<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>148</ContextCount>
  <ElementCount>373</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>58</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>19</UnitCount>
  <MyReports>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001501 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedStatementsOfOperations</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - CONSOLIDATED STATEMENTS OF EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedStatementsOfEquity</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1003501 - Statement - CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedStatementsOfEquityParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1004000 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1007000 - Statement - CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedStatementsOfCapitalKilroyRealtyLP</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>1007501 - Statement - CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ConsolidatedStatementsOfCapitalKilroyRealtyLPParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CAPITAL (KILROY REALTY, L.P.) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Organization, Ownership and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/OrganizationOwnershipAndBasisOfPresentation</Role>
      <ShortName>Organization, Ownership and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Prepaid Expenses and Other Assets, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/PrepaidExpensesAndOtherAssetsNet</Role>
      <ShortName>Prepaid Expenses and Other Assets, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Secured and Unsecured Debt of the Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SecuredAndUnsecuredDebtOfOperatingPartnership</Role>
      <ShortName>Secured and Unsecured Debt of the Operating Partnership</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Stockholders' Equity of the Company</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/StockholdersEquityOfCompany</Role>
      <ShortName>Stockholders' Equity of the Company</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Noncontrolling Interests on the Company's Consolidated Financial Statements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NoncontrollingInterestsOnCompanysConsolidatedFinancialStatements</Role>
      <ShortName>Noncontrolling Interests on the Company's Consolidated Financial Statements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Partners' Capital of the Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/PartnersCapitalOfOperatingPartnership</Role>
      <ShortName>Partners' Capital of the Operating Partnership</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Share-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ShareBasedCompensation</Role>
      <ShortName>Share-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Rental Income and Future Minimum Rent</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/RentalIncomeAndFutureMinimumRent</Role>
      <ShortName>Rental Income and Future Minimum Rent</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Fair Value Measurements and Disclosures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/FairValueMeasurementsAndDisclosures</Role>
      <ShortName>Fair Value Measurements and Disclosures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Net Income Available to Common Stockholders Per Share of the Company</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NetIncomeAvailableToCommonStockholdersPerShareOfCompany</Role>
      <ShortName>Net Income Available to Common Stockholders Per Share of the Company</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Net Income Available to Common Unitholders Per Unit of the Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NetIncomeAvailableToCommonUnitholdersPerUnitOfOperatingPartnership</Role>
      <ShortName>Net Income Available to Common Unitholders Per Unit of the Operating Partnership</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2115100 - Disclosure - Supplemental Cash Flow Information of the Company</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfCompany</Role>
      <ShortName>Supplemental Cash Flow Information of the Company</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Supplemental Cash Flow Information of the Operating Partnership</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfOperatingPartnership</Role>
      <ShortName>Supplemental Cash Flow Information of the Operating Partnership</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2117100 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - Organization, Ownership and Basis of Presentation (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/OrganizationOwnershipAndBasisOfPresentationPolicies</Role>
      <ShortName>Organization, Ownership and Basis of Presentation (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2301302 - Disclosure - Organization, Ownership and Basis of Presentation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/OrganizationOwnershipAndBasisOfPresentationTables</Role>
      <ShortName>Organization, Ownership and Basis of Presentation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/OrganizationOwnershipAndBasisOfPresentation</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - Prepaid Expenses and Other Assets, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/PrepaidExpensesAndOtherAssetsNetTables</Role>
      <ShortName>Prepaid Expenses and Other Assets, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/PrepaidExpensesAndOtherAssetsNet</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - Secured and Unsecured Debt of the Operating Partnership (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SecuredAndUnsecuredDebtOfOperatingPartnershipTables</Role>
      <ShortName>Secured and Unsecured Debt of the Operating Partnership (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/SecuredAndUnsecuredDebtOfOperatingPartnership</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Stockholders' Equity of the Company (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/StockholdersEquityOfCompanyTables</Role>
      <ShortName>Stockholders' Equity of the Company (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/StockholdersEquityOfCompany</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Partners' Capital of the Operating Partnership (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/PartnersCapitalOfOperatingPartnershipTables</Role>
      <ShortName>Partners' Capital of the Operating Partnership (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/PartnersCapitalOfOperatingPartnership</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - Share-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ShareBasedCompensationTables</Role>
      <ShortName>Share-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/ShareBasedCompensation</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Rental Income and Future Minimum Rent (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/RentalIncomeAndFutureMinimumRentTables</Role>
      <ShortName>Rental Income and Future Minimum Rent (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/RentalIncomeAndFutureMinimumRent</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2311301 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/CommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/CommitmentsAndContingencies</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - Fair Value Measurements and Disclosures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/FairValueMeasurementsAndDisclosuresTables</Role>
      <ShortName>Fair Value Measurements and Disclosures (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/FairValueMeasurementsAndDisclosures</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Net Income Available to Common Stockholders Per Share of the Company (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NetIncomeAvailableToCommonStockholdersPerShareOfCompanyTables</Role>
      <ShortName>Net Income Available to Common Stockholders Per Share of the Company (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/NetIncomeAvailableToCommonStockholdersPerShareOfCompany</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NetIncomeAvailableToCommonUnitholdersPerUnitOfOperatingPartnershipTables</Role>
      <ShortName>Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/NetIncomeAvailableToCommonUnitholdersPerUnitOfOperatingPartnership</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2315301 - Disclosure - Supplemental Cash Flow Information of the Company (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfCompanyTables</Role>
      <ShortName>Supplemental Cash Flow Information of the Company (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfCompany</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - Supplemental Cash Flow Information of the Operating Partnership (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfOperatingPartnershipTables</Role>
      <ShortName>Supplemental Cash Flow Information of the Operating Partnership (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfOperatingPartnership</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2401403 - Disclosure - Organization, Ownership and Basis of Presentation - Operating Properties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/OrganizationOwnershipAndBasisOfPresentationOperatingPropertiesDetails</Role>
      <ShortName>Organization, Ownership and Basis of Presentation - Operating Properties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2401404 - Disclosure - Organization, Ownership and Basis of Presentation - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/OrganizationOwnershipAndBasisOfPresentationNarrativeDetails</Role>
      <ShortName>Organization, Ownership and Basis of Presentation - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/OrganizationOwnershipAndBasisOfPresentationTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Prepaid Expenses and Other Assets, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/PrepaidExpensesAndOtherAssetsNetDetails</Role>
      <ShortName>Prepaid Expenses and Other Assets, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/PrepaidExpensesAndOtherAssetsNetTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Secured and Unsecured Debt of the Operating Partnership - Unsecured Revolving Credit Facility and Term Loan Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SecuredAndUnsecuredDebtOfOperatingPartnershipUnsecuredRevolvingCreditFacilityAndTermLoanFacilityDetails</Role>
      <ShortName>Secured and Unsecured Debt of the Operating Partnership - Unsecured Revolving Credit Facility and Term Loan Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2405403 - Disclosure - Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SecuredAndUnsecuredDebtOfOperatingPartnershipDebtMaturitiesDetails</Role>
      <ShortName>Secured and Unsecured Debt of the Operating Partnership - Debt Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2405404 - Disclosure - Secured and Unsecured Debt of the Operating Partnership - Capitalized Interest and Loan Fees (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SecuredAndUnsecuredDebtOfOperatingPartnershipCapitalizedInterestAndLoanFeesDetails</Role>
      <ShortName>Secured and Unsecured Debt of the Operating Partnership - Capitalized Interest and Loan Fees (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Stockholders' Equity of the Company (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/StockholdersEquityOfCompanyDetails</Role>
      <ShortName>Stockholders' Equity of the Company (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/StockholdersEquityOfCompanyTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2407401 - Disclosure - Noncontrolling Interests on the Company's Consolidated Financial Statements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NoncontrollingInterestsOnCompanysConsolidatedFinancialStatementsDetails</Role>
      <ShortName>Noncontrolling Interests on the Company's Consolidated Financial Statements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/NoncontrollingInterestsOnCompanysConsolidatedFinancialStatements</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Partners' Capital of the Operating Partnership (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/PartnersCapitalOfOperatingPartnershipDetails</Role>
      <ShortName>Partners' Capital of the Operating Partnership (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/PartnersCapitalOfOperatingPartnershipTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Share-Based Compensation - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ShareBasedCompensationNarrativeDetails</Role>
      <ShortName>Share-Based Compensation - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2409403 - Disclosure - Share-Based Compensation - Fair Value Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/ShareBasedCompensationFairValueAssumptionsDetails</Role>
      <ShortName>Share-Based Compensation - Fair Value Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Rental Income and Future Minimum Rent - Rental income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/RentalIncomeAndFutureMinimumRentRentalIncomeDetails</Role>
      <ShortName>Rental Income and Future Minimum Rent - Rental income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2410403 - Disclosure - Rental Income and Future Minimum Rent - Future Contractual Minimum Rent (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/RentalIncomeAndFutureMinimumRentFutureContractualMinimumRentDetails</Role>
      <ShortName>Rental Income and Future Minimum Rent - Future Contractual Minimum Rent (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2411402 - Disclosure - Commitments and Contingencies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/CommitmentsAndContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2411403 - Disclosure - Commitments and Contingencies - Minimum Commitment Under Ground Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/CommitmentsAndContingenciesMinimumCommitmentUnderGroundLeasesDetails</Role>
      <ShortName>Commitments and Contingencies - Minimum Commitment Under Ground Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Fair Value Measurements and Disclosures - Assets and Liabilities Reported at Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/FairValueMeasurementsAndDisclosuresAssetsAndLiabilitiesReportedAtFairValueDetails</Role>
      <ShortName>Fair Value Measurements and Disclosures - Assets and Liabilities Reported at Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2412403 - Disclosure - Fair Value Measurements and Disclosures - Financial Instruments Disclosed at Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/FairValueMeasurementsAndDisclosuresFinancialInstrumentsDisclosedAtFairValueDetails</Role>
      <ShortName>Fair Value Measurements and Disclosures - Financial Instruments Disclosed at Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Net Income Available to Common Stockholders Per Share of the Company (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NetIncomeAvailableToCommonStockholdersPerShareOfCompanyDetails</Role>
      <ShortName>Net Income Available to Common Stockholders Per Share of the Company (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/NetIncomeAvailableToCommonStockholdersPerShareOfCompanyTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/NetIncomeAvailableToCommonUnitholdersPerUnitOfOperatingPartnershipDetails</Role>
      <ShortName>Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/NetIncomeAvailableToCommonUnitholdersPerUnitOfOperatingPartnershipTables</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2415402 - Disclosure - Supplemental Cash Flow Information of the Company - Supplemental Cash Flow (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfCompanySupplementalCashFlowDetails</Role>
      <ShortName>Supplemental Cash Flow Information of the Company - Supplemental Cash Flow (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2415403 - Disclosure - Supplemental Cash Flow Information of the Company - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfCompanyReconciliationOfCashAndCashEquivalentsAndRestrictedCashDetails</Role>
      <ShortName>Supplemental Cash Flow Information of the Company - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - Supplemental Cash Flow Information of the Operating Partnership - Supplemental Cash Flow (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfOperatingPartnershipSupplementalCashFlowDetails</Role>
      <ShortName>Supplemental Cash Flow Information of the Operating Partnership - Supplemental Cash Flow (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2416403 - Disclosure - Supplemental Cash Flow Information of the Operating Partnership - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SupplementalCashFlowInformationOfOperatingPartnershipReconciliationOfCashAndCashEquivalentsAndRestrictedCashDetails</Role>
      <ShortName>Supplemental Cash Flow Information of the Operating Partnership - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2417401 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://kilroyrealty.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://kilroyrealty.com/role/SubsequentEvents</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="a33120krckrlp10-q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9999.htm</HtmlFileName>
      <LongName>Uncategorized Items - a33120krckrlp10-q.htm</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/role/uncategorizedFacts</Role>
      <ShortName>Uncategorized Items - a33120krckrlp10-q.htm</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>63</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="a33120krckrlp10-q.htm">a33120krckrlp10-q.htm</File>
    <File>exhibit311.htm</File>
    <File>exhibit312.htm</File>
    <File>exhibit313.htm</File>
    <File>exhibit314.htm</File>
    <File>exhibit321.htm</File>
    <File>exhibit322.htm</File>
    <File>exhibit323.htm</File>
    <File>exhibit324.htm</File>
    <File>krc-20200331.xsd</File>
    <File>krc-20200331_cal.xml</File>
    <File>krc-20200331_def.xml</File>
    <File>krc-20200331_lab.xml</File>
    <File>krc-20200331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/stpr/2018-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
