<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.19.3</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>126</ContextCount>
  <ElementCount>298</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>36</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001501 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - CONSOLIDATED STATEMENTS OF INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ConsolidatedStatementsOfIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1003501 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ConsolidatedStatementsOfComprehensiveIncomeParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1004000 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1005000 - Statement - CONSOLIDATED STATEMENTS OF SHAREHOLDER'S EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ConsolidatedStatementsOfShareholdersEquity</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF SHAREHOLDER'S EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - BASIS OF PRESENTATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/BasisOfPresentation</Role>
      <ShortName>BASIS OF PRESENTATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/SignificantAccountingPolicies</Role>
      <ShortName>SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - INVENTORIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/Inventories</Role>
      <ShortName>INVENTORIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - LONG-TERM DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/LongTermDebt</Role>
      <ShortName>LONG-TERM DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - TRADE ACCOUNTS RECEIVABLE PURCHASE PROGRAMS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/TradeAccountsReceivablePurchasePrograms</Role>
      <ShortName>TRADE ACCOUNTS RECEIVABLE PURCHASE PROGRAMS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/IncomeTaxes</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - EARNINGS PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/EarningsPerShare</Role>
      <ShortName>EARNINGS PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - SHARE-BASED COMPENSATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ShareBasedCompensation</Role>
      <ShortName>SHARE-BASED COMPENSATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - COMMITMENTS AND CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/CommitmentsAndContingencies</Role>
      <ShortName>COMMITMENTS AND CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - DERIVATIVE FINANCIAL INSTRUMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/DerivativeFinancialInstruments</Role>
      <ShortName>DERIVATIVE FINANCIAL INSTRUMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - FAIR VALUE MEASUREMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/FairValueMeasurements</Role>
      <ShortName>FAIR VALUE MEASUREMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/GoodwillAndOtherIntangibleAssets</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - REVENUE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/Revenue</Role>
      <ShortName>REVENUE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2117100 - Disclosure - LEASES LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/LeasesLeases</Role>
      <ShortName>LEASES LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/SignificantAccountingPoliciesPolicies</Role>
      <ShortName>SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - INVENTORIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/InventoriesTables</Role>
      <ShortName>INVENTORIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/Inventories</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - LONG-TERM DEBT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/LongTermDebtTables</Role>
      <ShortName>LONG-TERM DEBT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/LongTermDebt</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - EARNINGS PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/EarningsPerShareTables</Role>
      <ShortName>EARNINGS PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/EarningsPerShare</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - SHARE-BASED COMPENSATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ShareBasedCompensationTables</Role>
      <ShortName>SHARE-BASED COMPENSATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/ShareBasedCompensation</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2311301 - Disclosure - DERIVATIVE FINANCIAL INSTRUMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/DerivativeFinancialInstrumentsTables</Role>
      <ShortName>DERIVATIVE FINANCIAL INSTRUMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/DerivativeFinancialInstruments</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - FAIR VALUE MEASUREMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/FairValueMeasurementsTables</Role>
      <ShortName>FAIR VALUE MEASUREMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/FairValueMeasurements</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/GoodwillAndOtherIntangibleAssetsTables</Role>
      <ShortName>GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/GoodwillAndOtherIntangibleAssets</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - REVENUE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/RevenueTables</Role>
      <ShortName>REVENUE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/Revenue</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2317301 - Disclosure - LEASES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/LeasesTables</Role>
      <ShortName>LEASES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/LeasesLeases</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2402402 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/SignificantAccountingPoliciesDetail</Role>
      <ShortName>SIGNIFICANT ACCOUNTING POLICIES (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.keytronic.com/role/SignificantAccountingPoliciesPolicies</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Inventories (Components Of Inventories) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/InventoriesComponentsOfInventoriesDetail</Role>
      <ShortName>Inventories (Components Of Inventories) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Long-Term Debt (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/LongTermDebtDetail</Role>
      <ShortName>Long-Term Debt (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2406401 - Disclosure - Trade Accounts Receivable Purchase Programs (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/TradeAccountsReceivablePurchaseProgramsDetail</Role>
      <ShortName>Trade Accounts Receivable Purchase Programs (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2407401 - Disclosure - Income Taxes (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/IncomeTaxesDetail</Role>
      <ShortName>Income Taxes (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Earnings Per Share (Reconciliation Of Denominator And Number Of Antidilutive Common Share Awards Not Included In Diluted Earnings Per Share Calculation) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/EarningsPerShareReconciliationOfDenominatorAndNumberOfAntidilutiveCommonShareAwardsNotIncludedInDilutedEarningsPerShareCalculationDetail</Role>
      <ShortName>Earnings Per Share (Reconciliation Of Denominator And Number Of Antidilutive Common Share Awards Not Included In Diluted Earnings Per Share Calculation) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Share-Based Compensation (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ShareBasedCompensationDetail</Role>
      <ShortName>Share-Based Compensation (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2410401 - Disclosure - Commitments And Contingencies (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/CommitmentsAndContingenciesDetail</Role>
      <ShortName>Commitments And Contingencies (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2411402 - Disclosure - Derivative Financial Instruments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/DerivativeFinancialInstrumentsDetail</Role>
      <ShortName>Derivative Financial Instruments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2411403 - Disclosure - Schedule of Derivative Instruments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ScheduleOfDerivativeInstrumentsDetail</Role>
      <ShortName>Schedule of Derivative Instruments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2411404 - Disclosure - Derivative Financial Instruments (Summarized Fair Value Of Derivative Instruments In Consolidated Balance Sheets) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/DerivativeFinancialInstrumentsSummarizedFairValueOfDerivativeInstrumentsInConsolidatedBalanceSheetsDetail</Role>
      <ShortName>Derivative Financial Instruments (Summarized Fair Value Of Derivative Instruments In Consolidated Balance Sheets) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2411405 - Disclosure - Derivative Financial Instruments (Gain (Loss) Of Derivative Instruments In Statement Of Operations) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/DerivativeFinancialInstrumentsGainLossOfDerivativeInstrumentsInStatementOfOperationsDetail</Role>
      <ShortName>Derivative Financial Instruments (Gain (Loss) Of Derivative Instruments In Statement Of Operations) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Fair Value Measurements (Assets And Liabilities Measured At Fair Value On Recurring Basis) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/FairValueMeasurementsAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail</Role>
      <ShortName>Fair Value Measurements (Assets And Liabilities Measured At Fair Value On Recurring Basis) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - Goodwill and Other Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/GoodwillAndOtherIntangibleAssetsDetail</Role>
      <ShortName>Goodwill and Other Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - Revenue Contract with Customer, Asset and Liability (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/RevenueContractWithCustomerAssetAndLiabilityDetail</Role>
      <ShortName>Revenue Contract with Customer, Asset and Liability (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2416403 - Disclosure - Revenue Disaggregation of Revenue (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/RevenueDisaggregationOfRevenueDetail</Role>
      <ShortName>Revenue Disaggregation of Revenue (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2417402 - Disclosure - Leases (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/LeasesDetail</Role>
      <ShortName>Leases (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2417403 - Disclosure - Assets and Liabilities, Lessee (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/AssetsAndLiabilitiesLesseeDetail</Role>
      <ShortName>Assets and Liabilities, Lessee (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2417404 - Disclosure - Lessee, Operating Lease, Liability, Maturity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/LesseeOperatingLeaseLiabilityMaturityDetail</Role>
      <ShortName>Lessee, Operating Lease, Liability, Maturity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="ktcc-09282019x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2417405 - Disclosure - Schedule of Future Minimum Rental Payments for Operating Leases (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.keytronic.com/role/ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesDetail</Role>
      <ShortName>Schedule of Future Minimum Rental Payments for Operating Leases (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" original="ktcc-09282019x10q.htm">ktcc-09282019x10q.htm</File>
    <File>ktcc-20190928.xsd</File>
    <File>ktcc-20190928_cal.xml</File>
    <File>ktcc-20190928_def.xml</File>
    <File>ktcc-20190928_lab.xml</File>
    <File>ktcc-20190928_pre.xml</File>
    <File>q12020exhibit311.htm</File>
    <File>q12020exhibit312.htm</File>
    <File>q12020exhibit321.htm</File>
    <File>q12020exhibit322.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/currency/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
