<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.5.0.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>293</ContextCount>
  <ElementCount>323</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>90</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>13</UnitCount>
  <MyReports>
    <Report instance="fss-20160930.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.federalsignal.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Condensed Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedStatementsOfOperationsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Operations (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001001 - Statement - Condensed Consolidated Statements of Operations (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedStatementsOfOperationsUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Operations (Unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003000 - Statement - Condensed Consolidated Statements of Comprehensive Income (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003001 - Statement - Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005000 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1005001 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1007000 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedStatementsOfCashFlowsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>1008000 - Statement - Condensed Consolidated Statements of Stockholders' Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CondensedConsolidatedStatementsOfStockholdersEquityUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Stockholders' Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Acquisitions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/Acquisitions</Role>
      <ShortName>Acquisitions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2103100 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/Inventories</Role>
      <ShortName>Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Goodwill and Other Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/GoodwillAndOtherIntangibleAssets</Role>
      <ShortName>Goodwill and Other Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Pensions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/Pensions</Role>
      <ShortName>Pensions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/StockholdersEquity</Role>
      <ShortName>Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Restructuring</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/Restructuring</Role>
      <ShortName>Restructuring</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2115100 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Discontinued Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DiscontinuedOperations</Role>
      <ShortName>Discontinued Operations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/SummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2302301 - Disclosure - Acquisitions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/AcquisitionsTables</Role>
      <ShortName>Acquisitions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/Acquisitions</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/InventoriesTables</Role>
      <ShortName>Inventories (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/Inventories</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - Goodwill and Other Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/GoodwillAndOtherIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Other Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/GoodwillAndOtherIntangibleAssets</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/Debt</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Pensions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/PensionsTables</Role>
      <ShortName>Pensions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/Pensions</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/CommitmentsAndContingencies</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/EarningsPerShare</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - Stockholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/StockholdersEquityTables</Role>
      <ShortName>Stockholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/StockholdersEquity</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/SegmentInformation</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - Restructuring (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/RestructuringTables</Role>
      <ShortName>Restructuring (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/Restructuring</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2315301 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/FairValueMeasurements</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - Discontinued Operations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DiscontinuedOperationsTables</Role>
      <ShortName>Discontinued Operations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/DiscontinuedOperations</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2401402 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/SummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/SummaryOfSignificantAccountingPoliciesPolicies</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2402402 - Disclosure - Acquisitions - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/AcquisitionsNarrativeDetails</Role>
      <ShortName>Acquisitions - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2402403 - Disclosure - Acquisitions - JJE Acquisition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/AcquisitionsJjeAcquisitionDetails</Role>
      <ShortName>Acquisitions - JJE Acquisition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2403402 - Disclosure - Inventories - Components of Inventories (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/InventoriesComponentsOfInventoriesDetails</Role>
      <ShortName>Inventories - Components of Inventories (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/GoodwillAndOtherIntangibleAssetsChangesInCarryingAmountOfGoodwillDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2404403 - Disclosure - Goodwill and Other Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/GoodwillAndOtherIntangibleAssetsGrossCarryingAmountAndAccumulatedAmortizationOfIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Other Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Debt - Summary of Components of Long-Term Borrowings and Capital Lease Obligations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DebtSummaryOfComponentsOfLongTermBorrowingsAndCapitalLeaseObligationsDetails</Role>
      <ShortName>Debt - Summary of Components of Long-Term Borrowings and Capital Lease Obligations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2405403 - Disclosure - Debt - Long-term Borrowings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DebtLongTermBorrowingsDetails</Role>
      <ShortName>Debt - Long-term Borrowings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2405404 - Disclosure - Debt - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DebtAdditionalInformationDetails</Role>
      <ShortName>Debt - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2406401 - Disclosure - Income Taxes - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/IncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>Income Taxes - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Pensions - Summary of Components of Net Postretirement Pensions Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/PensionsSummaryOfComponentsOfNetPostretirementPensionsExpenseDetails</Role>
      <ShortName>Pensions - Summary of Components of Net Postretirement Pensions Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Pensions - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/PensionsAdditionalInformationDetails</Role>
      <ShortName>Pensions - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Commitments and Contingencies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CommitmentsAndContingenciesAdditionalInformationDetails</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Commitments and Contingencies - Summary of Changes in Warranty Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/CommitmentsAndContingenciesSummaryOfChangesInWarrantyLiabilitiesDetails</Role>
      <ShortName>Commitments and Contingencies - Summary of Changes in Warranty Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Earnings Per Share - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/EarningsPerShareAdditionalInformationDetails</Role>
      <ShortName>Earnings Per Share - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2409403 - Disclosure - Earnings Per Share - Reconciliation of Net Income (Loss) to Basic and Diluted EPS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/EarningsPerShareReconciliationOfNetIncomeLossToBasicAndDilutedEpsDetails</Role>
      <ShortName>Earnings Per Share - Reconciliation of Net Income (Loss) to Basic and Diluted EPS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2411401 - Disclosure - Stock-Based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/StockBasedCompensationDetails</Role>
      <ShortName>Stock-Based Compensation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/StockBasedCompensation</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Stockholders' Equity - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/StockholdersEquityAdditionalInformationDetails</Role>
      <ShortName>Stockholders' Equity - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2412403 - Disclosure - Stockholders' Equity - Changes in Each Component of Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/StockholdersEquityChangesInEachComponentOfAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Stockholders' Equity - Changes in Each Component of Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2412404 - Disclosure - Stockholders' Equity - Reclassifications from Accumulated Other Comprehensive Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/StockholdersEquityReclassificationsFromAccumulatedOtherComprehensiveLossDetails</Role>
      <ShortName>Stockholders' Equity - Reclassifications from Accumulated Other Comprehensive Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Segment Information - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/SegmentInformationAdditionalInformationDetails</Role>
      <ShortName>Segment Information - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2413403 - Disclosure - Segment Information - Summary of Net Sales, Operating Income (Loss), and Total Assets by Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/SegmentInformationSummaryOfNetSalesOperatingIncomeLossAndTotalAssetsBySegmentDetails</Role>
      <ShortName>Segment Information - Summary of Net Sales, Operating Income (Loss), and Total Assets by Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - Restructuring (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/RestructuringDetails</Role>
      <ShortName>Restructuring (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.federalsignal.com/role/RestructuringTables</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2415402 - Disclosure - Fair Value Measurements - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/FairValueMeasurementsNarrativeDetails</Role>
      <ShortName>Fair Value Measurements - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2415403 - Disclosure - Fair Value Measurements - Asset and Liabilities Measured at Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/FairValueMeasurementsAssetAndLiabilitiesMeasuredAtFairValueDetails</Role>
      <ShortName>Fair Value Measurements - Asset and Liabilities Measured at Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2415404 - Disclosure - Fair Value Measurements - Unobservable Input Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/FairValueMeasurementsUnobservableInputReconciliationDetails</Role>
      <ShortName>Fair Value Measurements - Unobservable Input Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - Discontinued Operations - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DiscontinuedOperationsAdditionalInformationDetails</Role>
      <ShortName>Discontinued Operations - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2416403 - Disclosure - Discontinued Operations - Operating Results of Discontinued Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DiscontinuedOperationsOperatingResultsOfDiscontinuedOperationsDetails</Role>
      <ShortName>Discontinued Operations - Operating Results of Discontinued Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="fss-20160930.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2416404 - Disclosure - Discontinued Operations - Assets and Liabilities of Discontinued Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.federalsignal.com/role/DiscontinuedOperationsAssetsAndLiabilitiesOfDiscontinuedOperationsDetails</Role>
      <ShortName>Discontinued Operations - Assets and Liabilities of Discontinued Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>fss-20160930.xml</File>
    <File>fss-20160930.xsd</File>
    <File>fss-20160930_cal.xml</File>
    <File>fss-20160930_def.xml</File>
    <File>fss-20160930_lab.xml</File>
    <File>fss-20160930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
