<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>87</ContextCount>
  <ElementCount>166</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>23</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>10</UnitCount>
  <MyReports>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>9952151 - Statement - Condensed Consolidated Balance Sheets (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CondensedConsolidatedBalanceSheetsUnaudited</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952152 - Statement - Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952153 - Statement - Condensed Consolidated Statements of Income (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CondensedConsolidatedStatementsofIncomeUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Income (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952154 - Statement - Condensed Consolidated Statements of Shareholders' Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CondensedConsolidatedStatementsofShareholdersEquityUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Shareholders' Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952155 - Statement - Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CondensedConsolidatedStatementsofShareholdersEquityUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952156 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CondensedConsolidatedStatementsofCashFlowsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952157 - Disclosure - Presentation of Financial Statements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/PresentationofFinancialStatements</Role>
      <ShortName>Presentation of Financial Statements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952158 - Disclosure - Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/BasisofPresentation</Role>
      <ShortName>Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952159 - Disclosure - Revenue and Cost of Goods Sold</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/RevenueandCostofGoodsSold</Role>
      <ShortName>Revenue and Cost of Goods Sold</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952160 - Disclosure - Long-term Debt and Finance Lease Obligations, Lines of Credit and Fair Value Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/LongtermDebtandFinanceLeaseObligationsLinesofCreditandFairValueDisclosure</Role>
      <ShortName>Long-term Debt and Finance Lease Obligations, Lines of Credit and Fair Value Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952161 - Disclosure - Compensation Related Costs and Share Based Payments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CompensationRelatedCostsandShareBasedPayments</Role>
      <ShortName>Compensation Related Costs and Share Based Payments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952162 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952163 - Disclosure - Unrecognized Tax Benefits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/UnrecognizedTaxBenefits</Role>
      <ShortName>Unrecognized Tax Benefits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952164 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/SegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - Basis of Presentation (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/BasisofPresentationPolicies</Role>
      <ShortName>Basis of Presentation (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - Compensation Related Costs and Share Based Payments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CompensationRelatedCostsandShareBasedPaymentsTables</Role>
      <ShortName>Compensation Related Costs and Share Based Payments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.caseys.com/role/CompensationRelatedCostsandShareBasedPayments</ParentRole>
      <Position>17</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/SegmentReportingTables</Role>
      <ShortName>Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.caseys.com/role/SegmentReporting</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - Presentation of Financial Statements - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/PresentationofFinancialStatementsNarrativeDetails</Role>
      <ShortName>Presentation of Financial Statements - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - Revenue and Cost of Goods Sold - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/RevenueandCostofGoodsSoldNarrativeDetails</Role>
      <ShortName>Revenue and Cost of Goods Sold - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - Long-term Debt and Finance Lease Obligations, Lines of Credit and Fair Value Disclosure - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/LongtermDebtandFinanceLeaseObligationsLinesofCreditandFairValueDisclosureNarrativeDetails</Role>
      <ShortName>Long-term Debt and Finance Lease Obligations, Lines of Credit and Fair Value Disclosure - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.caseys.com/role/LongtermDebtandFinanceLeaseObligationsLinesofCreditandFairValueDisclosure</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - Compensation Related Costs and Share Based Payments - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CompensationRelatedCostsandShareBasedPaymentsNarrativeDetails</Role>
      <ShortName>Compensation Related Costs and Share Based Payments - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.caseys.com/role/CompensationRelatedCostsandShareBasedPaymentsTables</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - Compensation Related Costs and Share Based Payments - Schedule of Restricted Stock Units Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CompensationRelatedCostsandShareBasedPaymentsScheduleofRestrictedStockUnitsActivityDetails</Role>
      <ShortName>Compensation Related Costs and Share Based Payments - Schedule of Restricted Stock Units Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - Commitments and Contingencies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/CommitmentsandContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - Unrecognized Tax Benefits - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/UnrecognizedTaxBenefitsNarrativeDetails</Role>
      <ShortName>Unrecognized Tax Benefits - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - Segment Reporting - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/SegmentReportingNarrativeDetails</Role>
      <ShortName>Segment Reporting - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="casy-20260131.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - Segment Reporting (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.caseys.com/role/SegmentReportingDetails</Role>
      <ShortName>Segment Reporting (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.caseys.com/role/SegmentReportingTables</ParentRole>
      <Position>27</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" isDefinitelyFs="true" isUsgaap="true" original="casy-20260131.htm">casy-20260131.htm</File>
    <File>casy-20260131.xsd</File>
    <File>casy-20260131_cal.xml</File>
    <File>casy-20260131_def.xml</File>
    <File>casy-20260131_lab.xml</File>
    <File>casy-20260131_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="414">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="29">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
