securities, after one year through five years, amortized cost	1,654,173
Available-for-sale securities, after five years through ten years, amortized cost	2,924,904
Available-for-sale securities, after ten years, amortized cost	5,020,425
Available-for-sale securities, amortized cost	9,646,277	$ 3,738,281
Available-for-sale securities, due within one year, fair value	46,157
Available-for-sale securities, after one year through five years, fair value	1,646,542
Available-for-sale securities, after five years through ten years, fair value	2,870,751
Available-for-sale securities, after ten years, fair value	4,686,150
Debt Securities, Available-for-sale	9,249,600	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	4
Held-to-maturity securities, after five years through ten years, amortized cost	2
Held-to-maturity securities, after ten years, amortized cost	2,426
Investment securities held to maturity	2,432	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	4
Held-to-maturity securities, after five years through ten years, fair value	2
Held-to-maturity securities, after ten years, fair value	3,169
Held-to-maturity securities, fair value	$ 3,175	$ 3,197