<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.3.1.900</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>315</ContextCount>
  <ElementCount>448</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>81</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>100000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>100010 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>100020 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100030 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/StatementConsolidatedStatementsOfOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100040 - Statement - Consolidated Statements of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100050 - Statement - Consolidated Statements of Comprehensive Income (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveIncomeParenthetical</Role>
      <ShortName>Consolidated Statements of Comprehensive Income (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100060 - Statement - Consolidated Statements of Changes in Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/StatementConsolidatedStatementsOfChangesInShareholdersEquity</Role>
      <ShortName>Consolidated Statements of Changes in Shareholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100070 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>100080 - Disclosure - Organization and Nature of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureOrganizationAndNatureOfOperations</Role>
      <ShortName>Organization and Nature of Operations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>100090 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>100100 - Disclosure - Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstruments</Role>
      <ShortName>Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>100110 - Disclosure - Securities Lending</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSecuritiesLending</Role>
      <ShortName>Securities Lending</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>100120 - Disclosure - Acquisition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureAcquisition</Role>
      <ShortName>Acquisition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>100130 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureGoodwillAndIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>100140 - Disclosure - Furniture, Equipment, Software and Leasehold Improvements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFurnitureEquipmentSoftwareAndLeaseholdImprovements</Role>
      <ShortName>Furniture, Equipment, Software and Leasehold Improvements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>100150 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>100160 - Disclosure - Regulatory Capital Requirements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureRegulatoryCapitalRequirements</Role>
      <ShortName>Regulatory Capital Requirements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>100170 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>100180 - Disclosure - Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquity</Role>
      <ShortName>Shareholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>100190 - Disclosure - Net (Loss) Income Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureNetLossIncomePerShare</Role>
      <ShortName>Net (Loss) Income Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>100200 - Disclosure - Financial Instruments with Off-Balance-Sheet Risk and Credit Risk</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsWithOffBalanceSheetRiskAndCreditRisk</Role>
      <ShortName>Financial Instruments with Off-Balance-Sheet Risk and Credit Risk</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>100210 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureRelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>100220 - Disclosure - Employee Benefits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureEmployeeBenefits</Role>
      <ShortName>Employee Benefits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>100230 - Disclosure - Discontinued Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureDiscontinuedOperations</Role>
      <ShortName>Discontinued Operations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>100240 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>100250 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>100260 - Disclosure - Quarterly Data</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureQuarterlyData</Role>
      <ShortName>Quarterly Data</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>100270 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>100280 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>100290 - Disclosure - Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsTables</Role>
      <ShortName>Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstruments</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>100300 - Disclosure - Securities Lending (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSecuritiesLendingTables</Role>
      <ShortName>Securities Lending (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureSecuritiesLending</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>100310 - Disclosure - Acquisition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureAcquisitionTables</Role>
      <ShortName>Acquisition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureAcquisition</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>100320 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureGoodwillAndIntangibleAssets</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>100330 - Disclosure - Furniture, Equipment, Software and Leasehold Improvements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFurnitureEquipmentSoftwareAndLeaseholdImprovementsTables</Role>
      <ShortName>Furniture, Equipment, Software and Leasehold Improvements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureFurnitureEquipmentSoftwareAndLeaseholdImprovements</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>100340 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxes</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>100350 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>100360 - Disclosure - Shareholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquityTables</Role>
      <ShortName>Shareholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquity</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>100370 - Disclosure - Net (Loss) Income Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureNetLossIncomePerShareTables</Role>
      <ShortName>Net (Loss) Income Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureNetLossIncomePerShare</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>100380 - Disclosure - Discontinued Operations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureDiscontinuedOperationsTables</Role>
      <ShortName>Discontinued Operations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureDiscontinuedOperations</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>100390 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureSegmentInformation</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>100400 - Disclosure - Quarterly Data (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureQuarterlyDataTables</Role>
      <ShortName>Quarterly Data (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureQuarterlyData</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>100410 - Disclosure - Organization and Nature of Operations - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureOrganizationAndNatureOfOperationsAdditionalInformationDetail</Role>
      <ShortName>Organization and Nature of Operations - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>100420 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetail</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>100430 - Disclosure - Summary of Significant Accounting Policies - Estimated Fair Values of Financial Instrument Assets and Liabilities Which are Not Measured at Fair Value on the Consolidated Balance Sheets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesEstimatedFairValuesOfFinancialInstrumentAssetsAndLiabilitiesWhichAreNotMeasuredAtFairValueOnConsolidatedBalanceSheetsDetail</Role>
      <ShortName>Summary of Significant Accounting Policies - Estimated Fair Values of Financial Instrument Assets and Liabilities Which are Not Measured at Fair Value on the Consolidated Balance Sheets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>100440 - Disclosure - Summary of Significant Accounting Policies - Estimated Fair Values of Financial Instrument Assets and Liabilities Which are Not Measured at Fair Value on the Consolidated Balance Sheets (Parenthetical) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesEstimatedFairValuesOfFinancialInstrumentAssetsAndLiabilitiesWhichAreNotMeasuredAtFairValueOnConsolidatedBalanceSheetsParentheticalDetail</Role>
      <ShortName>Summary of Significant Accounting Policies - Estimated Fair Values of Financial Instrument Assets and Liabilities Which are Not Measured at Fair Value on the Consolidated Balance Sheets (Parenthetical) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>100450 - Disclosure - Financial Instruments - Items Measured at Fair Value on Recurring Basis (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsItemsMeasuredAtFairValueOnRecurringBasisDetail</Role>
      <ShortName>Financial Instruments - Items Measured at Fair Value on Recurring Basis (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>100460 - Disclosure - Financial Instruments - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsAdditionalInformationDetail</Role>
      <ShortName>Financial Instruments - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>100470 - Disclosure - Financial Instruments - Valuation Technique and Unobservable Inputs (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsValuationTechniqueAndUnobservableInputsDetail</Role>
      <ShortName>Financial Instruments - Valuation Technique and Unobservable Inputs (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>100480 - Disclosure - Financial Instruments - Changes in Fair Value of Company's Level 3 Financial Assets and Liabilities Measured on Recurring Basis (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsChangesInFairValueOfCompanySLevel3FinancialAssetsAndLiabilitiesMeasuredOnRecurringBasisDetail</Role>
      <ShortName>Financial Instruments - Changes in Fair Value of Company's Level 3 Financial Assets and Liabilities Measured on Recurring Basis (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>100490 - Disclosure - Financial Instruments - Gains (Losses) from Level 3 Financial Assets and Liabilities Measured on Recurring Basis (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsGainsLossesFromLevel3FinancialAssetsAndLiabilitiesMeasuredOnRecurringBasisDetail</Role>
      <ShortName>Financial Instruments - Gains (Losses) from Level 3 Financial Assets and Liabilities Measured on Recurring Basis (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>100500 - Disclosure - Financial Instruments - Financial Instruments Held for Investment - Designated as Trading (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsFinancialInstrumentsHeldForInvestmentDesignatedAsTradingDetail</Role>
      <ShortName>Financial Instruments - Financial Instruments Held for Investment - Designated as Trading (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>100510 - Disclosure - Financial Instruments - Company's Investments in Hedge Funds and Private Equity Funds Measured at Fair Value Based on Net Asset Value (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsCompanySInvestmentsInHedgeFundsAndPrivateEquityFundsMeasuredAtFairValueBasedOnNetAssetValueDetail</Role>
      <ShortName>Financial Instruments - Company's Investments in Hedge Funds and Private Equity Funds Measured at Fair Value Based on Net Asset Value (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>100520 - Disclosure - Financial Instruments - Financial Instruments Held for Investment - Designated as Available-for-Sale (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsFinancialInstrumentsHeldForInvestmentDesignatedAsAvailableForSaleDetail</Role>
      <ShortName>Financial Instruments - Financial Instruments Held for Investment - Designated as Available-for-Sale (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>100530 - Disclosure - Financial Instruments - Detail of the Amounts Included in Accumulated Other Comprehensive Income and Reclassified to Earnings (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsDetailOfAmountsIncludedInAccumulatedOtherComprehensiveIncomeAndReclassifiedToEarningsDetail</Role>
      <ShortName>Financial Instruments - Detail of the Amounts Included in Accumulated Other Comprehensive Income and Reclassified to Earnings (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>100540 - Disclosure - Financial Instruments - Changes in the Company's Accumulated Other Comprehensive Income (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsChangesInCompanySAccumulatedOtherComprehensiveIncomeDetail</Role>
      <ShortName>Financial Instruments - Changes in the Company's Accumulated Other Comprehensive Income (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>100550 - Disclosure - Securities Lending - Gross and Net Securities Borrowing and Lending Balances (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSecuritiesLendingGrossAndNetSecuritiesBorrowingAndLendingBalancesDetail</Role>
      <ShortName>Securities Lending - Gross and Net Securities Borrowing and Lending Balances (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>100560 - Disclosure - Acquisitions - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetail</Role>
      <ShortName>Acquisitions - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>100570 - Disclosure - Acquisitions - Summary of Fair Value of Assets Acquired and Liabilities Assumed at Acquisition Date (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureAcquisitionsSummaryOfFairValueOfAssetsAcquiredAndLiabilitiesAssumedAtAcquisitionDateDetail</Role>
      <ShortName>Acquisitions - Summary of Fair Value of Assets Acquired and Liabilities Assumed at Acquisition Date (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>100590 - Disclosure - Goodwill and Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfChangesInCarryingAmountOfGoodwillDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>100600 - Disclosure - Goodwill and Intangible Assets - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsAdditionalInformationDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>100610 - Disclosure - Goodwill and Intangible Assets - Schedule of Components of Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfComponentsOfIntangibleAssetsDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Components of Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>100620 - Disclosure - Goodwill and Intangible Assets - Schedule of Estimated Amortization Expense (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfEstimatedAmortizationExpenseDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Estimated Amortization Expense (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>100630 - Disclosure - Furniture, Equipment, Software and Leasehold Improvements - Furniture, Equipment, Software and Leasehold Improvements Summarized by Major Classification (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFurnitureEquipmentSoftwareAndLeaseholdImprovementsFurnitureEquipmentSoftwareAndLeaseholdImprovementsSummarizedByMajorClassificationDetail</Role>
      <ShortName>Furniture, Equipment, Software and Leasehold Improvements - Furniture, Equipment, Software and Leasehold Improvements Summarized by Major Classification (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>100640 - Disclosure - Furniture, Equipment, Software and Leasehold Improvements - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFurnitureEquipmentSoftwareAndLeaseholdImprovementsAdditionalInformationDetail</Role>
      <ShortName>Furniture, Equipment, Software and Leasehold Improvements - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>100650 - Disclosure - Income Taxes - The Provision (Benefit) for Income Taxes (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxesTheProvisionBenefitForIncomeTaxesDetail</Role>
      <ShortName>Income Taxes - The Provision (Benefit) for Income Taxes (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>100660 - Disclosure - Income Taxes - Deferred Tax Assets and Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetail</Role>
      <ShortName>Income Taxes - Deferred Tax Assets and Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>100670 - Disclosure - Income Taxes - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail</Role>
      <ShortName>Income Taxes - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>100680 - Disclosure - Income Taxes - Provision Attributable to Continuing Operations to the Amount of Income Tax Expense (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxesProvisionAttributableToContinuingOperationsToAmountOfIncomeTaxExpenseDetail</Role>
      <ShortName>Income Taxes - Provision Attributable to Continuing Operations to the Amount of Income Tax Expense (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>100690 - Disclosure - Income Taxes - Components of (Loss) Income Before Income Taxes (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureIncomeTaxesComponentsOfLossIncomeBeforeIncomeTaxesDetail</Role>
      <ShortName>Income Taxes - Components of (Loss) Income Before Income Taxes (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>100700 - Disclosure - Regulatory Capital Requirements - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureRegulatoryCapitalRequirementsAdditionalInformationDetail</Role>
      <ShortName>Regulatory Capital Requirements - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>100710 - Disclosure - Commitments and Contingencies - Contractual Obligations by Fiscal Year (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureCommitmentsAndContingenciesContractualObligationsByFiscalYearDetail</Role>
      <ShortName>Commitments and Contingencies - Contractual Obligations by Fiscal Year (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>100720 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>100730 - Disclosure - Shareholders' Equity - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquityAdditionalInformationDetail</Role>
      <ShortName>Shareholders' Equity - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>100740 - Disclosure - Shareholders' Equity - Summary of Cash Dividends Declared on Common Stock (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquitySummaryOfCashDividendsDeclaredOnCommonStockDetail</Role>
      <ShortName>Shareholders' Equity - Summary of Cash Dividends Declared on Common Stock (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>100750 - Disclosure - Shareholders' Equity - Compensation Expense Related to Awards (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquityCompensationExpenseRelatedToAwardsDetail</Role>
      <ShortName>Shareholders' Equity - Compensation Expense Related to Awards (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>100760 - Disclosure - Shareholders' Equity - Unrecognized Compensation Related to Awards (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquityUnrecognizedCompensationRelatedToAwardsDetail</Role>
      <ShortName>Shareholders' Equity - Unrecognized Compensation Related to Awards (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>100770 - Disclosure - Shareholders' Equity - Unrecognized Compensation Related to Awards (Parenthetical) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquityUnrecognizedCompensationRelatedToAwardsParentheticalDetail</Role>
      <ShortName>Shareholders' Equity - Unrecognized Compensation Related to Awards (Parenthetical) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>100780 - Disclosure - Shareholders' Equity - Summary of Option Activity under the FBR &amp; Co. Long Term Incentive Plan (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquitySummaryOfOptionActivityUnderFBRCoLongTermIncentivePlanDetail</Role>
      <ShortName>Shareholders' Equity - Summary of Option Activity under the FBR &amp; Co. Long Term Incentive Plan (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>100790 - Disclosure - Shareholders' Equity - Summary of Unvested Restricted Stock Awards and Restricted Stock Units (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquitySummaryOfUnvestedRestrictedStockAwardsAndRestrictedStockUnitsDetail</Role>
      <ShortName>Shareholders' Equity - Summary of Unvested Restricted Stock Awards and Restricted Stock Units (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>100800 - Disclosure - Shareholders' Equity - Summary of Restricted Stock and Restricted Stock Unit Awards Held in the Irrevocable Trust (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureShareholdersEquitySummaryOfRestrictedStockAndRestrictedStockUnitAwardsHeldInIrrevocableTrustDetail</Role>
      <ShortName>Shareholders' Equity - Summary of Restricted Stock and Restricted Stock Unit Awards Held in the Irrevocable Trust (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>100810 - Disclosure - Net (Loss)Income Per Share - Computations of Basic and Diluted Earnings Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureNetLossIncomePerShareComputationsOfBasicAndDilutedEarningsPerShareDetail</Role>
      <ShortName>Net (Loss)Income Per Share - Computations of Basic and Diluted Earnings Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureNetLossIncomePerShareTables</ParentRole>
      <Position>81</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>100820 - Disclosure - Net (Loss) Income Per Share - Number of Antidilutive Stock Options, Unvested Restricted Stock and RSUs Outstanding (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureNetLossIncomePerShareNumberOfAntidilutiveStockOptionsUnvestedRestrictedStockAndRsusOutstandingDetail</Role>
      <ShortName>Net (Loss) Income Per Share - Number of Antidilutive Stock Options, Unvested Restricted Stock and RSUs Outstanding (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbr.com/20151231/taxonomy/role/DisclosureNetLossIncomePerShareTables</ParentRole>
      <Position>82</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>100830 - Disclosure - Financial Instruments with Off-Balance-Sheet Risk and Credit Risk - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureFinancialInstrumentsWithOffBalanceSheetRiskAndCreditRiskAdditionalInformationDetail</Role>
      <ShortName>Financial Instruments with Off-Balance-Sheet Risk and Credit Risk - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>100840 - Disclosure - Related-Party Transactions - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetail</Role>
      <ShortName>Related-Party Transactions - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>100850 - Disclosure - Employee Benefits - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureEmployeeBenefitsAdditionalInformationDetail</Role>
      <ShortName>Employee Benefits - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>100860 - Disclosure - Discontinued Operations - Summary of Asset Management Operations Reflected in Consolidated Statements of Operations (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureDiscontinuedOperationsSummaryOfAssetManagementOperationsReflectedInConsolidatedStatementsOfOperationsDetail</Role>
      <ShortName>Discontinued Operations - Summary of Asset Management Operations Reflected in Consolidated Statements of Operations (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>100870 - Disclosure - Discontinued Operations - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureDiscontinuedOperationsAdditionalInformationDetail</Role>
      <ShortName>Discontinued Operations - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>100880 - Disclosure - Segment Information - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetail</Role>
      <ShortName>Segment Information - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>100890 - Disclosure - Segment Information - Summary of Financial Information of Company's Segments (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSegmentInformationSummaryOfFinancialInformationOfCompanySSegmentsDetail</Role>
      <ShortName>Segment Information - Summary of Financial Information of Company's Segments (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>100900 - Disclosure - Subsequent Events - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetail</Role>
      <ShortName>Subsequent Events - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="fbrc-20151231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>100910 - Disclosure - Quarterly Data - Details of Quarterly Financial Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbr.com/20151231/taxonomy/role/DisclosureQuarterlyDataDetailsOfQuarterlyFinancialInformationDetail</Role>
      <ShortName>Quarterly Data - Details of Quarterly Financial Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>fbrc-20151231.xml</File>
    <File>fbrc-20151231.xsd</File>
    <File>fbrc-20151231_cal.xml</File>
    <File>fbrc-20151231_def.xml</File>
    <File>fbrc-20151231_lab.xml</File>
    <File>fbrc-20151231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
