<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.5.0.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>514</ContextCount>
  <ElementCount>393</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>69</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00000001 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/pgc-daei</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00000002 - Statement - CONSOLIDATED STATEMENTS OF CONDITION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Statement-CONSOLIDATEDSTATEMENTSOFCONDITION</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CONDITION</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00000003 - Statement - CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Statement-CONSOLIDATEDSTATEMENTSOFCONDITIONParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00000004 - Statement - CONSOLIDATED STATEMENTS OF INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Statement-CONSOLIDATEDSTATEMENTSOFINCOME</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00000005 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Statement-CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00000006 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS??? EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/ConsolidatedStatementsOfChangesInShareholdersEquity</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS??? EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00000007 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS??? EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/ConsolidatedStatementsOfChangesInShareholdersEquityParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS??? EQUITY (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00000008 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Statement-CONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>00000009 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>00000010 - Disclosure - INVESTMENT SECURITIES AVAILABLE FOR SALE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-INVESTMENTSECURITIESAVAILABLEFORSALE</Role>
      <ShortName>INVESTMENT SECURITIES AVAILABLE FOR SALE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>00000011 - Disclosure - LOANS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANS</Role>
      <ShortName>LOANS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>00000012 - Disclosure - DEPOSITS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-DEPOSITS</Role>
      <ShortName>DEPOSITS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>00000013 - Disclosure - FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FEDERALHOMELOANBANKADVANCESANDOTHERBORROWINGS</Role>
      <ShortName>FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>00000014 - Disclosure - BUSINESS SEGMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-BUSINESSSEGMENTS</Role>
      <ShortName>BUSINESS SEGMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>00000015 - Disclosure - FAIR VALUE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FAIRVALUE</Role>
      <ShortName>FAIR VALUE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>00000016 - Disclosure - OTHER OPERATING EXPENSES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-OTHEROPERATINGEXPENSES</Role>
      <ShortName>OTHER OPERATING EXPENSES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>00000017 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOME</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>00000018 - Disclosure - DERIVATIVES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-DERIVATIVES</Role>
      <ShortName>DERIVATIVES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>00000019 - Disclosure - SUBORDINATED DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/SubordinatedDebt</Role>
      <ShortName>SUBORDINATED DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>00000021 - Disclosure - RECENT ACCOUNTING PRONOUNCEMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-RECENTACCOUNTINGPRONOUNCEMENTS</Role>
      <ShortName>RECENT ACCOUNTING PRONOUNCEMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>00000022 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>00000023 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>00000024 - Disclosure - INVESTMENT SECURITIES AVAILABLE FOR SALE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-INVESTMENTSECURITIESAVAILABLEFORSALETables</Role>
      <ShortName>INVESTMENT SECURITIES AVAILABLE FOR SALE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-INVESTMENTSECURITIESAVAILABLEFORSALE</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>00000025 - Disclosure - LOANS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSTables</Role>
      <ShortName>LOANS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANS</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>00000026 - Disclosure - DEPOSITS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-DEPOSITSTables</Role>
      <ShortName>DEPOSITS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-DEPOSITS</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>00000027 - Disclosure - FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FEDERALHOMELOANBANKADVANCESANDOTHERBORROWINGSTables</Role>
      <ShortName>FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FEDERALHOMELOANBANKADVANCESANDOTHERBORROWINGS</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>00000028 - Disclosure - BUSINESS SEGMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-BUSINESSSEGMENTSTables</Role>
      <ShortName>BUSINESS SEGMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-BUSINESSSEGMENTS</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>00000029 - Disclosure - FAIR VALUE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FAIRVALUETables</Role>
      <ShortName>FAIR VALUE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FAIRVALUE</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>00000030 - Disclosure - OTHER OPERATING EXPENSES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-OTHEROPERATINGEXPENSESTables</Role>
      <ShortName>OTHER OPERATING EXPENSES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-OTHEROPERATINGEXPENSES</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>00000031 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMETables</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOME</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>00000032 - Disclosure - DERIVATIVES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-DERIVATIVESTables</Role>
      <ShortName>DERIVATIVES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-DERIVATIVES</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>00000033 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative - Other) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrative-OtherDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative - Other) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>00000034 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Stock-Based Compensation Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESStock-BasedCompensationNarrativeDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Stock-Based Compensation Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>00000035 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Changes in Options Outstanding) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofChangesinOptionsOutstandingDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Changes in Options Outstanding) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>00000037 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Changes in Restricted Common Shares) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofChangesinRestrictedCommonSharesDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Changes in Restricted Common Shares) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>00000038 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Earnings per Common Share) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofEarningsperCommonShareDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Earnings per Common Share) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>00000039 - Disclosure - INVESTMENT SECURITIES AVAILABLE FOR SALE (Schedule of Amortized Cost and Approximate Fair Value) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-INVESTMENTSECURITIESAVAILABLEFORSALEScheduleofAmortizedCostandApproximateFairValueDetails</Role>
      <ShortName>INVESTMENT SECURITIES AVAILABLE FOR SALE (Schedule of Amortized Cost and Approximate Fair Value) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-INVESTMENTSECURITIESAVAILABLEFORSALETables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>00000040 - Disclosure - INVESTMENT SECURITIES AVAILABLE FOR SALE (Schedule of Securities with Continuous Unrealized Losses) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-INVESTMENTSECURITIESAVAILABLEFORSALEScheduleofSecuritieswithContinuousUnrealizedLossesDetails</Role>
      <ShortName>INVESTMENT SECURITIES AVAILABLE FOR SALE (Schedule of Securities with Continuous Unrealized Losses) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-INVESTMENTSECURITIESAVAILABLEFORSALETables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>00000041 - Disclosure - LOANS (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSNarrativeDetails</Role>
      <ShortName>LOANS (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>00000042 - Disclosure - LOANS (Schedule of Loans Outstanding, by Classification) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofLoansOutstandingbyClassificationDetails</Role>
      <ShortName>LOANS (Schedule of Loans Outstanding, by Classification) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>00000043 - Disclosure - LOANS (Schedule of Loan Balances by Portfolio Class) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofLoanBalancesbyPortfolioClassDetails</Role>
      <ShortName>LOANS (Schedule of Loan Balances by Portfolio Class) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>00000044 - Disclosure - LOANS (Schedule of Balances by Portfolio Class, Based on Impairment Method) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofBalancesbyPortfolioClassBasedonImpairmentMethodDetails</Role>
      <ShortName>LOANS (Schedule of Balances by Portfolio Class, Based on Impairment Method) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>00000045 - Disclosure - LOANS (Schedule of Schedule of Loans Individually Evaluated for Impairment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofScheduleofLoansIndividuallyEvaluatedforImpairmentDetails</Role>
      <ShortName>LOANS (Schedule of Schedule of Loans Individually Evaluated for Impairment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>00000046 - Disclosure - LOANS (Schedule of Investment in Nonaccrual and Loans Past Due Over 90 Days) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofInvestmentinNonaccrualandLoansPastDueOver90DaysDetails</Role>
      <ShortName>LOANS (Schedule of Investment in Nonaccrual and Loans Past Due Over 90 Days) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>00000047 - Disclosure - LOANS (Schedule of Schedule of Aging of Past Due Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofScheduleofAgingofPastDueLoansDetails</Role>
      <ShortName>LOANS (Schedule of Schedule of Aging of Past Due Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>00000048 - Disclosure - LOANS (Schedule of Schedule of Risk Category of Loans by Class of Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofScheduleofRiskCategoryofLoansbyClassofLoansDetails</Role>
      <ShortName>LOANS (Schedule of Schedule of Risk Category of Loans by Class of Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>00000049 - Disclosure - LOANS (Schedule of Activity in Allowance for Loan Losses) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofActivityinAllowanceforLoanLossesDetails</Role>
      <ShortName>LOANS (Schedule of Activity in Allowance for Loan Losses) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>00000050 - Disclosure - LOANS (Schedule of Loans Modified as Troubled Debt Restructurings) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofLoansModifiedasTroubledDebtRestructuringsDetails</Role>
      <ShortName>LOANS (Schedule of Loans Modified as Troubled Debt Restructurings) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>00000051 - Disclosure - LOANS (Schedule of Modified as Troubled Debt Restructurings Subsequently Defaulted) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-LOANSScheduleofModifiedasTroubledDebtRestructuringsSubsequentlyDefaultedDetails</Role>
      <ShortName>LOANS (Schedule of Modified as Troubled Debt Restructurings Subsequently Defaulted) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-LOANSTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>00000052 - Disclosure - DEPOSITS (Details of Total Deposits) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-DEPOSITSDetailsofTotalDepositsDetails</Role>
      <ShortName>DEPOSITS (Details of Total Deposits) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-DEPOSITSTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>00000053 - Disclosure - DEPOSITS (Scheduled Maturities of Time Deposits) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-DEPOSITSScheduledMaturitiesofTimeDepositsDetails</Role>
      <ShortName>DEPOSITS (Scheduled Maturities of Time Deposits) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-DEPOSITSTables</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>00000054 - Disclosure - FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FEDERALHOMELOANBANKADVANCESANDOTHERBORROWINGSNarrativeDetails</Role>
      <ShortName>FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FEDERALHOMELOANBANKADVANCESANDOTHERBORROWINGSTables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>00000055 - Disclosure - FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS (Schedule of Maturities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FEDERALHOMELOANBANKADVANCESANDOTHERBORROWINGSScheduleofMaturitiesDetails</Role>
      <ShortName>FEDERAL HOME LOAN BANK ADVANCES AND OTHER BORROWINGS (Schedule of Maturities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FEDERALHOMELOANBANKADVANCESANDOTHERBORROWINGSTables</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>00000056 - Disclosure - BUSINESS SEGMENTS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-BUSINESSSEGMENTSDetails</Role>
      <ShortName>BUSINESS SEGMENTS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-BUSINESSSEGMENTSTables</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>00000057 - Disclosure - FAIR VALUE (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FAIRVALUENarrativeDetails</Role>
      <ShortName>FAIR VALUE (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FAIRVALUETables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>00000059 - Disclosure - FAIR VALUE (Schedule of Assets Measured on a Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FAIRVALUEScheduleofAssetsMeasuredonaRecurringBasisDetails</Role>
      <ShortName>FAIR VALUE (Schedule of Assets Measured on a Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FAIRVALUETables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>00000060 - Disclosure - FAIR VALUE (Schedule of Residential Loans Held for Sale, at Fair Value) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FAIRVALUEScheduleofResidentialLoansHeldforSaleatFairValueDetails</Role>
      <ShortName>FAIR VALUE (Schedule of Residential Loans Held for Sale, at Fair Value) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FAIRVALUETables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>00000061 - Disclosure - FAIR VALUE (Schedule of Assets Measured on a Non-Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FAIRVALUEScheduleofAssetsMeasuredonaNon-RecurringBasisDetails</Role>
      <ShortName>FAIR VALUE (Schedule of Assets Measured on a Non-Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FAIRVALUETables</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>00000062 - Disclosure - FAIR VALUE (Schedule of Financial Instruments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-FAIRVALUEScheduleofFinancialInstrumentsDetails</Role>
      <ShortName>FAIR VALUE (Schedule of Financial Instruments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-FAIRVALUETables</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>00000063 - Disclosure - OTHER OPERATING EXPENSES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-OTHEROPERATINGEXPENSESDetails</Role>
      <ShortName>OTHER OPERATING EXPENSES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-OTHEROPERATINGEXPENSESTables</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>00000064 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME (Schedule of Accumulated Other Comprehensive Income Balances, Net of Tax) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMEScheduleofAccumulatedOtherComprehensiveIncomeBalancesNetofTaxDetails</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME (Schedule of Accumulated Other Comprehensive Income Balances, Net of Tax) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMETables</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>00000065 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME (Schedule of Reclassifications out of AOCI) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMEScheduleofReclassificationsoutofAOCIDetails</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE (LOSS)/INCOME (Schedule of Reclassifications out of AOCI) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMETables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>00000066 - Disclosure - DERIVATIVES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/Disclosure-DERIVATIVESDetails</Role>
      <ShortName>DERIVATIVES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/Disclosure-DERIVATIVESTables</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="pgc-20160630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>00000067 - Disclosure - SUBORDINATED DEBT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://pgbank.com/role/SubordinatedDebtDetails</Role>
      <ShortName>SUBORDINATED DEBT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://pgbank.com/role/SubordinatedDebt</ParentRole>
      <Position>64</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>pgc-20160630.xml</File>
    <File>pgc-20160630.xsd</File>
    <File>pgc-20160630_cal.xml</File>
    <File>pgc-20160630_def.xml</File>
    <File>pgc-20160630_lab.xml</File>
    <File>pgc-20160630_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
