<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>59</ContextCount>
  <ElementCount>34</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>8</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>1</UnitCount>
  <MyReports>
    <Report instance="ny20058674x1_def14a.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>995100 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/dei/role/document/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ny20058674x1_def14a.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ny20058674x1_def14a.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>995443 - Disclosure - Award Timing Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/AwardTimingDisclosure</Role>
      <ShortName>Award Timing Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ny20058674x1_def14a.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>fbp-20260506.xsd</File>
    <File>fbp-20260506_def.xml</File>
    <File doctype="DEF 14A" isProxy="true" isUsgaap="true" original="ny20058674x1_def14a.htm">ny20058674x1_def14a.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>fbancorp_smarrow.jpg</File>
    <File>logo_firstbancorps.jpg</File>
    <File>ny20019846x1_member.jpg</File>
    <File>ny20019846x1_tick1.jpg</File>
    <File>ny20019846x1_tick3.jpg</File>
    <File>ny20058674x1_aaleman-skill.jpg</File>
    <File>ny20058674x1_aaleman.jpg</File>
    <File>ny20058674x1_arrow2.jpg</File>
    <File>ny20058674x1_arrow3.jpg</File>
    <File>ny20058674x1_chart02.jpg</File>
    <File>ny20058674x1_cover2026.jpg</File>
    <File>ny20058674x1_date.jpg</File>
    <File>ny20058674x1_dfrye-skill.jpg</File>
    <File>ny20058674x1_dfrye.jpg</File>
    <File>ny20058674x1_diversity1.jpg</File>
    <File>ny20058674x1_fmvillamil-sk.jpg</File>
    <File>ny20058674x1_fmvillamil.jpg</File>
    <File>ny20058674x1_glay.jpg</File>
    <File>ny20058674x1_inperson.jpg</File>
    <File>ny20058674x1_internet.jpg</File>
    <File>ny20058674x1_internet2.jpg</File>
    <File>ny20058674x1_jareboyras-sk.jpg</File>
    <File>ny20058674x1_jareboyras.jpg</File>
    <File>ny20058674x1_jheffern-skill.jpg</File>
    <File>ny20058674x1_jheffern.jpg</File>
    <File>ny20058674x1_josemlacasa.jpg</File>
    <File>ny20058674x1_juancpavia.jpg</File>
    <File>ny20058674x1_lcrespo-skill.jpg</File>
    <File>ny20058674x1_lcrespo.jpg</File>
    <File>ny20058674x1_legend.jpg</File>
    <File>ny20058674x1_liliandiaz.jpg</File>
    <File>ny20058674x1_linechart.jpg</File>
    <File>ny20058674x1_linechart01.jpg</File>
    <File>ny20058674x1_linechart02.jpg</File>
    <File>ny20058674x1_mail.jpg</File>
    <File>ny20058674x1_nrivera.jpg</File>
    <File>ny20058674x1_oberges.jpg</File>
    <File>ny20058674x1_pc01.jpg</File>
    <File>ny20058674x1_pc02.jpg</File>
    <File>ny20058674x1_pchartceo-neo.jpg</File>
    <File>ny20058674x1_peaves-skill.jpg</File>
    <File>ny20058674x1_peaves.jpg</File>
    <File>ny20058674x1_phone.jpg</File>
    <File>ny20058674x1_piechart1.jpg</File>
    <File>ny20058674x1_piechart2.jpg</File>
    <File>ny20058674x1_piechart3.jpg</File>
    <File>ny20058674x1_pvpchart01.jpg</File>
    <File>ny20058674x1_pvpchart03.jpg</File>
    <File>ny20058674x1_pvpchart04.jpg</File>
    <File>ny20058674x1_record.jpg</File>
    <File>ny20058674x1_rherencia-skill.jpg</File>
    <File>ny20058674x1_rherencia.jpg</File>
    <File>ny20058674x1_saraalvarez.jpg</File>
    <File>ny20058674x1_tdedrick-skill.jpg</File>
    <File>ny20058674x1_tdedrick.jpg</File>
    <File>ny20058674x1_tick2.jpg</File>
    <File>ny20058674x1_time.jpg</File>
    <File>ny20058674x1_tmcdonald.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="5">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="133">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
