v3.24.3

Acquisitions of Rental Property - Acquisitions of Rental Property Closed (Parenthetical) - (Detail) - USD ($) $ in Thousands |  | 9 Months Ended
--- | --- | ---
Apr. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2023
Business Acquisition [Line Items] |  |  |  |  |
Real estate asset acquisition amount | $ 52,000 | $ 286,233 | [1] | $ 43,365 | [2]
Acquisition costs capitalized |  | $ 2,500 |  | 3,200 |
September 2024 |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Acquisition of land |  |  |  | 204,800 |
October 2023 |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Acquisition of land |  |  |  | $ 1,700 |
[1] | Acquisition price excludes capitalized acquisition costs of $2.5 million.
[2] | Acquisit ion price excludes capitalized acquisition costs of $3.2 million

X
- Definition Acquisition of land + References No definition available. + Details
Name: | bnl_AcquisitionOfLand
Namespace Prefix: | bnl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479907/805-20-50-5 + Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of deferred policy acquisition cost capitalized on contract remaining in force. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (g)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480016/944-40-65-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479432/944-30-50-2B Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479401/944-30-55-2 Reference 4: 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)(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 45 -Paragraph 1 -SubTopic 825 -Topic 944 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478219/944-825-45-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479432/944-30-50-2B + Details
Name: | us-gaap_DeferredPolicyAcquisitionCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash outflow from the acquisition of a piece of land, anything permanently fixed to it, including buildings, structures on it and so forth; includes real estate intended to generate income for the owner; excludes real estate acquired for use by the owner. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 13 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-13 + Details
Name: | us-gaap_PaymentsToAcquireRealEstate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_AwardDateAxis=bnl_SeptemberTwoThousandTwentyFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardDateAxis=bnl_OctoberTwoThousandTwentyThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |