SECURITIES (Available-for-sale Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Equity securities with a readily determinable fair value	$ 20,314	$ 20,788
Amortized cost of securities	6,788,729	7,536,338
Gross Unrealized Gains	1,495	78,269
Gross Unrealized Losses	(643,080)	(84,233)
Estimated Fair Value	1,012,213
Estimated Fair Value	6,147,144	7,530,374
U.S. treasuries
Debt Securities, Available-for-sale [Line Items]
Total debt securities	32,369	997
Gross Unrealized Gains	8	11
Gross Unrealized Losses	(678)	0
Estimated Fair Value	31,699	1,008
U.S. agencies
Debt Securities, Available-for-sale [Line Items]
Total debt securities	49,437	193,932
Gross Unrealized Gains	0	264
Gross Unrealized Losses	(6,302)	(812)
Estimated Fair Value	43,135	193,384
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Total debt securities	1,049,578	2,045,386
Gross Unrealized Gains	14	56,263
Gross Unrealized Losses	(170,155)	(16,616)
Estimated Fair Value	879,437	2,085,033
Mortgage-backed securities - agency
Debt Securities, Available-for-sale [Line Items]
Total debt securities	2,042,092	2,388,601
Gross Unrealized Gains	56	11,870
Gross Unrealized Losses	(270,043)	(51,182)
Estimated Fair Value	1,772,105	2,349,289
Mortgage-backed securities - non-agency
Debt Securities, Available-for-sale [Line Items]
Total debt securities	2,327,308	1,749,838
Gross Unrealized Gains	1,417	4,570
Gross Unrealized Losses	(146,849)	(11,029)
Estimated Fair Value	2,181,876	1,743,379
Commercial mortgage-backed securities - agency
Debt Securities, Available-for-sale [Line Items]
Total debt securities	100,518	125,397
Gross Unrealized Gains	0	1,429
Gross Unrealized Losses	(15,395)	(2,914)
Estimated Fair Value	85,123	123,912
Commercial mortgage-backed securities - non-agency
Debt Securities, Available-for-sale [Line Items]
Total debt securities	679,511	600,253
Gross Unrealized Gains	0	998
Gross Unrealized Losses	(20,052)	(363)
Estimated Fair Value	659,459	600,888
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Total debt securities	428,397	408,167
Gross Unrealized Gains	0	2,803
Gross Unrealized Losses	(12,343)	(1,317)
Estimated Fair Value	416,054	409,653
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Total debt securities	59,205	2,979
Gross Unrealized Gains	0	61
Gross Unrealized Losses	(1,263)	0
Estimated Fair Value	57,942	3,040
Total debt securities
Debt Securities, Available-for-sale [Line Items]
Total debt securities	6,768,415	7,515,550
Gross Unrealized Gains	1,495	78,269
Gross Unrealized Losses	(643,080)	(84,233)
Estimated Fair Value	$ 6,126,830	$ 7,509,586

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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).

+ References

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-Publisher FASB
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-Topic 320
-SubTopic 10
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Amount of investment in marketable security.

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