XML 44 R35.htm IDEA: XBRL DOCUMENT
v3.23.1

SIGNIFICANT ACCOUNTING POLICIES (Business) (Details) | Mar. 31, 2023 property | Mar. 31, 2023 item | Mar. 31, 2023 ft² | Mar. 31, 2023 | Mar. 31, 2022
--- | --- | --- | --- | --- | ---
Wholly owned properties |  |  |  |  |
Line of Business |  |  |  |  |
Number of properties | 30 |  |  |  |
Wholly owned properties | Residential and mixed-use properties |  |  |  |  |
Line of Business |  |  |  |  |
Number of properties | 25 |  |  |  |
Number of units | item |  | 2,892 |  |  |
Wholly owned properties | Residential buildings |  |  |  |  |
Line of Business |  |  |  |  |
Number of properties | 21 |  |  |  |
Wholly owned properties | Mixed use residential, retail and office buildings |  |  |  |  |
Line of Business |  |  |  |  |
Number of properties | 4 |  |  |  |
Wholly owned properties | Commercial |  |  |  |  |
Line of Business |  |  |  |  |
Number of properties | 5 |  |  |  |
Area of property (in square feet) | ft² |  |  | 128,096 |  |
Wholly owned properties | Condominium |  |  |  |  |
Line of Business |  |  |  |  |
Number of properties | 1 |  |  |  |
Number of units | item |  | 19 |  |  |
Partially owned properties | Residential and mixed-use properties |  |  |  |  |
Line of Business |  |  |  |  |
Number of units | 688 | 688 |  |  |
Area of property (in square feet) | ft² |  |  | 12,500 |  |
Partially owned properties | Car parking lot |  |  |  |  |
Line of Business |  |  |  |  |
Capacity of real estate property (in cars per lot) | item |  | 50 |  |  |
Limited Partnerships | Partially owned properties | Residential and mixed-use properties |  |  |  |  |
Line of Business |  |  |  |  |
Number of properties | item |  | 7 |  |  |
NERA 40% |  |  |  |  |
Line of Business |  |  |  |  |
Ownership interest (as a percent) |  |  |  | 40.00% | 40.00%
NERA 50% |  |  |  |  |
Line of Business |  |  |  |  |
Ownership interest (as a percent) |  |  |  | 50.00% | 50.00%

X
- Definition Represents the capacity of real estate property. + References No definition available. + Details
Name: | nen_CapacityOfRealEstateProperty
Namespace Prefix: | nen_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Area of a real estate property. + References No definition available. + Details
Name: | us-gaap_AreaOfRealEstateProperty
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:areaItemType
Balance Type: | na
Period Type: | instant

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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of real estate properties owned as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfRealEstateProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of units in a real estate property owned as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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 No definition available. + Details
Name: | us-gaap_RealEstatePropertiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RealEstatePropertiesAxis=us-gaap_WhollyOwnedPropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nen_ResidentialAndMixedUseRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nen_ResidentialRetailAndOfficeBuildingMixedUseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nen_CondominiumRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RealEstatePropertiesAxis=us-gaap_PartiallyOwnedPropertiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nen_CarParkingLotRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nen_LimitedPartnershipsMember
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: |