Represents the number of depository receipts repurchased under the equity repurchase program.

No definition available.

Name:	nen_PartnersCapitalAccountDepositoryReceiptsTreasury
Namespace Prefix:	nen_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the quarterly distributions per depository receipt.

+ References

No definition available.

+ Details

Name:	nen_PartnersCapitalAccountQuarterlyDistributionPerDepositoryReceipt
Namespace Prefix:	nen_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the quarterly distributions per unit.

+ References

No definition available.

+ Details

Name:	nen_PartnersCapitalAccountQuarterlyDistributionPerUnit
Namespace Prefix:	nen_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the special distribution per depository receipt.

+ References

No definition available.

+ Details

Name:	nen_PartnersCapitalAccountSpecialDistributionPerDepositoryReceipt
Namespace Prefix:	nen_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of special distribution per unit of limited partner interest.

+ References

No definition available.

+ Details

Name:	nen_PartnersCapitalAccountSpecialDistributionPerUnitOfLimitedPartnerInterest
Namespace Prefix:	nen_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SUBSEQUENT EVENTS (Details) - $ / shares	1 Months Ended	2 Months Ended	12 Months Ended	208 Months Ended
SUBSEQUENT EVENTS (Details) - $ / shares	Mar. 31, 2025	Mar. 12, 2025	Dec. 31, 2024	Dec. 31, 2024
Subsequent events
Number of depository receipts repurchased				1,550,358
Class A
Subsequent events
Number of depository receipts repurchased			18,124
SUBSEQUENT EVENTS
Subsequent events
Number of depository receipts repurchased		84
Quarterly distribution (per unit)	$ 12
Quarterly distributions per depositary receipt (in dollars per receipt)	0.4
SUBSEQUENT EVENTS \| Class A
Subsequent events
Special distribution per unit (in dollars per unit)	96
Special distribution per depository receipt (in dollars per receipt)	$ 3.2