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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

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LOANS HELD FOR INVESTMENT - Loan Portfolio Held for Investment (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 12,446,024		$ 12,185,483
ACL for loans and finance leases	(246,996)	$ (254,532)	(261,843)	$ (263,615)	$ (267,058)	$ (260,464)
Loans held for investment, net	12,199,028		11,923,640
Puerto Rico and Virgin Islands regions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	10,277,735		10,163,222
Florida region [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,168,289		2,022,261
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,820,147		2,821,726
ACL for loans and finance leases	(40,651)	(46,051)	(57,397)	(57,200)	(60,514)	(62,760)
Residential Portfolio Segment [Member] \| Puerto Rico and Virgin Islands regions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,327,678		2,356,006
Residential Portfolio Segment [Member] \| Florida region [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	492,469		465,720
Commercial Portfolio Segment [Member] \| Construction loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	207,342		214,777
ACL for loans and finance leases	(3,998)	(5,646)	(5,605)	(5,621)	(4,804)	(2,308)
Commercial Portfolio Segment [Member] \| Construction loans [Member] \| Puerto Rico and Virgin Islands regions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	175,353		115,401
Commercial Portfolio Segment [Member] \| Construction loans [Member] \| Florida region [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	31,989		99,376
Commercial Portfolio Segment [Member] \| Mortgage loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,471,880		2,317,083
ACL for loans and finance leases	(24,205)	(30,078)	(32,631)	(41,157)	(42,427)	(35,064)
Commercial Portfolio Segment [Member] \| Mortgage loans [Member] \| Puerto Rico and Virgin Islands regions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,797,333		1,790,637
Commercial Portfolio Segment [Member] \| Mortgage loans [Member] \| Florida region [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	674,547		526,446
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member}
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,205,313		3,174,232
ACL for loans and finance leases	(34,446)	(34,448)	(33,190)	(30,097)	(28,014)	(32,906)
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member} \| Puerto Rico and Virgin Islands regions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,243,630		2,249,408
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member} \| Florida region [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	961,683		924,824
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,741,342		3,657,665
ACL for loans and finance leases	(143,696)	$ (138,309)	(133,020)	$ (129,540)	$ (131,299)	$ (127,426)
Consumer Portfolio Segment [Member] \| Puerto Rico and Virgin Islands regions [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,733,741		3,651,770
Consumer Portfolio Segment [Member] \| Florida region [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 7,601		$ 5,895