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INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Details 2) - 10Q (USD $) | Mar. 31, 2015 | Dec. 31, 2014 | Mar. 31, 2014 item | Mar. 07, 2005 item | Nov. 30, 2001 item | Mar. 02, 2005 item | Oct. 03, 2005 item | Sep. 30, 2004 item | May 31, 2008 item | Aug. 31, 2004 item | Oct. 28, 2009 item
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LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Equity Method Investments | $ 8,268,172 us-gaap_EquityMethodInvestments | $ 8,807,868 us-gaap_EquityMethodInvestments |  |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture | (1,487,939)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture | (1,425,369)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture |  |  |  |  |  |  |  |  |
Hamilton Essex 81 |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 8,636,396 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 8,665,490 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 53,122 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 31,408 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Rent Receivable | 30,694 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 28,674 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 114,280 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 101,256 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 76,589 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 71,795 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 25,978 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 42,259 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Total Assets | 8,937,059 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 8,940,881 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 8,075,681 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 8,202,370 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 44,904 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 52,518 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 174,416 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 163,668 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Total Liabilities | 8,295,001 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 8,418,556 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Partners' Capital | 642,058 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 522,325 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 8,937,059 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 8,940,881 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Equity Method Investments | 321,028 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 261,162 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Units to be retained | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 49 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  |  |  |  |  |  |  |
Total | 49 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember |  | 49 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssex81LLCMember | 48 us-gaap_NumberOfUnitsInRealEstateProperty / 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 |  |  |  |  |  |  |  |
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 |  |  |  |  |  |  |  |
Hamilton Essex Development |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 2,620,789 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 2,623,618 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 49,826 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 61,603 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 224 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 222 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 3,524 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 11,982 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Total Assets | 2,674,363 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 2,697,426 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 1,974,501 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 2,027,817 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 4,941 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 6,373 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Total Liabilities | 1,979,442 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 2,034,190 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Partners' Capital | 694,921 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 663,236 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 2,674,363 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 2,697,426 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Equity Method Investments | 347,460 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 331,618 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Units to be retained | 1 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 1 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  |  |  |  |  |  |  |
Total | 1 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonEssexDevelopmentLLCMember |  | 1 us-gaap_NumberOfUnitsInRealEstateProperty / 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 |  |  |  |  |  |  |  |
345 Franklin |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 7,040,787 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 7,409,606 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 107,441 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 26,136 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Rent Receivable | 5,470 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 2,565 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 41,532 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 40,681 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 26,198 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 32,078 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 88,225 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 94,884 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Total Assets | 7,309,653 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 7,605,950 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 10,000,000 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 10,000,000 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 81,557 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 81,538 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 203,975 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 190,001 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Total Liabilities | 10,285,532 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 10,271,539 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Partners' Capital | (2,975,879)us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | (2,665,589)us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 7,309,653 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 7,605,950 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |
Equity Method Investments |  |  |  |  | 1,533,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture | (1,487,939)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | (1,332,795)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Units to be retained | 40 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  | 40 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Franklin345LLCMember |  |  |  |  |  |  |  |
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 |  |  |  |  |  |
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 |  |  |  |  |  |  |  |
Hamilton 1025 |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 5,097,980 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 5,331,142 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 36,196 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 23,018 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Rent Receivable | 3,077 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 995 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 73,919 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 68,445 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 47,558 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 37,561 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 8,337 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 13,363 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Total Assets | 5,267,067 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 5,474,523 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 4,787,315 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 4,856,961 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 21,772 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 27,653 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 95,932 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 91,568 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Total Liabilities | 4,905,019 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 4,976,181 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Partners' Capital | 362,048 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 498,342 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 5,267,067 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 5,474,523 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |
Equity Method Investments | 181,023 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  | 249,171 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  | 2,352,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_Hamilton1025LLCMember |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
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 |  |  |  |  |
Number of Units in Real Estate Property to be Sold | 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 |  |  |  |  |
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 |  |  |  |  |
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 |  |  |  |  |  |  |  |
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 |  |  |  |  |  |  |  |
Hamilton Bay Sales |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 802,055 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 1,626,115 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 15,110 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 124,765 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Rent Receivable |  |  | 1,793 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 20,197 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 206,859 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Total Assets | 837,362 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 1,959,533 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 20,019 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 19,186 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 11,114 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 20,483 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Total Liabilities | 31,133 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 39,668 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Partners' Capital | 806,229 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 1,919,864 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 837,362 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 1,959,533 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Equity Method Investments | 403,114 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 959,932 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Number of Units in Real Estate Property to be Sold | 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 |  | 106 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Unsold units | 7 nen_NumberOfUnitsInRealEstatePropertyUnsold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 14 nen_NumberOfUnitsInRealEstatePropertyUnsold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  |  |  |  |  |  |  |
Total | 120 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayLLCMember |  | 120 us-gaap_NumberOfUnitsInRealEstateProperty / 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 |  |  |  |  |  |  |  |
Hamilton Bay Apartments |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 6,344,523 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 6,604,500 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 30,261 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 25,766 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Rent Receivable | 8,531 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 4,641 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 51,749 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 37,283 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 49,482 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 35,603 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 11,929 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 18,291 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Total Assets | 6,496,475 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 6,726,084 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 4,556,075 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 4,622,842 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 13,657 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 10,896 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 93,589 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 95,060 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Total Liabilities | 4,663,321 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 4,728,798 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Partners' Capital | 1,833,154 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 1,997,286 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 6,496,475 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 6,726,084 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |
Equity Method Investments | 916,577 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 998,643 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  | 2,500,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
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 |  |  |  |
Units sold |  |  |  |  |  |  | 120 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  |
Total | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  | 48 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonBayApartmentsLLCMember |  |  |  | 168 us-gaap_NumberOfUnitsInRealEstateProperty / 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 |  |  |  |  |  |  |  |
Hamilton Minuteman |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 6,483,432 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 6,702,438 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 51,370 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 80,847 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Rent Receivable | 287 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 737 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 39,769 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 35,466 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 42,326 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 42,400 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 7,020 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 10,989 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Total Assets | 6,624,204 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 6,872,876 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 5,271,998 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 5,348,277 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 52,119 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 64,247 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 96,246 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 80,327 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Total Liabilities | 5,420,363 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 5,492,851 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Partners' Capital | 1,203,841 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 1,380,025 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 6,624,204 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 6,872,876 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |
Equity Method Investments | 601,920 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 690,012 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  | 5,075,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Units to be retained | 42 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  | 42 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonMinutemanLLCMember |  |  |  |  |  |  |  |
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 |  |  |
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 |  |  |  |  |  |  |  |
Hamilton on Main Apts |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 19,225,373 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 20,026,347 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 191,526 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 118 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Rent Receivable | 8,901 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 8,623 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 78,483 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 43,577 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 92,912 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 712,377 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 151,150 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 6,001 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Total Assets | 19,748,345 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 20,797,043 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 16,900,000 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 15,263,225 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 142,669 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 172,902 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 316,025 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 291,564 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Total Liabilities | 17,358,694 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 15,727,691 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Partners' Capital | 2,389,651 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 5,069,351 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 19,748,345 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 20,797,043 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  | 50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |
Equity Method Investments | 1,194,825 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 2,534,676 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  | 8,000,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Units to be retained | 148 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  | 148 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |  |  |  |  |  |  |
Units sold |  |  |  |  |  |  |  |  | 137 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonOnMainLLCMember |  |
Total | 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 |
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 |  |  |  |  |  |  |  |
Dexter Park |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 96,374,735 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 100,826,473 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 985,394 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 1,027,202 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Rent Receivable | 71,152 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 74,141 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 260,698 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 339,330 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 1,800,526 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 1,607,358 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 266,643 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 325,532 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Total Assets | 99,759,148 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 104,200,037 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 85,896,923 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 87,179,208 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 626,221 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 708,297 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 2,480,438 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 2,294,713 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Total Liabilities | 89,003,582 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 90,182,218 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Partners' Capital | 10,755,566 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 14,017,818 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 99,759,148 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 104,200,037 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
Percentage of ownership interest | 40.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 40.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  | 40.00%us-gaap_EquityMethodInvestmentOwnershipPercentage / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember
Equity Method Investments | 4,302,225 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 5,607,127 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  | 15,925,000 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Units to be retained | 409 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  | 409 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = nen_HamiltonParkTowersLLCMember |  |  |  |  |  |  |  |
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
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 |  |  |  |  |  |  |  |
Total |  |  |  |  |  |  |  |  |  |  |
ASSETS |  |  |  |  |  |  |  |  |  |  |
Rental Properties | 152,626,070 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 159,815,729 nen_EquityMethodInvestmentSummarizedFinancialInformationRentalProperties / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Cash & Cash Equivalents | 1,520,246 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 1,400,862 nen_EquityMethodInvestmentSummarizedFinancialInformationCashAndCashEquivalentsAtCarryingValue / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Rent Receivable | 128,112 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 122,170 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsReceivableNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Real Estate Tax Escrow | 660,430 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 666,038 nen_EquityMethodInvestmentSummarizedFinancialInformationEscrowDeposit / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Prepaid Expenses & Other Assets | 2,156,012 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 2,746,253 nen_EquityMethodInvestmentSummarizedFinancialinformationPrepaidExpenseAndOtherAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Financing & Leasing Fees | 562,806 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 523,300 nen_EquityMethodInvestmentSummarizedFinancialInformationDeferredFinancingAndLeasingCostsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Total Assets | 157,653,676 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 165,274,352 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationAssets / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
LIABILITIES AND PARTNERS' CAPITAL |  |  |  |  |  |  |  |  |  |  |
Mortgage Notes Payable | 137,462,493 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 137,500,700 nen_EquityMethodInvestmentSummarizedFinancialInformationSecuredDebt / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Accounts Payable and Accrued Expenses | 1,007,859 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 1,143,611 nen_EquityMethodInvestmentSummarizedFinancialInformationAccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Advance Rental Payments and Security Deposits | 3,471,735 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 3,227,383 nen_EquityMethodInvestmentSummarizedFinancialInformationCustomerAdvancesAndDeposits / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Total Liabilities | 141,942,087 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 141,871,694 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilities / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Partners' Capital | 15,711,589 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 23,402,658 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationEquityOrCapital / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Total Liabilities and Partners' Capital | 157,653,676 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 165,274,352 us-gaap_EquityMethodInvestmentSummarizedFinancialInformationLiabilitiesAndEquity / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Equity Method Investments | 8,268,172 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 11,632,342 us-gaap_EquityMethodInvestments / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Distribution and Loss in Excess of Investment in Unconsolidated Joint Venture | (1,487,939)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | (1,332,795)nen_DistributionAndLossInExcessOfInvestmentInUnconsolidatedJointVenture / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Total Investment in Unconsolidated Joint Ventures (Net) | $ 6,780,233 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | $ 10,299,547 nen_PartnersCapitalAccountShareInInvestmentsNet / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Units to be retained | 786 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 786 nen_NumberOfUnitsInRealEstatePropertyRetainedForLongTermInvestment / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Number of Units in Real Estate Property to be Sold | 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 |  | 233 nen_NumberOfUnitsInRealEstatePropertySold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Unsold units | 7 nen_NumberOfUnitsInRealEstatePropertyUnsold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 14 nen_NumberOfUnitsInRealEstatePropertyUnsold / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Total | 1,033 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  | 1,033 us-gaap_NumberOfUnitsInRealEstateProperty / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = us-gaap_EquityMethodInvestmentsMember |  |  |  |  |  |  |  |
Total | Residential buildings |  |  |  |  |  |  |  |  |  |  |
Total units/ condominiums |  |  |  |  |  |  |  |  |  |  |
Total | 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 |  |  |  |  |  |  |  |

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