Investment Securities (Amortized Cost, Unrealized Gains And Losses, And Fair Value Of Investment Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	$ 9,262,777	$ 3,738,281
Available-for-sale securities, unrealized gains	55,201	234
Available-for-sale securities, unrealized losses	(488,108)	(542,349)
Available for sale, at fair value	8,829,870	3,196,166
Held to maturity, at amortized cost	2,300	2,476
Held-to-maturity securities, unrecognized gains	725	721
Held-to-maturity securities, unrecognized losses	0	0
Held-to-maturity securities, fair value	3,025	3,197
U.S. Treasury and agencies
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	1,551,074	1,035,532
Available-for-sale securities, unrealized gains	6,192	0
Available-for-sale securities, unrealized losses	(78,874)	(99,358)
Available for sale, at fair value	1,478,392	936,174
Obligations of states and political subdivisions
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	1,073,264	297,610
Available-for-sale securities, unrealized gains	20,451	231
Available-for-sale securities, unrealized losses	(21,610)	(28,041)
Available for sale, at fair value	1,072,105	269,800
Mortgage-backed securities and collateralized mortgage obligations
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	6,638,439	2,405,139
Available-for-sale securities, unrealized gains	28,558	3
Available-for-sale securities, unrealized losses	(387,624)	(414,950)
Available for sale, at fair value	6,279,373	1,990,192
Held to maturity, at amortized cost	2,300	2,476
Held-to-maturity securities, unrecognized gains	725	721
Held-to-maturity securities, unrecognized losses	0	0
Held-to-maturity securities, fair value	$ 3,025	$ 3,197

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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