<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>659</ContextCount>
  <ElementCount>735</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>201</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>11</UnitCount>
  <MyReports>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Document - Audit Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/AuditInformation</Role>
      <ShortName>Audit Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952151 - Statement - Consolidated Statements of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ConsolidatedStatementsofIncome</Role>
      <ShortName>Consolidated Statements of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952152 - Statement - Consolidated Statements of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ConsolidatedStatementsofComprehensiveIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952153 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952154 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952155 - Statement - Consolidated Statements of Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ConsolidatedStatementsofEquity</Role>
      <ShortName>Consolidated Statements of Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952156 - Statement - Consolidated Statements of Equity (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ConsolidatedStatementsofEquityParenthetical</Role>
      <ShortName>Consolidated Statements of Equity (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952157 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ConsolidatedStatementsofCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952158 - Disclosure - The Company</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/TheCompany</Role>
      <ShortName>The Company</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952159 - Disclosure - Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/AccountingPolicies</Role>
      <ShortName>Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952160 - Disclosure - Short-Term Deposits and Marketable Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShortTermDepositsandMarketableSecurities</Role>
      <ShortName>Short-Term Deposits and Marketable Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952161 - Disclosure - Trade Accounts Receivable, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/TradeAccountsReceivableNet</Role>
      <ShortName>Trade Accounts Receivable, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952162 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/Inventories</Role>
      <ShortName>Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952163 - Disclosure - Other Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherCurrentAssets</Role>
      <ShortName>Other Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9952164 - Disclosure - Public Funding</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PublicFunding</Role>
      <ShortName>Public Funding</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9952165 - Disclosure - Goodwill</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/Goodwill</Role>
      <ShortName>Goodwill</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9952166 - Disclosure - Other Intangible Assets, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIntangibleAssetsNet</Role>
      <ShortName>Other Intangible Assets, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9952167 - Disclosure - Property, Plant and Equipment, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PropertyPlantandEquipmentNet</Role>
      <ShortName>Property, Plant and Equipment, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9952168 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>9952169 - Disclosure - Long-Term Investments and Variable Interest Entities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermInvestmentsandVariableInterestEntities</Role>
      <ShortName>Long-Term Investments and Variable Interest Entities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9952170 - Disclosure - Other Non-Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherNonCurrentAssets</Role>
      <ShortName>Other Non-Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9952171 - Disclosure - Other Payables and Accrued Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherPayablesandAccruedLiabilities</Role>
      <ShortName>Other Payables and Accrued Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9952172 - Disclosure - Long-Term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermDebt</Role>
      <ShortName>Long-Term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9952173 - Disclosure - Post-Employment and Other Long-Term Employees Benefits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefits</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9952174 - Disclosure - Other Long-Term Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherLongTermLiabilities</Role>
      <ShortName>Other Long-Term Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9952175 - Disclosure - Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShareholdersEquity</Role>
      <ShortName>Shareholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>9952176 - Disclosure - Revenues</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/Revenues</Role>
      <ShortName>Revenues</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9952177 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9952178 - Disclosure - Other Income and Expenses, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIncomeandExpensesNet</Role>
      <ShortName>Other Income and Expenses, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9952179 - Disclosure - Impairment, Restructuring and Other Related Phase-Out Costs</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ImpairmentRestructuringandOtherRelatedPhaseOutCosts</Role>
      <ShortName>Impairment, Restructuring and Other Related Phase-Out Costs</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9952180 - Disclosure - Interest Income (Expense), Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/InterestIncomeExpenseNet</Role>
      <ShortName>Interest Income (Expense), Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9952181 - Disclosure - Income Tax</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTax</Role>
      <ShortName>Income Tax</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9952182 - Disclosure - Earnings per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/EarningsperShare</Role>
      <ShortName>Earnings per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9952183 - Disclosure - Commitments, Contingencies, Claims and Legal Proceedings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/CommitmentsContingenciesClaimsandLegalProceedings</Role>
      <ShortName>Commitments, Contingencies, Claims and Legal Proceedings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9952184 - Disclosure - Financial Instruments and Risk Management</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagement</Role>
      <ShortName>Financial Instruments and Risk Management</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9952185 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9952186 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9952187 - Disclosure - Valuation and Qualifying Accounts</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ValuationandQualifyingAccounts</Role>
      <ShortName>Valuation and Qualifying Accounts</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure</Role>
      <ShortName>Cybersecurity Risk Management and Strategy Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/AccountingPoliciesPolicies</Role>
      <ShortName>Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.st.com/role/AccountingPolicies</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/AccountingPoliciesTables</Role>
      <ShortName>Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/AccountingPolicies</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - Short-Term Deposits and Marketable Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShortTermDepositsandMarketableSecuritiesTables</Role>
      <ShortName>Short-Term Deposits and Marketable Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/ShortTermDepositsandMarketableSecurities</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - Trade Accounts Receivable, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/TradeAccountsReceivableNetTables</Role>
      <ShortName>Trade Accounts Receivable, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/TradeAccountsReceivableNet</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/InventoriesTables</Role>
      <ShortName>Inventories (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/Inventories</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - Other Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherCurrentAssetsTables</Role>
      <ShortName>Other Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherCurrentAssets</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - Goodwill (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/GoodwillTables</Role>
      <ShortName>Goodwill (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/Goodwill</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - Other Intangible Assets, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIntangibleAssetsNetTables</Role>
      <ShortName>Other Intangible Assets, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherIntangibleAssetsNet</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - Property, Plant and Equipment, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PropertyPlantandEquipmentNetTables</Role>
      <ShortName>Property, Plant and Equipment, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/PropertyPlantandEquipmentNet</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/Leases</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - Long-Term Investments and Variable Interest Entities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermInvestmentsandVariableInterestEntitiesTables</Role>
      <ShortName>Long-Term Investments and Variable Interest Entities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/LongTermInvestmentsandVariableInterestEntities</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - Other Non-Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherNonCurrentAssetsTables</Role>
      <ShortName>Other Non-Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherNonCurrentAssets</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - Other Payables and Accrued Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherPayablesandAccruedLiabilitiesTables</Role>
      <ShortName>Other Payables and Accrued Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherPayablesandAccruedLiabilities</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - Long-Term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermDebtTables</Role>
      <ShortName>Long-Term Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/LongTermDebt</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - Post-Employment and Other Long-Term Employees Benefits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsTables</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefits</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - Other Long-Term Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherLongTermLiabilitiesTables</Role>
      <ShortName>Other Long-Term Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherLongTermLiabilities</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - Shareholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShareholdersEquityTables</Role>
      <ShortName>Shareholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/ShareholdersEquity</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - Revenues (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/RevenuesTables</Role>
      <ShortName>Revenues (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/Revenues</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/SegmentInformation</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955530 - Disclosure - Other Income and Expenses, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIncomeandExpensesNetTables</Role>
      <ShortName>Other Income and Expenses, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherIncomeandExpensesNet</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955531 - Disclosure - Impairment, Restructuring and Other Related Phase-Out Costs (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ImpairmentRestructuringandOtherRelatedPhaseOutCostsTables</Role>
      <ShortName>Impairment, Restructuring and Other Related Phase-Out Costs (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/ImpairmentRestructuringandOtherRelatedPhaseOutCosts</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - Interest Income (Expense), Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/InterestIncomeExpenseNetTables</Role>
      <ShortName>Interest Income (Expense), Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/InterestIncomeExpenseNet</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - Income Tax (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxTables</Role>
      <ShortName>Income Tax (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/IncomeTax</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - Earnings per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/EarningsperShareTables</Role>
      <ShortName>Earnings per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/EarningsperShare</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - Financial Instruments and Risk Management (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementTables</Role>
      <ShortName>Financial Instruments and Risk Management (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/FinancialInstrumentsandRiskManagement</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - Related Party Transactions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/RelatedPartyTransactionsTables</Role>
      <ShortName>Related Party Transactions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.st.com/role/RelatedPartyTransactions</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/AccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>9955538 - Disclosure - Accounting Policies - Schedule of Property, Plant and Equipment Useful Lives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/AccountingPoliciesScheduleofPropertyPlantandEquipmentUsefulLivesDetails</Role>
      <ShortName>Accounting Policies - Schedule of Property, Plant and Equipment Useful Lives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>9955539 - Disclosure - Short-Term Deposits and Marketable Securities - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShortTermDepositsandMarketableSecuritiesAdditionalInformationDetails</Role>
      <ShortName>Short-Term Deposits and Marketable Securities - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - Short-Term Deposits and Marketable Securities - Changes in Value of Marketable Securities Reported in Current Assets on Consolidated Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShortTermDepositsandMarketableSecuritiesChangesinValueofMarketableSecuritiesReportedinCurrentAssetsonConsolidatedBalanceSheetsDetails</Role>
      <ShortName>Short-Term Deposits and Marketable Securities - Changes in Value of Marketable Securities Reported in Current Assets on Consolidated Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - Short-Term Deposits and Marketable Securities - Debt Securities in an Unrealized Loss Position (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShortTermDepositsandMarketableSecuritiesDebtSecuritiesinanUnrealizedLossPositionDetails</Role>
      <ShortName>Short-Term Deposits and Marketable Securities - Debt Securities in an Unrealized Loss Position (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - Trade Accounts Receivable, Net - Trade Accounts Receivable, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/TradeAccountsReceivableNetTradeAccountsReceivableNetDetails</Role>
      <ShortName>Trade Accounts Receivable, Net - Trade Accounts Receivable, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - Inventories (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/InventoriesDetails</Role>
      <ShortName>Inventories (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/InventoriesTables</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - Other Current Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherCurrentAssetsDetails</Role>
      <ShortName>Other Current Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherCurrentAssetsTables</ParentRole>
      <Position>75</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - Public Funding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PublicFundingDetails</Role>
      <ShortName>Public Funding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/PublicFunding</ParentRole>
      <Position>76</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - Goodwill - Changes in Carrying Amount of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/GoodwillChangesinCarryingAmountofGoodwillDetails</Role>
      <ShortName>Goodwill - Changes in Carrying Amount of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - Goodwill - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/GoodwillAdditionalInformationDetails</Role>
      <ShortName>Goodwill - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - Other Intangible Assets, Net - Other Intangible Assets, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIntangibleAssetsNetOtherIntangibleAssetsNetDetails</Role>
      <ShortName>Other Intangible Assets, Net - Other Intangible Assets, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - Other Intangible Assets, Net - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIntangibleAssetsNetAdditionalInformationDetails</Role>
      <ShortName>Other Intangible Assets, Net - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - Other Intangible Assets, Net - Estimated Future Amortization Expense Related to Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIntangibleAssetsNetEstimatedFutureAmortizationExpenseRelatedtoIntangibleAssetsDetails</Role>
      <ShortName>Other Intangible Assets, Net - Estimated Future Amortization Expense Related to Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - Property, Plant and Equipment, Net - Property, Plant and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PropertyPlantandEquipmentNetPropertyPlantandEquipmentNetDetails</Role>
      <ShortName>Property, Plant and Equipment, Net - Property, Plant and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>9955552 - Disclosure - Property, Plant and Equipment, Net - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PropertyPlantandEquipmentNetAdditionalInformationDetails</Role>
      <ShortName>Property, Plant and Equipment, Net - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>9955553 - Disclosure - Leases - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LeasesAdditionalInformationDetails</Role>
      <ShortName>Leases - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>9955554 - Disclosure - Leases - Schedule of Operating and Finance Lease (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LeasesScheduleofOperatingandFinanceLeaseDetails</Role>
      <ShortName>Leases - Schedule of Operating and Finance Lease (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>9955555 - Disclosure - Leases - Schedule of Maturities of Operating and Finance Lease Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LeasesScheduleofMaturitiesofOperatingandFinanceLeaseLiabilitiesDetails</Role>
      <ShortName>Leases - Schedule of Maturities of Operating and Finance Lease Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>9955556 - Disclosure - Leases - Schedule of Operating and Finance Lease Term and Discount Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LeasesScheduleofOperatingandFinanceLeaseTermandDiscountRateDetails</Role>
      <ShortName>Leases - Schedule of Operating and Finance Lease Term and Discount Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>9955557 - Disclosure - Leases - Schedule of Operating and Finance Lease Cost and Cash Paid (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LeasesScheduleofOperatingandFinanceLeaseCostandCashPaidDetails</Role>
      <ShortName>Leases - Schedule of Operating and Finance Lease Cost and Cash Paid (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>9955558 - Disclosure - Leases - Schedule of Right-of-Use Assets Obtained in Exchange for New Operating and Finance Lease Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LeasesScheduleofRightofUseAssetsObtainedinExchangeforNewOperatingandFinanceLeaseLiabilitiesDetails</Role>
      <ShortName>Leases - Schedule of Right-of-Use Assets Obtained in Exchange for New Operating and Finance Lease Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>9955559 - Disclosure - Long-Term Investments and Variable Interest Entities - Long-Term Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermInvestmentsandVariableInterestEntitiesLongTermInvestmentsDetails</Role>
      <ShortName>Long-Term Investments and Variable Interest Entities - Long-Term Investments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>9955560 - Disclosure - Long-Term Investments and Variable Interest Entities - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermInvestmentsandVariableInterestEntitiesAdditionalInformationDetails</Role>
      <ShortName>Long-Term Investments and Variable Interest Entities - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>9955561 - Disclosure - Other Non-Current Assets - Other Non-Current Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherNonCurrentAssetsOtherNonCurrentAssetsDetails</Role>
      <ShortName>Other Non-Current Assets - Other Non-Current Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>9955562 - Disclosure - Other Non-Current Assets - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherNonCurrentAssetsAdditionalInformationDetails</Role>
      <ShortName>Other Non-Current Assets - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>9955563 - Disclosure - Other Payables and Accrued Liabilities - Other Payables and Accrued Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherPayablesandAccruedLiabilitiesOtherPayablesandAccruedLiabilitiesDetails</Role>
      <ShortName>Other Payables and Accrued Liabilities - Other Payables and Accrued Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>9955564 - Disclosure - Long-Term Debt - Long-Term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermDebtLongTermDebtDetails</Role>
      <ShortName>Long-Term Debt - Long-Term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>9955565 - Disclosure - Long-Term Debt - Long-Term Debt Denominated by Currencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermDebtLongTermDebtDenominatedbyCurrenciesDetails</Role>
      <ShortName>Long-Term Debt - Long-Term Debt Denominated by Currencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>9955566 - Disclosure - Long-Term Debt - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermDebtAdditionalInformationDetails</Role>
      <ShortName>Long-Term Debt - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>9955567 - Disclosure - Long-Term Debt - Total Long-Term Debt Outstanding Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/LongTermDebtTotalLongTermDebtOutstandingMaturitiesDetails</Role>
      <ShortName>Long-Term Debt - Total Long-Term Debt Outstanding Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>9955568 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Changes in Benefit Obligation and Plan Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsChangesinBenefitObligationandPlanAssetsDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Changes in Benefit Obligation and Plan Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>9955569 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Rollforward Accumulated Other Comprehensive Income (Loss) Before Tax Effects (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsRollforwardAccumulatedOtherComprehensiveIncomeLossBeforeTaxEffectsDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Rollforward Accumulated Other Comprehensive Income (Loss) Before Tax Effects (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>9955570 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Schedule of Accumulated Benefit Obligations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsScheduleofAccumulatedBenefitObligationsDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Schedule of Accumulated Benefit Obligations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>9955571 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsAdditionalInformationDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>102</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>9955572 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Components of Net Periodic Benefit Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsComponentsofNetPeriodicBenefitCostDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Components of Net Periodic Benefit Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>9955573 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Weighted Average Assumptions Used in Determination of Benefit Obligation and Plan Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsWeightedAverageAssumptionsUsedinDeterminationofBenefitObligationandPlanAssetsDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Weighted Average Assumptions Used in Determination of Benefit Obligation and Plan Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>9955574 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Pension Plan Asset Allocation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsPensionPlanAssetAllocationDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Pension Plan Asset Allocation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>9955575 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Pension Plan Asset Allocation Including Fair-Value Measurements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsPensionPlanAssetAllocationIncludingFairValueMeasurementsDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Pension Plan Asset Allocation Including Fair-Value Measurements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>9955576 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Reconciliation for Plan Assets Measured at Fair Value Using Unobservable Inputs (Level 3) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsReconciliationforPlanAssetsMeasuredatFairValueUsingUnobservableInputsLevel3Details</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Reconciliation for Plan Assets Measured at Fair Value Using Unobservable Inputs (Level 3) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>9955577 - Disclosure - Post-Employment and Other Long-Term Employees Benefits - Estimated Future Benefit Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/PostEmploymentandOtherLongTermEmployeesBenefitsEstimatedFutureBenefitPaymentsDetails</Role>
      <ShortName>Post-Employment and Other Long-Term Employees Benefits - Estimated Future Benefit Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>9955578 - Disclosure - Other Long-Term Liabilities - Summary of Other Long-Term Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherLongTermLiabilitiesSummaryofOtherLongTermLiabilitiesDetails</Role>
      <ShortName>Other Long-Term Liabilities - Summary of Other Long-Term Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>9955579 - Disclosure - Shareholders' Equity - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShareholdersEquityAdditionalInformationDetails</Role>
      <ShortName>Shareholders' Equity - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>9955580 - Disclosure - Shareholders' Equity - Summary of Nonvested Share Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShareholdersEquitySummaryofNonvestedShareActivityDetails</Role>
      <ShortName>Shareholders' Equity - Summary of Nonvested Share Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>9955581 - Disclosure - Shareholders' Equity - Classification of Pre-Payroll Tax and Social Contribution Stock-Based Compensation Expense Included in Consolidated Statements of Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShareholdersEquityClassificationofPrePayrollTaxandSocialContributionStockBasedCompensationExpenseIncludedinConsolidatedStatementsofIncomeDetails</Role>
      <ShortName>Shareholders' Equity - Classification of Pre-Payroll Tax and Social Contribution Stock-Based Compensation Expense Included in Consolidated Statements of Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>9955582 - Disclosure - Shareholders' Equity - Changes in AOCI Attributable to Stockholders (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShareholdersEquityChangesinAOCIAttributabletoStockholdersDetails</Role>
      <ShortName>Shareholders' Equity - Changes in AOCI Attributable to Stockholders (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>9955583 - Disclosure - Shareholders' Equity - Schedule of Items Reclassified Out of Accumulated Other Comprehensive Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ShareholdersEquityScheduleofItemsReclassifiedOutofAccumulatedOtherComprehensiveIncomeDetails</Role>
      <ShortName>Shareholders' Equity - Schedule of Items Reclassified Out of Accumulated Other Comprehensive Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>114</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>9955584 - Disclosure - Revenues - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/RevenuesAdditionalInformationDetails</Role>
      <ShortName>Revenues - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>115</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>9955585 - Disclosure - Revenues - Summary of Consolidated Net Revenues Disaggregated by Reportable Segment, Geographical Region of Shipment, Nature and Market Channel (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/RevenuesSummaryofConsolidatedNetRevenuesDisaggregatedbyReportableSegmentGeographicalRegionofShipmentNatureandMarketChannelDetails</Role>
      <ShortName>Revenues - Summary of Consolidated Net Revenues Disaggregated by Reportable Segment, Geographical Region of Shipment, Nature and Market Channel (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>116</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>9955586 - Disclosure - Segment Reporting - Additional information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentReportingAdditionalinformationDetails</Role>
      <ShortName>Segment Reporting - Additional information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>117</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>9955587 - Disclosure - Segment Information - Net Revenues by Product Segment and by Product Line (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentInformationNetRevenuesbyProductSegmentandbyProductLineDetails</Role>
      <ShortName>Segment Information - Net Revenues by Product Segment and by Product Line (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>118</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>9955588 - Disclosure - Segment Information - Operating Income by Reportable Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentInformationOperatingIncomebyReportableSegmentDetails</Role>
      <ShortName>Segment Information - Operating Income by Reportable Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>119</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>9955589 - Disclosure - Segment Information - Reconciliation of Operating Income of Reportable Segments to Total Consolidated Operating Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentInformationReconciliationofOperatingIncomeofReportableSegmentstoTotalConsolidatedOperatingIncomeDetails</Role>
      <ShortName>Segment Information - Reconciliation of Operating Income of Reportable Segments to Total Consolidated Operating Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>120</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>9955590 - Disclosure - Segment Information - Net Revenues (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentInformationNetRevenuesDetails</Role>
      <ShortName>Segment Information - Net Revenues (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>121</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>9955591 - Disclosure - Segment Information - Property, Plant &amp; Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SegmentInformationPropertyPlantEquipmentDetails</Role>
      <ShortName>Segment Information - Property, Plant &amp; Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>122</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>9955592 - Disclosure - Other Income and Expenses Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/OtherIncomeandExpensesNetDetails</Role>
      <ShortName>Other Income and Expenses Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/OtherIncomeandExpensesNetTables</ParentRole>
      <Position>123</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>9955593 - Disclosure - Impairment, Restructuring and Other Related Phase-Out Costs - Summary of restructuring and related costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ImpairmentRestructuringandOtherRelatedPhaseOutCostsSummaryofrestructuringandrelatedcostsDetails</Role>
      <ShortName>Impairment, Restructuring and Other Related Phase-Out Costs - Summary of restructuring and related costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>124</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>9955594 - Disclosure - Impairment, Restructuring and Other Related Phase-Out Costs - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ImpairmentRestructuringandOtherRelatedPhaseOutCostsAdditionalInformationDetails</Role>
      <ShortName>Impairment, Restructuring and Other Related Phase-Out Costs - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>125</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R126.htm</HtmlFileName>
      <LongName>9955595 - Disclosure - Impairment, Restructuring and Other Related Phase-Out Costs - Schedule of restructuring reserve by type of cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ImpairmentRestructuringandOtherRelatedPhaseOutCostsScheduleofrestructuringreservebytypeofcostDetails</Role>
      <ShortName>Impairment, Restructuring and Other Related Phase-Out Costs - Schedule of restructuring reserve by type of cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>126</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R127.htm</HtmlFileName>
      <LongName>9955596 - Disclosure - Interest Income (Expense), Net - Summary of Interest Income (Expense), Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/InterestIncomeExpenseNetSummaryofInterestIncomeExpenseNetDetails</Role>
      <ShortName>Interest Income (Expense), Net - Summary of Interest Income (Expense), Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/InterestIncomeExpenseNetTables</ParentRole>
      <Position>127</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R128.htm</HtmlFileName>
      <LongName>9955597 - Disclosure - Interest Income (Expense), Net - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/InterestIncomeExpenseNetAdditionalInformationDetails</Role>
      <ShortName>Interest Income (Expense), Net - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/InterestIncomeExpenseNetTables</ParentRole>
      <Position>128</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R129.htm</HtmlFileName>
      <LongName>9955598 - Disclosure - Income Tax - Income (Loss) before Income Tax (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxIncomeLossbeforeIncomeTaxDetails</Role>
      <ShortName>Income Tax - Income (Loss) before Income Tax (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>129</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R130.htm</HtmlFileName>
      <LongName>9955599 - Disclosure - Income Tax - Income Tax Benefit (Expense) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxIncomeTaxBenefitExpenseDetails</Role>
      <ShortName>Income Tax - Income Tax Benefit (Expense) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>130</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R131.htm</HtmlFileName>
      <LongName>9955600 - Disclosure - Income Tax - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxAdditionalInformationDetails</Role>
      <ShortName>Income Tax - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>131</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R132.htm</HtmlFileName>
      <LongName>9955601 - Disclosure - Income Tax - Differences in Income Taxes Computed at Netherlands Statutory Rate and Effective Income Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxDifferencesinIncomeTaxesComputedatNetherlandsStatutoryRateandEffectiveIncomeTaxRateDetails</Role>
      <ShortName>Income Tax - Differences in Income Taxes Computed at Netherlands Statutory Rate and Effective Income Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>132</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R133.htm</HtmlFileName>
      <LongName>9955602 - Disclosure - Income Tax - Schedule of Cash Flow, Supplemental Disclosures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxScheduleofCashFlowSupplementalDisclosuresDetails</Role>
      <ShortName>Income Tax - Schedule of Cash Flow, Supplemental Disclosures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>133</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R134.htm</HtmlFileName>
      <LongName>9955603 - Disclosure - Income Tax - Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxDeferredTaxAssetsandLiabilitiesDetails</Role>
      <ShortName>Income Tax - Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>134</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R135.htm</HtmlFileName>
      <LongName>9955604 - Disclosure - Income Tax - Gross Deferred Tax Assets on Tax Loss Carryforwards and Investment Credits Expiration (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxGrossDeferredTaxAssetsonTaxLossCarryforwardsandInvestmentCreditsExpirationDetails</Role>
      <ShortName>Income Tax - Gross Deferred Tax Assets on Tax Loss Carryforwards and Investment Credits Expiration (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>135</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R136.htm</HtmlFileName>
      <LongName>9955605 - Disclosure - Income Tax - Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/IncomeTaxReconciliationofBeginningandEndingAmountsofUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>Income Tax - Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>136</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R137.htm</HtmlFileName>
      <LongName>9955606 - Disclosure - Earnings per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/EarningsperShareDetails</Role>
      <ShortName>Earnings per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/EarningsperShareTables</ParentRole>
      <Position>137</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R138.htm</HtmlFileName>
      <LongName>9955607 - Disclosure - Commitments, Contingencies, Claims and Legal Proceedings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/CommitmentsContingenciesClaimsandLegalProceedingsDetails</Role>
      <ShortName>Commitments, Contingencies, Claims and Legal Proceedings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/CommitmentsContingenciesClaimsandLegalProceedings</ParentRole>
      <Position>138</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R139.htm</HtmlFileName>
      <LongName>9955608 - Disclosure - Financial Instruments and Risk Management - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementAdditionalInformationDetails</Role>
      <ShortName>Financial Instruments and Risk Management - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>139</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R140.htm</HtmlFileName>
      <LongName>9955609 - Disclosure - Financial Instruments and Risk Management - Notional Amounts of Outstanding Derivative Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementNotionalAmountsofOutstandingDerivativeInstrumentsDetails</Role>
      <ShortName>Financial Instruments and Risk Management - Notional Amounts of Outstanding Derivative Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>140</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R141.htm</HtmlFileName>
      <LongName>9955610 - Disclosure - Financial Instruments and Risk Management - Fair Value of Derivative Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementFairValueofDerivativeInstrumentsDetails</Role>
      <ShortName>Financial Instruments and Risk Management - Fair Value of Derivative Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>141</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R142.htm</HtmlFileName>
      <LongName>9955611 - Disclosure - Financial Instruments and Risk Management - Effect on Consolidated Statements of Income of Derivative Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementEffectonConsolidatedStatementsofIncomeofDerivativeInstrumentsDetails</Role>
      <ShortName>Financial Instruments and Risk Management - Effect on Consolidated Statements of Income of Derivative Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>142</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R143.htm</HtmlFileName>
      <LongName>9955612 - Disclosure - Financial Instruments and Risk Management - Effect on Consolidated Statements of Income of Derivative Instruments Not Designated as Hedge (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementEffectonConsolidatedStatementsofIncomeofDerivativeInstrumentsNotDesignatedasHedgeDetails</Role>
      <ShortName>Financial Instruments and Risk Management - Effect on Consolidated Statements of Income of Derivative Instruments Not Designated as Hedge (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>143</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R144.htm</HtmlFileName>
      <LongName>9955613 - Disclosure - Financial Instruments and Risk Management - Schedule of Financial Assets (Liabilities) Measured at Fair Value on Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementScheduleofFinancialAssetsLiabilitiesMeasuredatFairValueonRecurringBasisDetails</Role>
      <ShortName>Financial Instruments and Risk Management - Schedule of Financial Assets (Liabilities) Measured at Fair Value on Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>144</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R145.htm</HtmlFileName>
      <LongName>9955614 - Disclosure - Financial Instruments and Risk Management - Fair Value Information on Other Financial Assets and Liabilities Recorded at Amortized Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/FinancialInstrumentsandRiskManagementFairValueInformationonOtherFinancialAssetsandLiabilitiesRecordedatAmortizedCostDetails</Role>
      <ShortName>Financial Instruments and Risk Management - Fair Value Information on Other Financial Assets and Liabilities Recorded at Amortized Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>145</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R146.htm</HtmlFileName>
      <LongName>9955615 - Disclosure - Related Party Transactions - Transactions with Related Parties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/RelatedPartyTransactionsTransactionswithRelatedPartiesDetails</Role>
      <ShortName>Related Party Transactions - Transactions with Related Parties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>146</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R147.htm</HtmlFileName>
      <LongName>9955616 - Disclosure - Related Party Transactions - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/RelatedPartyTransactionsAdditionalInformationDetails</Role>
      <ShortName>Related Party Transactions - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>147</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R148.htm</HtmlFileName>
      <LongName>9955617 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/SubsequentEvents</ParentRole>
      <Position>148</Position>
    </Report>
    <Report instance="stm-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R149.htm</HtmlFileName>
      <LongName>9955618 - Disclosure - Valuation and Qualifying Accounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.st.com/role/ValuationandQualifyingAccountsDetails</Role>
      <ShortName>Valuation and Qualifying Accounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.st.com/role/ValuationandQualifyingAccounts</ParentRole>
      <Position>149</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="20-F" isDefinitelyFs="true" isUsgaap="true" original="stm-20251231.htm">stm-20251231.htm</File>
    <File>stm-20251231.xsd</File>
    <File>stm-20251231_cal.xml</File>
    <File>stm-20251231_def.xml</File>
    <File>stm-20251231_lab.xml</File>
    <File>stm-20251231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>stm-20251231_g1.jpg</File>
    <File>stm-20251231_g2.jpg</File>
    <File>stm-20251231_g3.jpg</File>
    <File>stm-20251231_g4.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="3">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="2159">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="15">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="45">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="1">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
