v3.24.3

Significant Accounting Policies - Summary of Impairment Charge (Detail) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2024 USD ($) Property | Sep. 30, 2023 USD ($) Property | Sep. 30, 2024 USD ($) Property | Sep. 30, 2023 USD ($) Property
Impaired Long-Lived Assets Held and Used [Line Items] |  |  |  |
Number of properties | Property | 3 | 0 | 17 | 1
Impairment charge | $ | $ 1,059 | $ 0 | $ 31,311 | $ 1,473

X
- Definition The number of individual properties owned. + References No definition available. + Details
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Namespace Prefix: | bnl_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- 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 No definition available. + Details
Name: | us-gaap_ImpairedLongLivedAssetsHeldAndUsedLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The charge against earnings in the period to reduce the carrying amount of real property to fair value. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482099/360-10-50-2 + Details
Name: | us-gaap_ImpairmentOfRealEstate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration