| IRS990/AccountantCompileOrReviewInd | 0 | 0 |
| IRS990/AccountsPayableAccrExpnssGrp/BOYAmt | 0 | 252408 |
| IRS990/AccountsPayableAccrExpnssGrp/EOYAmt | 0 | 239539 |
| IRS990/AccountsReceivableGrp/BOYAmt | 0 | 1052518 |
| IRS990/AccountsReceivableGrp/EOYAmt | 0 | 743053 |
| IRS990/ActivitiesConductedPrtshpInd | 0 | 0 |
| IRS990/ActivityOrMissionDesc | 0 | MANOMET USES SCIENCE AND COLLABORATION TO IMPROVE THE HEALTH OF FLYWAYS, COASTAL ECOSYSTEMS, AND WORKING LANDS AND SEAS. |
| IRS990/AdvertisingGrp/FundraisingAmt | 0 | 345 |
| IRS990/AdvertisingGrp/ManagementAndGeneralAmt | 0 | 57 |
| IRS990/AdvertisingGrp/ProgramServicesAmt | 0 | 81 |
| IRS990/AdvertisingGrp/TotalAmt | 0 | 483 |
| IRS990/AllOtherContributionsAmt | 0 | 2785842 |
| IRS990/AmendedReturnInd | 0 | X |
| IRS990/AnnualDisclosureCoveredPrsnInd | 0 | 1 |
| IRS990/AuditCommitteeInd | 0 | 1 |
| IRS990/BackupWthldComplianceInd | 0 | 1 |
| IRS990/BooksInCareOfDetail/BusinessName/BusinessNameLine1Txt | 0 | KARON WIERMAN |
| IRS990/BooksInCareOfDetail/PhoneNum | 0 | 5082246521 |
| IRS990/BooksInCareOfDetail/USAddress/AddressLine1Txt | 0 | PO BOX 1770 |
| IRS990/BooksInCareOfDetail/USAddress/CityNm | 0 | MANOMET |
| IRS990/BooksInCareOfDetail/USAddress/StateAbbreviationCd | 0 | MA |
| IRS990/BooksInCareOfDetail/USAddress/ZIPCd | 0 | 02345 |
| IRS990/BusinessRlnWith35CtrlEntInd | 0 | 0 |
| IRS990/BusinessRlnWithFamMemInd | 0 | 0 |
| IRS990/BusinessRlnWithOrgMemInd | 0 | 0 |
| IRS990/CashNonInterestBearingGrp/BOYAmt | 0 | 123114 |
| IRS990/CashNonInterestBearingGrp/EOYAmt | 0 | 858688 |
| IRS990/ChangeToOrgDocumentsInd | 0 | 0 |
| IRS990/CntrctRcvdGreaterThan100KCnt | 0 | 1 |
| IRS990/CollectionsOfArtInd | 0 | 0 |
| IRS990/CompCurrentOfcrDirectorsGrp/FundraisingAmt | 0 | 22953 |
| IRS990/CompCurrentOfcrDirectorsGrp/ManagementAndGeneralAmt | 0 | 425377 |
| IRS990/CompCurrentOfcrDirectorsGrp/ProgramServicesAmt | 0 | 47076 |
| IRS990/CompCurrentOfcrDirectorsGrp/TotalAmt | 0 | 495406 |
| IRS990/CompensationFromOtherSrcsInd | 0 | 0 |
| IRS990/CompensationProcessCEOInd | 0 | 1 |
| IRS990/CompensationProcessOtherInd | 0 | 1 |
| IRS990/ConferencesMeetingsGrp/FundraisingAmt | 0 | 1327 |
| IRS990/ConferencesMeetingsGrp/ManagementAndGeneralAmt | 0 | 179 |
| IRS990/ConferencesMeetingsGrp/ProgramServicesAmt | 0 | 7209 |
| IRS990/ConferencesMeetingsGrp/TotalAmt | 0 | 8715 |
| IRS990/ConflictOfInterestPolicyInd | 0 | 1 |
| IRS990/ConservationEasementsInd | 0 | 0 |
| IRS990/ConsolidatedAuditFinclStmtInd | 0 | 0 |
| IRS990/ContractorCompensationGrp/CompensationAmt | 0 | 110500 |
| IRS990/ContractorCompensationGrp/ContractorAddress/ForeignAddress/AddressLine1Txt | 0 | 60 EDIFICIO EMILIA CERIO COTAY EEU |
| IRS990/ContractorCompensationGrp/ContractorAddress/ForeignAddress/CityNm | 0 | ASUNCION |
| IRS990/ContractorCompensationGrp/ContractorAddress/ForeignAddress/CountryCd | 0 | PA |
| IRS990/ContractorCompensationGrp/ContractorName/PersonNm | 0 | ROB CLAY |
| IRS990/ContractorCompensationGrp/ServicesDesc | 0 | CONSULTANT |
| IRS990/CreditCounselingInd | 0 | 0 |
| IRS990/CYBenefitsPaidToMembersAmt | 0 | 0 |
| IRS990/CYContributionsGrantsAmt | 0 | 3978567 |
| IRS990/CYGrantsAndSimilarPaidAmt | 0 | 0 |
| IRS990/CYInvestmentIncomeAmt | 0 | 501475 |
| IRS990/CYOtherExpensesAmt | 0 | 1774509 |
| IRS990/CYOtherRevenueAmt | 0 | 2439 |
| IRS990/CYProgramServiceRevenueAmt | 0 | 786 |
| IRS990/CYRevenuesLessExpensesAmt | 0 | -323647 |
| IRS990/CYSalariesCompEmpBnftPaidAmt | 0 | 3032405 |
| IRS990/CYTotalExpensesAmt | 0 | 4806914 |
| IRS990/CYTotalFundraisingExpenseAmt | 0 | 231691 |
| IRS990/CYTotalProfFndrsngExpnsAmt | 0 | 0 |
| IRS990/CYTotalRevenueAmt | 0 | 4483267 |
| IRS990/DecisionsSubjectToApprovaInd | 0 | 0 |
| IRS990/DeductibleArtContributionInd | 0 | 0 |
| IRS990/DeductibleNonCashContriInd | 0 | 1 |
| IRS990/DeferredRevenueGrp/BOYAmt | 0 | 437820 |
| IRS990/DeferredRevenueGrp/EOYAmt | 0 | 214158 |
| IRS990/DelegationOfMgmtDutiesInd | 0 | 0 |
| IRS990/DepreciationDepletionGrp/FundraisingAmt | 0 | 2678 |
| IRS990/DepreciationDepletionGrp/ManagementAndGeneralAmt | 0 | 56055 |
| IRS990/DepreciationDepletionGrp/ProgramServicesAmt | 0 | 5460 |
| IRS990/DepreciationDepletionGrp/TotalAmt | 0 | 64193 |
| IRS990/Desc | 0 | FLYWAYS - SAFEGUARDING THE HEALTH OF BIRDS -- SEE SCHEDULE O. |
| IRS990/DescribedInSection501c3Ind | 0 | 1 |
| IRS990/DisregardedEntityInd | 0 | 0 |
| IRS990/DocumentRetentionPolicyInd | 0 | 1 |
| IRS990/DonorAdvisedFundInd | 0 | 0 |
| IRS990/DonorRestrictionNetAssetsGrp/BOYAmt | 0 | 21465864 |
| IRS990/DonorRestrictionNetAssetsGrp/EOYAmt | 0 | 22522927 |
| IRS990/DonorRstrOrQuasiEndowmentsInd | 0 | 1 |
| IRS990/ElectionOfBoardMembersInd | 0 | 0 |
| IRS990/EmployeeCnt | 0 | 37 |
| IRS990/EmploymentTaxReturnsFiledInd | 0 | 1 |
| IRS990/EngagedInExcessBenefitTransInd | 0 | 0 |
| IRS990/ExpenseAmt | 0 | 1387872 |
| IRS990/FamilyOrBusinessRlnInd | 0 | 0 |
| IRS990/FederalGrantAuditPerformedInd | 0 | 1 |
| IRS990/FederalGrantAuditRequiredInd | 0 | 1 |
| IRS990/FeesForServicesAccountingGrp/ManagementAndGeneralAmt | 0 | 58400 |
| IRS990/FeesForServicesAccountingGrp/TotalAmt | 0 | 58400 |
| IRS990/FeesForServicesLegalGrp/ManagementAndGeneralAmt | 0 | 8960 |
| IRS990/FeesForServicesLegalGrp/TotalAmt | 0 | 8960 |
| IRS990/FeesForServicesOtherGrp/FundraisingAmt | 0 | 14563 |
| IRS990/FeesForServicesOtherGrp/ManagementAndGeneralAmt | 0 | 219243 |
| IRS990/FeesForServicesOtherGrp/ProgramServicesAmt | 0 | 764511 |
| IRS990/FeesForServicesOtherGrp/TotalAmt | 0 | 998317 |
| IRS990/FeesForSrvcInvstMgmntFeesGrp/ManagementAndGeneralAmt | 0 | 120448 |
| IRS990/FeesForSrvcInvstMgmntFeesGrp/TotalAmt | 0 | 120448 |
| IRS990/ForeignActivitiesInd | 0 | 1 |
| IRS990/ForeignFinancialAccountInd | 0 | 0 |
| IRS990/ForeignOfficeInd | 0 | 1 |
| IRS990/Form8282PropertyDisposedOfInd | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 0 | 1.00 |
| 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/AverageHoursPerWeekRt | 6 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 7 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 8 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 9 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 10 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 11 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 12 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 13 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 14 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 15 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 16 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 17 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 18 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 19 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 20 | 1.00 |
| 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/AverageHoursPerWeekRt | 25 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 26 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 27 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 28 | 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/IndividualTrusteeOrDirectorInd | 19 | X |
| IRS990/Form990PartVIISectionAGrp/IndividualTrusteeOrDirectorInd | 20 | 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/OfficerInd | 6 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 7 | X |
| IRS990/Form990PartVIISectionAGrp/OfficerInd | 8 | 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 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 20 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 21 | 25440 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 22 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 23 | 24025 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 24 | 20175 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 25 | 25523 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 26 | 27320 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 27 | 7823 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 28 | 22503 |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 0 | NANCY E DEMPZE |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 1 | DWIGHT H DEMAY |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 2 | MICHAEL TAUBENBERGER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 3 | DAVID BRYAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 4 | LOUISE CONANT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 5 | MOLLY N CORNELL |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 6 | DAVID ELLIS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 7 | ANDY J FALENDER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 8 | WALTER J GAMBLE MD |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 9 | DEBORAH I HARRISON |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 10 | WESTON HOWLAND III |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 11 | PETER LARKIN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 12 | BARBARA MCMILLAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 13 | JEFFREY F PETERS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 14 | J MICHAEL REED |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 15 | DANIEL G SARLES |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 16 | LAWRENCE A SELZER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 17 | DEAN H STEEGER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 18 | EMILY V WADE |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 19 | SUSANNA C HINDS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 20 | NANCY STAGER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 21 | JOHN M HAGAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 22 | ELIZABETH SCHUELER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 23 | MARK LAFAVER |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 24 | KARON WIERMAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 25 | STEPHEN BROWN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 26 | ANDREW WHITMAN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 27 | CHERYL BOTIERI |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 28 | ERIC WALBERG |
| 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 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 20 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 21 | 175455 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 22 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 23 | 74554 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 24 | 89062 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 25 | 129384 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 26 | 107924 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 27 | 130384 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 28 | 100868 |
| 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/ReportableCompFromRltdOrgAmt | 25 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 26 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 27 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromRltdOrgAmt | 28 | 0 |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 0 | CHAIR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 1 | VICE CHAIR |
| 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 | TRUSTEE (UNTIL 6/20) |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 20 | VICE CHAIR (UNTIL 6/20) |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 21 | PRESIDENT/CEO (UNTIL 12/19) |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 22 | PRESIDENT/CEO |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 23 | VP FINANCE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 24 | COMPTROLLER, DIR., HR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 25 | VP, SHOREBIRD CONSERVATION |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 26 | DIR., SUSTAINABLE ECONOMIES |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 27 | VP MISSION ADVANCEMENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 28 | SENIOR PROGRAM LEADER |
| IRS990/Form990ProvidedToGvrnBodyInd | 0 | 1 |
| IRS990/FormationYr | 0 | 1989 |
| IRS990/FormerOfcrEmployeesListedInd | 0 | 0 |
| IRS990/FSAuditedBasisGrp/SeparateBasisFinclStmtInd | 0 | X |
| IRS990/FSAuditedInd | 0 | 1 |
| IRS990/FundraisingActivitiesInd | 0 | 0 |
| IRS990/GamingActivitiesInd | 0 | 0 |
| IRS990/GoverningBodyVotingMembersCnt | 0 | 19 |
| IRS990/GovernmentGrantsAmt | 0 | 1192725 |
| IRS990/GrantsToIndividualsInd | 0 | 0 |
| IRS990/GrantsToOrganizationsInd | 0 | 0 |
| IRS990/GrantToRelatedPersonInd | 0 | 0 |
| IRS990/GrossReceiptsAmt | 0 | 4483267 |
| IRS990/GroupReturnForAffiliatesInd | 0 | 0 |
| IRS990/IncludeFIN48FootnoteInd | 0 | 1 |
| IRS990/IndependentAuditFinclStmtInd | 0 | 1 |
| IRS990/IndependentVotingMemberCnt | 0 | 19 |
| IRS990/IndivRcvdGreaterThan100KCnt | 0 | 5 |
| IRS990/IndoorTanningServicesInd | 0 | 0 |
| IRS990/InfoInScheduleOPartIIIInd | 0 | X |
| IRS990/InfoInScheduleOPartIXInd | 0 | X |
| IRS990/InfoInScheduleOPartVIInd | 0 | X |
| IRS990/InformationTechnologyGrp/FundraisingAmt | 0 | 103 |
| IRS990/InformationTechnologyGrp/ManagementAndGeneralAmt | 0 | 18622 |
| IRS990/InformationTechnologyGrp/ProgramServicesAmt | 0 | 30438 |
| IRS990/InformationTechnologyGrp/TotalAmt | 0 | 49163 |
| IRS990/InsuranceGrp/ManagementAndGeneralAmt | 0 | 40807 |
| IRS990/InsuranceGrp/ProgramServicesAmt | 0 | 15693 |
| IRS990/InsuranceGrp/TotalAmt | 0 | 56500 |
| IRS990/InvestmentIncomeGrp/ExclusionAmt | 0 | 501475 |
| IRS990/InvestmentIncomeGrp/TotalRevenueColumnAmt | 0 | 501475 |
| IRS990/InvestmentInJointVentureInd | 0 | 0 |
| IRS990/InvestmentsPubTradedSecGrp/BOYAmt | 0 | 21815272 |
| IRS990/InvestmentsPubTradedSecGrp/EOYAmt | 0 | 19623227 |
| IRS990/IRPDocumentCnt | 0 | 52 |
| IRS990/IRPDocumentW2GCnt | 0 | 0 |
| IRS990/LandBldgEquipAccumDeprecAmt | 0 | 2481473 |
| IRS990/LandBldgEquipBasisNetGrp/BOYAmt | 0 | 973840 |
| IRS990/LandBldgEquipBasisNetGrp/EOYAmt | 0 | 939576 |
| IRS990/LandBldgEquipCostOrOtherBssAmt | 0 | 3421049 |
| IRS990/LegalDomicileStateCd | 0 | MA |
| 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 | 1 |
| IRS990/MinutesOfGoverningBodyInd | 0 | 1 |
| IRS990/MissionDesc | 0 | MANOMET USES SCIENCE AND COLLABORATION TO IMPROVE THE HEALTH OF FLYWAYS, COASTAL ECOSYSTEMS, AND WORKING LANDS AND SEAS. |
| IRS990/MoreThan5000KToIndividualsInd | 0 | 0 |
| IRS990/MoreThan5000KToOrgInd | 0 | 0 |
| IRS990/NetAssetsOrFundBalancesBOYAmt | 0 | 27272969 |
| IRS990/NetAssetsOrFundBalancesEOYAmt | 0 | 28757168 |
| IRS990/NetUnrelatedBusTxblIncmAmt | 0 | 0 |
| IRS990/NetUnrlzdGainsLossesInvstAmt | 0 | 1807846 |
| IRS990/NoDonorRestrictionNetAssetsGrp/BOYAmt | 0 | 5807105 |
| IRS990/NoDonorRestrictionNetAssetsGrp/EOYAmt | 0 | 6234241 |
| IRS990/NoncashContributionsAmt | 0 | 383153 |
| IRS990/NondeductibleContributionsInd | 0 | 0 |
| IRS990/OccupancyGrp/ManagementAndGeneralAmt | 0 | 32031 |
| IRS990/OccupancyGrp/ProgramServicesAmt | 0 | 84394 |
| IRS990/OccupancyGrp/TotalAmt | 0 | 116425 |
| IRS990/OfficeExpensesGrp/FundraisingAmt | 0 | 1376 |
| IRS990/OfficeExpensesGrp/ManagementAndGeneralAmt | 0 | 37126 |
| IRS990/OfficeExpensesGrp/ProgramServicesAmt | 0 | 44121 |
| IRS990/OfficeExpensesGrp/TotalAmt | 0 | 82623 |
| IRS990/OfficerMailingAddressInd | 0 | 0 |
| IRS990/OperateHospitalInd | 0 | 0 |
| IRS990/Organization501c3Ind | 0 | X |
| IRS990/OrganizationFollowsFASB117Ind | 0 | X |
| IRS990/OtherAssetsTotalGrp/BOYAmt | 0 | 68411 |
| IRS990/OtherAssetsTotalGrp/EOYAmt | 0 | 74299 |
| IRS990/OtherChangesInNetAssetsAmt | 0 | 0 |
| IRS990/OtherEmployeeBenefitsGrp/FundraisingAmt | 0 | 19680 |
| IRS990/OtherEmployeeBenefitsGrp/ManagementAndGeneralAmt | 0 | 67315 |
| IRS990/OtherEmployeeBenefitsGrp/ProgramServicesAmt | 0 | 192623 |
| IRS990/OtherEmployeeBenefitsGrp/TotalAmt | 0 | 279618 |
| IRS990/OtherExpensesGrp/Desc | 0 | EQUIPMENT |
| IRS990/OtherExpensesGrp/Desc | 1 | PRINTING |
| IRS990/OtherExpensesGrp/Desc | 2 | BANK FEES |
| IRS990/OtherExpensesGrp/Desc | 3 | PAYROLL PROCESSING |
| IRS990/OtherExpensesGrp/FundraisingAmt | 0 | 7644 |
| IRS990/OtherExpensesGrp/FundraisingAmt | 1 | 1893 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 0 | 12502 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 1 | 3844 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 2 | 2216 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 3 | 8763 |