XML 53 R43.htm IDEA: XBRL DOCUMENT
v3.10.0.1

TREASURY UNITS (Details) |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended | 120 Months Ended | 130 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 10, 2015 shares | Aug. 31, 2007 $ / item shares | Aug. 20, 2007 shares | Sep. 30, 2007 $ / item shares | Dec. 31, 2007 $ / item shares | Jun. 30, 2018 $ / item shares | Jun. 30, 2017 USD ($) shares | Dec. 31, 2017 $ / item shares | Jun. 30, 2018 USD ($) $ / item shares | Mar. 06, 2008 shares
Treasury units |  |  |  |  |  | 55,839 |  |  | 55,839 |
Period for repurchase of depository receipts | 5 years |  | 12 months |  |  |  |  |  |  |
Depository receipts authorized to be repurchased | 2,000,000 |  | 300,000 |  |  |  |  |  |  | 1,500,000
Number of depository receipts repurchased |  | 1,365,306 |  | 1,365,306 | 1,365,306 | 1,365,306 |  | 1,365,306 |  |
Repurchase price of depository receipts (in dollars per receipt) | $ / item |  |  |  |  |  |  |  |  | 27.14 |
Units repurchased (in shares) |  |  |  |  |  |  | 23 |  |  |
Total cost of repurchase | $ |  |  |  |  |  |  | $ 42,548 |  | $ 40,274,000 |
General Partnership |  |  |  |  |  |  |  |  |  |
Treasury units |  |  |  |  |  | 559 |  |  | 559 |
Fixed distribution percentage of unit holders |  |  |  |  |  | 1.00% |  |  |  |
Number of depository receipts repurchased |  | 162 |  | 162 | 162 | 162 |  | 162 |  |
Total cost of repurchase | $ |  |  |  |  |  |  | $ 426 |  |  |
Treasury Units |  |  |  |  |  |  |  |  |  |
Units repurchased (in shares) |  |  |  |  |  |  | 23 |  |  |
Class A |  |  |  |  |  |  |  |  |  |
Treasury units |  |  |  |  |  | 44,671 |  |  | 44,671 |
Fixed distribution percentage of unit holders |  |  |  |  |  | 80.00% |  |  |  |
Repurchase price of units (in dollars per unit) | $ / item |  | 814.20 |  | 814.20 | 814.20 | 814.20 |  | 814.20 |  |
Total cost of repurchase | $ |  |  |  |  |  |  | $ 34,038 |  |  |
Class B |  |  |  |  |  |  |  |  |  |
Treasury units |  |  |  |  |  | 10,609 |  |  | 10,609 |
Fixed distribution percentage of unit holders |  |  |  |  |  | 19.00% |  |  |  |
Number of depository receipts repurchased |  | 3,072 |  | 3,072 | 3,072 | 3,072 |  | 3,072 |  |
Total cost of repurchase | $ |  |  |  |  |  |  | $ 8,084 |  |  |
Class B | General Partnership |  |  |  |  |  |  |  |  |  |
Repurchase price of units (in dollars per unit) | $ / item |  | 926.26 |  | 926.26 | 926.26 | 926.26 |  | 926.26 |  |

X
- Definition Represents the number of depository receipts repurchased under the equity repurchase program. + References No definition available. + Details
Name: | nen_PartnersCapitalAccountDepositoryReceiptsTreasury
Namespace Prefix: | nen_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the average price at which depository receipts are repurchased under the equity repurchase program. + References No definition available. + Details
Name: | nen_PartnersCapitalAccountDepositoryReceiptsTreasuryAverageRepurchasePricePerDepositoryReceipt
Namespace Prefix: | nen_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of depository receipts authorized to be repurchased under the equity repurchase program. + References No definition available. + Details
Name: | nen_PartnersCapitalAccountDepositoryReceiptsTreasuryReceiptsAuthorizedToBeRepurchased
Namespace Prefix: | nen_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the fixed distribution percentages of the holders of units based on which the entity is required to purchase the proportionate number of specific units with every purchase of depository receipts. + References No definition available. + Details
Name: | nen_PartnersCapitalAccountFixedDistributionPercentageOfHoldersOfUnits
Namespace Prefix: | nen_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period over which the entity is permitted to purchase its depository receipts. + References No definition available. + Details
Name: | nen_PartnersCapitalAccountPeriodForRepurchaseOfDepositoryReceipts
Namespace Prefix: | nen_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of treasury units outstanding as on the balance sheet date. + References No definition available. + Details
Name: | nen_PartnersCapitalAccountTreasuryUnitsIssued
Namespace Prefix: | nen_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the average price at which units are repurchased under the equity repurchase program. + References No definition available. + Details
Name: | nen_PartnersCapitalAccountUnitsTreasuryAverageRepurchasePricePerUnit
Namespace Prefix: | nen_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of units that were previously issued and have been repurchased during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6828210&loc=d3e70191-108054 + Details
Name: | us-gaap_PartnersCapitalAccountTreasuryUnitsPurchases
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Units that were previously issued and have been repurchased during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770 + Details
Name: | us-gaap_PartnersCapitalAccountUnitsTreasury
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=us-gaap_GeneralPartnerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=nen_TreasuryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=nen_LimitedClassAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=nen_LimitedClassBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LimitedPartnersCapitalAccountByClassAxis=nen_LimitedClassBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |