Summary Of Significant Accounting Policies And Estimates - Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Level 3 Inputs (Details) - USD ($) $ in Thousands	4 Months Ended	12 Months Ended
Dec. 31, 2023	Dec. 31, 2023
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance as of December 31, 2022		$ 50,000
Purchases		756,851
Sales		(12,603)
Distributions received		(52,420)
DST Program proceeds		0
Unrealized loss on sale of DST interests included in Other income, net		0
Income from unconsolidated real estate affiliates measured at fair value		13,977
Balance as of December 31, 2023	$ 755,805	755,805
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
DST Program proceeds	13,659
DST Financing Obligation
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of December 31, 2022		0
Purchases		0
Sales		0
Distributions received		0
DST Program proceeds		13,659
Unrealized loss on sale of DST interests included in Other income, net		35
Income from unconsolidated real estate affiliates measured at fair value		0
Balance as of December 31, 2023	13,694	13,694
Investments in real estate debt
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance as of December 31, 2022		50,000
Purchases		18,838
Sales		(12,603)
Distributions received		0
DST Program proceeds		0
Unrealized loss on sale of DST interests included in Other income, net		0
Income from unconsolidated real estate affiliates measured at fair value		0
Balance as of December 31, 2023	56,235	56,235
Investments in unconsolidated real estate affiliates
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance as of December 31, 2022		0
Purchases		738,013
Sales		0
Distributions received		(52,420)
DST Program proceeds		0
Unrealized loss on sale of DST interests included in Other income, net		0
Income from unconsolidated real estate affiliates measured at fair value		13,977
Balance as of December 31, 2023	$ 699,570	$ 699,570

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Distributions Received

No definition available.

Name:	osnl_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetDistributionsReceived
Namespace Prefix:	osnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Income From Unconsolidated Real Estate Affiliates Measured At Fair Value

+ References

No definition available.

+ Details

Name:	osnl_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIncomeFromUnconsolidatedRealEstateAffiliatesMeasuredAtFairValue
Namespace Prefix:	osnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Proceeds Received From Delaware Statutory Trust

+ References

No definition available.

+ Details

Name:	osnl_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetProceedsReceivedFromDelawareStatutoryTrust
Namespace Prefix:	osnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Unrealized Loss on Sale of Interests

+ References

No definition available.

+ Details

Name:	osnl_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetUnrealizedLossOnSaleOfInterests
Namespace Prefix:	osnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Distributions Received

+ References

No definition available.

+ Details

Name:	osnl_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDistributionsReceived
Namespace Prefix:	osnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Unrealized Loss on Sale of Interests

+ References

No definition available.

+ Details

Name:	osnl_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityUnrealizedLossOnSaleOfInterests
Namespace Prefix:	osnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liaiblity, Income From Unconsolidated Real Estate Affiliates Measured At Fair Value

+ References

No definition available.

+ Details

Name:	osnl_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiaiblityIncomeFromUnconsolidatedRealEstateAffiliatesMeasuredAtFairValue
Namespace Prefix:	osnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

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

- Definition

Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-SubTopic 10
-Topic 820
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

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

- Definition

Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of purchases of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of sales of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

+ Details

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

- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=osnl_DelawareStatutoryTrustFinancingObligationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=osnl_InvestmentsInRealEstateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_EquityMethodInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: