<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.6.0.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>275</ContextCount>
  <ElementCount>290</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>45</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00000001 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-daei</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00000002 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/BalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00000003 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-cbsp</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00000004 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-csoo</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="mgyr-20161231.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://magbank.com/role/mgyr-csoci</Role>
      <ShortName>Consolidated Statements of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00000006 - Statement - Consolidated Statements of Changes in Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-csocise</Role>
      <ShortName>Consolidated Statements of Changes in Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00000007 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/StatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00000008 - Disclosure - BASIS OF PRESENTATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-bop</Role>
      <ShortName>BASIS OF PRESENTATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>00000009 - Disclosure - RECENT ACCOUNTING PRONOUNCEMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-rap</Role>
      <ShortName>RECENT ACCOUNTING PRONOUNCEMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>00000010 - Disclosure - CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-c</Role>
      <ShortName>CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>00000011 - Disclosure - EARNINGS PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-eps</Role>
      <ShortName>EARNINGS PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>00000012 - Disclosure - STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-sbcasrp</Role>
      <ShortName>STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>00000013 - Disclosure - OTHER COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-ocil</Role>
      <ShortName>OTHER COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>00000014 - Disclosure - FAIR VALUE DISCLOSURES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-fvd</Role>
      <ShortName>FAIR VALUE DISCLOSURES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>00000015 - Disclosure - INVESTMENT SECURITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-is</Role>
      <ShortName>INVESTMENT SECURITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>00000016 - Disclosure - IMPAIRMENT OF INVESTMENT SECURITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-iois</Role>
      <ShortName>IMPAIRMENT OF INVESTMENT SECURITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>00000017 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafll</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>00000018 - Disclosure - DEPOSITS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-d</Role>
      <ShortName>DEPOSITS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>00000019 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-it</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>00000020 - Disclosure - FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-fiwobsr</Role>
      <ShortName>FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>00000021 - Disclosure - EARNINGS PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-epst</Role>
      <ShortName>EARNINGS PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-eps</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>00000022 - Disclosure - STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-sbcasrpt</Role>
      <ShortName>STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-sbcasrp</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>00000023 - Disclosure - OTHER COMPREHENSIVE INCOME (LOSS) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-ocilt</Role>
      <ShortName>OTHER COMPREHENSIVE INCOME (LOSS) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-ocil</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>00000024 - Disclosure - FAIR VALUE DISCLOSURES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-fvdt</Role>
      <ShortName>FAIR VALUE DISCLOSURES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-fvd</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>00000025 - Disclosure - INVESTMENT SECURITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-ist</Role>
      <ShortName>INVESTMENT SECURITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-is</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>00000026 - Disclosure - IMPAIRMENT OF INVESTMENT SECURITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-ioist</Role>
      <ShortName>IMPAIRMENT OF INVESTMENT SECURITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-iois</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>00000027 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafllt</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafll</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>00000028 - Disclosure - DEPOSITS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-dt</Role>
      <ShortName>DEPOSITS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-d</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>00000029 - Disclosure - INCOME TAXES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-itt</Role>
      <ShortName>INCOME TAXES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-it</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>00000030 - Disclosure - FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-fiwobsrt</Role>
      <ShortName>FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-fiwobsr</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>00000031 - Disclosure - EARNINGS PER SHARE (Schedule of Earnings Per Share) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-epssoepsd</Role>
      <ShortName>EARNINGS PER SHARE (Schedule of Earnings Per Share) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-epst</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>00000032 - Disclosure - EARNINGS PER SHARE (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-epsnd</Role>
      <ShortName>EARNINGS PER SHARE (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-epst</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>00000033 - Disclosure - STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-sbcasrpnd</Role>
      <ShortName>STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-sbcasrpt</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>00000034 - Disclosure - STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Schedule of Stock Option Activity And Related Information For Its Option Plan) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-sbcasrpsosoaarifiopd</Role>
      <ShortName>STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Schedule of Stock Option Activity And Related Information For Its Option Plan) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-sbcasrpt</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>00000035 - Disclosure - STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Schedule of Non-Vested Restricted Shares) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-sbcasrpsonvrsd</Role>
      <ShortName>STOCK-BASED COMPENSATION AND STOCK REPURCHASE PROGRAM (Schedule of Non-Vested Restricted Shares) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-sbcasrpt</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>00000036 - Disclosure - OTHER COMPREHENSIVE INCOME (LOSS) (Schedule of Components of Other Comprehensive Income (Loss) and the Related Income Tax Effects) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-ocilsocoaoclarited</Role>
      <ShortName>OTHER COMPREHENSIVE INCOME (LOSS) (Schedule of Components of Other Comprehensive Income (Loss) and the Related Income Tax Effects) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-ocilt</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>00000037 - Disclosure - FAIR VALUE DISCLOSURES (Schedule of Assets Measured at Fair Value on a Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-fvdsoamafvoarbd</Role>
      <ShortName>FAIR VALUE DISCLOSURES (Schedule of Assets Measured at Fair Value on a Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-fvdt</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>00000038 - Disclosure - FAIR VALUE DISCLOSURES (Schedule of Assets Measured at Fair Value on a Non-Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/FairValueDisclosuresScheduleOfAssetsMeasuredAtFairValueOnNon-recurringBasisDetails</Role>
      <ShortName>FAIR VALUE DISCLOSURES (Schedule of Assets Measured at Fair Value on a Non-Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-fvdt</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>00000039 - Disclosure - FAIR VALUE DISCLOSURES (Schedule of Additional Quantitative Information About Assets Measured at Fair Value) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-fvdsoaqiaamafvd</Role>
      <ShortName>FAIR VALUE DISCLOSURES (Schedule of Additional Quantitative Information About Assets Measured at Fair Value) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-fvdt</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>00000040 - Disclosure - FAIR VALUE DISCLOSURES (Schedule of the Carrying Amount, Fair Value, and Placement in the Fair Value Hierarchy of Financial Instruments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-fvdsotcafvapitfvhofid</Role>
      <ShortName>FAIR VALUE DISCLOSURES (Schedule of the Carrying Amount, Fair Value, and Placement in the Fair Value Hierarchy of Financial Instruments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-fvdt</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>00000041 - Disclosure - INVESTMENT SECURITIES (Summary of Amortized Cost and Fair Values of Securities Available For Sale) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-issoacafvosafsd</Role>
      <ShortName>INVESTMENT SECURITIES (Summary of Amortized Cost and Fair Values of Securities Available For Sale) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-ist</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>00000042 - Disclosure - INVESTMENT SECURITIES (Summary of Maturities of Debt Securities and Mortgage-backed Securities Available For Sale) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-issomodsambsafsd</Role>
      <ShortName>INVESTMENT SECURITIES (Summary of Maturities of Debt Securities and Mortgage-backed Securities Available For Sale) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-ist</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>00000043 - Disclosure - INVESTMENT SECURITIES (Summary of Maturities of Debt Securities and Mortgage-backed Securities Held to Maturity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-issomodsambshtmd</Role>
      <ShortName>INVESTMENT SECURITIES (Summary of Maturities of Debt Securities and Mortgage-backed Securities Held to Maturity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-ist</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>00000044 - Disclosure - INVESTMENT SECURITIES (Summary of Amortized Cost and Fair Values of Securities Held to Maturity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-issoacafvoshtmd</Role>
      <ShortName>INVESTMENT SECURITIES (Summary of Amortized Cost and Fair Values of Securities Held to Maturity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-ist</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>00000045 - Disclosure - IMPAIRMENT OF INVESTMENT SECURITIES (Schedule of Gross Unrealized Losses and Fair Value for Both Available For Sale and Held To Maturity Securities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-ioissogulafvfbafsahtmsd</Role>
      <ShortName>IMPAIRMENT OF INVESTMENT SECURITIES (Schedule of Gross Unrealized Losses and Fair Value for Both Available For Sale and Held To Maturity Securities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-ioist</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>00000046 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Loans Receivable, Net) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafllsolrnd</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Loans Receivable, Net) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>00000047 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Impaired Loans by Class) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafllsoilbcd</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Impaired Loans by Class) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>00000048 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Average Recorded Investment in Impaired Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafllsoariiild</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Average Recorded Investment in Impaired Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>00000049 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Classes of the Loan Portfolio Summarized by Bank's Internal Risk Rating System) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafllsocotlpsbbirrsd</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Classes of the Loan Portfolio Summarized by Bank's Internal Risk Rating System) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>00000050 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Classes of the Loan Portfolio Summarized by Aging Categories) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafllsocotlpsbacd</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Classes of the Loan Portfolio Summarized by Aging Categories) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>00000051 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Activity in the Allowance for Loan Losses by Loan Category) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/LoansReceivableNetAndRelatedAllowanceForLoanLossesScheduleOfActivityInAllowanceForLoanLossesByLoanCategoryDetails</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Activity in the Allowance for Loan Losses by Loan Category) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>00000052 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of ALL by Loan Category) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-lrnarafllsoablcd</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of ALL by Loan Category) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>00000053 - Disclosure - LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/LoansReceivableNetAndRelatedAllowanceForLoanLossesNarrativeDetails</Role>
      <ShortName>LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-lrnarafllt</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>00000054 - Disclosure - DEPOSITS (Schedule of Deposits by Type of Account) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/mgyr-dsodbtoad</Role>
      <ShortName>DEPOSITS (Schedule of Deposits by Type of Account) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-dt</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>00000055 - Disclosure - INCOME TAXES (Schedule of Reconciliation of Income Tax) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/IncomeTaxesScheduleOfReconciliationOfIncomeTaxDetails</Role>
      <ShortName>INCOME TAXES (Schedule of Reconciliation of Income Tax) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-itt</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="mgyr-20161231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>00000056 - Disclosure - FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK (Schedule of Financial Instruments Whose Contract Amounts Representing Credit Risk) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://magbank.com/role/FinancialInstrumentsWithOff-balanceSheetRiskScheduleOfFinancialInstrumentsWhoseContractAmountsRepresentingCreditRiskDetails</Role>
      <ShortName>FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK (Schedule of Financial Instruments Whose Contract Amounts Representing Credit Risk) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://magbank.com/role/mgyr-fiwobsrt</ParentRole>
      <Position>56</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>mgyr-20161231.xml</File>
    <File>mgyr-20161231.xsd</File>
    <File>mgyr-20161231_cal.xml</File>
    <File>mgyr-20161231_def.xml</File>
    <File>mgyr-20161231_lab.xml</File>
    <File>mgyr-20161231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
