<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.4.0.6</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>44</ContextCount>
  <ElementCount>164</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>8</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>3</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0010 - Statement - Consolidated and Combined Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/BalanceSheet</Role>
      <ShortName>Consolidated and Combined Balance Sheets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0015 - Statement - Consolidated and Combined Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/BalanceSheetParenthetical</Role>
      <ShortName>Consolidated and Combined Balance Sheets (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0020 - Statement - Consolidated and Combined Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/StatementOfIncome</Role>
      <ShortName>Consolidated and Combined Statements of Operations</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0030 - Statement - Consolidated and Combined Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/StatementOfStockholdersEquity</Role>
      <ShortName>Consolidated and Combined Statements of Stockholders' Equity</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0040 - Statement - Consolidated and Combined Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/CashFlows</Role>
      <ShortName>Consolidated and Combined Statements of Cash Flows</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1010 - Disclosure - Organization and Description of Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureOrganizationAndDescriptionOfBusiness</Role>
      <ShortName>Organization and Description of Business</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1020 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>1030 - Disclosure - Real Estate</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureRealEstate</Role>
      <ShortName>Real Estate</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>1040 - Disclosure - Deferred Leasing Intangibles</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureDeferredLeasingIntangibles</Role>
      <ShortName>Deferred Leasing Intangibles</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>1050 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureDebt</Role>
      <ShortName>Debt</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>1060 - Disclosure - Use of Derivative Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureUseOfDerivativeFinancialInstruments</Role>
      <ShortName>Use of Derivative Financial Instruments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>1070 - Disclosure - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureStockholdersEquity</Role>
      <ShortName>Stockholders' Equity</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>1080 - Disclosure - Noncontrolling Interest</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureNoncontrollingInterest</Role>
      <ShortName>Noncontrolling Interest</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>1090 - Disclosure - Future Minimum Rents</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureFutureMinimumRents</Role>
      <ShortName>Future Minimum Rents</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>1100 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureEarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>1110 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>1120 - Disclosure - Concentrations of Credit Risk</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureConcentrationsOfCreditRisk</Role>
      <ShortName>Concentrations of Credit Risk</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>1130 - Disclosure - Employee Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureEmployeeBenefitPlans</Role>
      <ShortName>Employee Benefit Plans</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>1140 - Disclosure - Equity Incentive Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureEquityIncentivePlan</Role>
      <ShortName>Equity Incentive Plan</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>1150 - Disclosure - Related-Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureRelatedPartyTransactions</Role>
      <ShortName>Related-Party Transactions</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>1160 - Disclosure - Selected Interim Financial Information (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureSelectedInterimFinancialInformation</Role>
      <ShortName>Selected Interim Financial Information (unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>1170 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>1180 - Disclosure - Schedule 2 - Valuation and Qualifying Accounts</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureValuationAndQualifyingAccounts</Role>
      <ShortName>Schedule 2 - Valuation and Qualifying Accounts</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>1190 - Disclosure - Schedule 3 - Real Estate and Accumulated Depreciation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.stagindustrial.com/role/DisclosureRealEstateAndAccumulatedDepreciation</Role>
      <ShortName>Schedule 3 - Real Estate and Accumulated Depreciation</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Process Flow-Through: 0010 - Statement - Consolidated and Combined Balance Sheets</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Apr. 19, 2011'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Apr. 19, 2011
STAG Predecessor Group'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2009
STAG Predecessor Group'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2008
STAG Predecessor Group'</Log>
    <Log type="Info">Process Flow-Through: 0015 - Statement - Consolidated and Combined Balance Sheets (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 0020 - Statement - Consolidated and Combined Statements of Operations</Log>
    <Log type="Info">Process Flow-Through: 0040 - Statement - Consolidated and Combined Statements of Cash Flows</Log>
  </Logs>
  <InputFiles>
    <File>stag-20111231.xml</File>
    <File>stag-20111231.xsd</File>
    <File>stag-20111231_cal.xml</File>
    <File>stag-20111231_def.xml</File>
    <File>stag-20111231_lab.xml</File>
    <File>stag-20111231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
