DERIVATIVE FINANCIAL INSTRUMENTS - Classification on the consolidated balance sheets (Details) - Interest Rate Swap - Designated as Hedging Instrument - Cash Flow Hedging - USD ($)	9 Months Ended	12 Months Ended
Sep. 30, 2023	Dec. 31, 2022
DERIVATIVE FINANCIAL INSTRUMENTS
Asset Derivatives designated as hedging instruments	$ 560,278	$ 294,931
DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration	Prepaid Expense and Other Assets	Prepaid Expense and Other Assets

Indicates line item in statement of financial position that includes derivative asset.

No definition available.

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Namespace Prefix:	nen_
Data Type:	enum2:enumerationSetItemType
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Period Type:	duration

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483466/210-20-50-3

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

+ Details

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Period Type:	duration

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
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- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
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- Details

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