| IRS990/AccountantCompileOrReviewInd | 0 | false |
| IRS990/AccountsPayableAccrExpnssGrp/BOYAmt | 0 | 907695 |
| IRS990/AccountsPayableAccrExpnssGrp/EOYAmt | 0 | 1715028 |
| IRS990/AccountsReceivableGrp/BOYAmt | 0 | 724287 |
| IRS990/AccountsReceivableGrp/EOYAmt | 0 | 311847 |
| IRS990/ActivitiesConductedPrtshpInd | 0 | false |
| IRS990/ActivityOrMissionDesc | 0 | TO PROVIDE THE OPPORTUNITY FOR CAPABLE STUDENTS TO EXCEL WITHIN A LIBERAL ARTS PROGRAM INFUSED WITH ARTISTIC AND ATHLETIC PURSUIT IN PREPARATION FOR A HIGHER EDUCATION. |
| IRS990/AdvertisingGrp/FundraisingAmt | 0 | 2063 |
| IRS990/AdvertisingGrp/ManagementAndGeneralAmt | 0 | 4814 |
| IRS990/AdvertisingGrp/ProgramServicesAmt | 0 | 61892 |
| IRS990/AdvertisingGrp/TotalAmt | 0 | 68769 |
| IRS990/AllOtherContributionsAmt | 0 | 6470 |
| IRS990/AllOtherExpensesGrp/ManagementAndGeneralAmt | 0 | 18646 |
| IRS990/AllOtherExpensesGrp/ProgramServicesAmt | 0 | 200596 |
| IRS990/AllOtherExpensesGrp/TotalAmt | 0 | 219242 |
| IRS990/AnnualDisclosureCoveredPrsnInd | 0 | true |
| IRS990/AuditCommitteeInd | 0 | true |
| IRS990/BackupWthldComplianceInd | 0 | true |
| IRS990/BenefitsToMembersGrp/TotalAmt | 0 | 0 |
| IRS990/BooksInCareOfDetail/PersonNm | 0 | KEVIN MCMENOMY |
| IRS990/BooksInCareOfDetail/PhoneNum | 0 | 6316861600 |
| IRS990/BooksInCareOfDetail/USAddress/AddressLine1Txt | 0 | 541 LONG BEACH ROAD |
| IRS990/BooksInCareOfDetail/USAddress/CityNm | 0 | ST JAMES |
| IRS990/BooksInCareOfDetail/USAddress/StateAbbreviationCd | 0 | NY |
| IRS990/BooksInCareOfDetail/USAddress/ZIPCd | 0 | 11780 |
| IRS990/BusinessRlnWith35CtrlEntInd | 0 | false |
| IRS990/BusinessRlnWithFamMemInd | 0 | false |
| IRS990/BusinessRlnWithOrgMemInd | 0 | false |
| IRS990/CashNonInterestBearingGrp/BOYAmt | 0 | 2174028 |
| IRS990/CashNonInterestBearingGrp/EOYAmt | 0 | 2803608 |
| IRS990/ChangeToOrgDocumentsInd | 0 | false |
| IRS990/CntrctRcvdGreaterThan100KCnt | 0 | 0 |
| IRS990/CollectionsOfArtInd | 0 | false |
| IRS990/CompCurrentOfcrDirectorsGrp/TotalAmt | 0 | 0 |
| IRS990/CompDisqualPersonsGrp/TotalAmt | 0 | 0 |
| IRS990/CompensationFromOtherSrcsInd | 0 | false |
| IRS990/CompensationProcessCEOInd | 0 | true |
| IRS990/CompensationProcessOtherInd | 0 | true |
| IRS990/ConferencesMeetingsGrp/TotalAmt | 0 | 0 |
| IRS990/ConflictOfInterestPolicyInd | 0 | true |
| IRS990/ConservationEasementsInd | 0 | false |
| IRS990/ConsolidatedAuditFinclStmtInd | 0 | false |
| IRS990/CreditCounselingInd | 0 | false |
| IRS990/CYBenefitsPaidToMembersAmt | 0 | 0 |
| IRS990/CYContributionsGrantsAmt | 0 | 6470 |
| IRS990/CYGrantsAndSimilarPaidAmt | 0 | 1033300 |
| IRS990/CYInvestmentIncomeAmt | 0 | 90106 |
| IRS990/CYOtherExpensesAmt | 0 | 3954732 |
| IRS990/CYOtherRevenueAmt | 0 | 174463 |
| IRS990/CYProgramServiceRevenueAmt | 0 | 6531690 |
| IRS990/CYRevenuesLessExpensesAmt | 0 | -966887 |
| IRS990/CYSalariesCompEmpBnftPaidAmt | 0 | 2781584 |
| IRS990/CYTotalExpensesAmt | 0 | 7769616 |
| IRS990/CYTotalFundraisingExpenseAmt | 0 | 171954 |
| IRS990/CYTotalProfFndrsngExpnsAmt | 0 | 0 |
| IRS990/CYTotalRevenueAmt | 0 | 6802729 |
| IRS990/DecisionsSubjectToApprovaInd | 0 | false |
| IRS990/DeductibleArtContributionInd | 0 | false |
| IRS990/DeductibleNonCashContriInd | 0 | false |
| IRS990/DeferredRevenueGrp/BOYAmt | 0 | 3885951 |
| IRS990/DeferredRevenueGrp/EOYAmt | 0 | 3471982 |
| IRS990/DelegationOfMgmtDutiesInd | 0 | false |
| IRS990/DepreciationDepletionGrp/FundraisingAmt | 0 | 7454 |
| IRS990/DepreciationDepletionGrp/ManagementAndGeneralAmt | 0 | 17392 |
| IRS990/DepreciationDepletionGrp/ProgramServicesAmt | 0 | 223616 |
| IRS990/DepreciationDepletionGrp/TotalAmt | 0 | 248462 |
| IRS990/Desc | 0 | SERVING 129 STUDENTS IN A COLLEGE PREPARATORY CURRICULUM OVER TWO SEMESTERS. FACULTY AND STAFF OF 59 FULL AND PART TIME. |
| IRS990/DescribedInSection501c3Ind | 0 | true |
| IRS990/DisregardedEntityInd | 0 | false |
| IRS990/DocumentRetentionPolicyInd | 0 | false |
| IRS990/DonorAdvisedFundInd | 0 | false |
| IRS990/DonorRestrictionNetAssetsGrp/BOYAmt | 0 | 830102 |
| IRS990/DonorRestrictionNetAssetsGrp/EOYAmt | 0 | 543181 |
| IRS990/DonorRstrOrQuasiEndowmentsInd | 0 | true |
| IRS990/ElectionOfBoardMembersInd | 0 | false |
| IRS990/EmployeeCnt | 0 | 59 |
| IRS990/EmploymentTaxReturnsFiledInd | 0 | true |
| IRS990/EngagedInExcessBenefitTransInd | 0 | false |
| IRS990/ExpenseAmt | 0 | 4657448 |
| IRS990/FamilyOrBusinessRlnInd | 0 | false |
| IRS990/FederalGrantAuditRequiredInd | 0 | false |
| IRS990/FeesForServicesAccountingGrp/ManagementAndGeneralAmt | 0 | 42760 |
| IRS990/FeesForServicesAccountingGrp/TotalAmt | 0 | 42760 |
| IRS990/FeesForServicesLegalGrp/ManagementAndGeneralAmt | 0 | 51275 |
| IRS990/FeesForServicesLegalGrp/TotalAmt | 0 | 51275 |
| IRS990/FeesForServicesLobbyingGrp/TotalAmt | 0 | 0 |
| IRS990/FeesForServicesManagementGrp/ManagementAndGeneralAmt | 0 | 571453 |
| IRS990/FeesForServicesManagementGrp/TotalAmt | 0 | 571453 |
| IRS990/FeesForServicesOtherGrp/ProgramServicesAmt | 0 | 569940 |
| IRS990/FeesForServicesOtherGrp/TotalAmt | 0 | 569940 |
| IRS990/FeesForServicesProfFundraising/TotalAmt | 0 | 0 |
| IRS990/FeesForSrvcInvstMgmntFeesGrp/TotalAmt | 0 | 0 |
| IRS990/ForeignActivitiesInd | 0 | false |
| IRS990/ForeignFinancialAccountInd | 0 | false |
| IRS990/ForeignGrantsGrp/TotalAmt | 0 | 0 |
| IRS990/ForeignOfficeInd | 0 | false |
| IRS990/Form1098CFiledInd | 0 | false |
| IRS990/Form8282FiledCnt | 0 | 0 |
| IRS990/Form8282PropertyDisposedOfInd | 0 | false |
| IRS990/Form8899Filedind | 0 | false |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 0 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 1 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 2 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 3 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 4 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 5 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 0 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 1 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 2 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 3 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 4 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 5 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 0 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 1 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 2 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 3 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 4 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 0 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 1 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 2 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 3 | X |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 1 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 2 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 3 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 4 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 5 | 0 |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 0 | Virginia Riccardi |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 1 | Anita Edwards |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 2 | Pamela Cullington-Hinrichs |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 3 | Craig Novak |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 4 | Manizha Parand |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 5 | Dr Joseph Vollaro |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 0 | 104166 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 1 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 2 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 3 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 4 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 5 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 1 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 2 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 3 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 4 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 5 | 0 |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 0 | Head of School |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 1 | Trustee |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 2 | Board Chair |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 3 | President |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 4 | Vice President |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 5 | Treasurer |
| IRS990/Form990ProvidedToGvrnBodyInd | 0 | true |
| IRS990/FormationYr | 0 | 1953 |
| IRS990/FormerOfcrEmployeesListedInd | 0 | false |
| IRS990/FSAuditedBasisGrp/SeparateBasisFinclStmtInd | 0 | X |
| IRS990/FSAuditedInd | 0 | true |
| IRS990/FundraisingActivitiesInd | 0 | false |
| IRS990/GamingActivitiesInd | 0 | false |
| IRS990/GoverningBodyVotingMembersCnt | 0 | 5 |
| IRS990/GrantAmt | 0 | 1033300 |
| IRS990/GrantsToDomesticIndividualsGrp/ProgramServicesAmt | 0 | 1033300 |
| IRS990/GrantsToDomesticIndividualsGrp/TotalAmt | 0 | 1033300 |
| IRS990/GrantsToDomesticOrgsGrp/TotalAmt | 0 | 0 |
| IRS990/GrantsToIndividualsInd | 0 | true |
| IRS990/GrantsToOrganizationsInd | 0 | false |
| IRS990/GrantToRelatedPersonInd | 0 | false |
| IRS990/GrossReceiptsAmt | 0 | 6802729 |
| IRS990/GroupReturnForAffiliatesInd | 0 | false |
| IRS990/IncludeFIN48FootnoteInd | 0 | true |
| IRS990/IncmFromInvestBondProceedsGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/IndependentAuditFinclStmtInd | 0 | true |
| IRS990/IndependentVotingMemberCnt | 0 | 5 |
| IRS990/IndivRcvdGreaterThan100KCnt | 0 | 1 |
| IRS990/IndoorTanningServicesInd | 0 | false |
| IRS990/InfoInScheduleOPartVIInd | 0 | X |
| IRS990/InformationTechnologyGrp/ManagementAndGeneralAmt | 0 | 8804 |
| IRS990/InformationTechnologyGrp/ProgramServicesAmt | 0 | 35214 |
| IRS990/InformationTechnologyGrp/TotalAmt | 0 | 44018 |
| IRS990/InsuranceGrp/ManagementAndGeneralAmt | 0 | 249945 |
| IRS990/InsuranceGrp/ProgramServicesAmt | 0 | 52924 |
| IRS990/InsuranceGrp/TotalAmt | 0 | 302869 |
| IRS990/IntangibleAssetsGrp/EOYAmt | 0 | 0 |
| IRS990/InterestGrp/ManagementAndGeneralAmt | 0 | 740774 |
| IRS990/InterestGrp/TotalAmt | 0 | 740774 |
| IRS990/InventoriesForSaleOrUseGrp/EOYAmt | 0 | 0 |
| IRS990/InvestmentIncomeGrp/ExclusionAmt | 0 | 90106 |
| IRS990/InvestmentIncomeGrp/TotalRevenueColumnAmt | 0 | 90106 |
| IRS990/InvestmentInJointVentureInd | 0 | false |
| IRS990/InvestmentsOtherSecuritiesGrp/EOYAmt | 0 | 0 |
| IRS990/InvestmentsProgramRelatedGrp/EOYAmt | 0 | 0 |
| IRS990/InvestmentsPubTradedSecGrp/EOYAmt | 0 | 0 |
| IRS990/IRPDocumentCnt | 0 | 11 |
| IRS990/IRPDocumentW2GCnt | 0 | 0 |
| IRS990/LandBldgEquipAccumDeprecAmt | 0 | 7561998 |
| IRS990/LandBldgEquipBasisNetGrp/BOYAmt | 0 | 1970511 |
| IRS990/LandBldgEquipBasisNetGrp/EOYAmt | 0 | 1830987 |
| IRS990/LandBldgEquipCostOrOtherBssAmt | 0 | 9392985 |
| IRS990/LegalDomicileStateCd | 0 | NY |
| IRS990/LoanOutstandingInd | 0 | false |
| IRS990/LobbyingActivitiesInd | 0 | false |
| IRS990/LocalChaptersInd | 0 | false |
| IRS990/MaterialDiversionOrMisuseInd | 0 | false |
| IRS990/MembersOrStockholdersInd | 0 | false |
| IRS990/MethodOfAccountingAccrualInd | 0 | X |
| IRS990/MinutesOfCommitteesInd | 0 | true |
| IRS990/MinutesOfGoverningBodyInd | 0 | true |
| IRS990/MissionDesc | 0 | THE KNOX SCHOOL IS A NOT-FOR-PROFIT ORGANIZATION INCORPORATED IN 1953 UNDER THE LAWS OF THE STATE OF NEW YORK. THE SCHOOL IS A NONSECTARIAN, INDEPENDENT, MULTICULTURAL, COED DAY AND BOARDING COLLEGE PREPARATORY SCHOOL THAT SERVICES APPROXIMATELY 126 STUDENTS IN GRADES 6 THROUGH 12. HOME TO MANY INTERNATIONAL STUDENTS, THE DIVERSE COMMUNITY OFFERS A NURTURING AND CARING ENVIRONMENT TO LIVE, LEARN AND GROW. IN ADDITION TO ITS WELL-ESTABLISHED EQUESTRIAN PROGRAM AND BEAUTIFUL WATERFRONT CAMPUS, THE SCHOOL PROVIDES STUDENTS WITH MANY OPPORTUNITIES TO PARTICIPATE IN A WIDE VARIETY OF SPORTS, CLUBS AND LEADSERSHIP ROLES. THE SCHOOL IS EXEMPT FROM FEDERAL INCOME TAX UNDER SECTION 501(C)(3) OF THE INTERNAL REVENUE CODE. THE SCHOOL IS SUPPORTED PRIMARILY BY TUITION AND FEES. |
| IRS990/MoreThan5000KToIndividualsInd | 0 | false |
| IRS990/MoreThan5000KToOrgInd | 0 | false |
| IRS990/MortgNotesPyblScrdInvstPropGrp/BOYAmt | 0 | 11592976 |
| IRS990/MortgNotesPyblScrdInvstPropGrp/EOYAmt | 0 | 11592976 |
| IRS990/NetAssetsOrFundBalancesBOYAmt | 0 | -12020634 |
| IRS990/NetAssetsOrFundBalancesEOYAmt | 0 | -12987521 |
| IRS990/NetGainOrLossInvestmentsGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetIncmFromFundraisingEvtGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetIncomeFromGamingGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetIncomeOrLossGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetRentalIncomeOrLossGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NoDonorRestrictionNetAssetsGrp/BOYAmt | 0 | -12850736 |
| IRS990/NoDonorRestrictionNetAssetsGrp/EOYAmt | 0 | -13530702 |
| IRS990/NoListedPersonsCompensatedInd | 0 | X |
| IRS990/NondeductibleContributionsInd | 0 | false |
| IRS990/OccupancyGrp/FundraisingAmt | 0 | 12359 |
| IRS990/OccupancyGrp/ManagementAndGeneralAmt | 0 | 28838 |
| IRS990/OccupancyGrp/ProgramServicesAmt | 0 | 370770 |
| IRS990/OccupancyGrp/TotalAmt | 0 | 411967 |
| IRS990/OfficeExpensesGrp/ManagementAndGeneralAmt | 0 | 6081 |
| IRS990/OfficeExpensesGrp/ProgramServicesAmt | 0 | 30378 |
| IRS990/OfficeExpensesGrp/TotalAmt | 0 | 36459 |
| IRS990/OfficerMailingAddressInd | 0 | false |
| IRS990/OperateHospitalInd | 0 | false |
| IRS990/Organization501c3Ind | 0 | X |
| IRS990/OrganizationFollowsFASB117Ind | 0 | X |
| IRS990/OtherAssetsTotalGrp/BOYAmt | 0 | 44280 |
| IRS990/OtherAssetsTotalGrp/EOYAmt | 0 | 27349 |
| IRS990/OtherEmployeeBenefitsGrp/FundraisingAmt | 0 | 6364 |
| IRS990/OtherEmployeeBenefitsGrp/ManagementAndGeneralAmt | 0 | 36860 |
| IRS990/OtherEmployeeBenefitsGrp/ProgramServicesAmt | 0 | 76766 |
| IRS990/OtherEmployeeBenefitsGrp/TotalAmt | 0 | 119990 |
| IRS990/OtherExpensesGrp/Desc | 0 | Admissions |
| IRS990/OtherExpensesGrp/Desc | 1 | Miscellaneous |
| IRS990/OtherExpensesGrp/Desc | 2 | Repairs and Maintenance |
| IRS990/OtherExpensesGrp/Desc | 3 | Athletics |
| IRS990/OtherExpensesGrp/FundraisingAmt | 0 | 2558 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 0 | 36713 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 1 | 5969 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 0 | 230759 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 1 | 146851 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 2 | 76739 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 3 | 78887 |
| IRS990/OtherExpensesGrp/TotalAmt | 0 | 230759 |
| IRS990/OtherExpensesGrp/TotalAmt | 1 | 183564 |
| IRS990/OtherExpensesGrp/TotalAmt | 2 | 85266 |
| IRS990/OtherExpensesGrp/TotalAmt | 3 | 78887 |
| IRS990/OtherInd | 0 | X |
| IRS990/OtherLiabilitiesGrp/BOYAmt | 0 | 44034 |
| IRS990/OtherLiabilitiesGrp/EOYAmt | 0 | 27349 |
| IRS990/OtherRevenueMiscGrp/BusinessCd | 0 | 900099 |
| IRS990/OtherRevenueMiscGrp/Desc | 0 | Other Income |
| IRS990/OtherRevenueMiscGrp/RelatedOrExemptFuncIncomeAmt | 0 | 174463 |
| IRS990/OtherRevenueMiscGrp/TotalRevenueColumnAmt | 0 | 174463 |
| IRS990/OtherRevenueTotalAmt | 0 | 174463 |
| IRS990/OtherSalariesAndWagesGrp/FundraisingAmt | 0 | 129033 |
| IRS990/OtherSalariesAndWagesGrp/ManagementAndGeneralAmt | 0 | 747412 |
| IRS990/OtherSalariesAndWagesGrp/ProgramServicesAmt | 0 | 1556563 |
| IRS990/OtherSalariesAndWagesGrp/TotalAmt | 0 | 2433008 |
| IRS990/OthNotesLoansReceivableNetGrp/EOYAmt | 0 | 0 |
| IRS990/PartialLiquidationInd | 0 | false |
| IRS990/PaymentsToAffiliatesGrp/TotalAmt | 0 | 0 |
| IRS990/PayPremiumsPrsnlBnftCntrctInd | 0 | false |
| IRS990/PayrollTaxesGrp/FundraisingAmt | 0 | 10221 |
| IRS990/PayrollTaxesGrp/ManagementAndGeneralAmt | 0 | 59202 |
| IRS990/PayrollTaxesGrp/ProgramServicesAmt | 0 | 123294 |
| IRS990/PayrollTaxesGrp/TotalAmt | 0 | 192717 |
| IRS990/PensionPlanContributionsGrp/FundraisingAmt | 0 | 1902 |
| IRS990/PensionPlanContributionsGrp/ManagementAndGeneralAmt | 0 | 11019 |
| IRS990/PensionPlanContributionsGrp/ProgramServicesAmt | 0 | 22948 |
| IRS990/PensionPlanContributionsGrp/TotalAmt | 0 | 35869 |
| IRS990/PledgesAndGrantsReceivableGrp/BOYAmt | 0 | 15000 |
| IRS990/PledgesAndGrantsReceivableGrp/EOYAmt | 0 | 15000 |
| IRS990/PoliticalCampaignActyInd | 0 | false |
| IRS990/PrepaidExpensesDefrdChargesGrp/BOYAmt | 0 | 20670 |
| IRS990/PrepaidExpensesDefrdChargesGrp/EOYAmt | 0 | 31323 |
| IRS990/PrincipalOfficerNm | 0 | Virginia Riccardi |
| IRS990/ProfessionalFundraisingInd | 0 | false |
| IRS990/ProgramServiceRevenueGrp/BusinessCd | 0 | 611710 |
| IRS990/ProgramServiceRevenueGrp/BusinessCd | 1 | 611110 |
| IRS990/ProgramServiceRevenueGrp/BusinessCd | 2 | 611710 |
| IRS990/ProgramServiceRevenueGrp/BusinessCd | 3 | 611110 |
| IRS990/ProgramServiceRevenueGrp/Desc | 0 | Auxiliary Services |
| IRS990/ProgramServiceRevenueGrp/Desc | 1 | Equestrian Program |
| IRS990/ProgramServiceRevenueGrp/Desc | 2 | Summer Program |
| IRS990/ProgramServiceRevenueGrp/Desc | 3 | Tuition and Fees |
| IRS990/ProgramServiceRevenueGrp/RelatedOrExemptFuncIncomeAmt | 0 | 410260 |
| IRS990/ProgramServiceRevenueGrp/RelatedOrExemptFuncIncomeAmt | 1 | 185622 |
| IRS990/ProgramServiceRevenueGrp/RelatedOrExemptFuncIncomeAmt | 2 | 195695 |
| IRS990/ProgramServiceRevenueGrp/RelatedOrExemptFuncIncomeAmt | 3 | 5740113 |
| IRS990/ProgramServiceRevenueGrp/TotalRevenueColumnAmt | 0 | 410260 |
| IRS990/ProgramServiceRevenueGrp/TotalRevenueColumnAmt | 1 | 185622 |
| IRS990/ProgramServiceRevenueGrp/TotalRevenueColumnAmt | 2 | 195695 |
| IRS990/ProgramServiceRevenueGrp/TotalRevenueColumnAmt | 3 | 5740113 |
| IRS990/ProgSrvcAccomActy2Grp/Desc | 0 | AUXILIARY SERVICES CONSISTS OF AN EQUESTRIAN PROGRAM, BOOST PROGRAM AND TRANSPORTATION. THE EQUESTRIAN PROGRAM SERVES BETWEEN 12-14 STUDENTS WHO COMPETE IN 5-6 COMPETITIONS EACH YEAR. THE KNOX SCHOOL ALSO OFFERS A WEEKEND PROGRAM TO LOCAL CHILDREN AND OFFERS PRIVATE LESSONS. THE BOOST DEPARTMENT OFFERS PROGRAMS AND SUPPORT SERVICES DESIGNED TO PROVIDE CAPABLE, COLLEGE-BOUND STUDENTS WITH THE FOUNDATION AND SKILLS NECESSARY TO DEVELOP THEIR ABILITIES AND TO REACH THEIR PERSONAL GOALS FOR ACADEMIC ACHIEVEMENT AND COLLEGE ADMISSION. |
| IRS990/ProgSrvcAccomActy2Grp/ExpenseAmt | 0 | 302257 |
| IRS990/ProgSrvcAccomActy2Grp/RevenueAmt | 0 | 791577 |
| IRS990/ProhibitedTaxShelterTransInd | 0 | false |
| IRS990/PYContributionsGrantsAmt | 0 | 598724 |
| IRS990/PYExcessBenefitTransInd | 0 | false |
| IRS990/PYGrantsAndSimilarPaidAmt | 0 | 1289055 |
| IRS990/PYInvestmentIncomeAmt | 0 | 8668 |
| IRS990/PymtTravelEntrtnmntPubOfclGrp/TotalAmt | 0 | 0 |
| IRS990/PYOtherExpensesAmt | 0 | 4188654 |
| IRS990/PYOtherRevenueAmt | 0 | 60749 |
| IRS990/PYProgramServiceRevenueAmt | 0 | 5638566 |
| IRS990/PYRevenuesLessExpensesAmt | 0 | -2575411 |
| IRS990/PYSalariesCompEmpBnftPaidAmt | 0 | 3404409 |
| IRS990/PYTotalExpensesAmt | 0 | 8882118 |
| IRS990/PYTotalRevenueAmt | 0 | 6306707 |
| IRS990/QuidProQuoContributionsInd | 0 | false |
| IRS990/RcvblFromDisqualifiedPrsnGrp/EOYAmt | 0 | 0 |
| IRS990/RcvFndsToPayPrsnlBnftCntrctInd | 0 | false |
| IRS990/ReceivablesFromOfficersEtcGrp/EOYAmt | 0 | 0 |
| IRS990/ReconcilationRevenueExpnssAmt | 0 | -966887 |
| IRS990/RegularMonitoringEnfrcInd | 0 | true |
| IRS990/RelatedEntityInd | 0 | false |
| IRS990/RelatedOrganizationCtrlEntInd | 0 | false |
| IRS990/ReportInvestmentsOtherSecInd | 0 | false |
| IRS990/ReportLandBuildingEquipmentInd | 0 | true |
| IRS990/ReportOtherAssetsInd | 0 | false |
| IRS990/ReportOtherLiabilitiesInd | 0 | true |
| IRS990/ReportProgramRelatedInvstInd | 0 | false |
| IRS990/RevenueAmt | 0 | 5740113 |
| IRS990/RoyaltiesGrp/TotalAmt | 0 | 0 |
| IRS990/RoyaltiesRevenueGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/SavingsAndTempCashInvstGrp/BOYAmt | 0 | 839257 |
| IRS990/SavingsAndTempCashInvstGrp/EOYAmt | 0 | 776603 |
| IRS990ScheduleA/SchoolInd | 0 | X |
| IRS990/ScheduleBRequiredInd | 0 | false |
| IRS990ScheduleD/BoardDesignatedBalanceEOYPct | 0 | 0.38500 |
| IRS990ScheduleD/BuildingsGrp/BookValueAmt | 0 | 1321843 |
| IRS990ScheduleD/BuildingsGrp/DepreciationAmt | 0 | 6020900 |
| IRS990ScheduleD/BuildingsGrp/OtherCostOrOtherBasisAmt | 0 | 7342743 |
| IRS990ScheduleD/CYEndwmtFundGrp/BeginningYearBalanceAmt | 0 | 706640 |
| IRS990ScheduleD/CYEndwmtFundGrp/EndYearBalanceAmt | 0 | 671699 |
| IRS990ScheduleD/CYEndwmtFundGrp/InvestmentEarningsOrLossesAmt | 0 | 69 |
| IRS990ScheduleD/CYEndwmtFundGrp/OtherExpendituresAmt | 0 | 35010 |
| IRS990ScheduleD/CYMinus1YrEndwmtFundGrp/BeginningYearBalanceAmt | 0 | 819644 |
| IRS990ScheduleD/CYMinus1YrEndwmtFundGrp/EndYearBalanceAmt | 0 | 706640 |
| IRS990ScheduleD/CYMinus1YrEndwmtFundGrp/InvestmentEarningsOrLossesAmt | 0 | 72 |
| IRS990ScheduleD/CYMinus1YrEndwmtFundGrp/OtherExpendituresAmt | 0 | 113076 |
| IRS990ScheduleD/CYMinus2YrEndwmtFundGrp/BeginningYearBalanceAmt | 0 | 818830 |
| IRS990ScheduleD/CYMinus2YrEndwmtFundGrp/EndYearBalanceAmt | 0 | 819237 |
| IRS990ScheduleD/CYMinus2YrEndwmtFundGrp/InvestmentEarningsOrLossesAmt | 0 | 407 |
| IRS990ScheduleD/CYMinus3YrEndwmtFundGrp/BeginningYearBalanceAmt | 0 | 1143982 |
| IRS990ScheduleD/CYMinus3YrEndwmtFundGrp/EndYearBalanceAmt | 0 | 1143982 |
| IRS990ScheduleD/CYMinus4YrEndwmtFundGrp/BeginningYearBalanceAmt | 0 | 1143531 |
| IRS990ScheduleD/CYMinus4YrEndwmtFundGrp/EndYearBalanceAmt | 0 | 1143982 |
| IRS990ScheduleD/CYMinus4YrEndwmtFundGrp/InvestmentEarningsOrLossesAmt | 0 | 451 |
| IRS990ScheduleD/EndowmentsHeldRelatedOrgInd | 0 | false |
| IRS990ScheduleD/EndowmentsHeldUnrelatedOrgInd | 0 | false |
| IRS990ScheduleD/EquipmentGrp/BookValueAmt | 0 | 157104 |
| IRS990ScheduleD/EquipmentGrp/DepreciationAmt | 0 | 1526831 |
| IRS990ScheduleD/EquipmentGrp/OtherCostOrOtherBasisAmt | 0 | 1683935 |
| IRS990ScheduleD/ExpensesNotRptFinclStmtAmt | 0 | 1033300 |
| IRS990ScheduleD/ExpensesSubtotalAmt | 0 | 6736316 |
| IRS990ScheduleD/FootnoteTextInd | 0 | X |
| IRS990ScheduleD/LandGrp/BookValueAmt | 0 | 320151 |
| IRS990ScheduleD/LandGrp/OtherCostOrOtherBasisAmt | 0 | 320151 |
| IRS990ScheduleD/OtherExpensesNotIncludedAmt | 0 | 1033300 |
| IRS990ScheduleD/OtherLandBuildingsGrp/BookValueAmt | 0 | 31889 |
| IRS990ScheduleD/OtherLandBuildingsGrp/DepreciationAmt | 0 | 14267 |
| IRS990ScheduleD/OtherLandBuildingsGrp/OtherCostOrOtherBasisAmt | 0 | 46156 |
| IRS990ScheduleD/OtherLiabilitiesOrgGrp/Amt | 0 | 27349 |
| IRS990ScheduleD/OtherLiabilitiesOrgGrp/Desc | 0 | Lease Liabilities - Operating |
| IRS990ScheduleD/OtherRevenuesNotIncludedAmt | 0 | 1033300 |
| IRS990ScheduleD/PrmnntEndowmentBalanceEOYPct | 0 | 0.61500 |
| IRS990ScheduleD/RelatedOrgListSchRInd | 0 | false |
| IRS990ScheduleD/RevenueNotReportedFinclStmtAmt | 0 | 1033300 |
| IRS990ScheduleD/RevenueSubtotalAmt | 0 | 5769429 |
| IRS990ScheduleD/SupplementalInformationDetail/ExplanationTxt | 0 | The school recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Management has determined that the school had no uncertain tax positions that would require financial statement recognition. The school is no longer subject to examination by the applicable taxing jurisdictions for tax years prior to 2021. |
| IRS990ScheduleD/SupplementalInformationDetail/ExplanationTxt | 1 | SCHOLARSHIPS AND FINANCIAL AID $1033300 |
| IRS990ScheduleD/SupplementalInformationDetail/ExplanationTxt | 2 | SCHOLARSHIPS AND FINANCIAL AID $1033300 |
| IRS990ScheduleD/SupplementalInformationDetail/FormAndLineReferenceDesc | 0 | Part X : FIN48 Footnote |
| IRS990ScheduleD/SupplementalInformationDetail/FormAndLineReferenceDesc | 1 | Part XI, Line 4b: Other revenue amounts included on 990 but not included in F/S |
| IRS990ScheduleD/SupplementalInformationDetail/FormAndLineReferenceDesc | 2 | Part XII, Line 4b: Other revenue amounts included on 990 but not included in F/S |
| IRS990ScheduleD/TotalBookValueLandBuildingsAmt | 0 | 1830987 |
| IRS990ScheduleD/TotalExpensesPerForm990Amt | 0 | 7769616 |
| IRS990ScheduleD/TotalLiabilityAmt | 0 | 27349 |
| IRS990ScheduleD/TotalRevenuePerForm990Amt | 0 | 6802729 |
| IRS990ScheduleD/TotalRevEtcAuditedFinclStmtAmt | 0 | 5769429 |
| IRS990ScheduleD/TotExpnsEtcAuditedFinclStmtAmt | 0 | 6736316 |
| IRS990ScheduleE/ComplianceWithRevProc7550Ind | 0 | true |
| IRS990ScheduleE/DiscriminateRaceAdmissPlcyInd | 0 | false |
| IRS990ScheduleE/DiscriminateRaceAthltProgInd | 0 | false |
| IRS990ScheduleE/DiscriminateRaceEducPlcyInd | 0 | false |
| IRS990ScheduleE/DiscriminateRaceEmplmFcultyInd | 0 | false |
| IRS990ScheduleE/DiscriminateRaceOtherActyInd | 0 | false |
| IRS990ScheduleE/DiscriminateRaceSchsInd | 0 | false |
| IRS990ScheduleE/DiscriminateRaceStdntsRghtsInd | 0 | false |
| IRS990ScheduleE/DiscriminateRaceUseOfFcltsInd | 0 | false |
| IRS990ScheduleE/GovernmentFinancialAidRcvdInd | 0 | false |