Investment Securities (Amortized Cost, Unrealized Gains And Losses, And Fair Value Of Investment Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	$ 9,646,277	$ 3,738,281
Available-for-sale securities, unrealized gains	94,099	234
Available-for-sale securities, unrealized losses	(490,776)	(542,349)
Available for sale, at fair value	9,249,600	3,196,166
Investment securities held to maturity	2,432	2,476
Held-to-maturity securities, unrealized gains	743	721
Held-to-maturity securities, unrealized losses	0	0
Held-to-maturity securities, fair value	3,175	3,197
U.S. Treasury and agencies
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	1,584,480	1,035,532
Available-for-sale securities, unrealized gains	3,940	0
Available-for-sale securities, unrealized losses	(86,058)	(99,358)
Available for sale, at fair value	1,502,362	936,174
Obligations of states and political subdivisions
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	1,086,982	297,610
Available-for-sale securities, unrealized gains	21,327	231
Available-for-sale securities, unrealized losses	(22,124)	(28,041)
Available for sale, at fair value	1,086,185	269,800
Mortgage-backed securities and collateralized mortgage obligations
Investment Holdings [Line Items]
Available-for-sale securities, amortized cost	6,974,815	2,405,139
Available-for-sale securities, unrealized gains	68,832	3
Available-for-sale securities, unrealized losses	(382,594)	(414,950)
Available for sale, at fair value	6,661,053	1,990,192
Investment securities held to maturity	2,432	2,476
Held-to-maturity securities, unrealized gains	743	721
Held-to-maturity securities, unrealized losses	0	0
Held-to-maturity securities, fair value	$ 3,175	$ 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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Amount, before tax, of unrealized loss 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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