<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>183</ContextCount>
  <ElementCount>496</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>70</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>15</UnitCount>
  <MyReports>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>995200090 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>995200100 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>995200105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>995200200 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/StatementConsolidatedStatementsOfOperations</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>995200205 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/StatementConsolidatedStatementsOfOperationsParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>995200300 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>995200400 - Statement - CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/StatementConsolidatedStatementsOfShareholdersEquity</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>995200500 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995210101 - Disclosure - Organization and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995210201 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995210301 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995210401 - Disclosure - Cash, Cash Equivalents, and Restricted Cash</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCashCashEquivalentsAndRestrictedCash</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995210501 - Disclosure - Investments and Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurements</Role>
      <ShortName>Investments and Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995210601 - Disclosure - Contract Derivative</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureContractDerivative</Role>
      <ShortName>Contract Derivative</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995210701 - Disclosure - Property and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosurePropertyAndEquipment</Role>
      <ShortName>Property and Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995210801 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995210901 - Disclosure - Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureNetGainOnRealizedContingentMilestoneAndRoyaltyAssetsAndMilestoneIncome</Role>
      <ShortName>Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995211001 - Disclosure - Ampreloxetine Funding</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureAmpreloxetineFunding</Role>
      <ShortName>Ampreloxetine Funding</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995211101 - Disclosure - Share-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensation</Role>
      <ShortName>Share-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995211201 - Disclosure - Defined Contribution Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureDefinedContributionPlan</Role>
      <ShortName>Defined Contribution Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995211301 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995211401 - Disclosure - Completion of Capital Return Program</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCompletionOfCapitalReturnProgram</Role>
      <ShortName>Completion of Capital Return Program</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995211501 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995211601 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995211701 - Disclosure - SUPPLEMENTARY FINANCIAL DATA (UNAUDITED)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnaudited</Role>
      <ShortName>SUPPLEMENTARY FINANCIAL DATA (UNAUDITED)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.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>28</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.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>29</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>99920102 - Disclosure - Organization and Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>99930103 - Disclosure - Organization and Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>99930203 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureRevenue</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>99930303 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureSegmentInformation</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>99930403 - Disclosure - Cash, Cash Equivalents, and Restricted Cash (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCashCashEquivalentsAndRestrictedCashTables</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureCashCashEquivalentsAndRestrictedCash</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>99930503 - Disclosure - Investments and Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsTables</Role>
      <ShortName>Investments and Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurements</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>99930603 - Disclosure - Contract Derivative (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureContractDerivativeTables</Role>
      <ShortName>Contract Derivative (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureContractDerivative</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>99930703 - Disclosure - Property and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosurePropertyAndEquipmentTables</Role>
      <ShortName>Property and Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosurePropertyAndEquipment</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>99930803 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureLeases</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>99930903 - Disclosure - Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureNetGainOnRealizedContingentMilestoneAndRoyaltyAssetsAndMilestoneIncomeTables</Role>
      <ShortName>Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureNetGainOnRealizedContingentMilestoneAndRoyaltyAssetsAndMilestoneIncome</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>99931003 - Disclosure - Ampreloxetine Funding (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureAmpreloxetineFundingTables</Role>
      <ShortName>Ampreloxetine Funding (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureAmpreloxetineFunding</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>99931103 - Disclosure - Share-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationTables</Role>
      <ShortName>Share-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureShareBasedCompensation</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>99931303 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureIncomeTaxes</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>99931403 - Disclosure - Completion of Capital Return Program (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCompletionOfCapitalReturnProgramTables</Role>
      <ShortName>Completion of Capital Return Program (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureCompletionOfCapitalReturnProgram</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>99931703 - Disclosure - SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnauditedTables</Role>
      <ShortName>SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnaudited</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>99940101 - Disclosure - Organization and Summary of Significant Accounting Policies - Segment Reporting (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesSegmentReportingDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Segment Reporting (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>99940102 - Disclosure - Organization and Summary of Significant Accounting Policies - Investments in Marketable Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesInvestmentsInMarketableSecuritiesDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Investments in Marketable Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>99940103 - Disclosure - Organization and Summary of Significant Accounting Policies - Concentration of Credit Risks (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesConcentrationOfCreditRisksDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Concentration of Credit Risks (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>99940104 - Disclosure - Organization and Summary of Significant Accounting Policies - Property and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Property and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>99940105 - Disclosure - Organization and Summary of Significant Accounting Policies - Impairment of Long-Lived Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesImpairmentOfLongLivedAssetsDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Impairment of Long-Lived Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>99940106 - Disclosure - Organization and Summary of Significant Accounting Policies - Advertising Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesAdvertisingExpensesDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Advertising Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>99940107 - Disclosure - Organization and Summary of Significant Accounting Policies - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesIncomeTaxesDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>99940108 - Disclosure - Organization and Summary of Significant Accounting Policies - Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesEarningsPerShareDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>99940109 - Disclosure - Organization and Summary of Significant Accounting Policies - Anti-dilutive Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesAntiDilutiveSecuritiesDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Anti-dilutive Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>99940110 - Disclosure - Organization and Summary of Significant Accounting Policies - Accounting Pronouncements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureOrganizationAndSummaryOfSignificantAccountingPoliciesAccountingPronouncementsDetails</Role>
      <ShortName>Organization and Summary of Significant Accounting Policies - Accounting Pronouncements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>99940201 - Disclosure - Revenue - Collaborative Arrangements - General Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenueCollaborativeArrangementsGeneralInformationDetails</Role>
      <ShortName>Revenue - Collaborative Arrangements - General Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>99940202 - Disclosure - Revenue - Collaborative Arrangements - Revenue Recognized (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenueCollaborativeArrangementsRevenueRecognizedDetails</Role>
      <ShortName>Revenue - Collaborative Arrangements - Revenue Recognized (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>99940203 - Disclosure - Revenue - Disaggregation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenueDisaggregationDetails</Role>
      <ShortName>Revenue - Disaggregation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>99940204 - Disclosure - Revenue - Implied Share of Net Sales (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenueImpliedShareOfNetSalesDetails</Role>
      <ShortName>Revenue - Implied Share of Net Sales (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>99940205 - Disclosure - Revenue - Geographic Region (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenueGeographicRegionDetails</Role>
      <ShortName>Revenue - Geographic Region (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>99940206 - Disclosure - Revenue - Concentration Risk (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureRevenueConcentrationRiskDetails</Role>
      <ShortName>Revenue - Concentration Risk (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>99940301 - Disclosure - Segment Information - General Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSegmentInformationGeneralInformationDetails</Role>
      <ShortName>Segment Information - General Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>99940302 - Disclosure - Segment Information - Tabular Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSegmentInformationTabularDisclosureDetails</Role>
      <ShortName>Segment Information - Tabular Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>99940401 - Disclosure - Cash, Cash Equivalents, and Restricted Cash - Tabular Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCashCashEquivalentsAndRestrictedCashTabularDisclosureDetails</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash - Tabular Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>99940402 - Disclosure - Cash, Cash Equivalents, and Restricted Cash - General Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCashCashEquivalentsAndRestrictedCashGeneralInformationDetails</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash - General Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>99940403 - Disclosure - Cash, Cash Equivalents, and Restricted Cash - Foreign Exchange Transactions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCashCashEquivalentsAndRestrictedCashForeignExchangeTransactionsDetails</Role>
      <ShortName>Cash, Cash Equivalents, and Restricted Cash - Foreign Exchange Transactions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>99940501 - Disclosure - Investments and Fair Value Measurements - Fair Value to Amortized Cost - Available-for-Sale Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsFairValueToAmortizedCostAvailableForSaleSecuritiesDetails</Role>
      <ShortName>Investments and Fair Value Measurements - Fair Value to Amortized Cost - Available-for-Sale Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>99940502 - Disclosure - Investments and Fair Value Measurements - Fair Value to Amortized Cost - Total (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsFairValueToAmortizedCostTotalDetails</Role>
      <ShortName>Investments and Fair Value Measurements - Fair Value to Amortized Cost - Total (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>99940503 - Disclosure - Investments and Fair Value Measurements - Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsMaturitiesDetails</Role>
      <ShortName>Investments and Fair Value Measurements - Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>99940504 - Disclosure - Investments and Fair Value Measurements - Transfers (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsTransfersDetails</Role>
      <ShortName>Investments and Fair Value Measurements - Transfers (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>99940505 - Disclosure - Investments and Fair Value Measurements - Unrealized Loss Position (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsUnrealizedLossPositionDetails</Role>
      <ShortName>Investments and Fair Value Measurements - Unrealized Loss Position (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>99940506 - Disclosure - Investments and Fair Value Measurements - Available-for-Sale Securities - Credit Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsAvailableForSaleSecuritiesCreditLossesDetails</Role>
      <ShortName>Investments and Fair Value Measurements - Available-for-Sale Securities - Credit Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>99940507 - Disclosure - Investments and Fair Value Measurements - Available-for-Sale Securities - Sales of Marketable Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureInvestmentsAndFairValueMeasurementsAvailableForSaleSecuritiesSalesOfMarketableSecuritiesDetails</Role>
      <ShortName>Investments and Fair Value Measurements - Available-for-Sale Securities - Sales of Marketable Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>99940601 - Disclosure - Contract Derivative - Fair Value Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureContractDerivativeFairValueAssumptionsDetails</Role>
      <ShortName>Contract Derivative - Fair Value Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>99940602 - Disclosure - Contract Derivative - Fair Value and Location on Consolidated Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureContractDerivativeFairValueAndLocationOnConsolidatedBalanceSheetsDetails</Role>
      <ShortName>Contract Derivative - Fair Value and Location on Consolidated Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>99940603 - Disclosure - Contract Derivative - Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Roll Forward (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureContractDerivativeAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationRollForwardDetails</Role>
      <ShortName>Contract Derivative - Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Roll Forward (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>99940701 - Disclosure - Property and Equipment - Tabular Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosurePropertyAndEquipmentTabularDisclosureDetails</Role>
      <ShortName>Property and Equipment - Tabular Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>99940702 - Disclosure - Property and Equipment - Impairment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosurePropertyAndEquipmentImpairmentDetails</Role>
      <ShortName>Property and Equipment - Impairment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>99940703 - Disclosure - Property and Equipment - Depreciation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosurePropertyAndEquipmentDepreciationExpenseDetails</Role>
      <ShortName>Property and Equipment - Depreciation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>99940801 - Disclosure - Leases - Subleases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesSubleasesDetails</Role>
      <ShortName>Leases - Subleases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>99940802 - Disclosure - Leases - Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesAssetsAndLiabilitiesDetails</Role>
      <ShortName>Leases - Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>99940803 - Disclosure - Leases - Operating Lease Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesOperatingLeaseExpenseDetails</Role>
      <ShortName>Leases - Operating Lease Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>99940804 - Disclosure - Leases - Sublease Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesSubleaseIncomeDetails</Role>
      <ShortName>Leases - Sublease Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>99940805 - Disclosure - Leases - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesAdditionalInformationDetails</Role>
      <ShortName>Leases - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>99940806 - Disclosure - Leases - Maturities of Lease Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesMaturitiesOfLeaseLiabilitiesDetails</Role>
      <ShortName>Leases - Maturities of Lease Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>99940807 - Disclosure - Leases - Gross Difference (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesGrossDifferenceDetails</Role>
      <ShortName>Leases - Gross Difference (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>99940808 - Disclosure - Leases - Undiscounted Cash Flows to be Received Related to Subleases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesUndiscountedCashFlowsToBeReceivedRelatedToSubleasesDetails</Role>
      <ShortName>Leases - Undiscounted Cash Flows to be Received Related to Subleases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>99940809 - Disclosure - Leases - Impairment of Long-Lived Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureLeasesImpairmentOfLongLivedAssetsDetails</Role>
      <ShortName>Leases - Impairment of Long-Lived Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>99940901 - Disclosure - Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income - General Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureNetGainOnRealizedContingentMilestoneAndRoyaltyAssetsAndMilestoneIncomeGeneralInformationDetails</Role>
      <ShortName>Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income - General Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>99940902 - Disclosure - Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income - Tabular Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureNetGainOnRealizedContingentMilestoneAndRoyaltyAssetsAndMilestoneIncomeTabularDisclosureDetails</Role>
      <ShortName>Net Gain on Realized Contingent Milestone and Royalty Assets and Milestone Income - Tabular Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>99941001 - Disclosure - Ampreloxetine Funding - Future Royalty Payment Contingency (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureAmpreloxetineFundingFutureRoyaltyPaymentContingencyDetails</Role>
      <ShortName>Ampreloxetine Funding - Future Royalty Payment Contingency (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>99941002 - Disclosure - Ampreloxetine Funding - Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Roll Forward (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureAmpreloxetineFundingLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationRollForwardDetails</Role>
      <ShortName>Ampreloxetine Funding - Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Roll Forward (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>99941101 - Disclosure - Share-Based Compensation - General Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationGeneralInformationDetails</Role>
      <ShortName>Share-Based Compensation - General Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>99941102 - Disclosure - Share-Based Compensation - Shares Available for Future Issuance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationSharesAvailableForFutureIssuanceDetails</Role>
      <ShortName>Share-Based Compensation - Shares Available for Future Issuance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>99941103 - Disclosure - Share-Based Compensation - Grants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationGrantsDetails</Role>
      <ShortName>Share-Based Compensation - Grants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>99941104 - Disclosure - Share-Based Compensation - Share-Based Compensation Expense Included in Statement of Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationShareBasedCompensationExpenseIncludedInStatementOfOperationsDetails</Role>
      <ShortName>Share-Based Compensation - Share-Based Compensation Expense Included in Statement of Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>95</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>99941105 - Disclosure - Share-Based Compensation - Share-Based Compensation Expense by Award Type (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationShareBasedCompensationExpenseByAwardTypeDetails</Role>
      <ShortName>Share-Based Compensation - Share-Based Compensation Expense by Award Type (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>96</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>99941106 - Disclosure - Share-Based Compensation - Unrecognized Compensation Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationUnrecognizedCompensationCostDetails</Role>
      <ShortName>Share-Based Compensation - Unrecognized Compensation Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>97</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>99941107 - Disclosure - Share-Based Compensation - Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationOptionActivityDetails</Role>
      <ShortName>Share-Based Compensation - Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>98</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>99941108 - Disclosure - Share-Based Compensation - RSU Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationRsuActivityDetails</Role>
      <ShortName>Share-Based Compensation - RSU Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>99</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>99941109 - Disclosure - Share-Based Compensation - Estimated Fair Value of RSUs Vested (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationEstimatedFairValueOfRsusVestedDetails</Role>
      <ShortName>Share-Based Compensation - Estimated Fair Value of RSUs Vested (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>100</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>99941111 - Disclosure - Share-Based Compensation - Valuation Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureShareBasedCompensationValuationAssumptionsDetails</Role>
      <ShortName>Share-Based Compensation - Valuation Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>99941201 - Disclosure - Defined Contribution Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureDefinedContributionPlanDetails</Role>
      <ShortName>Defined Contribution Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureDefinedContributionPlan</ParentRole>
      <Position>102</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>99941301 - Disclosure - Income Taxes - Components of Loss before Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesComponentsOfLossBeforeIncomeTaxesDetails</Role>
      <ShortName>Income Taxes - Components of Loss before Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>103</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>99941302 - Disclosure - Income Taxes - Components of Provision for Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesComponentsOfProvisionForIncomeTaxExpenseDetails</Role>
      <ShortName>Income Taxes - Components of Provision for Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>104</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>99941303 - Disclosure - Income Taxes - Income Tax Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesIncomeTaxExpenseDetails</Role>
      <ShortName>Income Taxes - Income Tax Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>105</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>99941304 - Disclosure - Income Taxes - Undistributed Earnings of Foreign Subsidiaries (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesUndistributedEarningsOfForeignSubsidiariesDetails</Role>
      <ShortName>Income Taxes - Undistributed Earnings of Foreign Subsidiaries (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>106</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>99941305 - Disclosure - Income Taxes - Effective Tax Rate Reconciliation, Amount (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesEffectiveTaxRateReconciliationAmountDetails</Role>
      <ShortName>Income Taxes - Effective Tax Rate Reconciliation, Amount (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>107</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>99941306 - Disclosure - Income Taxes - Effective Tax Rate Reconciliation, Percent (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesEffectiveTaxRateReconciliationPercentDetails</Role>
      <ShortName>Income Taxes - Effective Tax Rate Reconciliation, Percent (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>108</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>99941307 - Disclosure - Income Taxes - Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>Income Taxes - Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>109</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>99941308 - Disclosure - Income Taxes - Valuation Allowance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesValuationAllowanceDetails</Role>
      <ShortName>Income Taxes - Valuation Allowance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>110</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>99941309 - Disclosure - Income Taxes - Net Operating Loss Carryforwards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesNetOperatingLossCarryforwardsDetails</Role>
      <ShortName>Income Taxes - Net Operating Loss Carryforwards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>111</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>99941310 - Disclosure - Income Taxes - Tax Credit Carryforwards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesTaxCreditCarryforwardsDetails</Role>
      <ShortName>Income Taxes - Tax Credit Carryforwards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>112</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>99941311 - Disclosure - Income Taxes - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>Income Taxes - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>113</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>99941312 - Disclosure - Income Taxes - Taxes Paid (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesTaxesPaidDetails</Role>
      <ShortName>Income Taxes - Taxes Paid (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>114</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>99941313 - Disclosure - Income Taxes - Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>Income Taxes - Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>115</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>99941314 - Disclosure - Income Taxes - Uncertain Tax Positions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesUncertainTaxPositionsDetails</Role>
      <ShortName>Income Taxes - Uncertain Tax Positions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>116</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>99941315 - Disclosure - Income Taxes - Tax Examinations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureIncomeTaxesTaxExaminationsDetails</Role>
      <ShortName>Income Taxes - Tax Examinations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>117</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>99941401 - Disclosure - Completion of Capital Return Program (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCompletionOfCapitalReturnProgramDetails</Role>
      <ShortName>Completion of Capital Return Program (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureCompletionOfCapitalReturnProgramTables</ParentRole>
      <Position>118</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>99941501 - Disclosure - Commitments and Contingencies - Indemnifications (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCommitmentsAndContingenciesIndemnificationsDetails</Role>
      <ShortName>Commitments and Contingencies - Indemnifications (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>119</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>99941502 - Disclosure - Commitments and Contingencies - Legal Proceedings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCommitmentsAndContingenciesLegalProceedingsDetails</Role>
      <ShortName>Commitments and Contingencies - Legal Proceedings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>120</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>99941503 - Disclosure - Commitments and Contingencies - Litigation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureCommitmentsAndContingenciesLitigationDetails</Role>
      <ShortName>Commitments and Contingencies - Litigation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>121</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>99941601 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureSubsequentEvents</ParentRole>
      <Position>122</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>99941701 - Disclosure - SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) - Consolidated Quarterly Financial Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnauditedConsolidatedQuarterlyFinancialInformationDetails</Role>
      <ShortName>SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) - Consolidated Quarterly Financial Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnauditedTables</ParentRole>
      <Position>123</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>99941702 - Disclosure - SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) - Implied Share of Net Sales - Tabular Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnauditedImpliedShareOfNetSalesTabularDisclosureDetails</Role>
      <ShortName>SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) - Implied Share of Net Sales - Tabular Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnauditedTables</ParentRole>
      <Position>124</Position>
    </Report>
    <Report instance="tbph-20251231x10k.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>99941703 - Disclosure - SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) - Implied Share of Net Sales - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnauditedImpliedShareOfNetSalesAdditionalInformationDetails</Role>
      <ShortName>SUPPLEMENTARY FINANCIAL DATA (UNAUDITED) - Implied Share of Net Sales - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.theravance.com/role/DisclosureSupplementaryFinancialDataUnauditedTables</ParentRole>
      <Position>125</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>tbph-20251231.xsd</File>
    <File>tbph-20251231_cal.xml</File>
    <File>tbph-20251231_def.xml</File>
    <File>tbph-20251231_lab.xml</File>
    <File>tbph-20251231_pre.xml</File>
    <File doctype="10-K" isDefinitelyFs="true" isUsgaap="true" original="tbph-20251231x10k.htm">tbph-20251231x10k.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="814">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="12">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="40">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
