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DEPOSITS - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deposit Liabilities Disclosures [Line Items]
Interest expense on time deposits of $250,000 or more	$ 13,000,000	$ 2,100,000	$ 1,400,000
Maximum brokered certificates of deposit balance allowed per company policy	$ 1,200,000,000
Maximum brokered certificates of deposit balance allowed per company policy, percent	20.00%
Related party deposit liabilities	$ 9,800,000	11,000,000
Demand deposit overdrafts reclassified as loans	1,300,000	1,200,000
Certificates of deposit - CDs
Deposit Liabilities Disclosures [Line Items]
Brokered deposits	0	220,900,000
Brokered non-maturity deposits
Deposit Liabilities Disclosures [Line Items]
Brokered deposits	$ 828,000,000	$ 438,400,000
Weighted average cost, domestic deposit, brokered	3.23%

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Deposit Liabilities Disclosures [Line Items]

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Interest-bearing Domestic Deposit, Brokered, Maximum Balance Allowed per Company Policy

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Interest-bearing Domestic Deposit, Brokered, Maximum Balance Allowed per Company Policy, Percent

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Interest Expense, Time Deposits, $250,000 or More

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Amount of deposits held by the entity that have been reclassified as loan balances receivable, for example, but not limited to, overdrafts receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-SubTopic 405
-Topic 942
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481047/942-405-50-1

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Amount of interest-bearing domestic third-party deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

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Amount of deposits held by the entity for a related party (entity, shareholder, employee).

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

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