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| IRS990/AccountsPayableAccrExpnssGrp/EOYAmt | 0 | 733585 |
| IRS990/AccountsReceivableGrp/BOYAmt | 0 | 111732 |
| IRS990/AccountsReceivableGrp/EOYAmt | 0 | 108166 |
| IRS990/ActivitiesConductedPrtshpInd | 0 | 0 |
| IRS990/ActivityOrMissionDesc | 0 | DEDICATED TO ACADEMIC EXCELLENCE AND DEVELOPMENT OF HIGH PERSONAL STANDARDS, PINGREE BELIEVES THAT A LOVE OF LEARNING FLOURISHES BEST IN A DIVERSE COMMUNITY THAT RESPECTS TRUTH, CURIOSITY, CREATIVITY, HUMOR, AND INDEPENDENT AND IMAGINATIVE THINKING. ABOVE ALL, PINGREE STRIVES TO INSTILL IN ITS STUDENTS INTEGRITY, DECENCY, COMPASSION, SELF-ESTEEM AND COMMITMENT TO ONE ANOTHER AND TO THE WORLD AT LARGE. |
| IRS990/AdvertisingGrp/ManagementAndGeneralAmt | 0 | 67396 |
| IRS990/AdvertisingGrp/TotalAmt | 0 | 67396 |
| IRS990/AllOtherContributionsAmt | 0 | 4560750 |
| IRS990/AllOtherExpensesGrp/FundraisingAmt | 0 | 126586 |
| IRS990/AllOtherExpensesGrp/ManagementAndGeneralAmt | 0 | 379822 |
| IRS990/AllOtherExpensesGrp/ProgramServicesAmt | 0 | 143548 |
| IRS990/AllOtherExpensesGrp/TotalAmt | 0 | 649956 |
| IRS990/AnnualDisclosureCoveredPrsnInd | 0 | 1 |
| IRS990/AuditCommitteeInd | 0 | 1 |
| IRS990/BackupWthldComplianceInd | 0 | 1 |
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| IRS990/BooksInCareOfDetail/PhoneNum | 0 | 9784684415 |
| IRS990/BooksInCareOfDetail/USAddress/AddressLine1Txt | 0 | 537 HIGHLAND STREET |
| IRS990/BooksInCareOfDetail/USAddress/CityNm | 0 | SOUTH HAMILTON |
| IRS990/BooksInCareOfDetail/USAddress/StateAbbreviationCd | 0 | MA |
| IRS990/BooksInCareOfDetail/USAddress/ZIPCd | 0 | 019821399 |
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| IRS990/BusinessRlnWithOfficerEntInd | 0 | 0 |
| IRS990/BusinessRlnWithOrgMemInd | 0 | 1 |
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| IRS990/CashNonInterestBearingGrp/EOYAmt | 0 | 2065390 |
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| IRS990/CollectionsOfArtInd | 0 | 0 |
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| IRS990/CompCurrentOfcrDirectorsGrp/ManagementAndGeneralAmt | 0 | 194292 |
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| IRS990/CompCurrentOfcrDirectorsGrp/TotalAmt | 0 | 651611 |
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| IRS990/ConferencesMeetingsGrp/TotalAmt | 0 | 8857 |
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| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/AddressLine1Txt | 0 | 65 JACKMAN STREET |
| IRS990/ContractorCompensationGrp/ContractorAddress/USAddress/CityNm | 0 | GEORGETOWN |
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| IRS990/ContractorCompensationGrp/ServicesDesc | 0 | CUSTODIAL SERVICES |
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| IRS990/CostOfGoodsSoldAmt | 0 | 66166 |
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| IRS990/CYGrantsAndSimilarPaidAmt | 0 | 3326717 |
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| IRS990/CYTotalExpensesAmt | 0 | 18837424 |
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| IRS990/CYTotalRevenueAmt | 0 | 22707517 |
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| IRS990/DepreciationDepletionGrp/TotalAmt | 0 | 1198905 |
| IRS990/Desc | 0 | EDUCATIONAL PROGRAM - TO PROVIDE A HIGH QUALITY, FOUR YEAR, CO-EDUCATIONAL EXPERIENCE FOR DAY STUDENTS IN GRADES 9 THROUGH 12. THERE ARE APPROXIMATELY 375 STUDENTS. |
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| IRS990/EmployeeCnt | 0 | 227 |
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| IRS990/FamilyOrBusinessRlnInd | 0 | 0 |
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| IRS990/FeesForServicesAccountingGrp/TotalAmt | 0 | 45180 |
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| IRS990/FeesForServicesLegalGrp/TotalAmt | 0 | 59331 |
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| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 12 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 13 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 14 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 15 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 16 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 17 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 18 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 19 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 20 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 21 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 22 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 23 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 24 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 25 | 5.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 26 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 27 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 28 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 29 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 30 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 31 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 32 | 40.00 |
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| 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/IndividualTrusteeOrDirectorInd | 19 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 20 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 21 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 22 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 23 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 24 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 25 | X |
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| 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 |
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| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 27 | 46149 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 28 | 30139 |
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| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 30 | 34250 |
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| IRS990/Form990PartVIISectionAGrp/PersonNm | 4 | KIM GUERSTER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 5 | RYAN HENDRICKSON |
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| IRS990/Form990PartVIISectionAGrp/PersonNm | 7 | KARLA KANEB |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 8 | JAMES KELLOGG III |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 9 | KRISTEN KROHG |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 10 | RALPH MASSILLON |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 11 | MARY MCGRATH |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 12 | BIANKA MEJIA |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 13 | TIMOTHY MENZIE |
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| IRS990/Form990PartVIISectionAGrp/PersonNm | 15 | JUSTIN PARKER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 16 | ALAN RAY |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 17 | KAISY ROSARIO |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 18 | CLIFF RUCKER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 19 | TERESA SOARES-PENA |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 20 | BETH LEVITSKY STRACHER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 21 | JOAN SULLIVAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 22 | RICHARD TADLER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 23 | CLAUDIA REYNDERS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 24 | WILLIAM GRINNELL |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 25 | JEFFREY RAWLINS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 26 | TIMOTHY JOHNSON |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 27 | JOHN BURNS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 28 | KRISTIN BROWN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 29 | STEVE FILOSA |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 30 | HARRY TAFT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 31 | CARA LAWLER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 32 | DAVID JONES |
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| 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 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 20 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 21 | TRUSTEE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 22 | PRESIDENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 23 | VICE PRESIDENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 24 | SECRETARY |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 25 | TREASURER |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 26 | HEAD OF SCHOOL |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 27 | DIRECTOR OF FINANCE AND OPS |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 28 | ASSISTANT HEAD OF SCHOOL |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 29 | DIRECTOR, PREP@PINGREE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 30 | MAJOR GIFTS OFFICER |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 31 | DIRECTOR OF ADVANCEMENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 32 | DIRECTOR OF FACILITIES |
| IRS990/Form990ProvidedToGvrnBodyInd | 0 | 0 |
| IRS990/Form990TFiledInd | 0 | 1 |
| IRS990/FormationYr | 0 | 1960 |
| IRS990/FormerOfcrEmployeesListedInd | 0 | 0 |
| IRS990/FSAuditedBasisGrp/SeparateBasisFinclStmtInd | 0 | X |
| IRS990/FSAuditedInd | 0 | 1 |
| IRS990/FundraisingActivitiesInd | 0 | 1 |
| IRS990/FundraisingAmt | 0 | 25100 |
| IRS990/FundraisingDirectExpensesAmt | 0 | 32345 |
| IRS990/FundraisingGrossIncomeAmt | 0 | 21928 |
| IRS990/GainOrLossGrp/SecuritiesAmt | 0 | 347514 |
| IRS990/GamingActivitiesInd | 0 | 0 |
| IRS990/GoverningBodyVotingMembersCnt | 0 | 26 |
| IRS990/GrantAmt | 0 | 3326717 |
| IRS990/GrantsToDomesticIndividualsGrp/ProgramServicesAmt | 0 | 3326717 |
| IRS990/GrantsToDomesticIndividualsGrp/TotalAmt | 0 | 3326717 |
| IRS990/GrantsToIndividualsInd | 0 | 1 |
| IRS990/GrantsToOrganizationsInd | 0 | 0 |
| IRS990/GrantToRelatedPersonInd | 0 | 0 |
| IRS990/GrossAmountSalesAssetsGrp/SecuritiesAmt | 0 | 347514 |
| IRS990/GrossReceiptsAmt | 0 | 23249595 |
| IRS990/GrossRentsGrp/RealAmt | 0 | 514003 |
| IRS990/GrossSalesOfInventoryAmt | 0 | 78299 |
| IRS990/GroupReturnForAffiliatesInd | 0 | 0 |
| IRS990/IncludeFIN48FootnoteInd | 0 | 1 |
| IRS990/IndependentAuditFinclStmtInd | 0 | 1 |
| IRS990/IndependentVotingMemberCnt | 0 | 26 |
| IRS990/IndivRcvdGreaterThan100KCnt | 0 | 5 |
| IRS990/IndoorTanningServicesInd | 0 | 0 |
| IRS990/InfoInScheduleOPartIIIInd | 0 | X |
| IRS990/InfoInScheduleOPartVIInd | 0 | X |
| IRS990/InformationTechnologyGrp/ManagementAndGeneralAmt | 0 | 100466 |
| IRS990/InformationTechnologyGrp/ProgramServicesAmt | 0 | 30822 |
| IRS990/InformationTechnologyGrp/TotalAmt | 0 | 131288 |
| IRS990/InsuranceGrp/ProgramServicesAmt | 0 | 180483 |
| IRS990/InsuranceGrp/TotalAmt | 0 | 180483 |
| IRS990/InterestGrp/ManagementAndGeneralAmt | 0 | 15152 |
| IRS990/InterestGrp/ProgramServicesAmt | 0 | 136371 |
| IRS990/InterestGrp/TotalAmt | 0 | 151523 |
| IRS990/InventoriesForSaleOrUseGrp/BOYAmt | 0 | 33452 |
| IRS990/InventoriesForSaleOrUseGrp/EOYAmt | 0 | 35902 |
| IRS990/InvestmentIncomeGrp/ExclusionAmt | 0 | 160762 |
| IRS990/InvestmentIncomeGrp/TotalRevenueColumnAmt | 0 | 160762 |
| IRS990/InvestmentInJointVentureInd | 0 | 0 |
| IRS990/InvestmentsOtherSecuritiesGrp/BOYAmt | 0 | 970093 |
| IRS990/InvestmentsOtherSecuritiesGrp/EOYAmt | 0 | 1023647 |
| IRS990/InvestmentsPubTradedSecGrp/BOYAmt | 0 | 10417658 |
| IRS990/InvestmentsPubTradedSecGrp/EOYAmt | 0 | 13514178 |
| IRS990/InvestTaxExemptBondsInd | 0 | 0 |
| IRS990/IRPDocumentCnt | 0 | 30 |
| IRS990/IRPDocumentW2GCnt | 0 | 0 |
| IRS990/LandBldgEquipAccumDeprecAmt | 0 | 15587243 |
| IRS990/LandBldgEquipBasisNetGrp/BOYAmt | 0 | 29668113 |
| IRS990/LandBldgEquipBasisNetGrp/EOYAmt | 0 | 31558749 |
| IRS990/LandBldgEquipCostOrOtherBssAmt | 0 | 47145992 |
| IRS990/LegalDomicileStateCd | 0 | MA |
| IRS990/LessCostOthBasisSalesExpnssGrp/SecuritiesAmt | 0 | 0 |
| IRS990/LessRentalExpensesGrp/RealAmt | 0 | 443567 |
| IRS990/LoanOutstandingInd | 0 | 0 |
| IRS990/LobbyingActivitiesInd | 0 | 1 |
| 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 | SEE SCHEDULE O |
| IRS990/MoreThan5000KToIndividualsInd | 0 | 0 |
| IRS990/MoreThan5000KToOrgInd | 0 | 0 |