XML 53 R43.htm IDEA: XBRL DOCUMENT
v3.25.3

RELATED PARTY TRANSACTIONS (Details) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 USD ($) item | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) item | Sep. 30, 2024 USD ($)
RELATED PARTY TRANSACTIONS |  |  |  |
Management fee | $ 908,425 | $ 802,908 | $ 2,561,266 | $ 2,374,371
Repairs and maintenance | 4,587,034 | 3,618,610 | 10,927,118 | 9,967,034
Administrative expense | $ 871,135 | $ 679,674 | 2,160,314 | $ 2,093,671
Employer contributions in 401K plan |  |  | $ 48,000 |
Number of limited partnerships and limited liability companies in which the entity has invested | item |  |  | 7 |
Brown Family | Minimum |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Ownership interest (as a percent) | 47.60% |  | 47.60% |
Brown Family | Maximum |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Ownership interest (as a percent) | 59.00% |  | 59.00% |
Brown Family | Related party | Minimum |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Ownership interest (as a percent) | 47.60% |  | 47.60% |
Brown Family | Related party | Maximum |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Ownership interest (as a percent) | 59.00% |  | 59.00% |
NERA 40% |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Ownership interest (as a percent) | 40.00% | 40.00% | 40.00% | 40.00%
NERA 50% |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Ownership interest (as a percent) | 50.00% | 50.00% | 50.00% | 50.00%
Majority of Partnership Properties | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Management fee as percentage of gross receipts rental revenue |  |  | 4.00% |
Management fee (as a percent) |  |  | 4.00% |
Linewt | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Management fee as percentage of gross receipts rental revenue |  |  | 3.00% |
General Partner or Management Company | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Costs related to professional services |  |  | $ 1,422,000 | $ 798,000
Repairs and maintenance |  |  | 165,000 |
Administrative expense |  |  | 178,000 |
Expenses for construction, architectural services and supervision of capital projects |  |  | 1,075,000 |
Brokerage Fees |  |  | 4,000 |
Hamilton Company/Management Company | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Management fee |  |  | 2,561,000 | 2,374,000
Costs related to professional services |  |  | 93,750 | 125,000
Amount received for management fees |  |  | 710,000 |
Payroll and related expenses |  |  | 3,519,000 | 3,264,000
Employer contributions in 401K plan |  |  | $ 48,000 |
Number of accounting staff providing bookkeeping and accounting functions | item | 14 |  | 14 |
Hamilton Company/Management Company | Management fee | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Amount received for management fees |  |  | $ 580,000 |
Hamilton Company/Management Company | Construction, architectural services and supervision of capital projects | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Amount received for management fees |  |  | 93,000 |
Hamilton Company/Management Company | Repairs and maintenance | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Amount received for management fees |  |  | 27,000 |
Hamilton Company/Management Company | Legal expense | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Amount received for management fees |  |  | $ 10,000 |
Dexter Park | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Management fee (as a percent) |  |  | 2.00% |
Sally Michael | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Legal fees |  |  | $ 323,000 | $ 117,000
David Reier | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Legal fees |  |  | $ 7,400 |
Current and previous management company employees | Related party |  |  |  |
RELATED PARTY TRANSACTIONS |  |  |  |
Number of employees having ownership interest in the investment properties | item |  |  | 5 |

X
- Definition Number of persons employed by the Entity + References No definition available. + Details
Name: | dei_EntityNumberOfEmployees
Namespace Prefix: | dei_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of expense relating to brokerage fees. + References No definition available. + Details
Name: | nen_BrokerageFees
Namespace Prefix: | nen_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the amount aggregate cost of construction, architectural services and supervision of capital projects during the reporting period. + References No definition available. + Details
Name: | nen_CostOfServicesArchitecturalServicesAndSupervisionOfProjects
Namespace Prefix: | nen_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the number of limited partnerships and limited liability companies in which the entity has made investments which are accounted for using the equity method of consolidation. + References No definition available. + Details
Name: | nen_InvestmentsInNumberOfLimitedPartnershipsAndLimitedLiabilityCompanies
Namespace Prefix: | nen_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the amount of management fee incurred for payment to a management company during the reporting period. + References No definition available. + Details
Name: | nen_ManagementFees
Namespace Prefix: | nen_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of employees, excluding President, having ownership interest in the investment properties. + References No definition available. + Details
Name: | nen_NumberOfEmployeesHavingOwnershipInterest
Namespace Prefix: | nen_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the management fee expressed as a percentage of rental revenues from properties owned. + References No definition available. + Details
Name: | nen_RelatedPartyTransactionManagementFeeAsPercentageOfPropertyRentalRevenueAndLaundryIncome
Namespace Prefix: | nen_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Cost of labor directly related to good produced and service rendered. Includes, but is not limited to, payroll cost and equity-based compensation. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_CostDirectLabor
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The aggregate costs of keeping the property in good condition but that do not appreciably prolong the life or increase the value of the property. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_CostOfPropertyRepairsAndMaintenance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 70 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480794/715-70-50-1 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-28 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
Name: | us-gaap_GeneralAndAdministrativeExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Subparagraph (k) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479105/946-220-45-3 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(6)) -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_LegalFees
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A fee charged for services from professionals such as doctors, lawyers and accountants. The term is often expanded to include other professions, for example, pharmacists charging to maintain a medicinal profile of a client or customer. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479168/946-830-55-10 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 21 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476153/220-40-55-21 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 48 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-48 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Subparagraph (k) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479105/946-220-45-3 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
Name: | us-gaap_ProfessionalFees
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The percentage charged for managing real estate properties. + References No definition available. + Details
Name: | us-gaap_PropertyManagementFeePercentFee
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of revenue derived from managing real estate properties. + References No definition available. + Details
Name: | us-gaap_PropertyManagementFeeRevenue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 850 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483326/850-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 850 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483326/850-10-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 850 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483326/850-10-50-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(k)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(k)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481990/310-10-45-13 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)(2)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)(2)(ii)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(g)(3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
Name: | us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nen_BrownFamilyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nen_NewEnglandRealtyAssociatesLimitedPartnership40PercentOwnershipMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nen_NewEnglandRealtyAssociatesLimitedPartnership50PercentOwnershipMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_MajorityOfPartnershipPropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_HamiltonLinewtLLCCommercial1031ExchangeNewtonMassachusettsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_GeneralPartnerOrManagementCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_HamiltonCompanyIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_ManagementServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_ConstructionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_MaintenanceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=nen_LegalExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_HamiltonParkTowersLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_SallyMichaelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_DavidReierMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=nen_CurrentAndFormerManagementCompanyEmployeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |