DEPOSITS AND RELATED INTEREST (Narrative) (Details) $ in Thousands	Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($) client
Deposits and Related Interest [Line Items]
Uninsured deposits	$ 5,321,000	$ 4,915,000
Deposits percent	53.16%	51.17%
Weighted average interest rate of deposits	1.53%	1.56%
Time deposits in denominations in excess of $250,000	$ 1,128,000	$ 1,049,000
Deposits	10,008,633	9,604,786
Public funds collateral investments	1,683,000	1,507,000
Accrued interest on time deposits	4,200	3,100
Overdrafts in demand deposit accounts	894	3,200
Commercial loans
Deposits and Related Interest [Line Items]
Overdrafts in demand deposit accounts		$ 2,500
Number of commercial clients \| client		2
Puerto Rico \| Government
Deposits and Related Interest [Line Items]
Deposits	$ 1,649,000	$ 1,445,000

Deposits and Related Interest [Line Items]

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- Definition

Financing Receivable, Number of Commercial Clients

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- Definition

Commercial loans and securities pledged as collateral to secure PR public fund deposits.

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- Definition

Carrying value as of the balance sheet date of payments made in excess of existing cash balances, which will be honored by the bank but reflected as a loan to the entity. Overdrafts generally have a very short time frame for correction or repayment and are therefore more similar to short-term bank financing than trade financing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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-Topic 470
-SubTopic 10
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481573/470-10-45-10

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- Definition

Amount of accrued but unpaid interest on deposit liabilities.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(15)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

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Amount of uninsured deposit liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1406
-Paragraph e
-Publisher SEC

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- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Percentage of interest-bearing domestic deposit liabilities to total deposit liabilities.

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- Definition

Amount of time deposit liabilities, including certificates of deposit, in denominations that meet or exceed the Federal Deposit Insurance Corporation (FDIC) insurance limit.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-SubTopic 405
-Topic 942
-Publisher FASB
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Weighted average interest rate calculated at point in time for domestic deposit liability.

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