Debt Transferred

No definition available.

Name:	nlop_DebtTransferred
Namespace Prefix:	nlop_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of properties sold during the period.

+ References

No definition available.

+ Details

Name:	nlop_NumberOfPropertiesSold
Namespace Prefix:	nlop_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- 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

- Definition

Cash received from the sale of real estate that is held for investment, that is, it is part of an investing activity during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-12

+ Details

Name:	us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

+ Details

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

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-15

+ Details

Name:	us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_DebtInstrumentAxis=nlop_MortgageNotesPayableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nlop_SeniorSecuredMortgageLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LoansPayableMember
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:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=nlop_PropertyInColliervilleTennesseeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=nlop_PropertyInHoffmanEstatesIllinoisMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=nlop_PropertyInWarrensvilleIllinoisMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=nlop_PropertyInTempeArizonaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nlop_MezzanineLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Details) $ in Thousands	1 Months Ended	3 Months Ended
Subsequent Events (Details) $ in Thousands	Apr. 30, 2024 USD ($) property	Mar. 31, 2024 USD ($) property	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Subsequent Event
Investment in real estate		$ 1,542,375		$ 1,630,255
Proceeds from sales of real estate		32,423	$ 0
Repayment of debt		$ 30,916	$ 5,134
Number of real estate properties (property) \| property		53
Non-Recourse Mortgages
Subsequent Event
Repayment of debt		$ 19,200
Senior Secured Mortgage Loan \| Loans Payable
Subsequent Event
Repayment of debt		$ 11,300
Subsequent events
Subsequent Event
Number of properties sold (property) \| property	2
Proceeds from sales of real estate	$ 98,500
Subsequent events \| Loans Payable
Subsequent Event
Number of real estate properties (property) \| property	34
Subsequent events \| Collierville, Tennessee
Subsequent Event
Proceeds from sales of real estate	$ 62,500
Subsequent events \| Hoffman Estates, Illinois
Subsequent Event
Proceeds from sales of real estate	36,000
Subsequent events \| Non-Recourse Mortgages
Subsequent Event
Debt transferred	$ 33,000
Number of real estate properties (property) \| property	2
Subsequent events \| Non-Recourse Mortgages \| Warrensville, Illinois
Subsequent Event
Investment in real estate	$ 19,500
Debt transferred	19,800
Subsequent events \| Non-Recourse Mortgages \| Tempe Arizona
Subsequent Event
Investment in real estate	13,300
Debt transferred	13,200
Subsequent events \| Senior Secured Mortgage Loan \| Loans Payable
Subsequent Event
Repayment of debt	78,100
Subsequent events \| Mezzanine Loan Facility \| Loans Payable
Subsequent Event
Repayment of debt	$ 14,500