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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, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Loans held for investment	$ 11,950,932		$ 11,552,825
ACL for loans and finance leases	(263,615)	$ (267,058)	(260,464)	$ (257,859)	$ (252,152)	$ (269,030)
Loans held for investment, net	11,687,317		11,292,361
Puerto Rico and Virgin Islands regions [Member]
Loans held for investment	9,906,289		9,464,474
Florida region [Member}
Loans held for investment	2,044,643		2,088,351
Residential Portfolio Segment [Member]
Loans held for investment	2,812,631		2,847,290
ACL for loans and finance leases	(57,200)	(60,514)	(62,760)	(65,079)	(65,231)	(74,837)
Residential Portfolio Segment [Member] \| Puerto Rico and Virgin Islands regions [Member]
Loans held for investment	2,353,679		2,417,900
Residential Portfolio Segment [Member] \| Florida region [Member}
Loans held for investment	458,952		429,390
Commercial Portfolio Segment [Member] \| Commercial and Industrial loans [Member]
Loans held for investment	3,030,954		2,886,263
ACL for loans and finance leases	(30,097)	(28,014)	(32,906)	(35,461)	(36,203)	(34,284)
Commercial Portfolio Segment [Member] \| Commercial and Industrial loans [Member] \| Puerto Rico and Virgin Islands regions [Member]
Loans held for investment	2,088,274		1,860,109
Commercial Portfolio Segment [Member] \| Commercial and Industrial loans [Member] \| Florida region [Member}
Loans held for investment	942,680		1,026,154
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Loans held for investment	2,316,113		2,358,851
ACL for loans and finance leases	(41,157)	(42,427)	(35,064)	(30,290)	(32,619)	(52,771)
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member] \| Puerto Rico and Virgin Islands regions [Member]
Loans held for investment	1,780,008		1,834,204
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member] \| Florida region [Member}
Loans held for investment	536,105		524,647
Commercial Portfolio Segment [Member] \| Construction loans [Member]
Loans held for investment	202,774		132,953
ACL for loans and finance leases	(5,621)	(4,804)	(2,308)	(1,821)	(2,020)	(4,048)
Commercial Portfolio Segment [Member] \| Construction loans [Member] \| Puerto Rico and Virgin Islands regions [Member]
Loans held for investment	102,327		34,772
Commercial Portfolio Segment [Member] \| Construction loans [Member] \| Florida region [Member}
Loans held for investment	100,447		98,181
Consumer Portfolio Segment [Member]
Loans held for investment	3,588,460		3,327,468
ACL for loans and finance leases	(129,540)	$ (131,299)	(127,426)	$ (125,208)	$ (116,079)	$ (103,090)
Consumer Portfolio Segment [Member] \| Puerto Rico and Virgin Islands regions [Member]
Loans held for investment	3,582,001		3,317,489
Consumer Portfolio Segment [Member] \| Florida region [Member}
Loans held for investment	$ 6,459		$ 9,979