3.26.1 html 287 407 1 false 114 0 false 14 false false R1.htm 0000001 - Document - Cover Page Sheet http://www.kbsreitiii.com/role/CoverPage Cover Page Cover 1 false false R2.htm 0000002 - Document - Audit Information Sheet http://www.kbsreitiii.com/role/AuditInformation Audit Information Cover 2 false false R3.htm 9952151 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://www.kbsreitiii.com/role/CONSOLIDATEDBALANCESHEETS CONSOLIDATED BALANCE SHEETS Statements 3 false false R4.htm 9952152 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.kbsreitiii.com/role/CONSOLIDATEDBALANCESHEETSParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 4 false false R5.htm 9952153 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS Sheet http://www.kbsreitiii.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS CONSOLIDATED STATEMENTS OF OPERATIONS Statements 5 false false R6.htm 9952154 - Statement - CONSOLIDATED STATEMENTS OF EQUITY Sheet http://www.kbsreitiii.com/role/CONSOLIDATEDSTATEMENTSOFEQUITY CONSOLIDATED STATEMENTS OF EQUITY Statements 6 false false R7.htm 9952155 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.kbsreitiii.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 7 false false R8.htm 9952156 - Disclosure - ORGANIZATION Sheet http://www.kbsreitiii.com/role/ORGANIZATION ORGANIZATION Notes 8 false false R9.htm 9952157 - Disclosure - GOING CONCERN Sheet http://www.kbsreitiii.com/role/GOINGCONCERN GOING CONCERN Notes 9 false false R10.htm 9952158 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Sheet http://www.kbsreitiii.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Notes 10 false false R11.htm 9952159 - Disclosure - REAL ESTATE Sheet http://www.kbsreitiii.com/role/REALESTATE REAL ESTATE Notes 11 false false R12.htm 9952160 - Disclosure - REAL ESTATE SALES Sheet http://www.kbsreitiii.com/role/REALESTATESALES REAL ESTATE SALES Notes 12 false false R13.htm 9952161 - Disclosure - TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES Sheet http://www.kbsreitiii.com/role/TENANTORIGINATIONANDABSORPTIONCOSTSABOVEMARKETLEASEASSETSANDBELOWMARKETLEASELIABILITIES TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES Notes 13 false false R14.htm 9952162 - Disclosure - REAL ESTATE EQUITY SECURITIES Sheet http://www.kbsreitiii.com/role/REALESTATEEQUITYSECURITIES REAL ESTATE EQUITY SECURITIES Notes 14 false false R15.htm 9952163 - Disclosure - NOTES PAYABLE Notes http://www.kbsreitiii.com/role/NOTESPAYABLE NOTES PAYABLE Notes 15 false false R16.htm 9952164 - Disclosure - DERIVATIVE INSTRUMENTS Sheet http://www.kbsreitiii.com/role/DERIVATIVEINSTRUMENTS DERIVATIVE INSTRUMENTS Notes 16 false false R17.htm 9952165 - Disclosure - FAIR VALUE DISCLOSURES Sheet http://www.kbsreitiii.com/role/FAIRVALUEDISCLOSURES FAIR VALUE DISCLOSURES Notes 17 false false R18.htm 9952166 - Disclosure - RELATED PARTY TRANSACTIONS Sheet http://www.kbsreitiii.com/role/RELATEDPARTYTRANSACTIONS RELATED PARTY TRANSACTIONS Notes 18 false false R19.htm 9952167 - Disclosure - SEGMENT INFORMATION Sheet http://www.kbsreitiii.com/role/SEGMENTINFORMATION SEGMENT INFORMATION Notes 19 false false R20.htm 9952168 - Disclosure - COMMITMENTS AND CONTINGENCIES Sheet http://www.kbsreitiii.com/role/COMMITMENTSANDCONTINGENCIES COMMITMENTS AND CONTINGENCIES Notes 20 false false R21.htm 9952169 - Disclosure - SUBSEQUENT EVENTS Sheet http://www.kbsreitiii.com/role/SUBSEQUENTEVENTS SUBSEQUENT EVENTS Notes 21 false false R22.htm 9952170 - Disclosure - SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION AND AMORTIZATION Sheet http://www.kbsreitiii.com/role/SCHEDULEIIIREALESTATEASSETSANDACCUMULATEDDEPRECIATIONANDAMORTIZATION SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION AND AMORTIZATION Notes 22 false false R23.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 23 false false R24.htm 995447 - Disclosure - Insider Trading Policies and Procedures Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc Insider Trading Policies and Procedures Notes 24 false false R25.htm 995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure Sheet http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure Cybersecurity Risk Management and Strategy Disclosure Notes 25 false false R26.htm 9955511 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Sheet http://www.kbsreitiii.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Policies 26 false false R27.htm 9955512 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Sheet http://www.kbsreitiii.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Tables http://www.kbsreitiii.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES 27 false false R28.htm 9955513 - Disclosure - REAL ESTATE (Tables) Sheet http://www.kbsreitiii.com/role/REALESTATETables REAL ESTATE (Tables) Tables http://www.kbsreitiii.com/role/REALESTATE 28 false false R29.htm 9955514 - Disclosure - REAL ESTATE SALES (Tables) Sheet http://www.kbsreitiii.com/role/REALESTATESALESTables REAL ESTATE SALES (Tables) Tables http://www.kbsreitiii.com/role/REALESTATESALES 29 false false R30.htm 9955515 - Disclosure - TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Tables) Sheet http://www.kbsreitiii.com/role/TENANTORIGINATIONANDABSORPTIONCOSTSABOVEMARKETLEASEASSETSANDBELOWMARKETLEASELIABILITIESTables TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES (Tables) Tables http://www.kbsreitiii.com/role/TENANTORIGINATIONANDABSORPTIONCOSTSABOVEMARKETLEASEASSETSANDBELOWMARKETLEASELIABILITIES 30 false false R31.htm 9955516 - Disclosure - NOTES PAYABLE (Tables) Notes http://www.kbsreitiii.com/role/NOTESPAYABLETables NOTES PAYABLE (Tables) Tables http://www.kbsreitiii.com/role/NOTESPAYABLE 31 false false R32.htm 9955517 - Disclosure - DERIVATIVE INSTRUMENTS (Tables) Sheet http://www.kbsreitiii.com/role/DERIVATIVEINSTRUMENTSTables DERIVATIVE INSTRUMENTS (Tables) Tables http://www.kbsreitiii.com/role/DERIVATIVEINSTRUMENTS 32 false false R33.htm 9955518 - Disclosure - FAIR VALUE DISCLOSURES (Tables) Sheet http://www.kbsreitiii.com/role/FAIRVALUEDISCLOSURESTables FAIR VALUE DISCLOSURES (Tables) Tables http://www.kbsreitiii.com/role/FAIRVALUEDISCLOSURES 33 false false R34.htm 9955519 - Disclosure - RELATED PARTY TRANSACTIONS (Tables) Sheet http://www.kbsreitiii.com/role/RELATEDPARTYTRANSACTIONSTables RELATED PARTY TRANSACTIONS (Tables) Tables http://www.kbsreitiii.com/role/RELATEDPARTYTRANSACTIONS 34 false false R35.htm 9955520 - Disclosure - ORGANIZATION (Details) Sheet http://www.kbsreitiii.com/role/ORGANIZATIONDetails ORGANIZATION (Details) Details http://www.kbsreitiii.com/role/ORGANIZATION 35 false false R36.htm 9955521 - Disclosure - GOING CONCERN (Details) Sheet http://www.kbsreitiii.com/role/GOINGCONCERNDetails GOING CONCERN (Details) Details http://www.kbsreitiii.com/role/GOINGCONCERN 36 false false R37.htm 9955522 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) Sheet http://www.kbsreitiii.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAdditionalInformationDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) Details 37 false false R38.htm 9955523 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Useful Life (Details) Sheet http://www.kbsreitiii.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofUsefulLifeDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Useful Life (Details) Details 38 false false R39.htm 9955524 - Disclosure - REAL ESTATE - Additional Information (Details) Sheet http://www.kbsreitiii.com/role/REALESTATEAdditionalInformationDetails REAL ESTATE - Additional Information (Details) Details 39 false false R40.htm 9955525 - Disclosure - REAL ESTATE - Schedule of Real Estate Investments (Details) Sheet http://www.kbsreitiii.com/role/REALESTATEScheduleofRealEstateInvestmentsDetails REAL ESTATE - Schedule of Real Estate Investments (Details) Details 40 false false R41.htm 9955526 - Disclosure - REAL ESTATE - Schedule of Concentration of Risk, by Assets (Details) Sheet http://www.kbsreitiii.com/role/REALESTATEScheduleofConcentrationofRiskbyAssetsDetails REAL ESTATE - Schedule of Concentration of Risk, by Assets (Details) Details 41 false false R42.htm 9955527 - Disclosure - REAL ESTATE - Schedule of Future Minimum Rental Income for Company's Properties (Details) Sheet http://www.kbsreitiii.com/role/REALESTATEScheduleofFutureMinimumRentalIncomeforCompanysPropertiesDetails REAL ESTATE - Schedule of Future Minimum Rental Income for Company's Properties (Details) Details 42 false false R43.htm 9955528 - Disclosure - REAL ESTATE - Schedule of Revenue and Expenses of Real Estate Held-for-Sale (Details) Sheet http://www.kbsreitiii.com/role/REALESTATEScheduleofRevenueandExpensesofRealEstateHeldforSaleDetails REAL ESTATE - Schedule of Revenue and Expenses of Real Estate Held-for-Sale (Details) Details 43 false false R44.htm 9955529 - Disclosure - REAL ESTATE SALES - Additional Information (Details) Sheet http://www.kbsreitiii.com/role/REALESTATESALESAdditionalInformationDetails REAL ESTATE SALES - Additional Information (Details) Details 44 false false R45.htm 9955530 - Disclosure - REAL ESTATE SALES - Schedule of Revenue and Expenses of Real Estate Held-for-Sale (Details) Sheet http://www.kbsreitiii.com/role/REALESTATESALESScheduleofRevenueandExpensesofRealEstateHeldforSaleDetails REAL ESTATE SALES - Schedule of Revenue and Expenses of Real Estate Held-for-Sale (Details) Details 45 false false R46.htm 9955531 - Disclosure - REAL ESTATE SALES - Schedule of Major Components of Real Estate Held for Sale and Liabilities Related to Real Estate Held for Sale (Details) Sheet http://www.kbsreitiii.com/role/REALESTATESALESScheduleofMajorComponentsofRealEstateHeldforSaleandLiabilitiesRelatedtoRealEstateHeldforSaleDetails REAL ESTATE SALES - Schedule of Major Components of Real Estate Held for Sale and Liabilities Related to Real Estate Held for Sale (Details) Details 46 false false R47.htm 9955532 - Disclosure - TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES - Schedule of Amortization of Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities (Details) Sheet http://www.kbsreitiii.com/role/TENANTORIGINATIONANDABSORPTIONCOSTSABOVEMARKETLEASEASSETSANDBELOWMARKETLEASELIABILITIESScheduleofAmortizationofTenantOriginationandAbsorptionCostsAboveMarketLeaseAssetsandBelowMarketLeaseLiabilitiesDetails TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES - Schedule of Amortization of Tenant Origination and Absorption Costs, Above-Market Lease Assets and Below-Market Lease Liabilities (Details) Details 47 false false R48.htm 9955533 - Disclosure - TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES - Schedule of Remaining Unamortized Balance (Details) Sheet http://www.kbsreitiii.com/role/TENANTORIGINATIONANDABSORPTIONCOSTSABOVEMARKETLEASEASSETSANDBELOWMARKETLEASELIABILITIESScheduleofRemainingUnamortizedBalanceDetails TENANT ORIGINATION AND ABSORPTION COSTS, ABOVE-MARKET LEASE ASSETS AND BELOW-MARKET LEASE LIABILITIES - Schedule of Remaining Unamortized Balance (Details) Details 48 false false R49.htm 9955534 - Disclosure - REAL ESTATE EQUITY SECURITIES (Details) Sheet http://www.kbsreitiii.com/role/REALESTATEEQUITYSECURITIESDetails REAL ESTATE EQUITY SECURITIES (Details) Details http://www.kbsreitiii.com/role/REALESTATEEQUITYSECURITIES 49 false false R50.htm 9955535 - Disclosure - NOTES PAYABLE - Schedule of Long-term Debt Instruments (Details) Notes http://www.kbsreitiii.com/role/NOTESPAYABLEScheduleofLongtermDebtInstrumentsDetails NOTES PAYABLE - Schedule of Long-term Debt Instruments (Details) Details 50 false false R51.htm 9955536 - Disclosure - NOTES PAYABLE - Additional Information (Details) Notes http://www.kbsreitiii.com/role/NOTESPAYABLEAdditionalInformationDetails NOTES PAYABLE - Additional Information (Details) Details 51 false false R52.htm 9955537 - Disclosure - NOTES PAYABLE - Schedule of Maturities Including Principal Amortization Payments, for All Notes Payable Outstanding (Details) Notes http://www.kbsreitiii.com/role/NOTESPAYABLEScheduleofMaturitiesIncludingPrincipalAmortizationPaymentsforAllNotesPayableOutstandingDetails NOTES PAYABLE - Schedule of Maturities Including Principal Amortization Payments, for All Notes Payable Outstanding (Details) Details 52 false false R53.htm 9955538 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Notional Amount and Other Information Related to the Interest Rate Swaps and Interest Rate Cap (Details) Sheet http://www.kbsreitiii.com/role/DERIVATIVEINSTRUMENTSScheduleofNotionalAmountandOtherInformationRelatedtotheInterestRateSwapsandInterestRateCapDetails DERIVATIVE INSTRUMENTS - Schedule of Notional Amount and Other Information Related to the Interest Rate Swaps and Interest Rate Cap (Details) Details 53 false false R54.htm 9955539 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Derivative Instruments as well as their Classification on the Consolidated Balance Sheets (Details) Sheet http://www.kbsreitiii.com/role/DERIVATIVEINSTRUMENTSScheduleofDerivativeInstrumentsaswellastheirClassificationontheConsolidatedBalanceSheetsDetails DERIVATIVE INSTRUMENTS - Schedule of Derivative Instruments as well as their Classification on the Consolidated Balance Sheets (Details) Details 54 false false R55.htm 9955540 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Derivative Instruments in Statement of Operations (Details) Sheet http://www.kbsreitiii.com/role/DERIVATIVEINSTRUMENTSScheduleofDerivativeInstrumentsinStatementofOperationsDetails DERIVATIVE INSTRUMENTS - Schedule of Derivative Instruments in Statement of Operations (Details) Details 55 false false R56.htm 9955541 - Disclosure - FAIR VALUE DISCLOSURES - Schedule of Face Value, Carrying Amounts and Fair Value (Details) Sheet http://www.kbsreitiii.com/role/FAIRVALUEDISCLOSURESScheduleofFaceValueCarryingAmountsandFairValueDetails FAIR VALUE DISCLOSURES - Schedule of Face Value, Carrying Amounts and Fair Value (Details) Details 56 false false R57.htm 9955542 - Disclosure - FAIR VALUE DISCLOSURES - Schedule of Asset at Fair Value (Details) Sheet http://www.kbsreitiii.com/role/FAIRVALUEDISCLOSURESScheduleofAssetatFairValueDetails FAIR VALUE DISCLOSURES - Schedule of Asset at Fair Value (Details) Details 57 false false R58.htm 9955543 - Disclosure - FAIR VALUE DISCLOSURES - Schedule of Fair Value, Assets Measured on Nonrecurring Basis (Details) Sheet http://www.kbsreitiii.com/role/FAIRVALUEDISCLOSURESScheduleofFairValueAssetsMeasuredonNonrecurringBasisDetails FAIR VALUE DISCLOSURES - Schedule of Fair Value, Assets Measured on Nonrecurring Basis (Details) Details 58 false false R59.htm 9955544 - Disclosure - FAIR VALUE DISCLOSURES - Additional Information (Details) Sheet http://www.kbsreitiii.com/role/FAIRVALUEDISCLOSURESAdditionalInformationDetails FAIR VALUE DISCLOSURES - Additional Information (Details) Details 59 false false R60.htm 9955545 - Disclosure - RELATED PARTY TRANSACTIONS - Schedule of Related Party Costs (Details) Sheet http://www.kbsreitiii.com/role/RELATEDPARTYTRANSACTIONSScheduleofRelatedPartyCostsDetails RELATED PARTY TRANSACTIONS - Schedule of Related Party Costs (Details) Details 60 false false R61.htm 9955546 - Disclosure - RELATED PARTY TRANSACTIONS - Additional Information (Details) Sheet http://www.kbsreitiii.com/role/RELATEDPARTYTRANSACTIONSAdditionalInformationDetails RELATED PARTY TRANSACTIONS - Additional Information (Details) Details 61 false false R62.htm 9955547 - Disclosure - SEGMENT INFORMATION (Details) Sheet http://www.kbsreitiii.com/role/SEGMENTINFORMATIONDetails SEGMENT INFORMATION (Details) Details http://www.kbsreitiii.com/role/SEGMENTINFORMATION 62 false false R63.htm 9955548 - Disclosure - COMMITMENTS AND CONTINGENCIES - (Details) Sheet http://www.kbsreitiii.com/role/COMMITMENTSANDCONTINGENCIESDetails COMMITMENTS AND CONTINGENCIES - (Details) Details http://www.kbsreitiii.com/role/COMMITMENTSANDCONTINGENCIES 63 false false R64.htm 9955549 - Disclosure - SUBSEQUENT EVENTS (Details) Sheet http://www.kbsreitiii.com/role/SUBSEQUENTEVENTSDetails SUBSEQUENT EVENTS (Details) Details http://www.kbsreitiii.com/role/SUBSEQUENTEVENTS 64 false false R65.htm 9955550 - Disclosure - SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION AND AMORTIZATION - Schedule of Assets, Depreciation and Amortization (Details) Sheet http://www.kbsreitiii.com/role/SCHEDULEIIIREALESTATEASSETSANDACCUMULATEDDEPRECIATIONANDAMORTIZATIONScheduleofAssetsDepreciationandAmortizationDetails SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION AND AMORTIZATION - Schedule of Assets, Depreciation and Amortization (Details) Details 65 false false R66.htm 9955551 - Disclosure - SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION AND AMORTIZATION - Reconciliation (Details) Sheet http://www.kbsreitiii.com/role/SCHEDULEIIIREALESTATEASSETSANDACCUMULATEDDEPRECIATIONANDAMORTIZATIONReconciliationDetails SCHEDULE III REAL ESTATE ASSETS AND ACCUMULATED DEPRECIATION AND AMORTIZATION - Reconciliation (Details) Details http://www.kbsreitiii.com/role/SCHEDULEIIIREALESTATEASSETSANDACCUMULATEDDEPRECIATIONANDAMORTIZATION 66 false false All Reports Book All Reports kbsriii-20251231.htm kbsriii-20251231.xsd kbsriii-20251231_cal.xml kbsriii-20251231_def.xml kbsriii-20251231_lab.xml kbsriii-20251231_pre.xml kbsriii-20251231_g1.jpg kbsriii-20251231_g2.jpg kbsriii-20251231_g3.jpg http://fasb.org/srt/2025 http://fasb.org/us-gaap/2025 http://xbrl.sec.gov/cyd/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 true true