<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.2.0.25</Version>
  <ReportType />
  <MyReports>
    <Report>
      <IsDefault>true</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>001000 - Document - Document and Entity Information</LongName>
      <ShortName>Document and Entity Information</ShortName>
      <Role>http://twrgrp.com/role/DocumentDocumentAndEntityInformation</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R1.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>002000 - Statement - Consolidated Balance Sheets</LongName>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <Role>http://twrgrp.com/role/StatementConsolidatedBalanceSheets</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R2.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>002500 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <Role>http://twrgrp.com/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R3.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>003000 - Statement - Consolidated Statements of Income and Comprehensive Income (Unaudited)</LongName>
      <ShortName>Consolidated Statements of Income and Comprehensive Income (Unaudited)</ShortName>
      <Role>http://twrgrp.com/role/StatementConsolidatedStatementsOfIncomeAndComprehensiveIncomeUnaudited</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R4.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>004000 - Statement - Consolidated Statements of Changes in Stockholders Equity (Unaudited)</LongName>
      <ShortName>Consolidated Statements of Changes in Stockholders Equity (Unaudited)</ShortName>
      <Role>http://twrgrp.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquityUnaudited</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R5.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>005000 - Statement - Consolidated Statements of Cash Flow (Unaudited)</LongName>
      <ShortName>Consolidated Statements of Cash Flow (Unaudited)</ShortName>
      <Role>http://twrgrp.com/role/StatementConsolidatedStatementsOfCashFlowUnaudited</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R6.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006001 - Disclosure - Nature of Business</LongName>
      <ShortName>Nature of Business</ShortName>
      <Role>http://twrgrp.com/role/DisclosureNatureOfBusiness</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R7.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006002 - Disclosure - Accounting Policies and Basis of Presentation</LongName>
      <ShortName>Accounting Policies and Basis of Presentation</ShortName>
      <Role>http://twrgrp.com/role/DisclosureAccountingPoliciesAndBasisOfPresentation</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R8.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006003 - Statement - Acquisitions</LongName>
      <ShortName>Acquisitions</ShortName>
      <Role>http://twrgrp.com/role/StatementAcquisitions</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R9.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006004 - Disclosure - Disclosure - Variable Interest Entities</LongName>
      <ShortName>Disclosure - Variable Interest Entities</ShortName>
      <Role>http://twrgrp.com/role/DisclosureDisclosureVariableInterestEntities</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R10.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006005 - Disclosure - Investments</LongName>
      <ShortName>Investments</ShortName>
      <Role>http://twrgrp.com/role/DisclosureInvestments</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R11.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006006 - Disclosure - Fair Value Measurements</LongName>
      <ShortName>Fair Value Measurements</ShortName>
      <Role>http://twrgrp.com/role/DisclosureFairValueMeasurements</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R12.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006008 - Disclosure - Loss and Loss Adjustment Expense</LongName>
      <ShortName>Loss and Loss Adjustment Expense</ShortName>
      <Role>http://twrgrp.com/role/DisclosureLossAndLossAdjustmentExpense</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R13.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006009 - Disclosure - Stockholders Equity</LongName>
      <ShortName>Stockholders Equity</ShortName>
      <Role>http://twrgrp.com/role/DisclosureStockholdersEquity</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R14.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006010 - Disclosure - Debt</LongName>
      <ShortName>Debt</ShortName>
      <Role>http://twrgrp.com/role/DisclosureDebt</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R15.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006011 - Disclosure - Stock Based Compensation</LongName>
      <ShortName>Stock Based Compensation</ShortName>
      <Role>http://twrgrp.com/role/DisclosureStockBasedCompensation</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R16.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006013 - Disclosure - Earnings per Share</LongName>
      <ShortName>Earnings per Share</ShortName>
      <Role>http://twrgrp.com/role/DisclosureEarningsPerShare</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R17.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006014 - Disclosure - Segment Information</LongName>
      <ShortName>Segment Information</ShortName>
      <Role>http://twrgrp.com/role/DisclosureSegmentInformation</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R18.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Sheet</ReportType>
      <LongName>006015 - Disclosure - Contingencies</LongName>
      <ShortName>Contingencies</ShortName>
      <Role>http://twrgrp.com/role/DisclosureContingencies</Role>
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName>R19.xml</XmlFileName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <ReportType>Book</ReportType>
      <LongName>All Reports</LongName>
      <ShortName>All Reports</ShortName>
      <Role />
      <ContainEmbeddedReports>false</ContainEmbeddedReports>
      <XmlFileName />
    </Report>
  </MyReports>
  <EntityCount>1</EntityCount>
  <ContextCount>51</ContextCount>
  <SegmentCount>8</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <UnitCount>2</UnitCount>
  <ElementCount>142</ElementCount>
  <FootnotesReported>false</FootnotesReported>
  <TuplesReported>false</TuplesReported>
  <ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2010_TO_Mar31_2010_us-gaap_StatementEquityComponentsAxis_AccumulatedOtherComprehensiveIncomeMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_May05_2011</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_AdditionalPaidInCapitalMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2010_us-gaap_StatementEquityComponentsAxis_CommonStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2010_TO_Mar31_2010_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2010</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2010_us-gaap_StatementEquityComponentsAxis_AccumulatedOtherComprehensiveIncomeMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2011_TO_Mar31_2011_us-gaap_StatementEquityComponentsAxis_MinorityInterestAndEarningsLossesEquityInvestmentsMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011_us-gaap_StatementEquityComponentsAxis_AdditionalPaidInCapitalMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2011_TO_Mar31_2011_us-gaap_StatementEquityComponentsAxis_AccumulatedOtherComprehensiveIncomeMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2011_TO_Mar31_2011</ContextName>
      <ElementCount>95</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2009_TO_Dec31_2009_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_AdditionalPaidInCapitalMember_us-gaap_StatementScenarioAxis_ScenarioPreviouslyReportedMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2010_us-gaap_StatementEquityComponentsAxis_AdditionalPaidInCapitalMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2010_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_CommonStockMember_us-gaap_StatementScenarioAxis_ScenarioPreviouslyReportedMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011_us-gaap_VariableInterestByInterestTypeAxis_VariableInterestEnterpriseMember</ContextName>
      <ElementCount>19</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_CommonStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2011_TO_Mar31_2011_us-gaap_StatementEquityComponentsAxis_TreasuryStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2009_TO_Dec31_2009</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2010_TO_Mar31_2010_us-gaap_StatementEquityComponentsAxis_CommonStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2010_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2010_us-gaap_StatementEquityComponentsAxis_AccumulatedOtherComprehensiveIncomeMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011_us-gaap_StatementEquityComponentsAxis_TreasuryStockMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Jun30_2010</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementScenarioAxis_ScenarioPreviouslyReportedMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2010</ContextName>
      <ElementCount>42</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2011_TO_Mar31_2011_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2010_us-gaap_StatementEquityComponentsAxis_TreasuryStockMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2010_us-gaap_StatementEquityComponentsAxis_AdditionalPaidInCapitalMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011_us-gaap_StatementEquityComponentsAxis_MinorityInterestAndEarningsLossesEquityInvestmentsMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementScenarioAxis_ScenarioPreviouslyReportedMember_us-gaap_StatementEquityComponentsAxis_TreasuryStockMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2010_us-gaap_VariableInterestByInterestTypeAxis_VariableInterestEnterpriseMember</ContextName>
      <ElementCount>19</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011_us-gaap_StatementEquityComponentsAxis_CommonStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_AccumulatedOtherComprehensiveIncomeMember_us-gaap_StatementScenarioAxis_ScenarioPreviouslyReportedMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2010_TO_Mar31_2010_us-gaap_StatementEquityComponentsAxis_AdditionalPaidInCapitalMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011_us-gaap_StatementEquityComponentsAxis_AccumulatedOtherComprehensiveIncomeMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2011</ContextName>
      <ElementCount>42</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2010_us-gaap_StatementEquityComponentsAxis_CommonStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember_us-gaap_StatementScenarioAxis_ScenarioPreviouslyReportedMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_TreasuryStockMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2010_us-gaap_StatementEquityComponentsAxis_TreasuryStockMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2011_TO_Mar31_2011_us-gaap_StatementEquityComponentsAxis_AdditionalPaidInCapitalMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Mar31_2010_us-gaap_StatementEquityComponentsAxis_MinorityInterestAndEarningsLossesEquityInvestmentsMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2010_TO_Mar31_2010</ContextName>
      <ElementCount>69</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2010_TO_Mar31_2010_us-gaap_StatementEquityComponentsAxis_TreasuryStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_AccumulatedOtherComprehensiveIncomeMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>FROM_Jan01_2011_TO_Mar31_2011_us-gaap_StatementEquityComponentsAxis_CommonStockMember</ContextName>
      <ElementCount>2</ElementCount>
    </ContextSummary>
    <ContextSummary>
      <ContextName>AS_OF_Dec31_2009_us-gaap_StatementEquityComponentsAxis_RetainedEarningsMember</ContextName>
      <ElementCount>1</ElementCount>
    </ContextSummary>
  </ContextSummary>
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
