XML 33 R36.htm IDEA: XBRL DOCUMENT
v3.20.1

SIGNIFICANT ACCOUNTING POLICIES (Business) (Details) | Dec. 31, 2019 ft² property item | Dec. 31, 2018 item | Dec. 31, 2017 item
--- | --- | --- | ---
Line of Business |  |  |
Number of units | 913 | 913 | 913
Residential buildings |  |  |
Line of Business |  |  |
Number of units | 910 | 910 | 910
Commercial |  |  |
Line of Business |  |  |
Number of units | 3 | 3 | 3
Wholly owned properties |  |  |
Line of Business |  |  |
Number of Real Estate Properties | property | 29 |  |
Wholly owned properties | Residential and mixed-use properties |  |  |
Line of Business |  |  |
Number of Real Estate Properties | property | 25 |  |
Number of units | 2,892 |  |
Wholly owned properties | Residential buildings |  |  |
Line of Business |  |  |
Number of Real Estate Properties | property | 21 |  |
Wholly owned properties | Mixed use residential, retail and office buildings |  |  |
Line of Business |  |  |
Number of Real Estate Properties | property | 4 |  |
Wholly owned properties | Commercial |  |  |
Line of Business |  |  |
Number of Real Estate Properties | property | 3 |  |
Area of property (in square feet) | ft² | 108,043 |  |
Wholly owned properties | Condominium |  |  |
Line of Business |  |  |
Number of Real Estate Properties | property | 1 |  |
Number of units | 19 |  |
Partially owned properties | Residential and mixed-use properties |  |  |
Line of Business |  |  |
Number of Real Estate Properties | 7 |  |
Number of properties after balance sheet date | 688 |  |
Number of units | 688 |  |
Partially owned properties | Residential and mixed-use properties | Minimum |  |  |
Line of Business |  |  |
Ownership interest (as a percent) | 40.00% |  |
Partially owned properties | Commercial |  |  |
Line of Business |  |  |
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) | 50 |  |
Investment Properties | Minimum |  |  |
Line of Business |  |  |
Ownership interest (as a percent) | 40.00% |  |
Investment Properties | Maximum |  |  |
Line of Business |  |  |
Ownership interest (as a percent) | 50.00% |  |
Investment Properties | Partially owned properties | Residential and mixed-use properties |  |  |
Line of Business |  |  |
Number of Real Estate Properties | 7 |  |
Investment Properties | Partially owned properties | Residential and mixed-use properties | Minimum |  |  |
Line of Business |  |  |
Ownership interest (as a percent) | 40.00% |  |
Investment Properties | Partially owned properties | Residential and mixed-use properties | Maximum |  |  |
Line of Business |  |  |
Ownership interest (as a percent) | 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 The number of real estate properties owned after the balance sheet date but prior to the reporting date. + References No definition available. + Details
Name: | nen_NumberOfRealEstatePropertiesAfterBalanceSheetDate
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: | num: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 http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num: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: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_ResidentialRealEstateMember
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: | 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=nen_ResidentialRetailAndOfficeBuildingMixedUseMember
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_RangeAxis=srt_MinimumMember
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_InvestmentPropertiesMember
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: |