OTHER ASSETS (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2011
OTHER ASSETS
Security deposits and prepaid rent deposits	$ 1,923,000	$ 1,879,000
Escrow deposits to fund future capital improvements	710,000	1,014,000
Financing and leasing fees, net	960,000	919,000
Accumulated amortization on financing and leasing fees	$ 740,000	$ 636,000

Represents the accumulated amortization on financing and leasing fees.

No definition available.

Name:	nen_AccumulatedAmortizationOnFinancingAndLeasingFees
Namespace Prefix:	nen_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Restricted cash held in escrow to fund future capital improvements.

+ References

No definition available.

+ Details

Name:	nen_EscrowDepositToFundCapitalImprovements
Namespace Prefix:	nen_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the financing and leasing fees, net of accumulated amortization.

+ References

No definition available.

+ Details

Name:	nen_FinancingAndLeasingFeesNet
Namespace Prefix:	nen_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Definition

The amount of an asset, typically cash, provided to a counterparty to provide certain assurance of performance by the entity pursuant to the terms of a written or oral agreement, such as a lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.8,17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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