<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.4.0.6</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>38</ContextCount>
  <ElementCount>124</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>5</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>3</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000 - Disclosure - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/ConsolidatedBalanceSheet</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>002 - Statement - Consolidated Balance Sheets (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/ConsolidatedBalanceSheet_Parentheticals</Role>
      <ShortName>Consolidated Balance Sheets (Parentheticals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>003 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/ConsolidatedIncomeStatement</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>004 - Statement - Consolidated Statements of Shareholders' Equity and Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/ShareholdersEquityType1</Role>
      <ShortName>Consolidated Statements of Shareholders' Equity and Comprehensive Income</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>005 - Statement - Consolidated Statements of Shareholders' Equity and Comprehensive Income (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/ShareholdersEquityType1_Parentheticals</Role>
      <ShortName>Consolidated Statements of Shareholders' Equity and Comprehensive Income (Parentheticals)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>006 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/ConsolidatedCashFlow</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>007 - Disclosure - Note 1 - Description of the Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note</Role>
      <ShortName>Note 1 - Description of the Business</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>008 - Disclosure - Note 2 - Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note0</Role>
      <ShortName>Note 2 - Significant Accounting Policies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>009 - Disclosure - Note 3 - Acquisitions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note00</Role>
      <ShortName>Note 3 - Acquisitions</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>010 - Disclosure - Note 4 - Cash and Cash Equivalents</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note000</Role>
      <ShortName>Note 4 - Cash and Cash Equivalents</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>011 - Disclosure - Note 5 - Trade Receivables</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note0000</Role>
      <ShortName>Note 5 - Trade Receivables</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>012 - Disclosure - Note 6 - Inventory</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note00000</Role>
      <ShortName>Note 6 - Inventory</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>013 - Disclosure - Note 7 - Investment in Affiliate</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note000000</Role>
      <ShortName>Note 7 - Investment in Affiliate</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>014 - Disclosure - Note 8 - Capital Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note0000000</Role>
      <ShortName>Note 8 - Capital Assets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>015 - Disclosure - Note 9 - Goodwill</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note00000000</Role>
      <ShortName>Note 9 - Goodwill</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>016 - Disclosure - Note 10 - Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note000000000</Role>
      <ShortName>Note 10 - Intangible Assets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>017 - Disclosure - Note 11 - Accrued Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note0000000000</Role>
      <ShortName>Note 11 - Accrued Liabilities</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>018 - Disclosure - Note 12 - Commitments, Contingencies and Guarantees</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note00000000000</Role>
      <ShortName>Note 12 - Commitments, Contingencies and Guarantees</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>019 - Disclosure - Note 13 - Share Capital</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note000000000000</Role>
      <ShortName>Note 13 - Share Capital</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>020 - Disclosure - Note 14 - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note0000000000000</Role>
      <ShortName>Note 14 - Earnings Per Share</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>021 - Disclosure - Note 15 - Stock-Based Compensation Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note00000000000000</Role>
      <ShortName>Note 15 - Stock-Based Compensation Plans</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>022 - Disclosure - Note 16 - Employee Pension Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note000000000000000</Role>
      <ShortName>Note 16 - Employee Pension Plans</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>023 - Disclosure - Note 17 - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note0000000000000000</Role>
      <ShortName>Note 17 - Income Taxes</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>024 - Disclosure - Note 18 - Other Charges</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note00000000000000000</Role>
      <ShortName>Note 18 - Other Charges</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>025 - Disclosure - Note 19 - Segmented Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.descartes.com/role/Note000000000000000000</Role>
      <ShortName>Note 19 - Segmented Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Process Flow-Through: 001 - Statement - Consolidated Balance Sheets</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Jan. 31, 2010'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Jan. 31, 2009'</Log>
    <Log type="Info">Process Flow-Through: 002 - Statement - Consolidated Balance Sheets (Parentheticals)</Log>
    <Log type="Info">Process Flow-Through: 003 - Statement - Consolidated Statements of Operations</Log>
    <Log type="Info">Process Flow-Through: 005 - Statement - Consolidated Statements of Shareholders' Equity and Comprehensive Income (Parentheticals)</Log>
    <Log type="Info">Process Flow-Through: 006 - Statement - Consolidated Statements of Cash Flows</Log>
  </Logs>
  <InputFiles>
    <File>dsgx-20120131.xml</File>
    <File>dsgx-20120131.xsd</File>
    <File>dsgx-20120131_cal.xml</File>
    <File>dsgx-20120131_def.xml</File>
    <File>dsgx-20120131_lab.xml</File>
    <File>dsgx-20120131_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
