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INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Details 2) (USD $) | 0 Months Ended | 12 Months Ended |  |  |  |  |  |  |  |  |  |
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Feb. 01, 2015 item | Dec. 31, 2014 item | Dec. 31, 2013 item | Dec. 31, 2012 item | Dec. 31, 2011 | Nov. 30, 2001 item | Mar. 02, 2005 item | Apr. 30, 2008 item | Feb. 28, 2007 item | Oct. 03, 2005 item | Sep. 30, 2004 item | May 31, 2008 item | Aug. 31, 2004 item | Oct. 28, 2009
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | $ 149,116,084 us-gaap_RentalProperties | $ 152,904,661 us-gaap_RentalProperties |  |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 14,015,898 us-gaap_CashAndCashEquivalentsAtCarryingValue | 14,013,380 us-gaap_CashAndCashEquivalentsAtCarryingValue | 6,981,906 us-gaap_CashAndCashEquivalentsAtCarryingValue | 4,050,157 us-gaap_CashAndCashEquivalentsAtCarryingValue |  |  |  |  |  |  |  |  |
Rent Receivable |  | 474,225 us-gaap_AccountsReceivableNet | 496,149 us-gaap_AccountsReceivableNet |  |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 340,341 us-gaap_EscrowDeposit | 375,560 us-gaap_EscrowDeposit |  |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 3,287,005 us-gaap_PrepaidExpenseAndOtherAssets | 3,895,189 us-gaap_PrepaidExpenseAndOtherAssets |  |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 1,735,652 nen_DeferredFinancingAndLeasingCostsNet | 1,635,076 nen_DeferredFinancingAndLeasingCostsNet |  |  |  |  |  |  |  |  |  |  |
Total Assets |  | 177,777,073 us-gaap_Assets | 185,345,157 us-gaap_Assets |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 196,071,540 us-gaap_SecuredDebt | 198,520,478 us-gaap_SecuredDebt |  |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 3,099,117 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent | 3,178,495 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent |  |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 4,548,729 us-gaap_CustomerAdvancesAndDeposits | 4,242,401 us-gaap_CustomerAdvancesAndDeposits |  |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 205,144,755 us-gaap_Liabilities | 207,193,720 us-gaap_Liabilities |  |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | (27,367,682)us-gaap_PartnersCapital | (21,848,563)us-gaap_PartnersCapital | (22,515,677)us-gaap_PartnersCapital | (21,310,851)us-gaap_PartnersCapital |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 177,777,073 us-gaap_LiabilitiesAndStockholdersEquity | 185,345,157 us-gaap_LiabilitiesAndStockholdersEquity |  |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 8,807,868 us-gaap_EquityMethodInvestments | 12,025,142 us-gaap_EquityMethodInvestments |  |  |  |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | (1,425,369)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture | (1,252,346)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture |  |  |  |  |  |  |  |  |  |  |
Hamilton Essex 81 |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 8,732,134 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 8,764,215 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 9,103,858 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 759 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 30,360 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 27,848 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 44,399 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 31,426 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 44,005 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 105,474 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 101,395 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 49,793 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 83,881 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 77,141 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 61,895 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 30,109 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 46,630 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 64,116 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 8,996,756 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 9,051,167 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 9,351,515 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 8,109,676 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 8,234,548 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 8,352,317 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 49,426 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 44,299 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 34,673 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 174,186 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 167,143 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 175,871 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 8,333,288 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 8,445,990 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 8,562,861 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 663,468 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 605,177 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 788,654 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 8,996,756 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 9,051,167 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 9,351,515 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 49 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 49 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 49 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Units to be retained |  | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 0 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units sold |  | 0 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Essex 81 | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 331,734 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 302,589 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 394,327 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Essex 81 | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Essex 81 | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Essex Development |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 2,621,495 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,624,325 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,610,574 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 4,216 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 35,644 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 20,214 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 0 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 0 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 559 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 555 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 505 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 5,639 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 14,097 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 4,325 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 2,631,909 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,674,621 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,635,617 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 1,987,830 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,041,146 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,093,184 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 6,088 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 6,084 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 6,319 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 0 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 0 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 1,993,918 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,047,230 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,099,503 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 637,991 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 627,391 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 536,114 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 2,631,909 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,674,621 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 2,635,617 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Units to be retained |  | 1 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 1 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 1 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 0 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units sold |  | 0 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Essex Development | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 318,995 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 313,695 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 268,057 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Essex Development | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 0 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Essex Development | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |  |  |
345 Franklin |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 7,132,916 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 7,494,954 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 7,885,745 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 111,875 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 78,691 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 3,533 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 2,116 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 1,512 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 600 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 17,731 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 16,970 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 20,242 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 36,911 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 36,979 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 75,222 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 89,890 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 96,548 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 8,164 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 7,391,439 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 7,725,654 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 7,993,505 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 10,000,000 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 10,000,000 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 6,850,179 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 51,122 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 60,638 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 93,810 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 191,054 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 169,709 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 140,759 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 10,242,176 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 10,230,346 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 7,084,748 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | (2,850,737)us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | (2,504,692)us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 908,757 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 7,391,439 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 7,725,654 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 7,993,505 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  |  |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 0 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  | 1,533,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 40 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 40 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 40 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 40 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Units to be retained |  | 40 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 40 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 40 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 0 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units sold |  | 0 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |  |  |
345 Franklin | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  |  |  | 454,379 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | (1,425,369)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | (1,252,346)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |  |
345 Franklin | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 40 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 40 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember | 40 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |
345 Franklin | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 0 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton 1025 |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 5,156,752 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,389,763 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,621,970 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 23,008 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 9,085 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 2,706 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 2,111 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 7,970 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 7,283 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 75,027 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 80,767 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 74,443 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 45,704 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 44,737 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 33,659 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 9,594 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 14,619 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 19,645 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 5,312,196 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,546,941 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,759,706 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 4,806,039 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 4,869,583 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 4,934,741 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 28,751 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 50,279 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 49,566 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 96,142 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 92,057 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 80,264 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 4,930,932 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,011,919 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,064,570 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 381,264 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 535,022 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 695,135 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 5,312,196 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,546,941 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 5,759,706 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  |  |  |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  |  |  |  |  |  | 2,352,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 176 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 176 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 176 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  | 176 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |
Units to be retained |  | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |
Units to be sold |  | 127 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 127 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 127 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Units sold |  | 127 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 127 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 127 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  | 127 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton 1025 | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 190,632 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 267,511 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 347,568 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Hamilton 1025 | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 175 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 175 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 175 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Hamilton 1025 | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Bay Sales |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 811,043 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 1,766,132 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 1,844,219 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 28,636 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 36,423 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 20,695 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 1,770 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 1,251 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 2,200 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 0 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 198,603 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 101,507 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 127,530 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 0 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 5,505 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 1,040,052 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 1,905,314 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 2,000,148 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 0 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 1,668,000 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 21,454 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 16,993 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 7,481 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 10,999 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 24,687 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 25,147 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 32,453 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 41,680 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 1,700,628 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 1,007,599 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 1,863,634 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 299,520 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 1,040,052 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 1,905,314 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 2,000,148 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 120 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 120 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 120 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Units to be retained |  | 0 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 0 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 120 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 120 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 120 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Units sold |  | 113 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 105 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 105 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Units left to sell | 7 nen_NumberOfUnitsLeftToSell / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 7 nen_NumberOfUnitsLeftToSell / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 15 nen_NumberOfUnitsLeftToSell / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 15 nen_NumberOfUnitsLeftToSell / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Bay Sales | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 503,800 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 931,817 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 149,760 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Bay Sales | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 120 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 120 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember | 120 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Bay Sales | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 0 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Bay Apartments |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 6,416,511 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 6,680,834 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 6,975,854 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 32,379 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 17,861 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 62,473 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 945 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 2,766 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 2,686 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 46,978 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 45,679 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 41,225 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 46,290 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 31,435 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 14,345 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 13,519 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 19,881 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 26,243 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 6,556,622 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 6,798,456 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 7,122,825 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 4,574,002 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 4,639,848 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 4,702,087 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 10,193 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 7,570 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 49,690 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 99,043 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 85,413 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 86,028 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 4,683,238 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 4,732,831 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 4,837,806 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 1,873,384 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 2,065,625 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 2,285,019 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 6,556,622 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 6,798,456 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 7,122,825 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  |  |  |  |  |  |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |
Investment in Unconsolidated Joint Ventures |  |  |  |  |  |  |  |  |  | 2,500,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  | 20 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 168 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |
Units to be retained |  | 48 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 48 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 48 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  | 48 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 48 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |
Units to be sold |  | 0 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units sold |  | 0 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Bay Apartments | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 936,692 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 1,032,812 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 1,142,510 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Bay Apartments | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Bay Apartments | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 0 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Minuteman |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 6,551,038 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 6,778,029 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 7,020,471 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 66,705 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 33,921 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 44,170 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 0 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 2,626 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 40,532 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 41,268 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 43,612 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 44,736 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 50,721 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 48,715 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 8,012 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 11,981 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 15,950 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 6,711,023 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 6,915,919 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 7,175,545 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 5,292,511 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 5,362,109 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 5,433,472 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 52,095 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 73,289 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 58,378 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 95,642 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 74,615 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 71,025 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 5,440,248 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 5,510,013 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 5,562,875 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 1,270,775 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 1,405,906 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 1,612,669 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 6,711,023 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 6,915,919 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 7,175,545 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  |  |  |  |  |  |  |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |
Investment in Unconsolidated Joint Ventures |  |  |  |  |  |  |  |  |  |  | 5,075,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 42 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 42 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 42 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  | 42 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |
Units to be retained |  | 42 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 42 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 42 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 0 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units sold |  | 0 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton Minuteman | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 635,388 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 702,953 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 806,335 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Minuteman | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 42 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 42 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember | 42 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton Minuteman | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 0 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton on Main Apts |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 19,408,575 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 20,253,587 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 21,148,813 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 158,515 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 189,004 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 103,990 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 7,495 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 5,697 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 11,108 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 62,290 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 72,308 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 70,364 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 71,703 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 322,667 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 154,396 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 155,162 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 7,716 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 14,581 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 19,863,740 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 20,850,980 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 21,503,252 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 16,900,000 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 15,317,643 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 15,611,045 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 156,578 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 290,008 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 204,413 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 305,809 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 291,825 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 273,302 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 17,362,387 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 15,899,477 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 16,088,760 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 2,501,353 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 4,951,504 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 5,414,492 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 19,863,740 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 20,850,980 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 21,503,252 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  |  |  |  |  |  |  |  |  |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |
Investment in Unconsolidated Joint Ventures |  |  |  |  |  |  |  |  |  |  |  |  | 8,000,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 148 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 148 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 148 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  | 280 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |
Units to be retained |  | 148 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 148 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 148 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 0 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units sold |  | 0 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  | 137 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Hamilton on Main Apts | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 1,250,676 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 2,475,752 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 2,707,246 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton on Main Apts | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 148 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 148 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember | 148 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |
Hamilton on Main Apts | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 0 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Dexter Park |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 97,142,777 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 102,120,964 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 107,496,918 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 1,128,780 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 961,622 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 941,391 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 94,857 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 91,701 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 35,250 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 294,748 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 427,084 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 424,159 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 1,917,136 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 1,529,591 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 1,367,274 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 281,222 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 340,362 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 399,678 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 100,859,520 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 105,471,324 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 110,664,670 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 86,240,813 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 87,410,638 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 88,611,686 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 793,995 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 944,140 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 843,422 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 2,224,824 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 2,121,509 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 1,919,573 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 89,259,632 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 90,476,287 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 91,374,681 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 11,599,888 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 14,995,037 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 19,289,989 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 100,859,520 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 105,471,324 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 110,664,670 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  |  |  |  |  |  |  |  |  |  |  |  |  | 40.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember
Investment in Unconsolidated Joint Ventures |  |  |  |  |  |  |  |  |  |  |  |  |  | 15,925,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | 0 nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 0 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 409 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 409 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 409 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Units to be retained |  | 409 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 409 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 409 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 0 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units sold |  | 0 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Units unsold with deposits for future sale |  | 0 nen_NumberOfUnitsInRealEstateWithDepositsForFutureSale / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Dexter Park | NERA 40% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest |  | 40.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership40PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 40.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership40PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 40.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership40PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 4,639,953 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership40PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 5,998,015 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership40PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 7,715,996 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership40PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |
Dexter Park | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 409 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 409 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember | 409 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  | 409 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember
Dexter Park | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 0 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |  |  |  |  |
Total |  |  |  |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rental Properties |  | 153,973,241 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 161,872,803 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 169,708,422 us-gaap_RentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Cash & Cash Equivalents |  | 1,554,873 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,392,611 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,227,018 us-gaap_CashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Rent Receivable |  | 153,693 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 142,324 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 105,758 us-gaap_AccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Real Estate Tax Escrow |  | 642,780 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 785,470 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 723,838 us-gaap_EscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets |  | 2,445,523 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 2,195,335 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,883,541 us-gaap_PrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Financing & Leasing Fees |  | 593,147 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 551,834 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 558,206 nen_DeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Total Assets |  | 159,363,257 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 166,940,376 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 174,206,783 us-gaap_Assets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable |  | 137,910,871 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 137,875,517 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 138,256,711 us-gaap_SecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses |  | 1,169,702 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,493,299 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,347,752 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits |  | 3,197,699 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 3,026,957 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 2,771,968 us-gaap_CustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Total Liabilities |  | 142,278,272 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 142,395,772 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 142,376,432 us-gaap_Liabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Partners' Capital |  | 17,084,985 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 24,544,604 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 31,830,352 us-gaap_PartnersCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital |  | 159,363,257 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 166,940,376 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 174,206,783 us-gaap_LiabilitiesAndStockholdersEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  | 8,807,868 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 12,025,144 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture |  | (1,425,369)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | (1,252,346)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) |  | 7,382,500 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 10,772,798 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 13,986,177 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 1,034 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,033 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,033 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Units to be retained |  | 786 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 786 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 786 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Units to be sold |  | 247 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 247 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 247 nen_NumberOfUnitsInRealEstatePropertyToBeSold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Units sold |  | 240 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 232 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 232 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Units left to sell |  | 7 nen_NumberOfUnitsLeftToSell / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 15 nen_NumberOfUnitsLeftToSell / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 15 nen_NumberOfUnitsLeftToSell / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Total | NERA 50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |
Investment in Unconsolidated Joint Ventures |  |  |  | $ 13,986,177 us-gaap_EquityMethodInvestments / nen_PartnershipOwnershipAxis = nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Total | Residential buildings |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 1,031 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,030 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 1,030 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |
Total | Commercial |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  | 3 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 3 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember | 3 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis = us-gaap_CommercialRealEstateMember / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |  |  |

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- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3044-108585 + Details
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- Definition Refundable consideration, usually cash, held by the entity pending satisfactory completion of the entity's obligations or pending the closing of a contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.15a) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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- Definition The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19-26) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The amount of ownership interest of different classes of partners in limited partnership. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 + Details
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