<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Version>2.4.1.9</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>263</ContextCount>
  <ElementCount>499</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>76</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00090 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00100 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00200 - Statement - CONSOLIDATED STATEMENTS OF INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF INCOME</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00300 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00400 - Statement - CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/StatementConsolidatedStatementOfChangesInStockholdersEquity</Role>
      <ShortName>CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00405 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquityParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00500 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>10101 - Disclosure - Corporate Structure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCorporateStructure</Role>
      <ShortName>Corporate Structure</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>10201 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>10301 - Disclosure - Restrictions on Cash and Amounts Due from Banks</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureRestrictionsOnCashAndAmountsDueFromBanks</Role>
      <ShortName>Restrictions on Cash and Amounts Due from Banks</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>10401 - Disclosure - Short-Term Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureShortTermInvestments</Role>
      <ShortName>Short-Term Investments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>10501 - Disclosure - Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSecurities</Role>
      <ShortName>Securities</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>10601 - Disclosure - Loans and Servicing</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicing</Role>
      <ShortName>Loans and Servicing</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>10701 - Disclosure - Premises and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosurePremisesAndEquipment</Role>
      <ShortName>Premises and Equipment</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>10801 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureDeposits</Role>
      <ShortName>Deposits</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>10901 - Disclosure - Federal Home Loan Bank Advances</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFederalHomeLoanBankAdvances</Role>
      <ShortName>Federal Home Loan Bank Advances</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>11001 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>11101 - Disclosure - Minimum Regulatory Capital Requirments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureMinimumRegulatoryCapitalRequirments</Role>
      <ShortName>Minimum Regulatory Capital Requirments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>11201 - Disclosure - Employee Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureEmployeeBenefitPlans</Role>
      <ShortName>Employee Benefit Plans</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>11301 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>11401 - Disclosure - Loans to Related Parties</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansToRelatedParties</Role>
      <ShortName>Loans to Related Parties</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>11501 - Disclosure - Derivative Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureDerivativeFinancialInstruments</Role>
      <ShortName>Derivative Financial Instruments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>11601 - Disclosure - Fair Value of Assets and Liabilites</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFairValueOfAssetsAndLiabilites</Role>
      <ShortName>Fair Value of Assets and Liabilites</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>11701 - Disclosure - Liquidation Account Related to Reorganization</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLiquidationAccountRelatedToReorganization</Role>
      <ShortName>Liquidation Account Related to Reorganization</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>11801 - Disclosure - Condensed Parent Company Financial Statements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCondensedParentCompanyFinancialStatements</Role>
      <ShortName>Condensed Parent Company Financial Statements</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>11901 - Disclosure - Quarterly Data (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureQuarterlyDataUnaudited</Role>
      <ShortName>Quarterly Data (Unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>20202 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>30203 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>30403 - Disclosure - Short-Term Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureShortTermInvestmentsTables</Role>
      <ShortName>Short-Term Investments (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>30503 - Disclosure - Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSecuritiesTables</Role>
      <ShortName>Securities (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>30603 - Disclosure - Loans and Servicing (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingTables</Role>
      <ShortName>Loans and Servicing (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>30703 - Disclosure - Premises and Equipments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosurePremisesAndEquipmentsTables</Role>
      <ShortName>Premises and Equipments (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>30803 - Disclosure - Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureDepositsTables</Role>
      <ShortName>Deposits (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>30903 - Disclosure - Federal Home Loan Bank Advances (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFederalHomeLoanBankAdvancesTables</Role>
      <ShortName>Federal Home Loan Bank Advances (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>31003 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>31103 - Disclosure - Minimum Regulatory Capital Requirements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureMinimumRegulatoryCapitalRequirementsTables</Role>
      <ShortName>Minimum Regulatory Capital Requirements (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>31203 - Disclosure - Employee Benefit Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureEmployeeBenefitPlansTables</Role>
      <ShortName>Employee Benefit Plans (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>31303 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>31603 - Disclosure - Fair Value of Assets and Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFairValueOfAssetsAndLiabilitiesTables</Role>
      <ShortName>Fair Value of Assets and Liabilities (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>31803 - Disclosure - Condensed Parent Company Financial Statements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCondensedParentCompanyFinancialStatementsTables</Role>
      <ShortName>Condensed Parent Company Financial Statements (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>31903 - Disclosure - Quarterly Data (Unaudited) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureQuarterlyDataUnauditedTables</Role>
      <ShortName>Quarterly Data (Unaudited) (Tables)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>40101 - Disclosure - Corporate Structure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCorporateStructureDetails</Role>
      <ShortName>Corporate Structure (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>40201 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>40202 - Disclosure - Summary of Significant Accounting Policies (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2</Role>
      <ShortName>Summary of Significant Accounting Policies (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>40301 - Disclosure - Restrictions on Cash and Amounts Due from Banks (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureRestrictionsOnCashAndAmountsDueFromBanksDetails</Role>
      <ShortName>Restrictions on Cash and Amounts Due from Banks (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>40401 - Disclosure - Short-Term Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureShortTermInvestmentsDetails</Role>
      <ShortName>Short-Term Investments (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>40501 - Disclosure - Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSecuritiesDetails</Role>
      <ShortName>Securities (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>40502 - Disclosure - Securities (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureSecuritiesDetails2</Role>
      <ShortName>Securities (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>40601 - Disclosure - Loans and Servicing (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingDetails</Role>
      <ShortName>Loans and Servicing (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>40602 - Disclosure - Loans and Servicing (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingDetails2</Role>
      <ShortName>Loans and Servicing (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>40603 - Disclosure - Loans and Servicing (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingDetails3</Role>
      <ShortName>Loans and Servicing (Details 3)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>40604 - Disclosure - Loans and Servicing (Details 4)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingDetails4</Role>
      <ShortName>Loans and Servicing (Details 4)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>40605 - Disclosure - Loans and Servicing (Details 5)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingDetails5</Role>
      <ShortName>Loans and Servicing (Details 5)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>40606 - Disclosure - Loans and Servicing (Details 6)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingDetails6</Role>
      <ShortName>Loans and Servicing (Details 6)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>40607 - Disclosure - Loans and Servicing (Details 7)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansAndServicingDetails7</Role>
      <ShortName>Loans and Servicing (Details 7)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>40701 - Disclosure - Premises and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosurePremisesAndEquipmentDetails</Role>
      <ShortName>Premises and Equipment (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>40801 - Disclosure - Deposits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureDepositsDetails</Role>
      <ShortName>Deposits (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>40901 - Disclosure - Federal Home Loan Bank Advances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFederalHomeLoanBankAdvancesDetails</Role>
      <ShortName>Federal Home Loan Bank Advances (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>41001 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureIncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>41002 - Disclosure - Income Taxes (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureIncomeTaxesDetails2</Role>
      <ShortName>Income Taxes (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>41003 - Disclosure - Income Taxes (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureIncomeTaxesDetails3</Role>
      <ShortName>Income Taxes (Details 3)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>41101 - Disclosure - Minimum Regulatory Requirements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureMinimumRegulatoryRequirementsDetails</Role>
      <ShortName>Minimum Regulatory Requirements (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>41201 - Disclosure - Employee Benefit Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureEmployeeBenefitPlansDetails</Role>
      <ShortName>Employee Benefit Plans (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>41202 - Disclosure - Employee Benefit Plans (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureEmployeeBenefitPlansDetails2</Role>
      <ShortName>Employee Benefit Plans (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>41203 - Disclosure - Employee Benefit Plan (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureEmployeeBenefitPlanDetails3</Role>
      <ShortName>Employee Benefit Plan (Details 3)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>41204 - Disclosure - Employee Benefit Plans (Details 4)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureEmployeeBenefitPlansDetails4</Role>
      <ShortName>Employee Benefit Plans (Details 4)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>41205 - Disclosure - Employee Benefit Plans (Details 5)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureEmployeeBenefitPlansDetails5</Role>
      <ShortName>Employee Benefit Plans (Details 5)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>41301 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCommitmentsAndContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>41302 - Disclosure - Commitments and Contingencies (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCommitmentsAndContingenciesDetails2</Role>
      <ShortName>Commitments and Contingencies (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>41401 - Disclosure - Loans to Related Parties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureLoansToRelatedPartiesDetails</Role>
      <ShortName>Loans to Related Parties (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>41501 - Disclosure - Derivative Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureDerivativeFinancialInstrumentsDetails</Role>
      <ShortName>Derivative Financial Instruments (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>41601 - Disclosure - Fair Value Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFairValueAssetsAndLiabilitiesDetails</Role>
      <ShortName>Fair Value Assets and Liabilities (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>41602 - Disclosure - Fair Value Assets and Liabilities (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFairValueAssetsAndLiabilitiesDetails2</Role>
      <ShortName>Fair Value Assets and Liabilities (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>41603 - Disclosure - Fair Value Assets and Liabilites (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureFairValueAssetsAndLiabilitesDetails3</Role>
      <ShortName>Fair Value Assets and Liabilites (Details 3)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>41801 - Disclosure - Condensed Parent Company Financial Statements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCondensedParentCompanyFinancialStatementsDetails</Role>
      <ShortName>Condensed Parent Company Financial Statements (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>41802 - Disclosure - Condensed Parent Company Financial Statements (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCondensedParentCompanyFinancialStatementsDetails2</Role>
      <ShortName>Condensed Parent Company Financial Statements (Details 2)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>41803 - Disclosure - Condensed Parent Company Financial Statements (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureCondensedParentCompanyFinancialStatementsDetails3</Role>
      <ShortName>Condensed Parent Company Financial Statements (Details 3)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>41901 - Disclosure - Quarterly Data (Unaudited) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.georgetownsb.com/role/DisclosureQuarterlyDataUnauditedDetails</Role>
      <ShortName>Quarterly Data (Unaudited) (Details)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Element us-gaap_AvailableForSaleSecurities had a mix of decimals attribute values: -3 0.</Log>
    <Log type="Info">Element us-gaap_FederalHomeLoanBankStock had a mix of decimals attribute values: -3 0.</Log>
    <Log type="Info">Element us-gaap_HeldToMaturitySecuritiesFairValue had a mix of decimals attribute values: -3 0.</Log>
    <Log type="Info">Element us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions had a mix of decimals attribute values: 0 3.</Log>
    <Log type="Info">'Monetary' elements on report '00100 - Statement - CONSOLIDATED BALANCE SHEETS' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '10/1/2012 - 12/31/2012' is shorter (91 days) and has only 3 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '1/1/2013 - 3/31/2013' is shorter (89 days) and has only 3 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '4/1/2013 - 6/30/2013' is shorter (90 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '7/1/2013 - 9/30/2013' is shorter (91 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '1/1/2014 - 3/31/2014' is shorter (89 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '4/1/2014 - 6/30/2014' is shorter (90 days) and has only 1 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '7/1/2014 - 9/30/2014' is shorter (91 days) and has only 2 values, so it is being removed.</Log>
    <Log type="Info">Columns in Cash Flows statement 'CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)' have maximum duration 364 days and at least 44 values. Shorter duration columns must have at least one fourth (11) as many values. Column '10/1/2014 - 12/31/2014' is shorter (91 days) and has only 3 values, so it is being removed.</Log>
    <Log type="Info">'Monetary' elements on report '40502 - Disclosure - Securities (Details 2)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '40604 - Disclosure - Loans and Servicing (Details 4)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '40801 - Disclosure - Deposits (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '40901 - Disclosure - Federal Home Loan Bank Advances (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '41302 - Disclosure - Commitments and Contingencies (Details 2)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Process Flow-Through: 00100 - Statement - CONSOLIDATED BALANCE SHEETS</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2012'</Log>
    <Log type="Info">Process Flow-Through: 00105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2012'</Log>
    <Log type="Info">Process Flow-Through: 00200 - Statement - CONSOLIDATED STATEMENTS OF INCOME</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2012'</Log>
    <Log type="Info">Process Flow-Through: 00300 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2014'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2013'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2012'</Log>
    <Log type="Info">Process Flow-Through: 00405 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 00500 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</Log>
  </Logs>
  <InputFiles>
    <File>gtwn-20141231.xml</File>
    <File>gtwn-20141231.xsd</File>
    <File>gtwn-20141231_cal.xml</File>
    <File>gtwn-20141231_def.xml</File>
    <File>gtwn-20141231_lab.xml</File>
    <File>gtwn-20141231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
