| IRS990/AccountantCompileOrReviewInd | 0 | 0 |
| IRS990/AccountsPayableAccrExpnssGrp/BOYAmt | 0 | 514103 |
| IRS990/AccountsPayableAccrExpnssGrp/EOYAmt | 0 | 634711 |
| IRS990/AccountsReceivableGrp/BOYAmt | 0 | 49725 |
| IRS990/AccountsReceivableGrp/EOYAmt | 0 | 71603 |
| IRS990/ActivitiesConductedPrtshpInd | 0 | 0 |
| IRS990/ActivityOrMissionDesc | 0 | OPEN WINDOW SCHOOL NURTURES AND INSPIRES STUDENTS OF HIGH INTELLECTUAL POTENTIAL. |
| IRS990/AdvertisingGrp/FundraisingAmt | 0 | 1742 |
| IRS990/AdvertisingGrp/ManagementAndGeneralAmt | 0 | 6969 |
| IRS990/AdvertisingGrp/ProgramServicesAmt | 0 | 26132 |
| IRS990/AdvertisingGrp/TotalAmt | 0 | 34843 |
| IRS990/AllOtherContributionsAmt | 0 | 701653 |
| IRS990/AnnualDisclosureCoveredPrsnInd | 0 | 1 |
| IRS990/AuditCommitteeInd | 0 | 1 |
| IRS990/BackupWthldComplianceInd | 0 | 1 |
| IRS990/BooksInCareOfDetail/BusinessName/BusinessNameLine1Txt | 0 | MARJA ZIUZIN CFO |
| IRS990/BooksInCareOfDetail/PhoneNum | 0 | 4257472911 |
| IRS990/BooksInCareOfDetail/USAddress/AddressLine1Txt | 0 | 6128 168TH PLACE SE |
| IRS990/BooksInCareOfDetail/USAddress/CityNm | 0 | BELLEVUE |
| IRS990/BooksInCareOfDetail/USAddress/StateAbbreviationCd | 0 | WA |
| IRS990/BooksInCareOfDetail/USAddress/ZIPCd | 0 | 98006 |
| IRS990/BusinessRlnWithFamMemInd | 0 | 0 |
| IRS990/BusinessRlnWithOfficerEntInd | 0 | 0 |
| IRS990/BusinessRlnWithOrgMemInd | 0 | 0 |
| IRS990/CashNonInterestBearingGrp/BOYAmt | 0 | 2183419 |
| IRS990/CashNonInterestBearingGrp/EOYAmt | 0 | 1414003 |
| IRS990/ChangeToOrgDocumentsInd | 0 | 1 |
| IRS990/CntrctRcvdGreaterThan100KCnt | 0 | 1 |
| IRS990/CollectionsOfArtInd | 0 | 0 |
| IRS990/CompCurrentOfcrDirectorsGrp/ManagementAndGeneralAmt | 0 | 513302 |
| IRS990/CompCurrentOfcrDirectorsGrp/TotalAmt | 0 | 513302 |
| IRS990/CompensationFromOtherSrcsInd | 0 | 0 |
| IRS990/CompensationProcessCEOInd | 0 | 1 |
| IRS990/CompensationProcessOtherInd | 0 | 1 |
| IRS990/ConflictOfInterestPolicyInd | 0 | 1 |
| IRS990/ConservationEasementsInd | 0 | 0 |
| IRS990/ConsolidatedAuditFinclStmtInd | 0 | 0 |
| IRS990/ContractorCompensationGrp/CompensationAmt | 0 | 148091 |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/AddressLine1Txt | 0 | 71 COLUMBIA ST 6TH FLOOR |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/CityNm | 0 | SEATTLE |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/StateAbbreviationCd | 0 | WA |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/ZIPCd | 0 | 98104 |
| IRS990/ContractorCompensationGrp/ContractorName/BusinessName/BusinessNameLine1Txt | 0 | MILLER HULL |
| IRS990/ContractorCompensationGrp/ServicesDesc | 0 | DESIGN CONSULTING |
| IRS990/ContriRptFundraisingEventAmt | 0 | 420477 |
| IRS990/CreditCounselingInd | 0 | 0 |
| IRS990/CYBenefitsPaidToMembersAmt | 0 | 0 |
| IRS990/CYContributionsGrantsAmt | 0 | 1122130 |
| IRS990/CYGrantsAndSimilarPaidAmt | 0 | 0 |
| IRS990/CYInvestmentIncomeAmt | 0 | 181123 |
| IRS990/CYOtherExpensesAmt | 0 | 2784274 |
| IRS990/CYOtherRevenueAmt | 0 | -40936 |
| IRS990/CYProgramServiceRevenueAmt | 0 | 9023770 |
| IRS990/CYRevenuesLessExpensesAmt | 0 | 673891 |
| IRS990/CYSalariesCompEmpBnftPaidAmt | 0 | 6827922 |
| IRS990/CYTotalExpensesAmt | 0 | 9612196 |
| IRS990/CYTotalFundraisingExpenseAmt | 0 | 329139 |
| IRS990/CYTotalProfFndrsngExpnsAmt | 0 | 0 |
| IRS990/CYTotalRevenueAmt | 0 | 10286087 |
| IRS990/DecisionsSubjectToApprovaInd | 0 | 0 |
| IRS990/DeductibleArtContributionInd | 0 | 0 |
| IRS990/DeductibleNonCashContriInd | 0 | 1 |
| IRS990/DeferredRevenueGrp/BOYAmt | 0 | 1766552 |
| IRS990/DeferredRevenueGrp/EOYAmt | 0 | 1262441 |
| IRS990/DelegationOfMgmtDutiesInd | 0 | 0 |
| IRS990/DepreciationDepletionGrp/FundraisingAmt | 0 | 13138 |
| IRS990/DepreciationDepletionGrp/ManagementAndGeneralAmt | 0 | 52551 |
| IRS990/DepreciationDepletionGrp/ProgramServicesAmt | 0 | 591201 |
| IRS990/DepreciationDepletionGrp/TotalAmt | 0 | 656890 |
| IRS990/Desc | 0 | OPEN WINDOW SCHOOL NURTURES AND INSPIRES APPROXIMATELY 331 STUDENTS OF HIGH INTELLECTUAL POTENTIAL, AGE 5 TO 13, BY PROVIDING A COMPREHENSIVE SCHOOL PROGRAM FOR GIFTED LEARNERS AND ENRICHING AFTER-SCHOOL AND SUMMER ACTIVITIES. |
| IRS990/DescribedInSection501c3Ind | 0 | 1 |
| IRS990/DisregardedEntityInd | 0 | 0 |
| IRS990/DocumentRetentionPolicyInd | 0 | 0 |
| IRS990/DonorAdvisedFundInd | 0 | 0 |
| IRS990/ElectionOfBoardMembersInd | 0 | 0 |
| IRS990/EmployeeCnt | 0 | 117 |
| IRS990/EmploymentTaxReturnsFiledInd | 0 | 1 |
| IRS990/EngagedInExcessBenefitTransInd | 0 | 0 |
| IRS990/EscrowAccountInd | 0 | 0 |
| IRS990/ExpenseAmt | 0 | 6532417 |
| IRS990/FamilyOrBusinessRlnInd | 0 | 0 |
| IRS990/FederalGrantAuditRequiredInd | 0 | 0 |
| IRS990/FeesForServicesAccountingGrp/ManagementAndGeneralAmt | 0 | 20900 |
| IRS990/FeesForServicesAccountingGrp/TotalAmt | 0 | 20900 |
| IRS990/FeesForServicesLegalGrp/ManagementAndGeneralAmt | 0 | 1933 |
| IRS990/FeesForServicesLegalGrp/TotalAmt | 0 | 1933 |
| IRS990/FeesForServicesOtherGrp/ManagementAndGeneralAmt | 0 | 133063 |
| IRS990/FeesForServicesOtherGrp/TotalAmt | 0 | 133063 |
| IRS990/FeesForSrvcInvstMgmntFeesGrp/ManagementAndGeneralAmt | 0 | 40457 |
| IRS990/FeesForSrvcInvstMgmntFeesGrp/TotalAmt | 0 | 40457 |
| IRS990/ForeignActivitiesInd | 0 | 0 |
| IRS990/ForeignFinancialAccountInd | 0 | 0 |
| IRS990/ForeignOfficeInd | 0 | 0 |
| IRS990/Form8282PropertyDisposedOfInd | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 0 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 1 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 2 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 3 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 4 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 5 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 6 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 7 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 8 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 9 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 10 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 11 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 12 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 13 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 14 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 15 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 16 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 17 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 18 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 19 | 50.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 20 | 50.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 21 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 22 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 23 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 24 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 0 | X |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 1 | X |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 2 | X |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 3 | X |
| 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/IndividualTrusteeOrDirectorInd | 5 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 6 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 7 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 8 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 9 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 10 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 11 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 12 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 13 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 14 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 15 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 16 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 17 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 18 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 0 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 1 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 2 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 3 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 4 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 5 | 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/OtherCompensationAmt | 6 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 7 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 8 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 9 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 10 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 11 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 12 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 13 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 14 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 15 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 16 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 17 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 18 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 19 | 34446 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 20 | 36833 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 21 | 16333 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 22 | 15336 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 23 | 16035 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 24 | 15833 |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 0 | CYDNIE HORWAT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 1 | CHAD FLETCHER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 2 | JEFF DERSTADT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 3 | NANCY WOO |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 4 | GLYNIS ABDALLAH |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 5 | THAO BLANCHARD |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 6 | JASON BOERNER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 7 | LIZ BOHLIN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 8 | MICHAEL CROWSON |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 9 | VINCE CURLEY |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 10 | ANDREA DANCS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 11 | SUSAN GELLATLY |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 12 | KEVIN GRUBEN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 13 | MONA KHANUJA |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 14 | SHONA SMITH |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 15 | MOZ THOMAS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 16 | MIKE THOLFSEN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 17 | CHARLES WHITMER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 18 | WILLIAM KENNEDY |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 19 | JEFFREY STROEBEL |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 20 | MARJA ZIUZIN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 21 | SHERI BROWN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 22 | MIKE MONTGOMERY |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 23 | MEGHANN KERRIN SCOTT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 24 | MARY KERN |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 0 | 0 |
| 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/ReportableCompFromOrgAmt | 6 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 7 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 8 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 9 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 10 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 11 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 12 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 13 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 14 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 15 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 16 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 17 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 18 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 19 | 260210 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 20 | 159349 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 21 | 122828 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 22 | 115448 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 23 | 108934 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 24 | 101371 |
| 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/ReportableCompFromRltdOrgAmt | 6 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 7 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 8 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 9 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 10 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 11 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 12 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 13 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 14 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 15 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 16 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 17 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 18 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 19 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 20 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 21 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 22 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 23 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 24 | 0 |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 0 | PRESIDENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 1 | VICE PRESIDENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 2 | TREASURER |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 3 | SECRETARY |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 4 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 5 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 6 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 7 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 8 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 9 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 10 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 11 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 12 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 13 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 14 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 15 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 16 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 17 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 18 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 19 | HEAD OF SCHOOL |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 20 | CHIEF FINANCIAL OFFICER |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 21 | LOWER SCHOOL HEAD |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 22 | MIDDLE SCHOOL HEAD |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 23 | MIDDLE SCHOOT DEAN OF STUDENTS |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 24 | CONTROLLER |
| IRS990/Form990ProvidedToGvrnBodyInd | 0 | 0 |
| IRS990/FormationYr | 0 | 1985 |
| IRS990/FormerOfcrEmployeesListedInd | 0 | 0 |
| IRS990/FSAuditedBasisGrp/SeparateBasisFinclStmtInd | 0 | X |
| IRS990/FSAuditedInd | 0 | 1 |
| IRS990/FundraisingActivitiesInd | 0 | 1 |
| IRS990/FundraisingAmt | 0 | 420477 |
| IRS990/FundraisingDirectExpensesAmt | 0 | 73844 |
| IRS990/FundraisingGrossIncomeAmt | 0 | 27405 |
| IRS990/GainOrLossGrp/OtherAmt | 0 | -5200 |
| IRS990/GamingActivitiesInd | 0 | 0 |
| IRS990/GamingDirectExpensesAmt | 0 | 0 |
| IRS990/GamingGrossIncomeAmt | 0 | 5000 |
| IRS990/GoverningBodyVotingMembersCnt | 0 | 19 |
| IRS990/GrantsToIndividualsInd | 0 | 0 |
| IRS990/GrantsToOrganizationsInd | 0 | 0 |
| IRS990/GrantToRelatedPersonInd | 0 | 0 |
| IRS990/GrossReceiptsAmt | 0 | 10365131 |
| IRS990/GroupReturnForAffiliatesInd | 0 | 0 |
| IRS990/IncludeFIN48FootnoteInd | 0 | 0 |
| IRS990/IndependentAuditFinclStmtInd | 0 | 1 |
| IRS990/IndependentVotingMemberCnt | 0 | 19 |
| IRS990/IndivRcvdGreaterThan100KCnt | 0 | 6 |
| IRS990/IndoorTanningServicesInd | 0 | 0 |
| IRS990/InfoInScheduleOPartVIInd | 0 | X |
| IRS990/InfoInScheduleOPartXIInd | 0 | X |
| IRS990/InsuranceGrp/ManagementAndGeneralAmt | 0 | 17228 |
| IRS990/InsuranceGrp/ProgramServicesAmt | 0 | 33443 |
| IRS990/InsuranceGrp/TotalAmt | 0 | 50671 |
| IRS990/InterestGrp/ManagementAndGeneralAmt | 0 | 12323 |
| IRS990/InterestGrp/ProgramServicesAmt | 0 | 110906 |
| IRS990/InterestGrp/TotalAmt | 0 | 123229 |
| IRS990/InvestmentIncomeGrp/ExclusionAmt | 0 | 186323 |
| IRS990/InvestmentIncomeGrp/TotalRevenueColumnAmt | 0 | 186323 |
| IRS990/InvestmentInJointVentureInd | 0 | 0 |
| IRS990/InvestmentsPubTradedSecGrp/BOYAmt | 0 | 9302282 |
| IRS990/InvestmentsPubTradedSecGrp/EOYAmt | 0 | 10185454 |
| IRS990/InvestTaxExemptBondsInd | 0 | 0 |
| IRS990/IRPDocumentCnt | 0 | 48 |
| IRS990/IRPDocumentW2GCnt | 0 | 0 |
| IRS990/LandBldgEquipAccumDeprecAmt | 0 | 5604958 |
| IRS990/LandBldgEquipBasisNetGrp/BOYAmt | 0 | 13908100 |
| IRS990/LandBldgEquipBasisNetGrp/EOYAmt | 0 | 13830334 |
| IRS990/LandBldgEquipCostOrOtherBssAmt | 0 | 19435292 |
| IRS990/LegalDomicileStateCd | 0 | WA |
| IRS990/LessCostOthBasisSalesExpnssGrp/OtherAmt | 0 | 5200 |
| IRS990/LoanOutstandingInd | 0 | 0 |
| IRS990/LobbyingActivitiesInd | 0 | 0 |
| IRS990/LocalChaptersInd | 0 | 0 |
| IRS990/MaterialDiversionOrMisuseInd | 0 | 0 |
| IRS990/MembersOrStockholdersInd | 0 | 0 |
| IRS990/MethodOfAccountingAccrualInd | 0 | X |
| IRS990/MinutesOfCommitteesInd | 0 | 0 |
| IRS990/MinutesOfGoverningBodyInd | 0 | 1 |
| IRS990/MissionDesc | 0 | OPEN WINDOW SCHOOL NURTURES AND INSPIRES STUDENTS OF HIGH INTELLECTUAL POTENTIAL. |
| IRS990/MoreThan5000KToIndividualsInd | 0 | 0 |
| IRS990/MoreThan5000KToOrgInd | 0 | 0 |
| IRS990/NetAssetsOrFundBalancesBOYAmt | 0 | 19782898 |
| IRS990/NetAssetsOrFundBalancesEOYAmt | 0 | 20967290 |
| IRS990/NetGainOrLossInvestmentsGrp/ExclusionAmt | 0 | -5200 |
| IRS990/NetGainOrLossInvestmentsGrp/TotalRevenueColumnAmt | 0 | -5200 |
| IRS990/NetIncmFromFundraisingEvtGrp/ExclusionAmt | 0 | -46439 |
| IRS990/NetIncmFromFundraisingEvtGrp/TotalRevenueColumnAmt | 0 | -46439 |
| IRS990/NetIncomeFromGamingGrp/RelatedOrExemptFuncIncomeAmt | 0 | 5000 |
| IRS990/NetIncomeFromGamingGrp/TotalRevenueColumnAmt | 0 | 5000 |
| IRS990/NetUnrelatedBusTxblIncmAmt | 0 | 0 |
| IRS990/NetUnrlzdGainsLossesInvstAmt | 0 | 534233 |
| IRS990/NoncashContributionsAmt | 0 | 57259 |
| IRS990/NondeductibleContributionsInd | 0 | 0 |
| IRS990/OfficeExpensesGrp/FundraisingAmt | 0 | 9304 |
| IRS990/OfficeExpensesGrp/ManagementAndGeneralAmt | 0 | 104634 |
| IRS990/OfficeExpensesGrp/ProgramServicesAmt | 0 | 224452 |
| IRS990/OfficeExpensesGrp/TotalAmt | 0 | 338390 |
| IRS990/OfficerMailingAddressInd | 0 | 0 |
| IRS990/OnBehalfOfIssuerInd | 0 | 0 |
| IRS990/OperateHospitalInd | 0 | 0 |
| IRS990/Organization501c3Ind | 0 | X |
| IRS990/OrganizationFollowsSFAS117Ind | 0 | X |
| IRS990/OtherAssetsTotalGrp/BOYAmt | 0 | 407969 |
| IRS990/OtherAssetsTotalGrp/EOYAmt | 0 | 312410 |
| IRS990/OtherChangesInNetAssetsAmt | 0 | -23732 |
| IRS990/OtherEmployeeBenefitsGrp/FundraisingAmt | 0 | 30679 |
| IRS990/OtherEmployeeBenefitsGrp/ManagementAndGeneralAmt | 0 | 259654 |
| IRS990/OtherEmployeeBenefitsGrp/ProgramServicesAmt | 0 | 597920 |
| IRS990/OtherEmployeeBenefitsGrp/TotalAmt | 0 | 888253 |
| IRS990/OtherExpensesGrp/Desc | 0 | SITE MANAGEMENT & SAFET |
| IRS990/OtherExpensesGrp/Desc | 1 | MISCELLANEOUS |
| IRS990/OtherExpensesGrp/Desc | 2 | CLASSROOM ENRICHMENT |
| IRS990/OtherExpensesGrp/Desc | 3 | BUS PROGRAM |
| IRS990/OtherExpensesGrp/FundraisingAmt | 0 | 5954 |
| IRS990/OtherExpensesGrp/FundraisingAmt | 1 | 69089 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 0 | 35723 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 1 | 47830 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 0 | 553700 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 1 | 239963 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 2 | 337230 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 3 | 94409 |
| IRS990/OtherExpensesGrp/TotalAmt | 0 | 595377 |
| IRS990/OtherExpensesGrp/TotalAmt | 1 | 356882 |
| IRS990/OtherExpensesGrp/TotalAmt | 2 | 337230 |
| IRS990/OtherExpensesGrp/TotalAmt | 3 | 94409 |
| IRS990/OtherRevenueMiscGrp/BusinessCd | 0 | 900099 |
| IRS990/OtherRevenueMiscGrp/BusinessCd | 1 | 900099 |
| IRS990/OtherRevenueMiscGrp/Desc | 0 | LIBRARY INCOME |
| IRS990/OtherRevenueMiscGrp/Desc | 1 | MISCELLANEOUS INCOME |
| IRS990/OtherRevenueMiscGrp/ExclusionAmt | 0 | 493 |
| IRS990/OtherRevenueMiscGrp/ExclusionAmt | 1 | 10 |
| IRS990/OtherRevenueMiscGrp/TotalRevenueColumnAmt | 0 | 493 |
| IRS990/OtherRevenueMiscGrp/TotalRevenueColumnAmt | 1 | 10 |
| IRS990/OtherRevenueTotalAmt | 0 | 503 |
| IRS990/OtherSalariesAndWagesGrp/FundraisingAmt | 0 | 176749 |
| IRS990/OtherSalariesAndWagesGrp/ManagementAndGeneralAmt | 0 | 1289214 |
| IRS990/OtherSalariesAndWagesGrp/ProgramServicesAmt | 0 | 3321838 |
| IRS990/OtherSalariesAndWagesGrp/TotalAmt | 0 | 4787801 |
| IRS990/PartialLiquidationInd | 0 | 0 |
| IRS990/PayPremiumsPrsnlBnftCntrctInd | 0 | 0 |
| IRS990/PayrollTaxesGrp/FundraisingAmt | 0 | 14561 |
| IRS990/PayrollTaxesGrp/ManagementAndGeneralAmt | 0 | 144208 |
| IRS990/PayrollTaxesGrp/ProgramServicesAmt | 0 | 273655 |
| IRS990/PayrollTaxesGrp/TotalAmt | 0 | 432424 |
| IRS990/PensionPlanContributionsGrp/FundraisingAmt | 0 | 7923 |
| IRS990/PensionPlanContributionsGrp/ManagementAndGeneralAmt | 0 | 70651 |
| IRS990/PensionPlanContributionsGrp/ProgramServicesAmt | 0 | 127568 |
| IRS990/PensionPlanContributionsGrp/TotalAmt | 0 | 206142 |
| IRS990/PermanentlyRstrNetAssetsGrp/BOYAmt | 0 | 2337940 |
| IRS990/PermanentlyRstrNetAssetsGrp/EOYAmt | 0 | 2697863 |
| IRS990/PledgesAndGrantsReceivableGrp/BOYAmt | 0 | 22970 |