REGULATORY MATTERS, COMMITMENTS AND CONTINGENCIES - Regulatory Capital Positions (Details) $ in Thousands	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
First BanCorp [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets) Actual	$ 2,404,581	$ 2,403,319
Total Capital (to Risk-Weighted Assets) Actual Ratio	0.1802	0.1857
Total Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 1,067,380	$ 1,035,589
Total Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio	0.080	0.080
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Actual	$ 2,177,748	$ 2,084,432
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1632	0.1610
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 600,401	$ 528,519
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio	0.045	0.045
Tier 1 Capital (to Risk-Weighted Assets) Actual	$ 2,177,748	$ 2,084,432
Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1632	0.1610
Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 800,535	$ 776,692
Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio	0.060	0.060
Leverage Ratio Actual Amount	$ 2,177,748	$ 2,084,432
Leverage Ratio Actual Ratio	0.1107	0.1078
Leverage Ratio Required For Capital Adequacy	$ 786,937	$ 773,615
Leverage Ratio Required For Capital Adequacy Ratio	0.040	0.040
FirstBank [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total Capital (to Risk-Weighted Assets) Actual	$ 2,369,441	$ 2,376,003
Total Capital (to Risk-Weighted Assets) Actual Ratio	0.1776	0.1836
Total Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 1,067,033	$ 1,035,406
Total Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio	0.080	0.080
Total Capital (to Risk-Weighted Assets) Required To Be Well Capitalized	$ 1,333,791	$ 1,294,257
Total Capital (to Risk-Weighted Assets) Required To Be Well Capitalized Ratio	0.100	0.100
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Actual	$ 2,102,512	$ 2,113,995
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1576	0.1633
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 600,206	$ 582,416
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio	0.045	0.045
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required To Be Well Capitalized	$ 866,964	$ 841,267
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required To Be Well Capitalized Ratio	0.065	0.065
Tier 1 Capital (to Risk-Weighted Assets) Actual	$ 2,202,512	$ 2,213,995
Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1651	0.1711
Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 800,275	$ 776,554
Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio	0.060	0.060
Tier 1 Capital (to Risk-Weighted Assets) Required To Be Well Capitalized	$ 1,067,033	$ 1,035,406
Tier 1 Capital (to Risk-Weighted Assets) Required To Be Well Capitalized Ratio	0.080	0.080
Leverage Ratio Actual Amount	$ 2,202,512	$ 2,213,995
Leverage Ratio Actual Ratio	0.1120	0.1145
Leverage Ratio Required For Capital Adequacy	$ 786,712	$ 773,345
Leverage Ratio Required For Capital Adequacy Ratio	0.040	0.040
Leverage Ratio Required To Be Well Capitalized	$ 983,390	$ 966,682
Leverage Ratio Required To Be Well Capitalized Ratio	0.050	0.050

Common Equity Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio

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Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio

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Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required To Be Well Capitalized Ratio

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Amount of total capital as defined by regulatory framework.

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Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
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-Section 50
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