<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>185</ContextCount>
  <ElementCount>335</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>67</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>13</UnitCount>
  <MyReports>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001501 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - Condensed Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/CondensedConsolidatedStatementsOfOperations</Role>
      <ShortName>Condensed Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - Condensed Consolidated Statements of Comprehensive Loss</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/CondensedConsolidatedStatementsOfComprehensiveLoss</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Loss</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1004000 - Statement - Consolidated Statements of Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ConsolidatedStatementsOfEquity</Role>
      <ShortName>Consolidated Statements of Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1005000 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Nature of Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/NatureOfBusiness</Role>
      <ShortName>Nature of Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Summary of Significant Accounting Policies and Basis of Presentations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SummaryOfSignificantAccountingPoliciesAndBasisOfPresentations</Role>
      <ShortName>Summary of Significant Accounting Policies and Basis of Presentations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2103100 - Disclosure - Real Estate</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/RealEstate</Role>
      <ShortName>Real Estate</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Lease Accounting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/LeaseAccounting</Role>
      <ShortName>Lease Accounting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Mortgage Notes Payable</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.washreit.com/role/MortgageNotesPayable</Role>
      <ShortName>Mortgage Notes Payable</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Unsecured Line of Credit Payable</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/UnsecuredLineOfCreditPayable</Role>
      <ShortName>Unsecured Line of Credit Payable</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Derivative Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/DerivativeInstruments</Role>
      <ShortName>Derivative Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Fair Value Disclosures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/FairValueDisclosures</Role>
      <ShortName>Fair Value Disclosures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Stock Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/StockBasedCompensation</Role>
      <ShortName>Stock Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Earnings per Common Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/EarningsPerCommonShare</Role>
      <ShortName>Earnings per Common Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ShareholdersEquity</Role>
      <ShortName>Shareholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Subsequent Event</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SubsequentEvent</Role>
      <ShortName>Subsequent Event</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - Summary of Significant Accounting Policies and Basis of Presentations (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SummaryOfSignificantAccountingPoliciesAndBasisOfPresentationsPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies and Basis of Presentations (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.washreit.com/role/SummaryOfSignificantAccountingPoliciesAndBasisOfPresentations</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Real Estate (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/RealEstateTables</Role>
      <ShortName>Real Estate (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/RealEstate</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - Lease Accounting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/LeaseAccountingTables</Role>
      <ShortName>Lease Accounting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/LeaseAccounting</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Unsecured Line of Credit Payable (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/UnsecuredLineOfCreditPayableTables</Role>
      <ShortName>Unsecured Line of Credit Payable (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/UnsecuredLineOfCreditPayable</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Derivative Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/DerivativeInstrumentsTables</Role>
      <ShortName>Derivative Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/DerivativeInstruments</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Fair Value Disclosures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/FairValueDisclosuresTables</Role>
      <ShortName>Fair Value Disclosures (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/FairValueDisclosures</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Earnings per Common Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/EarningsPerCommonShareTables</Role>
      <ShortName>Earnings per Common Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/EarningsPerCommonShare</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2311301 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/SegmentInformation</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - Shareholders' Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ShareholdersEquityTables</Role>
      <ShortName>Shareholders' Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.washreit.com/role/ShareholdersEquity</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2401401 - Disclosure - Nature of Business - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/NatureOfBusinessNarrativeDetails</Role>
      <ShortName>Nature of Business - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2403402 - Disclosure - Real Estate - Development/Redevelopment Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/RealEstateDevelopmentRedevelopmentNarrativeDetails</Role>
      <ShortName>Real Estate - Development/Redevelopment Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2403403 - Disclosure - Real Estate - Properties Sold and Held for Sale (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/RealEstatePropertiesSoldAndHeldForSaleDetails</Role>
      <ShortName>Real Estate - Properties Sold and Held for Sale (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2403404 - Disclosure - Real Estate - Properties Sold and Held for Sale Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/RealEstatePropertiesSoldAndHeldForSaleNarrativeDetails</Role>
      <ShortName>Real Estate - Properties Sold and Held for Sale Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2403405 - Disclosure - Real Estate - Discontinued Operations Results of Retail Portfolio (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/RealEstateDiscontinuedOperationsResultsOfRetailPortfolioDetails</Role>
      <ShortName>Real Estate - Discontinued Operations Results of Retail Portfolio (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Lease Accounting - Leasing as a Lessor Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/LeaseAccountingLeasingAsLessorNarrativeDetails</Role>
      <ShortName>Lease Accounting - Leasing as a Lessor Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2404403 - Disclosure - Lease Accounting - Schedule of Future Minimum Rental Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/LeaseAccountingScheduleOfFutureMinimumRentalIncomeDetails</Role>
      <ShortName>Lease Accounting - Schedule of Future Minimum Rental Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2404404 - Disclosure - Lease Accounting - Leasing as a Lessee Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/LeaseAccountingLeasingAsLesseeNarrativeDetails</Role>
      <ShortName>Lease Accounting - Leasing as a Lessee Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2404405 - Disclosure - Lease Accounting - Schedule of Obligations for Future Minimum Payments on Operating Ground Lease (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/LeaseAccountingScheduleOfObligationsForFutureMinimumPaymentsOnOperatingGroundLeaseDetails</Role>
      <ShortName>Lease Accounting - Schedule of Obligations for Future Minimum Payments on Operating Ground Lease (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2405401 - Disclosure - Mortgage Notes Payable (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.washreit.com/role/MortgageNotesPayableDetails</Role>
      <ShortName>Mortgage Notes Payable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.washreit.com/role/MortgageNotesPayable</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Unsecured Line of Credit Payable - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/UnsecuredLineOfCreditPayableNarrativeDetails</Role>
      <ShortName>Unsecured Line of Credit Payable - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Unsecured Line of Credit Payable - Revolving Credit Facility Unused and Available Credit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/UnsecuredLineOfCreditPayableRevolvingCreditFacilityUnusedAndAvailableCreditDetails</Role>
      <ShortName>Unsecured Line of Credit Payable - Revolving Credit Facility Unused and Available Credit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2406404 - Disclosure - Unsecured Line of Credit Payable - Revolving Credit Facility Borrowings and Repayments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/UnsecuredLineOfCreditPayableRevolvingCreditFacilityBorrowingsAndRepaymentsDetails</Role>
      <ShortName>Unsecured Line of Credit Payable - Revolving Credit Facility Borrowings and Repayments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Derivative Instruments - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/DerivativeInstrumentsNarrativeDetails</Role>
      <ShortName>Derivative Instruments - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Derivative Instruments - Fair Value of Interest Rate Swaps (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/DerivativeInstrumentsFairValueOfInterestRateSwapsDetails</Role>
      <ShortName>Derivative Instruments - Fair Value of Interest Rate Swaps (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2407404 - Disclosure - Derivative Instruments - Net Unrealized Gains or Losses on Derivatives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/DerivativeInstrumentsNetUnrealizedGainsOrLossesOnDerivativesDetails</Role>
      <ShortName>Derivative Instruments - Net Unrealized Gains or Losses on Derivatives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Fair Value Disclosures - Assets and Liabilities Measured at Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/FairValueDisclosuresAssetsAndLiabilitiesMeasuredAtFairValueDetails</Role>
      <ShortName>Fair Value Disclosures - Assets and Liabilities Measured at Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Fair Value Disclosures - Financial Assets and Liabilities Not Measured at Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/FairValueDisclosuresFinancialAssetsAndLiabilitiesNotMeasuredAtFairValueDetails</Role>
      <ShortName>Fair Value Disclosures - Financial Assets and Liabilities Not Measured at Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2409401 - Disclosure - Stock Based Compensation - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/StockBasedCompensationNarrativeDetails</Role>
      <ShortName>Stock Based Compensation - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Stock Based Compensation - Officer LTIP (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/StockBasedCompensationOfficerLtipDetails</Role>
      <ShortName>Stock Based Compensation - Officer LTIP (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Earnings per Common Share - Computation of Basic and Diluted Earnings per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/EarningsPerCommonShareComputationOfBasicAndDilutedEarningsPerShareDetails</Role>
      <ShortName>Earnings per Common Share - Computation of Basic and Diluted Earnings per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2411402 - Disclosure - Segment Information - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SegmentInformationNarrativeDetails</Role>
      <ShortName>Segment Information - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2411403 - Disclosure - Segment Information - Financial Information by Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SegmentInformationFinancialInformationBySegmentDetails</Role>
      <ShortName>Segment Information - Financial Information by Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Shareholders' Equity - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ShareholdersEquityNarrativeDetails</Role>
      <ShortName>Shareholders' Equity - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2412403 - Disclosure - Shareholders' Equity - Dividend Reinvestment Program Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/ShareholdersEquityDividendReinvestmentProgramActivityDetails</Role>
      <ShortName>Shareholders' Equity - Dividend Reinvestment Program Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2413401 - Disclosure - Subsequent Event (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.washreit.com/role/SubsequentEventDetails</Role>
      <ShortName>Subsequent Event (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.washreit.com/role/SubsequentEvent</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="wre-331202010xq.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9999.htm</HtmlFileName>
      <LongName>Uncategorized Items - wre-331202010xq.htm</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/role/uncategorizedFacts</Role>
      <ShortName>Uncategorized Items - wre-331202010xq.htm</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" original="wre-331202010xq.htm">wre-331202010xq.htm</File>
    <File>wre-03312020exhibit311.htm</File>
    <File>wre-03312020exhibit312.htm</File>
    <File>wre-03312020exhibit32.htm</File>
    <File>wre-03312020xexhibit313.htm</File>
    <File>wre-20200331.xsd</File>
    <File>wre-20200331_cal.xml</File>
    <File>wre-20200331_def.xml</File>
    <File>wre-20200331_lab.xml</File>
    <File>wre-20200331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>chart-6396fa3291215e7f86f.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
