<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.19.3.a.u2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>224</ContextCount>
  <ElementCount>568</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>95</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>11</UnitCount>
  <MyReports>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/ConsolidatedStatementsOfOperationsAndComprehensiveIncomeLoss</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001001 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/ConsolidatedStatementsOfOperationsAndComprehensiveIncomeLossParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1002501 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1004000 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1004000 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/ConsolidatedStatementsOfChangesInStockholdersEquity</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Description of Company and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DescriptionOfCompanyAndBasisOfPresentation</Role>
      <ShortName>Description of Company and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2103100 - Disclosure - Discontinued Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DiscontinuedOperations</Role>
      <ShortName>Discontinued Operations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Acquisitions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/Acquisitions</Role>
      <ShortName>Acquisitions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/GoodwillAndIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Property and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/PropertyAndEquipment</Role>
      <ShortName>Property and Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Long-Term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/LongTermDebt</Role>
      <ShortName>Long-Term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Derivatives and Hedging Activities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DerivativesAndHedgingActivities</Role>
      <ShortName>Derivatives and Hedging Activities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Accumulated Other Comprehensive Loss</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/AccumulatedOtherComprehensiveLoss</Role>
      <ShortName>Accumulated Other Comprehensive Loss</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - Related Parties</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RelatedParties</Role>
      <ShortName>Related Parties</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Right-of-Use (ROU) Assets and Lease Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilities</Role>
      <ShortName>Right-of-Use (ROU) Assets and Lease Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Long-Term Incentive Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/LongTermIncentivePlan</Role>
      <ShortName>Long-Term Incentive Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2115100 - Disclosure - Retirement Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RetirementPlan</Role>
      <ShortName>Retirement Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/Contingencies</Role>
      <ShortName>Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2117100 - Disclosure - Fair Value Measurement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/FairValueMeasurement</Role>
      <ShortName>Fair Value Measurement</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2118100 - Disclosure - Segments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/Segments</Role>
      <ShortName>Segments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2119100 - Disclosure - Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/OtherCurrentLiabilities</Role>
      <ShortName>Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2120100 - Disclosure - Tax Receivable Agreement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/TaxReceivableAgreement</Role>
      <ShortName>Tax Receivable Agreement</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2121100 - Disclosure - Earnings (Loss) Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/EarningsLossPerShare</Role>
      <ShortName>Earnings (Loss) Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2122100 - Disclosure - Quarterly Results of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/QuarterlyResultsOfOperationsUnaudited</Role>
      <ShortName>Quarterly Results of Operations (Unaudited)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2123100 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2302302 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Discontinued Operations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DiscontinuedOperationsTables</Role>
      <ShortName>Discontinued Operations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/DiscontinuedOperations</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - Acquisitions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/AcquisitionsTables</Role>
      <ShortName>Acquisitions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/Acquisitions</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/GoodwillAndIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/GoodwillAndIntangibleAssets</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/IncomeTaxes</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Property and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/PropertyAndEquipmentTables</Role>
      <ShortName>Property and Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/PropertyAndEquipment</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Long-Term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/LongTermDebtTables</Role>
      <ShortName>Long-Term Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/LongTermDebt</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Accumulated Other Comprehensive Loss (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/AccumulatedOtherComprehensiveLossTables</Role>
      <ShortName>Accumulated Other Comprehensive Loss (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/AccumulatedOtherComprehensiveLoss</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - Right-of-Use ("ROU") Assets and Lease Liabilities  (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesTables</Role>
      <ShortName>Right-of-Use ("ROU") Assets and Lease Liabilities  (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilities</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/StockBasedCompensation</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2317301 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/FairValueMeasurement</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2318301 - Disclosure - Segments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SegmentsTables</Role>
      <ShortName>Segments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/Segments</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2319301 - Disclosure - Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/OtherCurrentLiabilitiesTables</Role>
      <ShortName>Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/OtherCurrentLiabilities</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2321301 - Disclosure - Earnings (Loss) Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/EarningsLossPerShareTables</Role>
      <ShortName>Earnings (Loss) Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/EarningsLossPerShare</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2322301 - Disclosure - Quarterly Results of Operations (Unaudited) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/QuarterlyResultsOfOperationsUnauditedTables</Role>
      <ShortName>Quarterly Results of Operations (Unaudited) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/QuarterlyResultsOfOperationsUnaudited</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2401401 - Disclosure - Description of Company and Basis of Presentation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DescriptionOfCompanyAndBasisOfPresentationDetails</Role>
      <ShortName>Description of Company and Basis of Presentation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/DescriptionOfCompanyAndBasisOfPresentation</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2402403 - Disclosure - Summary of Significant Accounting Policies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2402404 - Disclosure - Summary of Significant Accounting Policies - Schedule of Depreciation and Amortization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfDepreciationAndAmortizationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Schedule of Depreciation and Amortization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2402405 - Disclosure - Summary of Significant Accounting Polices - Schedule of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SummaryOfSignificantAccountingPolicesScheduleOfIntangibleAssetsDetails</Role>
      <ShortName>Summary of Significant Accounting Polices - Schedule of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2403402 - Disclosure - Discontinued Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DiscontinuedOperationsDetails</Role>
      <ShortName>Discontinued Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/DiscontinuedOperationsTables</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Acquisitions - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/AcquisitionsNarrativeDetails</Role>
      <ShortName>Acquisitions - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2404403 - Disclosure - Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/AcquisitionsScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedDetails</Role>
      <ShortName>Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Goodwill and Intangible Assets - Schedule of Finite-Lived Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/GoodwillAndIntangibleAssetsScheduleOfFiniteLivedIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Finite-Lived Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2405403 - Disclosure - Goodwill and Intangible Assets - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/GoodwillAndIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2405404 - Disclosure - Goodwill and Intangible Assets - Schedule of Future Amortization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/GoodwillAndIntangibleAssetsScheduleOfFutureAmortizationDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Future Amortization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2405405 - Disclosure - Goodwill and Intangible Assets - Schedule of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/GoodwillAndIntangibleAssetsScheduleOfGoodwillDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Income Taxes - Schedule of Income (Loss) before Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxesScheduleOfIncomeLossBeforeIncomeTaxesDetails</Role>
      <ShortName>Income Taxes - Schedule of Income (Loss) before Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Income Taxes - Schedule of Income Tax Benefit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxesScheduleOfIncomeTaxBenefitDetails</Role>
      <ShortName>Income Taxes - Schedule of Income Tax Benefit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2406404 - Disclosure - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxesScheduleOfEffectiveIncomeTaxRateReconciliationDetails</Role>
      <ShortName>Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2406405 - Disclosure - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxesScheduleOfDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2406406 - Disclosure - Income taxes - Operating Loss Carryforwards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxesOperatingLossCarryforwardsDetails</Role>
      <ShortName>Income taxes - Operating Loss Carryforwards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2406407 - Disclosure - Income Taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Property and Equipment - Schedule of Property and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/PropertyAndEquipmentScheduleOfPropertyAndEquipmentDetails</Role>
      <ShortName>Property and Equipment - Schedule of Property and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Property and Equipment - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/PropertyAndEquipmentNarrativeDetails</Role>
      <ShortName>Property and Equipment - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Long-Term Debt - Schedule of Notes Payable (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.fbmsales.com/role/LongTermDebtScheduleOfNotesPayableDetails</Role>
      <ShortName>Long-Term Debt - Schedule of Notes Payable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Long-Term Debt - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/LongTermDebtNarrativeDetails</Role>
      <ShortName>Long-Term Debt - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>2409401 - Disclosure - Derivatives and Hedging Activities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/DerivativesAndHedgingActivitiesDetails</Role>
      <ShortName>Derivatives and Hedging Activities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/DerivativesAndHedgingActivities</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/AccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/AccumulatedOtherComprehensiveLossTables</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>2411401 - Disclosure - Related Parties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RelatedPartiesDetails</Role>
      <ShortName>Related Parties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/RelatedParties</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Right-of-Use ("ROU") Assets and Lease Liabilities  - Operating and Finance Lease Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesOperatingAndFinanceLeaseLiabilityDetails</Role>
      <ShortName>Right-of-Use ("ROU") Assets and Lease Liabilities  - Operating and Finance Lease Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesTables</ParentRole>
      <Position>71</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>2412403 - Disclosure - Right-of-Use (ROU) Assets and Lease Liabilities Right-of-Use ("ROU") Assets and Lease Liabilities - Lease Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesRightOfUseRouAssetsAndLeaseLiabilitiesLeaseCostDetails</Role>
      <ShortName>Right-of-Use (ROU) Assets and Lease Liabilities Right-of-Use ("ROU") Assets and Lease Liabilities - Lease Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesTables</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>2412404 - Disclosure - Right-of-Use ("ROU") Assets and Lease Liabilities - Schedule of Operating and Finance Lease Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesScheduleOfOperatingAndFinanceLeaseMaturityDetails</Role>
      <ShortName>Right-of-Use ("ROU") Assets and Lease Liabilities - Schedule of Operating and Finance Lease Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesTables</ParentRole>
      <Position>73</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>2412405 - Disclosure - Right-of-Use ("ROU") Assets and Lease Liabilities - Schedule of Future Minimum Lease Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesScheduleOfFutureMinimumLeasePaymentsDetails</Role>
      <ShortName>Right-of-Use ("ROU") Assets and Lease Liabilities - Schedule of Future Minimum Lease Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/RightOfUseRouAssetsAndLeaseLiabilitiesTables</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Stock-Based Compensation - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>2413403 - Disclosure - Stock-Based Compensation - Schedule of Valuation Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationScheduleOfValuationAssumptionsDetails</Role>
      <ShortName>Stock-Based Compensation - Schedule of Valuation Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>2413404 - Disclosure - Stock-Based Compensation - Schedule of Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationScheduleOfStockOptionsDetails</Role>
      <ShortName>Stock-Based Compensation - Schedule of Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>2413405 - Disclosure - Stock-Based Compensation - Schedule of Non-Vested Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationScheduleOfNonVestedStockOptionsDetails</Role>
      <ShortName>Stock-Based Compensation - Schedule of Non-Vested Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>2413406 - Disclosure - Stock-Based Compensation - Schedule of Options Exercisable (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationScheduleOfOptionsExercisableDetails</Role>
      <ShortName>Stock-Based Compensation - Schedule of Options Exercisable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>2413407 - Disclosure - Stock-Based Compensation - Schedule of Restricted Stock Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationScheduleOfRestrictedStockActivityDetails</Role>
      <ShortName>Stock-Based Compensation - Schedule of Restricted Stock Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>2413408 - Disclosure - Stock-Based Compensation Stock Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/StockBasedCompensationStockBasedCompensationExpenseDetails</Role>
      <ShortName>Stock-Based Compensation Stock Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>2414401 - Disclosure - Long-Term Incentive Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/LongTermIncentivePlanDetails</Role>
      <ShortName>Long-Term Incentive Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/LongTermIncentivePlan</ParentRole>
      <Position>82</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>2415401 - Disclosure - Retirement Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/RetirementPlanDetails</Role>
      <ShortName>Retirement Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/RetirementPlan</ParentRole>
      <Position>83</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>2417402 - Disclosure - Fair Value Measurements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/FairValueMeasurementsDetails</Role>
      <ShortName>Fair Value Measurements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/FairValueMeasurementsTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>2418402 - Disclosure - Segments - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SegmentsNarrativeDetails</Role>
      <ShortName>Segments - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>2418403 - Disclosure - Segments - Schedule of Information by Geographic Areas (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SegmentsScheduleOfInformationByGeographicAreasDetails</Role>
      <ShortName>Segments - Schedule of Information by Geographic Areas (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>2418404 - Disclosure - Segments - Schedule of Geographic Areas (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SegmentsScheduleOfGeographicAreasDetails</Role>
      <ShortName>Segments - Schedule of Geographic Areas (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>2418405 - Disclosure - Segments - Schedule of Net Sales From External Customers (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/SegmentsScheduleOfNetSalesFromExternalCustomersDetails</Role>
      <ShortName>Segments - Schedule of Net Sales From External Customers (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>2419402 - Disclosure - Other Current Liabilities - Schedule of Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/OtherCurrentLiabilitiesScheduleOfOtherCurrentLiabilitiesDetails</Role>
      <ShortName>Other Current Liabilities - Schedule of Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>2420401 - Disclosure - Tax Receivable Agreement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/TaxReceivableAgreementDetails</Role>
      <ShortName>Tax Receivable Agreement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/TaxReceivableAgreement</ParentRole>
      <Position>90</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>2421402 - Disclosure - Earnings (Loss) Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/EarningsLossPerShareDetails</Role>
      <ShortName>Earnings (Loss) Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/EarningsLossPerShareTables</ParentRole>
      <Position>91</Position>
    </Report>
    <Report instance="fbm-20191231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>2422402 - Disclosure - Quarterly Results of Operations (Unaudited) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.fbmsales.com/role/QuarterlyResultsOfOperationsUnauditedDetails</Role>
      <ShortName>Quarterly Results of Operations (Unaudited) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.fbmsales.com/role/QuarterlyResultsOfOperationsUnauditedTables</ParentRole>
      <Position>92</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>fbm-20191231.xml</File>
    <File>fbm-20191231.xsd</File>
    <File>fbm-20191231_cal.xml</File>
    <File>fbm-20191231_def.xml</File>
    <File>fbm-20191231_lab.xml</File>
    <File>fbm-20191231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/stpr/2018-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/country/2017-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
