| IRS990/AccountantCompileOrReviewInd | 0 | 0 |
| IRS990/AccountsPayableAccrExpnssGrp/BOYAmt | 0 | 574036 |
| IRS990/AccountsPayableAccrExpnssGrp/EOYAmt | 0 | 677817 |
| IRS990/AccountsReceivableGrp/BOYAmt | 0 | 304066 |
| IRS990/AccountsReceivableGrp/EOYAmt | 0 | 671600 |
| IRS990/ActivitiesConductedPrtshpInd | 0 | 0 |
| IRS990/ActivityOrMissionDesc | 0 | THE ORGANIZATION IS DEDICATED TO THE PROTECTION, RESTORATION, SUSTAINABLE USE AND ENJOYMENT OF BUZZARDS BAY AND ITS WATERSHED. |
| IRS990/AdvertisingGrp/FundraisingAmt | 0 | 362 |
| IRS990/AdvertisingGrp/ManagementAndGeneralAmt | 0 | 3613 |
| IRS990/AdvertisingGrp/ProgramServicesAmt | 0 | 7026 |
| IRS990/AdvertisingGrp/TotalAmt | 0 | 11001 |
| IRS990/AllOtherContributionsAmt | 0 | 7878787 |
| IRS990/AnnualDisclosureCoveredPrsnInd | 0 | 1 |
| IRS990/AuditCommitteeInd | 0 | 1 |
| IRS990/BackupWthldComplianceInd | 0 | 1 |
| IRS990/BooksInCareOfDetail/BusinessName/BusinessNameLine1Txt | 0 | THE ORGANIZATION |
| IRS990/BooksInCareOfDetail/PhoneNum | 0 | 5089996363 |
| IRS990/BooksInCareOfDetail/USAddress/AddressLine1Txt | 0 | 114 FRONT STREET |
| IRS990/BooksInCareOfDetail/USAddress/CityNm | 0 | NEW BEDFORD |
| IRS990/BooksInCareOfDetail/USAddress/StateAbbreviationCd | 0 | MA |
| IRS990/BooksInCareOfDetail/USAddress/ZIPCd | 0 | 02740 |
| IRS990/BusinessRlnWith35CtrlEntInd | 0 | 0 |
| IRS990/BusinessRlnWithFamMemInd | 0 | 0 |
| IRS990/BusinessRlnWithOrgMemInd | 0 | 1 |
| IRS990/CashNonInterestBearingGrp/BOYAmt | 0 | 220209 |
| IRS990/CashNonInterestBearingGrp/EOYAmt | 0 | 305283 |
| IRS990/ChangeToOrgDocumentsInd | 0 | 0 |
| IRS990/CntrctRcvdGreaterThan100KCnt | 0 | 0 |
| IRS990/CollectionsOfArtInd | 0 | 0 |
| IRS990/CompCurrentOfcrDirectorsGrp/FundraisingAmt | 0 | 61479 |
| IRS990/CompCurrentOfcrDirectorsGrp/ManagementAndGeneralAmt | 0 | 245913 |
| IRS990/CompCurrentOfcrDirectorsGrp/TotalAmt | 0 | 307392 |
| IRS990/CompensationFromOtherSrcsInd | 0 | 0 |
| IRS990/CompensationProcessCEOInd | 0 | 1 |
| IRS990/CompensationProcessOtherInd | 0 | 0 |
| IRS990/ConferencesMeetingsGrp/FundraisingAmt | 0 | 18144 |
| IRS990/ConferencesMeetingsGrp/ManagementAndGeneralAmt | 0 | 9859 |
| IRS990/ConferencesMeetingsGrp/ProgramServicesAmt | 0 | 12796 |
| IRS990/ConferencesMeetingsGrp/TotalAmt | 0 | 40799 |
| IRS990/ConflictOfInterestPolicyInd | 0 | 1 |
| IRS990/ConservationEasementsInd | 0 | 1 |
| IRS990/ConsolidatedAuditFinclStmtInd | 0 | 1 |
| IRS990/ContriRptFundraisingEventAmt | 0 | 540816 |
| IRS990/CreditCounselingInd | 0 | 0 |
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| IRS990/CYContributionsGrantsAmt | 0 | 12525360 |
| IRS990/CYGrantsAndSimilarPaidAmt | 0 | 0 |
| IRS990/CYInvestmentIncomeAmt | 0 | 512330 |
| IRS990/CYOtherExpensesAmt | 0 | 5860342 |
| IRS990/CYOtherRevenueAmt | 0 | 196777 |
| IRS990/CYProgramServiceRevenueAmt | 0 | 0 |
| IRS990/CYRevenuesLessExpensesAmt | 0 | 4103767 |
| IRS990/CYSalariesCompEmpBnftPaidAmt | 0 | 3270358 |
| IRS990/CYTotalExpensesAmt | 0 | 9130700 |
| IRS990/CYTotalFundraisingExpenseAmt | 0 | 691083 |
| IRS990/CYTotalProfFndrsngExpnsAmt | 0 | 0 |
| IRS990/CYTotalRevenueAmt | 0 | 13234467 |
| IRS990/DecisionsSubjectToApprovaInd | 0 | 0 |
| IRS990/DeductibleArtContributionInd | 0 | 0 |
| IRS990/DeductibleNonCashContriInd | 0 | 1 |
| IRS990/DeferredRevenueGrp/BOYAmt | 0 | 782089 |
| IRS990/DeferredRevenueGrp/EOYAmt | 0 | 772664 |
| IRS990/DelegationOfMgmtDutiesInd | 0 | 0 |
| IRS990/DepreciationDepletionGrp/FundraisingAmt | 0 | 1167 |
| IRS990/DepreciationDepletionGrp/ManagementAndGeneralAmt | 0 | 134283 |
| IRS990/DepreciationDepletionGrp/ProgramServicesAmt | 0 | 369962 |
| IRS990/DepreciationDepletionGrp/TotalAmt | 0 | 505412 |
| IRS990/Desc | 0 | WATERSHED PROTECTION - ACTIVITIES IN OUR WATERSHED PROTECTION PROGRAM INCLUDE LAND CONSERVATION EFFORTS AIMED AT COLLABORATIONS AND ACCELERATING THE RATE OF PERMANENT LAND PROTECTION IN THE BAY WATERSHED. OUR BAY LANDS REVOLVING FUND HELPS LOCAL LAND CONSERVATION INITIATIVES COMPETE IN THE REAL ESTATE MARKET. |
| IRS990/DescribedInSection501c3Ind | 0 | 1 |
| IRS990/DisregardedEntityInd | 0 | 0 |
| IRS990/DocumentRetentionPolicyInd | 0 | 1 |
| IRS990/DonorAdvisedFundInd | 0 | 0 |
| IRS990/DonorRestrictionNetAssetsGrp/BOYAmt | 0 | 12442010 |
| IRS990/DonorRestrictionNetAssetsGrp/EOYAmt | 0 | 12442010 |
| IRS990/DonorRstrOrQuasiEndowmentsInd | 0 | 1 |
| IRS990/ElectionOfBoardMembersInd | 0 | 0 |
| IRS990/EmployeeCnt | 0 | 63 |
| IRS990/EmploymentTaxReturnsFiledInd | 0 | 1 |
| IRS990/EngagedInExcessBenefitTransInd | 0 | 0 |
| IRS990/ExpenseAmt | 0 | 4270349 |
| IRS990/FamilyOrBusinessRlnInd | 0 | 0 |
| IRS990/FederalGrantAuditRequiredInd | 0 | 0 |
| IRS990/FeesForServicesAccountingGrp/ManagementAndGeneralAmt | 0 | 50923 |
| IRS990/FeesForServicesAccountingGrp/TotalAmt | 0 | 50923 |
| IRS990/FeesForServicesLegalGrp/ManagementAndGeneralAmt | 0 | 755 |
| IRS990/FeesForServicesLegalGrp/ProgramServicesAmt | 0 | 37824 |
| IRS990/FeesForServicesLegalGrp/TotalAmt | 0 | 38579 |
| IRS990/FeesForServicesLobbyingGrp/ProgramServicesAmt | 0 | 6626 |
| IRS990/FeesForServicesLobbyingGrp/TotalAmt | 0 | 6626 |
| IRS990/FeesForServicesOtherGrp/FundraisingAmt | 0 | 42778 |
| IRS990/FeesForServicesOtherGrp/ManagementAndGeneralAmt | 0 | 114403 |
| IRS990/FeesForServicesOtherGrp/ProgramServicesAmt | 0 | 3560298 |
| IRS990/FeesForServicesOtherGrp/TotalAmt | 0 | 3717479 |
| IRS990/ForeignActivitiesInd | 0 | 0 |
| IRS990/ForeignFinancialAccountInd | 0 | 0 |
| IRS990/ForeignOfficeInd | 0 | 0 |
| IRS990/Form8282PropertyDisposedOfInd | 0 | 0 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 0 | 0.50 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 1 | 0.50 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 2 | 0.50 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 3 | 0.50 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 4 | 0.50 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 5 | 0.50 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 6 | 0.50 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 0 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 1 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 2 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 3 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 4 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 5 | 40.00 |
| 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 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 22 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 23 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 24 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 25 | 1.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 26 | 1.00 |
| 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/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/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 | 27992 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 1 | 15333 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 2 | 11634 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 3 | 14171 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 4 | 2845 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 5 | 11678 |
| 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 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 22 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 23 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 24 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 25 | 0 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 26 | 0 |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 0 | MARK RASMUSSEN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 1 | BRENDAN ANNETT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 2 | RACHEL JAKUBA |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 3 | KORRIN PETERSEN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 4 | BETH MCDERMOTT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 5 | STUART DOWNIE |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 6 | MICHAEL ANGELINI ESQ |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 7 | MICHAEL HUGUENIN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 8 | CHRIS SCHADE |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 9 | MELISSA HASKELL |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 10 | SCOTT ZEIEN |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 11 | LAURA RYAN SHACHOY ESQ |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 12 | JOHN BULLARD |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 13 | ANDREW DIMMICK |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 14 | KATHERINE JONES |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 15 | D LLOYD MACDONALD ESQ |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 16 | CHRISTOPHER NEILL PHD |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 17 | JULIUS BRITTO |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 18 | VIRGINIA CLARK |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 19 | DAVID CROLL |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 20 | KENDRA MEDINA |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 21 | CHRISTINE PARKS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 22 | SKYLAH REIS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 23 | DON DUFAULT |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 24 | EMMA GREEN-BEACH |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 25 | PAUL ELIAS |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 26 | HILARY PROUTY VINEYARD |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 0 | 247172 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 1 | 175180 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 2 | 129245 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 3 | 119447 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 4 | 121765 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 5 | 100255 |
| 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 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 22 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 23 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 24 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 25 | 0 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 26 | 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/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/TitleTxt | 0 | PRESIDENT & CEO |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 1 | VP WATERSHED PROTECTION |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 2 | VP BAY SCIENCE |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 3 | VP ADVOCACY |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 4 | VP ADVANCEMENT |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 5 | VP OUTDOOR EXPLORATION |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 6 | CHAIR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 7 | VICE-CHAIR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 8 | TREASURER |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 9 | CLERK ( AS OF 8/2023) |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 10 | CLERK (UNTIL 8/2023) |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 11 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 12 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 13 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 14 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 15 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 16 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 17 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 18 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 19 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 20 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 21 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 22 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 23 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 24 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 25 | DIRECTOR |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 26 | DIRECTOR (UNTIL 8/2023) |
| IRS990/Form990ProvidedToGvrnBodyInd | 0 | 1 |
| IRS990/FormationYr | 0 | 1987 |
| IRS990/FormerOfcrEmployeesListedInd | 0 | 0 |
| IRS990/FSAuditedBasisGrp/ConsolidatedBasisFinclStmtInd | 0 | X |
| IRS990/FSAuditedInd | 0 | 1 |
| IRS990/FundraisingActivitiesInd | 0 | 1 |
| IRS990/FundraisingAmt | 0 | 540816 |
| IRS990/FundraisingDirectExpensesAmt | 0 | 164232 |
| IRS990/FundraisingGrossIncomeAmt | 0 | 34794 |
| IRS990/GainOrLossGrp/OtherAmt | 0 | 316718 |
| IRS990/GainOrLossGrp/SecuritiesAmt | 0 | -24882 |
| IRS990/GamingActivitiesInd | 0 | 0 |
| IRS990/GoverningBodyVotingMembersCnt | 0 | 20 |
| IRS990/GovernmentGrantsAmt | 0 | 4105757 |
| IRS990/GrantsToIndividualsInd | 0 | 0 |
| IRS990/GrantsToOrganizationsInd | 0 | 0 |
| IRS990/GrantToRelatedPersonInd | 0 | 0 |
| IRS990/GrossAmountSalesAssetsGrp/OtherAmt | 0 | 390473 |
| IRS990/GrossAmountSalesAssetsGrp/SecuritiesAmt | 0 | 113281 |
| IRS990/GrossReceiptsAmt | 0 | 13622272 |
| IRS990/GrossRentsGrp/RealAmt | 0 | 164384 |
| IRS990/GroupReturnForAffiliatesInd | 0 | 0 |
| IRS990/IncludeFIN48FootnoteInd | 0 | 1 |
| IRS990/IndependentAuditFinclStmtInd | 0 | 0 |
| IRS990/IndependentVotingMemberCnt | 0 | 19 |
| IRS990/IndivRcvdGreaterThan100KCnt | 0 | 6 |
| IRS990/IndoorTanningServicesInd | 0 | 0 |
| IRS990/InfoInScheduleOPartIXInd | 0 | X |
| IRS990/InfoInScheduleOPartVIInd | 0 | X |
| IRS990/InfoInScheduleOPartXIIInd | 0 | X |
| IRS990/InformationTechnologyGrp/FundraisingAmt | 0 | 34270 |
| IRS990/InformationTechnologyGrp/ManagementAndGeneralAmt | 0 | 37854 |
| IRS990/InformationTechnologyGrp/ProgramServicesAmt | 0 | 4533 |
| IRS990/InformationTechnologyGrp/TotalAmt | 0 | 76657 |
| IRS990/InsuranceGrp/FundraisingAmt | 0 | 4256 |
| IRS990/InsuranceGrp/ManagementAndGeneralAmt | 0 | 67033 |
| IRS990/InsuranceGrp/ProgramServicesAmt | 0 | 48313 |
| IRS990/InsuranceGrp/TotalAmt | 0 | 119602 |
| IRS990/InterestGrp/ManagementAndGeneralAmt | 0 | 2125 |
| IRS990/InterestGrp/ProgramServicesAmt | 0 | 177887 |
| IRS990/InterestGrp/TotalAmt | 0 | 180012 |
| IRS990/InvestmentIncomeGrp/ExclusionAmt | 0 | 220494 |
| IRS990/InvestmentIncomeGrp/TotalRevenueColumnAmt | 0 | 220494 |
| IRS990/InvestmentInJointVentureInd | 0 | 0 |
| IRS990/InvestmentsPubTradedSecGrp/BOYAmt | 0 | 7703461 |
| IRS990/InvestmentsPubTradedSecGrp/EOYAmt | 0 | 7563174 |
| IRS990/IRPDocumentCnt | 0 | 32 |
| IRS990/IRPDocumentW2GCnt | 0 | 0 |
| IRS990/LandBldgEquipAccumDeprecAmt | 0 | 3740281 |
| IRS990/LandBldgEquipBasisNetGrp/BOYAmt | 0 | 12686848 |
| IRS990/LandBldgEquipBasisNetGrp/EOYAmt | 0 | 12894951 |
| IRS990/LandBldgEquipCostOrOtherBssAmt | 0 | 16635232 |
| IRS990/LegalDomicileStateCd | 0 | MA |
| IRS990/LessCostOthBasisSalesExpnssGrp/OtherAmt | 0 | 73755 |
| IRS990/LessCostOthBasisSalesExpnssGrp/SecuritiesAmt | 0 | 138163 |
| IRS990/LessRentalExpensesGrp/RealAmt | 0 | 11655 |
| IRS990/LoanOutstandingInd | 0 | 0 |
| IRS990/LobbyingActivitiesInd | 0 | 1 |
| IRS990/LocalChaptersInd | 0 | 1 |
| IRS990/MaterialDiversionOrMisuseInd | 0 | 0 |
| IRS990/MembersOrStockholdersInd | 0 | 0 |
| IRS990/MethodOfAccountingAccrualInd | 0 | X |
| IRS990/MinutesOfCommitteesInd | 0 | 1 |
| IRS990/MinutesOfGoverningBodyInd | 0 | 1 |
| IRS990/MissionDesc | 0 | THE ORGANIZATION IS DEDICATED TO THE PROTECTION, RESTORATION, SUSTAINABLE USE AND ENJOYMENT OF BUZZARDS BAY AND ITS WATERSHED. |
| IRS990/MoreThan5000KToIndividualsInd | 0 | 0 |
| IRS990/MoreThan5000KToOrgInd | 0 | 0 |
| IRS990/MortgNotesPyblScrdInvstPropGrp/BOYAmt | 0 | 1953534 |
| IRS990/MortgNotesPyblScrdInvstPropGrp/EOYAmt | 0 | 2649680 |
| IRS990/NetAssetsOrFundBalancesBOYAmt | 0 | 34937934 |
| IRS990/NetAssetsOrFundBalancesEOYAmt | 0 | 39899964 |
| IRS990/NetGainOrLossInvestmentsGrp/ExclusionAmt | 0 | 291836 |
| IRS990/NetGainOrLossInvestmentsGrp/TotalRevenueColumnAmt | 0 | 291836 |
| IRS990/NetIncmFromFundraisingEvtGrp/ExclusionAmt | 0 | -129438 |
| IRS990/NetIncmFromFundraisingEvtGrp/TotalRevenueColumnAmt | 0 | -129438 |
| IRS990/NetRentalIncomeOrLossGrp/ExclusionAmt | 0 | 152729 |
| IRS990/NetRentalIncomeOrLossGrp/TotalRevenueColumnAmt | 0 | 152729 |
| IRS990/NetUnrelatedBusTxblIncmAmt | 0 | 0 |
| IRS990/NetUnrlzdGainsLossesInvstAmt | 0 | 858263 |
| IRS990/NoDonorRestrictionNetAssetsGrp/BOYAmt | 0 | 22495924 |
| IRS990/NoDonorRestrictionNetAssetsGrp/EOYAmt | 0 | 27457954 |
| IRS990/NoncashContributionsAmt | 0 | 72507 |
| IRS990/NondeductibleContributionsInd | 0 | 0 |
| IRS990/OccupancyGrp/ManagementAndGeneralAmt | 0 | 46046 |
| IRS990/OccupancyGrp/ProgramServicesAmt | 0 | 78454 |
| IRS990/OccupancyGrp/TotalAmt | 0 | 124500 |
| IRS990/OfficeExpensesGrp/FundraisingAmt | 0 | 21932 |
| IRS990/OfficeExpensesGrp/ManagementAndGeneralAmt | 0 | 100517 |
| IRS990/OfficeExpensesGrp/ProgramServicesAmt | 0 | 128622 |
| IRS990/OfficeExpensesGrp/TotalAmt | 0 | 251071 |
| IRS990/OfficerMailingAddressInd | 0 | 0 |
| IRS990/OperateHospitalInd | 0 | 0 |
| IRS990/Organization501c3Ind | 0 | X |
| IRS990/OrganizationFollowsFASB117Ind | 0 | X |
| IRS990/OtherAssetsTotalGrp/BOYAmt | 0 | 14399190 |
| IRS990/OtherAssetsTotalGrp/EOYAmt | 0 | 18686207 |
| IRS990/OtherChangesInNetAssetsAmt | 0 | 0 |
| IRS990/OtherEmployeeBenefitsGrp/FundraisingAmt | 0 | 30329 |
| IRS990/OtherEmployeeBenefitsGrp/ManagementAndGeneralAmt | 0 | 24320 |
| IRS990/OtherEmployeeBenefitsGrp/ProgramServicesAmt | 0 | 122354 |
| IRS990/OtherEmployeeBenefitsGrp/TotalAmt | 0 | 177003 |