| IRS990/AccountantCompileOrReviewInd | 0 | false |
| IRS990/AccountsPayableAccrExpnssGrp/BOYAmt | 0 | 49226 |
| IRS990/AccountsPayableAccrExpnssGrp/EOYAmt | 0 | 87226 |
| IRS990/AccountsReceivableGrp/EOYAmt | 0 | 85000 |
| IRS990/ActivitiesConductedPrtshpInd | 0 | false |
| IRS990/ActivityOrMissionDesc | 0 | Muir Heritage Land Trust protects and cares for open space, ranches, farms, parkland, and shoreline in Contra Costa County. |
| IRS990/AdvertisingGrp/TotalAmt | 0 | 0 |
| IRS990/AllAffiliatesIncludedInd | 0 | false |
| IRS990/AllOtherContributionsAmt | 0 | 2578697 |
| IRS990/AllOtherExpensesGrp/FundraisingAmt | 0 | -59292 |
| IRS990/AllOtherExpensesGrp/ManagementAndGeneralAmt | 0 | 8981 |
| IRS990/AllOtherExpensesGrp/ProgramServicesAmt | 0 | 36449 |
| IRS990/AllOtherExpensesGrp/TotalAmt | 0 | -13862 |
| IRS990/AnnualDisclosureCoveredPrsnInd | 0 | true |
| IRS990/AuditCommitteeInd | 0 | true |
| IRS990/BackupWthldComplianceInd | 0 | true |
| IRS990/BenefitsToMembersGrp/TotalAmt | 0 | 0 |
| IRS990/BooksInCareOfDetail/PersonNm | 0 | Neil Roscoe |
| IRS990/BooksInCareOfDetail/PhoneNum | 0 | 9252285460 |
| IRS990/BooksInCareOfDetail/USAddress/AddressLine1Txt | 0 | PO Box 31 |
| IRS990/BooksInCareOfDetail/USAddress/CityNm | 0 | Martinez |
| IRS990/BooksInCareOfDetail/USAddress/StateAbbreviationCd | 0 | CA |
| IRS990/BooksInCareOfDetail/USAddress/ZIPCd | 0 | 94553 |
| IRS990/BusinessRlnWithFamMemInd | 0 | false |
| IRS990/BusinessRlnWithOfficerEntInd | 0 | false |
| IRS990/BusinessRlnWithOrgMemInd | 0 | false |
| IRS990/CashNonInterestBearingGrp/BOYAmt | 0 | 13974 |
| IRS990/CashNonInterestBearingGrp/EOYAmt | 0 | 134782 |
| IRS990/ChangeToOrgDocumentsInd | 0 | false |
| IRS990/CntrctRcvdGreaterThan100KCnt | 0 | 0 |
| IRS990/CollectionsOfArtInd | 0 | false |
| IRS990/CompCurrentOfcrDirectorsGrp/FundraisingAmt | 0 | 7426 |
| IRS990/CompCurrentOfcrDirectorsGrp/ManagementAndGeneralAmt | 0 | 22279 |
| IRS990/CompCurrentOfcrDirectorsGrp/ProgramServicesAmt | 0 | 118821 |
| IRS990/CompCurrentOfcrDirectorsGrp/TotalAmt | 0 | 148526 |
| IRS990/CompDisqualPersonsGrp/TotalAmt | 0 | 0 |
| IRS990/CompensationFromOtherSrcsInd | 0 | false |
| IRS990/CompensationProcessCEOInd | 0 | true |
| IRS990/CompensationProcessOtherInd | 0 | true |
| IRS990/ConferencesMeetingsGrp/FundraisingAmt | 0 | 1763 |
| IRS990/ConferencesMeetingsGrp/ManagementAndGeneralAmt | 0 | 9120 |
| IRS990/ConferencesMeetingsGrp/ProgramServicesAmt | 0 | 5701 |
| IRS990/ConferencesMeetingsGrp/TotalAmt | 0 | 16584 |
| IRS990/ConflictOfInterestPolicyInd | 0 | true |
| IRS990/ConservationEasementsInd | 0 | true |
| IRS990/ConsolidatedAuditFinclStmtInd | 0 | false |
| IRS990/CreditCounselingInd | 0 | false |
| IRS990/CYBenefitsPaidToMembersAmt | 0 | 0 |
| IRS990/CYContributionsGrantsAmt | 0 | 2628864 |
| IRS990/CYGrantsAndSimilarPaidAmt | 0 | 21955 |
| IRS990/CYInvestmentIncomeAmt | 0 | 63798 |
| IRS990/CYOtherExpensesAmt | 0 | 592606 |
| IRS990/CYOtherRevenueAmt | 0 | 138312 |
| IRS990/CYProgramServiceRevenueAmt | 0 | 5647 |
| IRS990/CYRevenuesLessExpensesAmt | 0 | 1415881 |
| IRS990/CYSalariesCompEmpBnftPaidAmt | 0 | 806179 |
| IRS990/CYTotalExpensesAmt | 0 | 1420740 |
| IRS990/CYTotalFundraisingExpenseAmt | 0 | 456766 |
| IRS990/CYTotalProfFndrsngExpnsAmt | 0 | 0 |
| IRS990/CYTotalRevenueAmt | 0 | 2836621 |
| IRS990/DAFExcessBusinessHoldingsInd | 0 | false |
| IRS990/DecisionsSubjectToApprovaInd | 0 | false |
| IRS990/DeductibleArtContributionInd | 0 | false |
| IRS990/DeductibleNonCashContriInd | 0 | true |
| IRS990/DelegationOfMgmtDutiesInd | 0 | false |
| IRS990/DepreciationDepletionGrp/FundraisingAmt | 0 | 3301 |
| IRS990/DepreciationDepletionGrp/ManagementAndGeneralAmt | 0 | 2335 |
| IRS990/DepreciationDepletionGrp/ProgramServicesAmt | 0 | 5597 |
| IRS990/DepreciationDepletionGrp/TotalAmt | 0 | 11233 |
| IRS990/Desc | 0 | During the year ended June 30, 2018, funds were expended in order to carry out the goals of the John Muir Land Trust Program: to protect, restore, and enhance each property's natural ecosystem and resource values, and preserve, in perpetuity, each property's open space values, scenic beauty and diverse habitats.For a complete discussion of the Land Trust's accomplishments, please visit the organization's website where additional information is available:www.jmlt.org |
| IRS990/DescribedInSection501c3Ind | 0 | true |
| IRS990/DisregardedEntityInd | 0 | false |
| IRS990/DistributionToDonorInd | 0 | false |
| IRS990/DocumentRetentionPolicyInd | 0 | true |
| IRS990/DonorAdvisedFundInd | 0 | false |
| IRS990/ElectionOfBoardMembersInd | 0 | false |
| IRS990/EmployeeCnt | 0 | 16 |
| IRS990/EmploymentTaxReturnsFiledInd | 0 | true |
| IRS990/EngagedInExcessBenefitTransInd | 0 | false |
| IRS990/EscrowAccountInd | 0 | false |
| IRS990/ExpenseAmt | 0 | 644800 |
| IRS990/FamilyOrBusinessRlnInd | 0 | false |
| IRS990/FederalGrantAuditRequiredInd | 0 | false |
| IRS990/FeesForServicesAccountingGrp/ManagementAndGeneralAmt | 0 | 11410 |
| IRS990/FeesForServicesAccountingGrp/TotalAmt | 0 | 11410 |
| IRS990/FeesForServicesLegalGrp/TotalAmt | 0 | 0 |
| IRS990/FeesForServicesLobbyingGrp/TotalAmt | 0 | 0 |
| IRS990/FeesForServicesManagementGrp/TotalAmt | 0 | 0 |
| IRS990/FeesForServicesOtherGrp/FundraisingAmt | 0 | 25349 |
| IRS990/FeesForServicesOtherGrp/ManagementAndGeneralAmt | 0 | 15350 |
| IRS990/FeesForServicesOtherGrp/ProgramServicesAmt | 0 | 350 |
| IRS990/FeesForServicesOtherGrp/TotalAmt | 0 | 41049 |
| IRS990/FeesForServicesProfFundraising/TotalAmt | 0 | 0 |
| IRS990/FeesForSrvcInvstMgmntFeesGrp/ManagementAndGeneralAmt | 0 | 8317 |
| IRS990/FeesForSrvcInvstMgmntFeesGrp/TotalAmt | 0 | 8317 |
| IRS990/ForeignActivitiesInd | 0 | false |
| IRS990/ForeignFinancialAccountInd | 0 | false |
| IRS990/ForeignGrantsGrp/TotalAmt | 0 | 0 |
| IRS990/ForeignOfficeInd | 0 | false |
| IRS990/Form1098CFiledInd | 0 | false |
| IRS990/Form8282FiledCnt | 0 | 0 |
| IRS990/Form8282PropertyDisposedOfInd | 0 | false |
| IRS990/Form8899Filedind | 0 | false |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 0 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 1 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 2 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 3 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 4 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 5 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 6 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 7 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 8 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 9 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 10 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 11 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 12 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 13 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 14 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRltdOrgRt | 15 | 0.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 0 | 4.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 1 | 4.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 2 | 4.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 3 | 4.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 4 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 5 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 6 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 7 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 8 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 9 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 10 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 11 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 12 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 13 | 2.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 14 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/AverageHoursPerWeekRt | 15 | 40.00 |
| IRS990/Form990PartVIISectionAGrp/HighestCompensatedEmployeeInd | 0 | 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/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 | 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 | 7318 |
| IRS990/Form990PartVIISectionAGrp/OtherCompensationAmt | 15 | 17298 |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 0 | Eliot Hudson |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 1 | Katie Hill |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 2 | Arthur Bart-Williams |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 3 | Bill Wadsworth |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 4 | Dawn Block |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 5 | Charles Lewis IV |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 6 | Stephanie Becker |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 7 | Peggy Cabaniss |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 8 | Jack Cortis |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 9 | Steve Hutchcraft |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 10 | Steve Kirby |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 11 | Eileen McCauley |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 12 | Ted C Radosevich |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 13 | Karen Sakata |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 14 | Linus Eukel |
| IRS990/Form990PartVIISectionAGrp/PersonNm | 15 | Jay Dean |
| 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 | 146363 |
| IRS990/Form990PartVIISectionAGrp/ReportableCompFromOrgAmt | 15 | 103000 |
| 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/TitleTxt | 0 | Chair |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 1 | Vice Chair |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 2 | Secretary |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 3 | Treasurer |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 4 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 5 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 6 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 7 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 8 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 9 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 10 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 11 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 12 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 13 | Director |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 14 | Executive Dir. |
| IRS990/Form990PartVIISectionAGrp/TitleTxt | 15 | Creative Strat Dir |
| IRS990/Form990ProvidedToGvrnBodyInd | 0 | true |
| IRS990/Form990TFiledInd | 0 | false |
| IRS990/FormationYr | 0 | 1989 |
| IRS990/FormerOfcrEmployeesListedInd | 0 | false |
| IRS990/FSAuditedBasisGrp/SeparateBasisFinclStmtInd | 0 | X |
| IRS990/FSAuditedInd | 0 | true |
| IRS990/FundraisingActivitiesInd | 0 | true |
| IRS990/FundraisingDirectExpensesAmt | 0 | 65992 |
| IRS990/FundraisingGrossIncomeAmt | 0 | 204199 |
| IRS990/GamingActivitiesInd | 0 | false |
| IRS990/GoverningBodyVotingMembersCnt | 0 | 14 |
| IRS990/GovernmentGrantsAmt | 0 | 50167 |
| IRS990/GrantsToDomesticIndividualsGrp/TotalAmt | 0 | 0 |
| IRS990/GrantsToDomesticOrgsGrp/ProgramServicesAmt | 0 | 21955 |
| IRS990/GrantsToDomesticOrgsGrp/TotalAmt | 0 | 21955 |
| IRS990/GrantsToIndividualsInd | 0 | false |
| IRS990/GrantsToOrganizationsInd | 0 | true |
| IRS990/GrantToRelatedPersonInd | 0 | false |
| IRS990/GrossReceiptsAmt | 0 | 2902613 |
| IRS990/GroupReturnForAffiliatesInd | 0 | false |
| IRS990/IncludeFIN48FootnoteInd | 0 | true |
| IRS990/IncmFromInvestBondProceedsGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/IndependentAuditFinclStmtInd | 0 | true |
| IRS990/IndependentVotingMemberCnt | 0 | 14 |
| IRS990/IndivRcvdGreaterThan100KCnt | 0 | 2 |
| IRS990/IndoorTanningServicesInd | 0 | false |
| IRS990/InfoInScheduleOPartVIInd | 0 | X |
| IRS990/InformationTechnologyGrp/FundraisingAmt | 0 | 8456 |
| IRS990/InformationTechnologyGrp/ManagementAndGeneralAmt | 0 | 951 |
| IRS990/InformationTechnologyGrp/ProgramServicesAmt | 0 | 17325 |
| IRS990/InformationTechnologyGrp/TotalAmt | 0 | 26732 |
| IRS990/InsuranceGrp/FundraisingAmt | 0 | 10446 |
| IRS990/InsuranceGrp/ManagementAndGeneralAmt | 0 | 19903 |
| IRS990/InsuranceGrp/ProgramServicesAmt | 0 | 17712 |
| IRS990/InsuranceGrp/TotalAmt | 0 | 48061 |
| IRS990/IntangibleAssetsGrp/EOYAmt | 0 | 0 |
| IRS990/InterestGrp/TotalAmt | 0 | 0 |
| IRS990/InventoriesForSaleOrUseGrp/EOYAmt | 0 | 0 |
| IRS990/InvestmentIncomeGrp/ExclusionAmt | 0 | 63798 |
| IRS990/InvestmentIncomeGrp/TotalRevenueColumnAmt | 0 | 63798 |
| IRS990/InvestmentInJointVentureInd | 0 | false |
| IRS990/InvestmentsOtherSecuritiesGrp/BOYAmt | 0 | 1246383 |
| IRS990/InvestmentsOtherSecuritiesGrp/EOYAmt | 0 | 992961 |
| IRS990/InvestmentsProgramRelatedGrp/EOYAmt | 0 | 0 |
| IRS990/InvestmentsPubTradedSecGrp/EOYAmt | 0 | 9816 |
| IRS990/InvestTaxExemptBondsInd | 0 | false |
| IRS990/IRPDocumentCnt | 0 | 16 |
| IRS990/IRPDocumentW2GCnt | 0 | 0 |
| IRS990/LandBldgEquipAccumDeprecAmt | 0 | 124172 |
| IRS990/LandBldgEquipBasisNetGrp/BOYAmt | 0 | 21448 |
| IRS990/LandBldgEquipBasisNetGrp/EOYAmt | 0 | 89156 |
| IRS990/LandBldgEquipCostOrOtherBssAmt | 0 | 213328 |
| IRS990/LegalDomicileStateCd | 0 | CA |
| IRS990/LicensedMoreThanOneStateInd | 0 | false |
| IRS990/LoanOutstandingInd | 0 | false |
| IRS990/LobbyingActivitiesInd | 0 | true |
| IRS990/LocalChaptersInd | 0 | false |
| IRS990/MaterialDiversionOrMisuseInd | 0 | false |
| IRS990/MembersOrStockholdersInd | 0 | false |
| IRS990/MethodOfAccountingAccrualInd | 0 | X |
| IRS990/MinutesOfCommitteesInd | 0 | true |
| IRS990/MinutesOfGoverningBodyInd | 0 | true |
| IRS990/MissionDesc | 0 | The vitality of open spaces is essential to the health of our earth, air, water, native plants, and animals. Our goal is to ensure that the beauty, diversity, and fullness of our wild lands continue to enrich and sustain all generations of life. |
| IRS990/MoreThan5000KToIndividualsInd | 0 | false |
| IRS990/MoreThan5000KToOrgInd | 0 | false |
| IRS990/NetAssetsOrFundBalancesBOYAmt | 0 | 13987979 |
| IRS990/NetAssetsOrFundBalancesEOYAmt | 0 | 15376502 |
| IRS990/NetGainOrLossInvestmentsGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetIncmFromFundraisingEvtGrp/TotalRevenueColumnAmt | 0 | 138207 |
| IRS990/NetIncomeFromGamingGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetIncomeOrLossGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetRentalIncomeOrLossGrp/TotalRevenueColumnAmt | 0 | 0 |
| IRS990/NetUnrlzdGainsLossesInvstAmt | 0 | -27358 |
| IRS990/NoncashContributionsAmt | 0 | 225415 |
| IRS990/NondeductibleContributionsInd | 0 | true |
| IRS990/NondeductibleContriDisclInd | 0 | true |
| IRS990/OccupancyGrp/FundraisingAmt | 0 | 10050 |
| IRS990/OccupancyGrp/ManagementAndGeneralAmt | 0 | 7109 |
| IRS990/OccupancyGrp/ProgramServicesAmt | 0 | 17041 |
| IRS990/OccupancyGrp/TotalAmt | 0 | 34200 |
| IRS990/OfficeExpensesGrp/FundraisingAmt | 0 | 14076 |
| IRS990/OfficeExpensesGrp/ManagementAndGeneralAmt | 0 | 19607 |
| IRS990/OfficeExpensesGrp/ProgramServicesAmt | 0 | 14495 |
| IRS990/OfficeExpensesGrp/TotalAmt | 0 | 48178 |
| IRS990/OfficerMailingAddressInd | 0 | false |
| IRS990/OnBehalfOfIssuerInd | 0 | false |
| IRS990/OperateHospitalInd | 0 | false |
| IRS990/Organization501c3Ind | 0 | X |
| IRS990/OrganizationFollowsSFAS117Ind | 0 | X |
| IRS990/OrgFiledInLieuOfForm1041Ind | 0 | false |
| IRS990/OtherAssetsTotalGrp/BOYAmt | 0 | 12464165 |
| IRS990/OtherAssetsTotalGrp/EOYAmt | 0 | 13588673 |
| IRS990/OtherEmployeeBenefitsGrp/FundraisingAmt | 0 | 12505 |
| IRS990/OtherEmployeeBenefitsGrp/ManagementAndGeneralAmt | 0 | 8846 |
| IRS990/OtherEmployeeBenefitsGrp/ProgramServicesAmt | 0 | 21205 |
| IRS990/OtherEmployeeBenefitsGrp/TotalAmt | 0 | 42556 |
| IRS990/OtherExpensesGrp/Desc | 0 | Printing and Publications |
| IRS990/OtherExpensesGrp/Desc | 1 | Events |
| IRS990/OtherExpensesGrp/Desc | 2 | Land stewardship |
| IRS990/OtherExpensesGrp/Desc | 3 | Postage and Shipping |
| IRS990/OtherExpensesGrp/FundraisingAmt | 0 | 90577 |
| IRS990/OtherExpensesGrp/FundraisingAmt | 1 | 83975 |
| IRS990/OtherExpensesGrp/FundraisingAmt | 2 | 27981 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 0 | 16518 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 1 | 8178 |
| IRS990/OtherExpensesGrp/ManagementAndGeneralAmt | 2 | 13170 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 0 | 23031 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 1 | 378 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 2 | 78428 |
| IRS990/OtherExpensesGrp/ProgramServicesAmt | 3 | 4634 |
| IRS990/OtherExpensesGrp/TotalAmt | 0 | 130126 |
| IRS990/OtherExpensesGrp/TotalAmt | 1 | 92531 |
| IRS990/OtherExpensesGrp/TotalAmt | 2 | 78428 |
| IRS990/OtherExpensesGrp/TotalAmt | 3 | 45785 |
| IRS990/OtherLiabilitiesGrp/EOYAmt | 0 | 182508 |
| IRS990/OtherRevenueMiscGrp/BusinessCd | 0 | 110000 |
| IRS990/OtherRevenueMiscGrp/Desc | 0 | Other Income |
| IRS990/OtherRevenueMiscGrp/RelatedOrExemptFuncIncomeAmt | 0 | 105 |
| IRS990/OtherRevenueMiscGrp/TotalRevenueColumnAmt | 0 | 105 |
| IRS990/OtherRevenueTotalAmt | 0 | 105 |
| IRS990/OtherSalariesAndWagesGrp/FundraisingAmt | 0 | 193239 |
| IRS990/OtherSalariesAndWagesGrp/ManagementAndGeneralAmt | 0 | 119663 |
| IRS990/OtherSalariesAndWagesGrp/ProgramServicesAmt | 0 | 221422 |
| IRS990/OtherSalariesAndWagesGrp/TotalAmt | 0 | 534324 |
| IRS990/OtherWebsiteInd | 0 | X |
| IRS990/OthNotesLoansReceivableNetGrp/EOYAmt | 0 | 0 |
| IRS990/PartialLiquidationInd | 0 | false |
| IRS990/PaymentsToAffiliatesGrp/TotalAmt | 0 | 0 |
| IRS990/PayPremiumsPrsnlBnftCntrctInd | 0 | false |
| IRS990/PayrollTaxesGrp/FundraisingAmt | 0 | 15521 |
| IRS990/PayrollTaxesGrp/ManagementAndGeneralAmt | 0 | 10979 |
| IRS990/PayrollTaxesGrp/ProgramServicesAmt | 0 | 26316 |
| IRS990/PayrollTaxesGrp/TotalAmt | 0 | 52816 |
| IRS990/PensionPlanContributionsGrp/FundraisingAmt | 0 | 8216 |
| IRS990/PensionPlanContributionsGrp/ManagementAndGeneralAmt | 0 | 5811 |
| IRS990/PensionPlanContributionsGrp/ProgramServicesAmt | 0 | 13930 |
| IRS990/PensionPlanContributionsGrp/TotalAmt | 0 | 27957 |
| IRS990/PermanentlyRstrNetAssetsGrp/BOYAmt | 0 | 200000 |
| IRS990/PermanentlyRstrNetAssetsGrp/EOYAmt | 0 | 200000 |
| IRS990/PledgesAndGrantsReceivableGrp/BOYAmt | 0 | 110535 |
| IRS990/PledgesAndGrantsReceivableGrp/EOYAmt | 0 | 455000 |
| IRS990/PoliticalCampaignActyInd | 0 | false |
| IRS990/PrepaidExpensesDefrdChargesGrp/BOYAmt | 0 | 180646 |
| IRS990/PrepaidExpensesDefrdChargesGrp/EOYAmt | 0 | 220806 |
| IRS990/PrincipalOfficerNm | 0 | Linus Eukel |
| IRS990/ProfessionalFundraisingInd | 0 | false |
| IRS990/ProgramServiceRevenueGrp/BusinessCd | 0 | 110000 |
| IRS990/ProgramServiceRevenueGrp/Desc | 0 | Grazing Revenue |
| IRS990/ProgramServiceRevenueGrp/RelatedOrExemptFuncIncomeAmt | 0 | 5647 |
| IRS990/ProgramServiceRevenueGrp/TotalRevenueColumnAmt | 0 | 5647 |
| IRS990/ProhibitedTaxShelterTransInd | 0 | false |
| IRS990/PYContributionsGrantsAmt | 0 | 1066230 |
| IRS990/PYExcessBenefitTransInd | 0 | false |
| IRS990/PYGrantsAndSimilarPaidAmt | 0 | 45000 |
| IRS990/PYInvestmentIncomeAmt | 0 | 28687 |
| IRS990/PymtTravelEntrtnmntPubOfclGrp/TotalAmt | 0 | 0 |
| IRS990/PYOtherExpensesAmt | 0 | 635823 |
| IRS990/PYOtherRevenueAmt | 0 | 156067 |
| IRS990/PYProgramServiceRevenueAmt | 0 | 10182 |
| IRS990/PYRevenuesLessExpensesAmt | 0 | -14837 |
| IRS990/PYSalariesCompEmpBnftPaidAmt | 0 | 595180 |
| IRS990/PYTotalExpensesAmt | 0 | 1276003 |
| IRS990/PYTotalRevenueAmt | 0 | 1261166 |
| IRS990/QuidProQuoContributionsInd | 0 | true |
| IRS990/QuidProQuoContriDisclInd | 0 | true |