v3.22.2.2

Internalization - Additional Information (Detail) - Merger Agreement $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($) Tranche
Internalization [Line Items]
Number of tranches | Tranche	4
VWAP per REIT Share Days	40 days
Maximum
Internalization [Line Items]
Additional consideration payable	$ 75.0
Tranche One
Internalization [Line Items]
Additional consideration payable	10.0
Tranche Two
Internalization [Line Items]
Additional consideration payable	15.0
Tranche Three
Internalization [Line Items]
Additional consideration payable	25.0
Tranche Four
Internalization [Line Items]
Additional consideration payable	$ 25.0

X

- Definition

Business combination additional consideration payable number of tranches.

+ References

No definition available.

+ Details

Name:	bnl_BusinessCombinationAdditionalConsiderationPayableNumberOfTranches
Namespace Prefix:	bnl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Internalization.

+ References

No definition available.

+ Details

Name:	bnl_InternalizationLineItems
Namespace Prefix:	bnl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

VWAP per REIT Share Days.

+ References

No definition available.

+ Details

Name:	bnl_VWAPPerREITShareDays
Namespace Prefix:	bnl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI https://asc.fasb.org/extlink&oid=126975305&loc=d3e6927-128479

+ Details

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

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=bnl_MergerAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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