| IRS990/AccountantCompileOrReviewInd | 0 | 0 |
| IRS990/AccountsPayableAccrExpnssGrp/BOYAmt | 0 | 1055796 |
| IRS990/AccountsPayableAccrExpnssGrp/EOYAmt | 0 | 1509678 |
| IRS990/AccountsReceivableGrp/BOYAmt | 0 | 25000 |
| IRS990/ActivitiesConductedPrtshpInd | 0 | 0 |
| IRS990/ActivityOrMissionDesc | 0 | EAGLE HILL SCHOOL IS A COEDUCATIONAL BOARDING SCHOOL THAT EDUCATES STUDENTS WITH LEARNING DISABILITIES, INCLUDING ATTENTION DEFICIT DISORDER, IN GRADES EIGHT THROUGH TWELVE. EAGLE HILL STUDENTS DEMONSTRATE AVERAGE TO ABOVE AVERAGE COGNITIVE ABILITY AND ARE MOTIVATED TO EXPLORE ACADEMIC AND INTELLECTUAL PURSUITS IN A SUPPORTIVE ENVIRONMENT. ALTHOUGH EAGLE HILL ENCOURAGES EMOTIONAL AND BEHAVIORAL GROWTH, IT DOES NOT ACCEPT STUDENTS WITH PRIMARY CONCERNS IN THESE AREAS. EAGLE HILL DRAWS ITS 206 STUDENTS FROM ACROSS THE US AND THE INTERNATIONAL COMMUNITY, BRINGING A WELCOME DIVERSITY TO THE CAMPUS. |
| IRS990/AdvertisingGrp/FundraisingAmt | 0 | 290 |
| IRS990/AdvertisingGrp/ManagementAndGeneralAmt | 0 | 14017 |
| IRS990/AdvertisingGrp/ProgramServicesAmt | 0 | 61349 |
| IRS990/AdvertisingGrp/TotalAmt | 0 | 75656 |
| IRS990/AllOtherContributionsAmt | 0 | 3503159 |
| IRS990/AllOtherExpensesGrp/ManagementAndGeneralAmt | 0 | 9965 |
| IRS990/AllOtherExpensesGrp/ProgramServicesAmt | 0 | 304089 |
| IRS990/AllOtherExpensesGrp/TotalAmt | 0 | 314054 |
| IRS990/AnnualDisclosureCoveredPrsnInd | 0 | 1 |
| IRS990/AuditCommitteeInd | 0 | 1 |
| IRS990/BackupWthldComplianceInd | 0 | 1 |
| IRS990/BooksInCareOfDetail/PersonNm | 0 | JAMES BARKUS CONTROLLER |
| IRS990/BooksInCareOfDetail/PhoneNum | 0 | 4134776000 |
| IRS990/BooksInCareOfDetail/USAddress/AddressLine1Txt | 0 | 242 OLD PETERSHAM ROAD |
| IRS990/BooksInCareOfDetail/USAddress/CityNm | 0 | HARDWICK |
| IRS990/BooksInCareOfDetail/USAddress/StateAbbreviationCd | 0 | MA |
| IRS990/BooksInCareOfDetail/USAddress/ZIPCd | 0 | 01037 |
| IRS990/BusinessRlnWithFamMemInd | 0 | 0 |
| IRS990/BusinessRlnWithOfficerEntInd | 0 | 0 |
| IRS990/BusinessRlnWithOrgMemInd | 0 | 0 |
| IRS990/CashNonInterestBearingGrp/BOYAmt | 0 | 3962839 |
| IRS990/CashNonInterestBearingGrp/EOYAmt | 0 | 5511717 |
| IRS990/ChangeToOrgDocumentsInd | 0 | 0 |
| IRS990/CntrctRcvdGreaterThan100KCnt | 0 | 3 |
| IRS990/CollectionsOfArtInd | 0 | 0 |
| IRS990/CompCurrentOfcrDirectorsGrp/FundraisingAmt | 0 | 51251 |
| IRS990/CompCurrentOfcrDirectorsGrp/ManagementAndGeneralAmt | 0 | 76877 |
| IRS990/CompCurrentOfcrDirectorsGrp/ProgramServicesAmt | 0 | 384386 |
| IRS990/CompCurrentOfcrDirectorsGrp/TotalAmt | 0 | 512514 |
| IRS990/CompensationFromOtherSrcsInd | 0 | 0 |
| IRS990/CompensationProcessCEOInd | 0 | 1 |
| IRS990/CompensationProcessOtherInd | 0 | 1 |
| IRS990/ConflictOfInterestPolicyInd | 0 | 1 |
| IRS990/ConservationEasementsInd | 0 | 0 |
| IRS990/ConsolidatedAuditFinclStmtInd | 0 | 1 |
| IRS990/ContractorCompensationGrp/CompensationAmt | 0 | 402744 |
| IRS990/ContractorCompensationGrp/CompensationAmt | 1 | 248078 |
| IRS990/ContractorCompensationGrp/CompensationAmt | 2 | 215270 |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/AddressLine1Txt | 0 | PO BOX 47 |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/AddressLine1Txt | 1 | PO BOX 35 |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/AddressLine1Txt | 2 | 71 WORCESTER ROAD PO BOX 638 |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/CityNm | 0 | PALMER |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/CityNm | 1 | WARE |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/CityNm | 2 | BARRE |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/StateAbbreviationCd | 0 | MA |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/StateAbbreviationCd | 1 | MA |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/StateAbbreviationCd | 2 | MA |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/ZIPCd | 0 | 01069 |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/ZIPCd | 1 | 01082 |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/ZIPCd | 2 | 01005 |
| IRS990/ContractorCompensationGrp/ContractorName/BusinessName/BusinessNameLine1Txt | 0 | PALMER PAVING CORPORATION |
| IRS990/ContractorCompensationGrp/ContractorName/BusinessName/BusinessNameLine1Txt | 1 | DW EQUIPMENT RENTALS LLC |
| IRS990/ContractorCompensationGrp/ContractorName/BusinessName/BusinessNameLine1Txt | 2 | RJ MCDONALD INC |
| IRS990/ContractorCompensationGrp/ServicesDesc | 0 | PAVING CONTRACTOR |
| IRS990/ContractorCompensationGrp/ServicesDesc | 1 | CONSTRUCTION EQUIPMENT CONTRACTOR |
| IRS990/ContractorCompensationGrp/ServicesDesc | 2 | HEATING CONTRACTOR, HEATING FUEL, CRUSHE |
| IRS990/CreditCounselingInd | 0 | 0 |
| IRS990/CYBenefitsPaidToMembersAmt | 0 | 0 |
| IRS990/CYContributionsGrantsAmt | 0 | 3674971 |
| IRS990/CYGrantsAndSimilarPaidAmt | 0 | 870316 |
| IRS990/CYInvestmentIncomeAmt | 0 | 70024 |
| IRS990/CYOtherExpensesAmt | 0 | 7400185 |
| IRS990/CYOtherRevenueAmt | 0 | 0 |
| IRS990/CYProgramServiceRevenueAmt | 0 | 16677884 |
| IRS990/CYRevenuesLessExpensesAmt | 0 | 2072978 |
| IRS990/CYSalariesCompEmpBnftPaidAmt | 0 | 10079400 |
| IRS990/CYTotalExpensesAmt | 0 | 18349901 |
| IRS990/CYTotalFundraisingExpenseAmt | 0 | 583899 |
| IRS990/CYTotalProfFndrsngExpnsAmt | 0 | 0 |
| IRS990/CYTotalRevenueAmt | 0 | 20422879 |
| IRS990/DecisionsSubjectToApprovaInd | 0 | 0 |
| IRS990/DeductibleArtContributionInd | 0 | 0 |
| IRS990/DeductibleNonCashContriInd | 0 | 1 |
| IRS990/DeferredRevenueGrp/BOYAmt | 0 | 5515438 |
| IRS990/DeferredRevenueGrp/EOYAmt | 0 | 5317040 |
| IRS990/DelegationOfMgmtDutiesInd | 0 | 0 |
| IRS990/DepreciationDepletionGrp/FundraisingAmt | 0 | 34596 |
| IRS990/DepreciationDepletionGrp/ManagementAndGeneralAmt | 0 | 34027 |
| IRS990/DepreciationDepletionGrp/ProgramServicesAmt | 0 | 1677901 |
| IRS990/DepreciationDepletionGrp/TotalAmt | 0 | 1746524 |
| IRS990/Desc | 0 | EDUCATION SERVICES FOR THE ACADEMIC YEAR WHICH RUNS FROM SEPTEMBER TO JUNE ADMINISTERED TO 192 RESIDENTIAL AND 14 DAY STUDENTS IN GRADES 8 THROUGH 12. THE SCHOOL OFFERS COLLEGE PREPARATORY CURRICULUM THAT CHALLENGES AND SUPPORTS EACH STUDENT. UNCOMPROMISING STANDARDS OF ACADEMIC EXCELLENCE, COMBINED WITH A SCHOOL STRUCTURE AND CULTURE THAT FOSTER DIFFERENTIATED INSTRUCTION BASED ON INDIVIDUAL NEEDS, CREATE THE IDEAL ENVIRONMENT IN WHICH YOUNG MINDS CAN PREPARE FOR COLLEGE. THE DEVELOPMENT OF CRITICAL THINKING SKILLS IS AS IMPORTANT AS THE MASTERY OF FACTS AND FIGURES AS STUDENTS ARE PREPARED TO BE INTELLECTUALLY ENGAGED CITIZENS. IN CREATING AN ENVIRONMENT THAT FOSTERS THIS LEVEL OF ACADEMIC AND SOCIAL SUCCESS, CAREFUL ATTENTION IS GIVEN TO THE DEVELOPMENT OF EACH STUDENT'S UNIQUE COURSE SCHEDULE. BY DESIGNING COURSES BASED ON AGE, DEMONSTRATED SKILL LEVELS, AND LEARNING PREFERENCES, EAGLE HILL ENSURES THAT EACH STUDENT IS PLACED IN A POSITION TO TAKE FULL ADVANTAGE OF THE ACADEMIC CULTURE. MULTISENSORY APPROACHES ARE USED ACROSS THE CURRICULUM TO REINFORCE LEARNING AND THINKING, AND EVERY STUDENT AT EAGLE HILL BENEFITS FROM AN INTEGRATED STUDY SKILLS CURRICULUM THAT ENCOURAGES EACH STUDENT TO DEVELOP A METHOD FOR SUCCESS. |
| IRS990/DescribedInSection501c3Ind | 0 | 1 |
| IRS990/DisregardedEntityInd | 0 | 0 |
| IRS990/DocumentRetentionPolicyInd | 0 | 1 |
| IRS990/DonorAdvisedFundInd | 0 | 0 |
| IRS990/ElectionOfBoardMembersInd | 0 | 0 |
| IRS990/EmployeeCnt | 0 | 173 |
| IRS990/EmploymentTaxReturnsFiledInd | 0 | 1 |
| IRS990/EngagedInExcessBenefitTransInd | 0 | 0 |
| IRS990/EscrowAccountInd | 0 | 0 |
| IRS990/ExpenseAmt | 0 | 14938603 |
| IRS990/FamilyOrBusinessRlnInd | 0 | 0 |
| IRS990/FederalGrantAuditRequiredInd | 0 | 0 |
| IRS990/FeesForServicesAccountingGrp/ManagementAndGeneralAmt | 0 | 55671 |
| IRS990/FeesForServicesAccountingGrp/TotalAmt | 0 | 55671 |
| IRS990/FeesForServicesLegalGrp/ManagementAndGeneralAmt | 0 | 18409 |
| IRS990/FeesForServicesLegalGrp/TotalAmt | 0 | 18409 |
| IRS990/FeesForServicesOtherGrp/FundraisingAmt | 0 | 13262 |
| IRS990/FeesForServicesOtherGrp/ManagementAndGeneralAmt | 0 | 72674 |
| IRS990/FeesForServicesOtherGrp/ProgramServicesAmt | 0 | 47997 |
| IRS990/FeesForServicesOtherGrp/TotalAmt | 0 | 133933 |
| IRS990/ForeignActivitiesInd | 0 | 1 |
| IRS990/ForeignFinancialAccountInd | 0 | 0 |
| IRS990/ForeignGrantsGrp/ProgramServicesAmt | 0 | 164843 |
| IRS990/ForeignGrantsGrp/TotalAmt | 0 | 164843 |
| IRS990/ForeignOfficeInd | 0 | 0 |
| IRS990/Form1098CFiledInd | 0 | 0 |
| IRS990/Form8282PropertyDisposedOfInd | 0 | 0 |
| IRS990/Form8899Filedind | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 0 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 1 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 2 | 60.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 3 | 7.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 4 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 5 | 4.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 6 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 7 | 4.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 8 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 9 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 10 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 11 | 3.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 12 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 13 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 14 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 15 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 16 | 60.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 17 | 60.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 18 | 60.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 19 | 60.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 20 | 60.00 |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 0 | X |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 1 | X |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 2 | X |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 3 | X |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 4 | 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/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/OtherCompensationAmt | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 1 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 2 | 153242 |
| 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 | 37701 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 17 | 21985 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 18 | 36770 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 19 | 11347 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 20 | 37613 |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 0 | JAMES B RICHARDSON |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 1 | ALDEN BIANCHI |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 2 | PETER J MCDONALD |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 3 | MARILYN WALLER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 4 | JEFFREY MENDELSOHN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 5 | CANDACE ALSOP |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 6 | JANIE WHITNEY |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 7 | JOHN GEE |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 8 | PETER JOSEPH |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 9 | ERIK FLEMMING |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 10 | DAVID HOYT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 11 | DIANA MERRIAM |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 12 | SUZANNE CHAPMAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 13 | JOHN GATES |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 14 | SARAH KAPLAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 15 | WILLIAM KENNARD |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 16 | MICHAEL RIENDEAU |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 17 | EUGENE LABONTE |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 18 | DANA HARBERT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 19 | FREDERICK MACDONALD |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 20 | JARED GEARY |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 1 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 2 | 358822 |
| 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 | 164050 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 17 | 120018 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 18 | 123581 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 19 | 124992 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 20 | 108950 |
| 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/TitleTxt | 0 | CHAIRMAN |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 1 | VICE PRESIDENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 2 | TRUSTEE/HEADMASTER |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 3 | PRESIDENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 4 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 5 | CLERK |
| 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 | ASSISTANT HEAD OF EDUCATIO |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 17 | DIRECTOR OF FINANCE AND OP |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 18 | DIRECTOR OF ADMISSIONS |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 19 | DIRECTOR OF DEVELOPMENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 20 | DIRECTOR OF GUIDANCE |
| IRS990/Form990ProvidedToGvrnBodyInd | 0 | 1 |
| IRS990/FormationYr | 0 | 1982 |
| IRS990/FormerOfcrEmployeesListedInd | 0 | 0 |
| IRS990/FSAuditedBasisGrp/ConsolidatedBasisFinclStmtInd | 0 | X |
| IRS990/FSAuditedInd | 0 | 1 |
| IRS990/FundraisingActivitiesInd | 0 | 0 |
| IRS990/GainOrLossGrp/SecuritiesAmt | 0 | -101181 |
| IRS990/GamingActivitiesInd | 0 | 0 |
| IRS990/GoverningBodyVotingMembersCnt | 0 | 14 |
| IRS990/GovernmentGrantsAmt | 0 | 171812 |
| IRS990/GrantAmt | 0 | 771976 |
| IRS990/GrantsToDomesticIndividualsGrp/ProgramServicesAmt | 0 | 705473 |
| IRS990/GrantsToDomesticIndividualsGrp/TotalAmt | 0 | 705473 |
| IRS990/GrantsToIndividualsInd | 0 | 1 |
| IRS990/GrantsToOrganizationsInd | 0 | 0 |
| IRS990/GrantToRelatedPersonInd | 0 | 0 |
| IRS990/GrossAmountSalesAssetsGrp/SecuritiesAmt | 0 | 1314795 |
| IRS990/GrossReceiptsAmt | 0 | 21838855 |
| IRS990/GroupReturnForAffiliatesInd | 0 | 0 |
| IRS990/IncludeFIN48FootnoteInd | 0 | 1 |
| IRS990/IndependentAuditFinclStmtInd | 0 | 0 |
| IRS990/IndependentVotingMemberCnt | 0 | 14 |
| IRS990/IndivRcvdGreaterThan100KCnt | 0 | 7 |
| IRS990/IndoorTanningServicesInd | 0 | 0 |
| IRS990/InfoInScheduleOPartIIIInd | 0 | X |
| IRS990/InfoInScheduleOPartVIInd | 0 | X |
| IRS990/InfoInScheduleOPartXIIInd | 0 | X |
| IRS990/InsuranceGrp/ManagementAndGeneralAmt | 0 | 49840 |
| IRS990/InsuranceGrp/ProgramServicesAmt | 0 | 121158 |
| IRS990/InsuranceGrp/TotalAmt | 0 | 170998 |
| IRS990/InterestGrp/FundraisingAmt | 0 | 15867 |
| IRS990/InterestGrp/ManagementAndGeneralAmt | 0 | 1587 |
| IRS990/InterestGrp/ProgramServicesAmt | 0 | 769573 |
| IRS990/InterestGrp/TotalAmt | 0 | 787027 |
| IRS990/InvestmentIncomeGrp/ExclusionAmt | 0 | 171205 |
| IRS990/InvestmentIncomeGrp/TotalRevenueColumnAmt | 0 | 171205 |
| IRS990/InvestmentInJointVentureInd | 0 | 0 |
| IRS990/InvestmentsPubTradedSecGrp/BOYAmt | 0 | 4540681 |
| IRS990/InvestmentsPubTradedSecGrp/EOYAmt | 0 | 5107488 |
| IRS990/InvestTaxExemptBondsInd | 0 | 0 |
| IRS990/IRPDocumentCnt | 0 | 119 |
| IRS990/IRPDocumentW2GCnt | 0 | 0 |
| IRS990/LandBldgEquipAccumDeprecAmt | 0 | 14985003 |
| IRS990/LandBldgEquipBasisNetGrp/BOYAmt | 0 | 45009162 |
| IRS990/LandBldgEquipBasisNetGrp/EOYAmt | 0 | 46367599 |
| IRS990/LandBldgEquipCostOrOtherBssAmt | 0 | 61352602 |
| IRS990/LegalDomicileStateCd | 0 | MA |
| IRS990/LessCostOthBasisSalesExpnssGrp/SecuritiesAmt | 0 | 1415976 |
| IRS990/LoanOutstandingInd | 0 | 1 |
| IRS990/LobbyingActivitiesInd | 0 | 0 |
| IRS990/LocalChaptersInd | 0 | 0 |
| IRS990/MaterialDiversionOrMisuseInd | 0 | 0 |
| IRS990/MembersOrStockholdersInd | 0 | 0 |
| IRS990/MethodOfAccountingAccrualInd | 0 | X |
| IRS990/MinutesOfCommitteesInd | 0 | 1 |
| IRS990/MinutesOfGoverningBodyInd | 0 | 1 |
| IRS990/MissionDesc | 0 | EAGLE HILL SCHOOL IS A COEDUCATIONAL BOARDING SCHOOL THAT EDUCATES STUDENTS WITH LEARNING DISABILITIES, INCLUDING ATTENTION DEFICIT DISORDER, IN GRADES EIGHT THROUGH TWELVE. EAGLE HILL STUDENTS DEMONSTRATE AVERAGE TO ABOVE AVERAGE COGNITIVE ABILITY AND ARE MOTIVATED TO EXPLORE ACADEMIC AND INTELLECTUAL PURSUITS IN A SUPPORTIVE ENVIRONMENT. ALTHOUGH EAGLE HILL ENCOURAGES EMOTIONAL AND BEHAVIORAL GROWTH, IT DOES NOT ACCEPT STUDENTS WITH PRIMARY CONCERNS IN THESE AREAS. EAGLE HILL DRAWS ITS 206 STUDENTS FROM ACROSS THE US AND THE INTERNATIONAL COMMUNITY, BRINGING A WELCOME DIVERSITY TO THE CAMPUS. |
| IRS990/MoreThan5000KToIndividualsInd | 0 | 1 |
| IRS990/MoreThan5000KToOrgInd | 0 | 0 |
| IRS990/NetAssetsOrFundBalancesBOYAmt | 0 | 41524069 |
| IRS990/NetAssetsOrFundBalancesEOYAmt | 0 | 43560315 |
| IRS990/NetGainOrLossInvestmentsGrp/ExclusionAmt | 0 | -101181 |
| IRS990/NetGainOrLossInvestmentsGrp/TotalRevenueColumnAmt | 0 | -101181 |
| IRS990/NetUnrelatedBusTxblIncmAmt | 0 | 0 |
| IRS990/NetUnrlzdGainsLossesInvstAmt | 0 | -36732 |
| IRS990/NoncashContributionsAmt | 0 | 854728 |
| IRS990/NondeductibleContributionsInd | 0 | 0 |
| IRS990/OccupancyGrp/FundraisingAmt | 0 | 20537 |
| IRS990/OccupancyGrp/ManagementAndGeneralAmt | 0 | 166654 |
| IRS990/OccupancyGrp/ProgramServicesAmt | 0 | 1390855 |
| IRS990/OccupancyGrp/TotalAmt | 0 | 1578046 |
| IRS990/OfficeExpensesGrp/FundraisingAmt | 0 | 36867 |
| IRS990/OfficeExpensesGrp/ManagementAndGeneralAmt | 0 | 342614 |
| IRS990/OfficeExpensesGrp/ProgramServicesAmt | 0 | 259525 |
| IRS990/OfficeExpensesGrp/TotalAmt | 0 | 639006 |
| IRS990/OfficerMailingAddressInd | 0 | 0 |
| IRS990/OnBehalfOfIssuerInd | 0 | 0 |
| IRS990/OperateHospitalInd | 0 | 0 |
| IRS990/Organization501c3Ind | 0 | X |
| IRS990/OrganizationFollowsSFAS117Ind | 0 | X |
| IRS990/OtherAssetsTotalGrp/BOYAmt | 0 | 5634065 |
| IRS990/OtherAssetsTotalGrp/EOYAmt | 0 | 4894526 |
| IRS990/OtherChangesInNetAssetsAmt | 0 | 0 |
| IRS990/OtherEmployeeBenefitsGrp/FundraisingAmt | 0 | 30624 |
| IRS990/OtherEmployeeBenefitsGrp/ManagementAndGeneralAmt | 0 | 4310 |
| IRS990/OtherEmployeeBenefitsGrp/ProgramServicesAmt | 0 | 937983 |
| IRS990/OtherEmployeeBenefitsGrp/TotalAmt | 0 | 972917 |
| IRS990/OtherExpensesGrp/Desc | 0 | FOOD SERVICE |
| IRS990/OtherExpensesGrp/Desc | 1 | MISCELLANEOUS |
| IRS990/OtherExpensesGrp/Desc | 2 | STUDENT ACTIVITIES |
| IRS990/OtherExpensesGrp/Desc | 3 | EDUCATIONAL SUPPLIES |
| IRS990/OtherExpensesGrp/FundraisingAmt | 0 | 24010 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 0 | 521222 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 1 | 83420 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 0 | 719359 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 1 | 30926 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 2 | 184233 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 3 | 191690 |
| IRS990/OtherExpensesGrp/TotalAmt | 0 | 719359 |
| IRS990/OtherExpensesGrp/TotalAmt | 1 | 576158 |
| IRS990/OtherExpensesGrp/TotalAmt | 2 | 267653 |
| IRS990/OtherExpensesGrp/TotalAmt | 3 | 191690 |
| IRS990/OtherSalariesAndWagesGrp/FundraisingAmt | 0 | 281015 |
| IRS990/OtherSalariesAndWagesGrp/ManagementAndGeneralAmt | 0 | 394580 |
| IRS990/OtherSalariesAndWagesGrp/ProgramServicesAmt | 0 | 6842529 |
| IRS990/OtherSalariesAndWagesGrp/TotalAmt | 0 | 7518124 |
| IRS990/PartialLiquidationInd | 0 | 0 |
| IRS990/PayPremiumsPrsnlBnftCntrctInd | 0 | 0 |
| IRS990/PayrollTaxesGrp/FundraisingAmt | 0 | 23336 |
| IRS990/PayrollTaxesGrp/ManagementAndGeneralAmt | 0 | 24218 |
| IRS990/PayrollTaxesGrp/ProgramServicesAmt | 0 | 505426 |
| IRS990/PayrollTaxesGrp/TotalAmt | 0 | 552980 |
| IRS990/PensionPlanContributionsGrp/FundraisingAmt | 0 | 33886 |
| IRS990/PensionPlanContributionsGrp/ManagementAndGeneralAmt | 0 | 106259 |
| IRS990/PensionPlanContributionsGrp/ProgramServicesAmt | 0 | 382720 |
| IRS990/PensionPlanContributionsGrp/TotalAmt | 0 | 522865 |
| IRS990/PermanentlyRstrNetAssetsGrp/BOYAmt | 0 | 3244487 |
| IRS990/PermanentlyRstrNetAssetsGrp/EOYAmt | 0 | 3368220 |
| IRS990/PledgesAndGrantsReceivableGrp/BOYAmt | 0 | 2265588 |
| IRS990/PledgesAndGrantsReceivableGrp/EOYAmt | 0 | 1108100 |
| IRS990/PoliticalCampaignActyInd | 0 | 0 |
| IRS990/PrepaidExpensesDefrdChargesGrp/BOYAmt | 0 | 150914 |
| IRS990/PrepaidExpensesDefrdChargesGrp/EOYAmt | 0 | 194415 |
| IRS990/PrincipalOfficerNm | 0 | PETER J MCDONALD |
| IRS990/ProfessionalFundraisingInd | 0 | 0 |
| IRS990/ProgramServiceRevenueGrp/BusinessCd | 0 | 900099 |
| IRS990/ProgramServiceRevenueGrp/BusinessCd | 1 | 900099 |
| IRS990/ProgramServiceRevenueGrp/Desc | 0 | TUITION AND FEES |
| IRS990/ProgramServiceRevenueGrp/Desc | 1 | OTHER |
| IRS990/ProgramServiceRevenueGrp/RelatedOrExemptFuncIncomeAmt | 0 | 16278299 |
| IRS990/ProgramServiceRevenueGrp/RelatedOrExemptFuncIncomeAmt | 1 | 399585 |
| IRS990/ProgramServiceRevenueGrp/TotalRevenueColumnAmt | 0 | 16278299 |
| IRS990/ProgramServiceRevenueGrp/TotalRevenueColumnAmt | 1 | 399585 |