REGULATORY MATTERS, COMMITMENTS AND CONTINGENCIES - Regulatory capital positions (Detail) $ in Thousands	Mar. 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	$ 2,388,964	$ 2,403,319
Total Capital (to Risk-Weighted Assets) Actual Ratio	0.1836	0.1857
Total Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 1,040,707	$ 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	$ 2,068,978	$ 2,084,432
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1590	0.1610
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 585,398	$ 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	$ 2,068,978	$ 2,084,432
Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1590	0.1610
Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 780,531	$ 776,692
Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy Ratio	0.060	0.060
Leverage Ratio Actual Amount	$ 2,068,978	$ 2,084,432
Leverage Ratio Actual Ratio	0.1065	0.1078
Leverage Ratio Required For Capital Adequacy	$ 777,406	$ 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	$ 2,360,406	$ 2,376,003
Total Capital (to Risk-Weighted Assets) Actual Ratio	0.1815	0.1836
Total Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 1,040,576	$ 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	$ 1,300,720	$ 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	$ 2,097,291	$ 2,113,995
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1612	0.1633
Common Equity Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 585,324	$ 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	$ 845,468	$ 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	$ 2,197,291	$ 2,213,995
Tier 1 Capital (to Risk-Weighted Assets) Actual Ratio	0.1689	0.1711
Tier 1 Capital (to Risk-Weighted Assets) Required For Capital Adequacy	$ 780,432	$ 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	$ 1,040,576	$ 1,035,406
Tier 1 Capital (to Risk-Weighted Assets) Required To Be Well Capitalized Ratio	0.080	0.080
Leverage Ratio Actual Amount	$ 2,197,291	$ 2,213,995
Leverage Ratio Actual Ratio	0.1131	0.1145
Leverage Ratio Required For Capital Adequacy	$ 777,103	$ 773,345
Leverage Ratio Required For Capital Adequacy Ratio	0.040	0.040
Leverage Ratio Required To Be Well Capitalized	$ 971,379	$ 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//1943274/2147480696/942-505-50-1

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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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