<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>318</ContextCount>
  <ElementCount>342</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>119</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>75000 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>75010 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/StatementCondensedConsolidatedBalanceSheets1</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>75020 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>75030 - Statement - Condensed Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/StatementCondensedConsolidatedStatementsOfOperationsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Operations (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>75040 - Statement - Condensed Consolidated Statements of Comprehensive Loss (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/StatementCondensedConsolidatedStatementsOfComprehensiveLossUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Loss (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>75050 - Statement - Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/StatementCondensedConsolidatedStatementsOfChangesInStockholdersEquityUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>75060 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/StatementCondensedConsolidatedStatementsOfCashFlowsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995455 - Disclosure - Nature of Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureNatureOfBusiness</Role>
      <ShortName>Nature of Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995465 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995485 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligations</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995495 - Disclosure - Balance Sheet Components</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponents</Role>
      <ShortName>Balance Sheet Components</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995505 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureGoodwillAndIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995525 - Disclosure - Maritime Transaction</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureMaritimeTransaction1</Role>
      <ShortName>Maritime Transaction</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995545 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureLeases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995555 - Disclosure - Fair Value Measurement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureFairValueMeasurement</Role>
      <ShortName>Fair Value Measurement</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995565 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995575 - Disclosure - Stock Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureStockBasedCompensation</Role>
      <ShortName>Stock Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995585 - Disclosure - Equity Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureEquityTransactions1</Role>
      <ShortName>Equity Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995605 - Disclosure - Net Loss per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureNetLossPerShare</Role>
      <ShortName>Net Loss per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995615 - Disclosure - Information on Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureInformationOnSegmentReporting</Role>
      <ShortName>Information on Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995625 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995645 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995655 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995665 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsTables</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligations</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995675 - Disclosure - Balance Sheet Components (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponentsTables</Role>
      <ShortName>Balance Sheet Components (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponents</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995685 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureGoodwillAndIntangibleAssets</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995715 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureLeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureLeases</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995725 - Disclosure - Fair Value Measurement (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureFairValueMeasurementTables</Role>
      <ShortName>Fair Value Measurement (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureFairValueMeasurement</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995745 - Disclosure - Stock Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureStockBasedCompensationTables</Role>
      <ShortName>Stock Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureStockBasedCompensation</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995755 - Disclosure - Net Loss per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureNetLossPerShareTables</Role>
      <ShortName>Net Loss per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureNetLossPerShare</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995765 - Disclosure - Information on Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureInformationOnSegmentReportingTables</Role>
      <ShortName>Information on Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureInformationOnSegmentReporting</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995785 - Disclosure - Nature of Business - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureNatureOfBusinessAdditionalInformationDetail</Role>
      <ShortName>Nature of Business - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995795 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995805 - Disclosure - Summary of Significant Accounting Policies - Unaudited Condensed Consolidated Balance Sheet (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesUnauditedCondensedConsolidatedBalanceSheetDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Unaudited Condensed Consolidated Balance Sheet (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995815 - Disclosure - Summary of Significant Accounting Policies - Unaudited Condensed Consolidated Statements of Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesUnauditedCondensedConsolidatedStatementsOfOperationsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Unaudited Condensed Consolidated Statements of Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995825 - Disclosure - Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents, and Restricted Cash (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesSummaryOfCashCashEquivalentsAndRestrictedCashDetail</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents, and Restricted Cash (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995835 - Disclosure - Summary of Significant Accounting Policies - Allocation of Company's Assets and Operations by Region (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAllocationOfCompanysAssetsAndOperationsByRegionDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Allocation of Company's Assets and Operations by Region (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995855 - Disclosure - Summary of Significant Accounting Policies - Summary of Customers Whose Revenue and Accounts Receivable Balances (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesSummaryOfCustomersWhoseRevenueAndAccountsReceivableBalancesDetail</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Customers Whose Revenue and Accounts Receivable Balances (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995865 - Disclosure - Summary of Significant Accounting Policies - Summary of Customers Whose Revenue and Accounts Receivable Balances (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesSummaryOfCustomersWhoseRevenueAndAccountsReceivableBalancesParentheticalDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Customers Whose Revenue and Accounts Receivable Balances (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995875 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Revenue from Subscription and Non-Subscription Contracts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfRevenueFromSubscriptionAndNonsubscriptionContra</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Revenue from Subscription and Non-Subscription Contracts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995885 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsAdditionalInformationDetail</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995895 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Disaggregation of Revenue by Geography (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfDisaggregationOfRevenueByGeographyDetail</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Disaggregation of Revenue by Geography (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995905 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Disaggregation of Revenue by Geography (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfDisaggregationOfRevenueByGeographyParenthetical1</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Disaggregation of Revenue by Geography (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995915 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Changes in Contract Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfChangesInContractAssetsDetail</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Changes in Contract Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995925 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule Of Changes In Contract With Customer Liability Reported on Consolidated Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfChangesInContractWithCustomerLiabilityReported</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule Of Changes In Contract With Customer Liability Reported on Consolidated Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995935 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Changes in Contract Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfChangesInContractLiabilitiesDetail</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Changes in Contract Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995945 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Revenue Remaining Performance Obligation Expected Timing of Satisfaction (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfRevenueRemainingPerformanceObligationExpectedTi</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule of Revenue Remaining Performance Obligation Expected Timing of Satisfaction (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995955 - Disclosure - Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule Of Expects To Recognize Its Remaining Performance Obligations (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureRevenueContractAssetsContractLiabilitiesAndRemainingPerformanceObligationsScheduleOfExpectsToRecognizeItsRemainingPerformanceOblig</Role>
      <ShortName>Revenue, Contract Assets, Contract Liabilities and Remaining Performance Obligations - Schedule Of Expects To Recognize Its Remaining Performance Obligations (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995965 - Disclosure - Balance Sheet Components - Summary of Other Current Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponentsSummaryOfOtherCurrentAssetsDetail</Role>
      <ShortName>Balance Sheet Components - Summary of Other Current Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995975 - Disclosure - Balance Sheet Components - Schedule of Property and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponentsScheduleOfPropertyAndEquipmentNetDetails</Role>
      <ShortName>Balance Sheet Components - Schedule of Property and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995985 - Disclosure - Balance Sheet Components - Schedule of Other Accrued Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponentsScheduleOfOtherAccruedExpensesDetails</Role>
      <ShortName>Balance Sheet Components - Schedule of Other Accrued Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995995 - Disclosure - Balance Sheet Components - Schedule of Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponentsScheduleOfAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Balance Sheet Components - Schedule of Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>996005 - Disclosure - Balance Sheet Components - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureBalanceSheetComponentsAdditionalInformationDetails</Role>
      <ShortName>Balance Sheet Components - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>996015 - Disclosure - Goodwill and Intangible Assets - Schedule of Changes in Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfChangesInGoodwillDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Changes in Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>996025 - Disclosure - Goodwill and Intangible Assets - Schedule of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>996035 - Disclosure - Goodwill and Intangible Assets - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsAdditionalInformationDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>996045 - Disclosure - Goodwill and Intangible Assets - Schedule of Annual Amortization of Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfAnnualAmortizationOfIntangibleAssetsDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Annual Amortization of Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>996055 - Disclosure - Maritime Transaction (Additional Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureMaritimeTransactionAdditionalInformationDetails</Role>
      <ShortName>Maritime Transaction (Additional Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureMaritimeTransaction1</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>996065 - Disclosure - Assets Held for Sale - Summary of the Carrying Values of Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureAssetsHeldForSaleSummaryOfTheCarryingValuesOfAssetsAndLiabilitiesDetails</Role>
      <ShortName>Assets Held for Sale - Summary of the Carrying Values of Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>996105 - Disclosure - Leases - Schedule of Components of Lease Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureLeasesScheduleOfComponentsOfLeaseExpenseDetails</Role>
      <ShortName>Leases - Schedule of Components of Lease Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>996115 - Disclosure - Leases - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureLeasesAdditionalInformationDetails</Role>
      <ShortName>Leases - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>996125 - Disclosure - Leases - Schedule of Maturity of Operating Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureLeasesScheduleOfMaturityOfOperatingLeasesDetails</Role>
      <ShortName>Leases - Schedule of Maturity of Operating Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>996145 - Disclosure - Fair Value Measurement - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureFairValueMeasurementSummaryOfAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail</Role>
      <ShortName>Fair Value Measurement - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>996155 - Disclosure - Fair Value Measurement - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureFairValueMeasurementAdditionalInformationDetail</Role>
      <ShortName>Fair Value Measurement - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>996165 - Disclosure - Fair Value Measurement - Schedule of Quantitative Information Regarding Warrant Liability (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureFairValueMeasurementScheduleOfQuantitativeInformationRegardingWarrantLiabilityDetail</Role>
      <ShortName>Fair Value Measurement - Schedule of Quantitative Information Regarding Warrant Liability (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>996185 - Disclosure - Fair Value Measurement - Schedule of Cash and Cash Equivalents and Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureFairValueMeasurementScheduleOfCashAndCashEquivalentsAndInvestmentsDetails</Role>
      <ShortName>Fair Value Measurement - Schedule of Cash and Cash Equivalents and Investments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>996195 - Disclosure - Fair Value Measurement - Amortized Cost and Estimated Fair Value of Marketable Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureFairValueMeasurementAmortizedCostAndEstimatedFairValueOfMarketableSecuritiesDetails</Role>
      <ShortName>Fair Value Measurement - Amortized Cost and Estimated Fair Value of Marketable Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>996205 - Disclosure - Commitments and Contingencies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesAdditionalInformationDetails</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>996225 - Disclosure - Stock Based Compensation - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail</Role>
      <ShortName>Stock Based Compensation - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>996235 - Disclosure - Stock Based Compensation - Summary of Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStockOptionActivityDetails</Role>
      <ShortName>Stock Based Compensation - Summary of Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>996245 - Disclosure - Stock Based Compensation - Summary of Restricted Stock Units Activity (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureStockBasedCompensationSummaryOfRestrictedStockUnitsActivityDetail</Role>
      <ShortName>Stock Based Compensation - Summary of Restricted Stock Units Activity (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>996255 - Disclosure - Stock-Based Compensation - Summary of the Stock Based Compensation Expense based on Roles and Responsibilities of the Employees (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/Role_DisclosureStockBasedCompensationSummaryOfStockBasedCompensationExpenseBasedOnRolesAndResponsibilitiesOfEmployeesDetail</Role>
      <ShortName>Stock-Based Compensation - Summary of the Stock Based Compensation Expense based on Roles and Responsibilities of the Employees (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>996265 - Disclosure - Equity Transactions (Additional Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureEquityTransactionsAdditionalInformationDetails</Role>
      <ShortName>Equity Transactions (Additional Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureEquityTransactions1</ParentRole>
      <Position>75</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>996275 - Disclosure - Net Loss per Share - Schedule of Earnings Per Share Basic and Diluted Attributable to Common Stockholders (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureNetLossPerShareScheduleOfEarningsPerShareBasicAndDilutedAttributableToCommonStockholdersDetail</Role>
      <ShortName>Net Loss per Share - Schedule of Earnings Per Share Basic and Diluted Attributable to Common Stockholders (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>996285 - Disclosure - Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetail</Role>
      <ShortName>Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>996295 - Disclosure - Information on Segment Reporting (Additional Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureInformationOnSegmentReportingAdditionalInformationDetails</Role>
      <ShortName>Information on Segment Reporting (Additional Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureInformationOnSegmentReportingTables</ParentRole>
      <Position>78</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>996305 - Disclosure - Information on Segment Reporting - Summary of Segment Revenue and Significant Segment Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureInformationOnSegmentReportingSummaryOfSegmentRevenueAndSignificantSegmentExpensesDetails</Role>
      <ShortName>Information on Segment Reporting - Summary of Segment Revenue and Significant Segment Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>996315 - Disclosure - Information on Segment Reporting - Summary of Segment Revenue and Significant Segment Expenses (Parenthetical) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureInformationOnSegmentReportingSummaryOfSegmentRevenueAndSignificantSegmentExpensesParentheticalDetails</Role>
      <ShortName>Information on Segment Reporting - Summary of Segment Revenue and Significant Segment Expenses (Parenthetical) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="spir-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>996325 - Disclosure - Subsequent Events (Additional Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails</Role>
      <ShortName>Subsequent Events (Additional Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.spireglobalinc.com/20260331/taxonomy/role/DisclosureSubsequentEvents</ParentRole>
      <Position>81</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="spir-20260331.htm">spir-20260331.htm</File>
    <File>spir-20260331.xsd</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="2">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="863">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="31">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
