<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>196</ContextCount>
  <ElementCount>178</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>35</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001002 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002003 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003004 - Statement - Condensed Consolidated Statements Of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CondensedConsolidatedStatementsOfIncome</Role>
      <ShortName>Condensed Consolidated Statements Of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004005 - Statement - Condensed Consolidated Statements Of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CondensedConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Condensed Consolidated Statements Of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005006 - Statement - Condensed Consolidated Statements Of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Condensed Consolidated Statements Of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1006007 - Statement - Condensed Consolidated Statements Of Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CondensedConsolidatedStatementsOfShareholdersEquity</Role>
      <ShortName>Condensed Consolidated Statements Of Shareholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1007008 - Statement - Condensed Consolidated Statements Of Shareholders' Equity (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CondensedConsolidatedStatementsOfShareholdersEquityParenthetical</Role>
      <ShortName>Condensed Consolidated Statements Of Shareholders' Equity (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - Summary Of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary Of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2108102 - Disclosure - Fair Value</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/FairValue</Role>
      <ShortName>Fair Value</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2113103 - Disclosure - Long-Term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/LongTermDebt</Role>
      <ShortName>Long-Term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2115104 - Disclosure - Commitments And Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments And Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2117105 - Disclosure - Goodwill And Other Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssets</Role>
      <ShortName>Goodwill And Other Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2123106 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2125107 - Disclosure - Business Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/BusinessSegmentInformation</Role>
      <ShortName>Business Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2130108 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - Summary Of Significant Accounting Policies (Policy)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesPolicy</Role>
      <ShortName>Summary Of Significant Accounting Policies (Policy)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>17</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Summary Of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary Of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2309302 - Disclosure - Fair Value (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/FairValueTables</Role>
      <ShortName>Fair Value (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/FairValue</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2318303 - Disclosure - Goodwill And Other Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsTables</Role>
      <ShortName>Goodwill And Other Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssets</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2326304 - Disclosure - Business Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/BusinessSegmentInformationTables</Role>
      <ShortName>Business Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/BusinessSegmentInformation</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2404401 - Disclosure - Summary Of Significant Accounting Policies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Summary Of Significant Accounting Policies (Schedule Of Construction In Progress In Accounts Payable) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfConstructionInProgressInAccountsPayableDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Schedule Of Construction In Progress In Accounts Payable) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Summary Of Significant Accounting Policies (Schedule Of Basic And Diluted Net Income Per Common Share Calculations) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfBasicAndDilutedNetIncomePerCommonShareCalculationsDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Schedule Of Basic And Diluted Net Income Per Common Share Calculations) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2407404 - Disclosure - Summary Of Significant Accounting Policies (Schedule Of Amounts Reclassified Out Of Accumulated Other Comprehensive Loss) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfAmountsReclassifiedOutOfAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Schedule Of Amounts Reclassified Out Of Accumulated Other Comprehensive Loss) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/SummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2410405 - Disclosure - Fair Value (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/FairValueNarrativeDetails</Role>
      <ShortName>Fair Value (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/FairValueTables</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2411406 - Disclosure - Fair Value (Schedule Of Contingent Consideration Measured At Fair Value On A Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/FairValueScheduleOfContingentConsiderationMeasuredAtFairValueOnARecurringBasisDetails</Role>
      <ShortName>Fair Value (Schedule Of Contingent Consideration Measured At Fair Value On A Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/FairValueTables</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2412407 - Disclosure - Fair Value (Schedule Of Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs For Contingent Consideration) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/FairValueScheduleOfLevel3FairValueMeasurementsUsingSignificantOtherUnobservableInputsForContingentConsiderationDetails</Role>
      <ShortName>Fair Value (Schedule Of Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs For Contingent Consideration) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/FairValueTables</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2414408 - Disclosure - Long-Term Debt (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/LongTermDebtNarrativeDetails</Role>
      <ShortName>Long-Term Debt (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/LongTermDebt</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2416409 - Disclosure - Commitments And Contingencies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/CommitmentsAndContingenciesNarrativeDetails</Role>
      <ShortName>Commitments And Contingencies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/CommitmentsAndContingencies</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2419410 - Disclosure - Goodwill And Other Intangible Assets (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsTables</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2420411 - Disclosure - Goodwill And Other Intangible Assets (Summary Of Other Intangible Assets) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsSummaryOfOtherIntangibleAssetsDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Summary Of Other Intangible Assets) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsTables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2421412 - Disclosure - Goodwill And Other Intangible Assets (Schedule Of Amortization Expense) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsScheduleOfAmortizationExpenseDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Schedule Of Amortization Expense) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2422413 - Disclosure - Goodwill And Other Intangible Assets (Estimated Annual Amortization Expense) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsEstimatedAnnualAmortizationExpenseDetails</Role>
      <ShortName>Goodwill And Other Intangible Assets (Estimated Annual Amortization Expense) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/GoodwillAndOtherIntangibleAssetsTables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2424414 - Disclosure - Income Taxes (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/IncomeTaxes</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2427415 - Disclosure - Business Segment Information (Summary Of Financial Information Attributable To Reportable Segments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/BusinessSegmentInformationSummaryOfFinancialInformationAttributableToReportableSegmentsDetails</Role>
      <ShortName>Business Segment Information (Summary Of Financial Information Attributable To Reportable Segments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/BusinessSegmentInformationTables</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2428416 - Disclosure - Business Segment Information (Disaggregation Of Net Sales By Class Of Similar Products) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/BusinessSegmentInformationDisaggregationOfNetSalesByClassOfSimilarProductsDetails</Role>
      <ShortName>Business Segment Information (Disaggregation Of Net Sales By Class Of Similar Products) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/BusinessSegmentInformationTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2429417 - Disclosure - Business Segment Information (Disaggregation Of Foodservice Net Sales By Type Of Customer) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/BusinessSegmentInformationDisaggregationOfFoodserviceNetSalesByTypeOfCustomerDetails</Role>
      <ShortName>Business Segment Information (Disaggregation Of Foodservice Net Sales By Type Of Customer) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/BusinessSegmentInformationTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="lanc-20220331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2431418 - Disclosure - Stock-Based Compensation (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lancastercolony.com/role/StockBasedCompensationNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lancastercolony.com/role/StockBasedCompensation</ParentRole>
      <Position>39</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="lanc-20220331.htm">lanc-20220331.htm</File>
    <File>lanc-20220331.xsd</File>
    <File>lanc-20220331_cal.xml</File>
    <File>lanc-20220331_def.xml</File>
    <File>lanc-20220331_lab.xml</File>
    <File>lanc-20220331_pre.xml</File>
    <File>lanc-2022331xexhibit311.htm</File>
    <File>lanc-2022331xexhibit312.htm</File>
    <File>lanc-2022331xexhibit32.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="649">http://fasb.org/us-gaap/2021-01-31</BaseTaxonomy>
    <BaseTaxonomy items="30">http://xbrl.sec.gov/dei/2021</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
