v3.22.2.2

Non-Controlling Interests - Additional Information (Details) - shares | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2021
Noncontrolling Interest [Abstract] |  |
Number of OP Units Issued During Period | 1,611,358 | 1,859,257

X
- Definition Number of OP units issued during period. + References No definition available. + Details
Name: | bnl_NumberOfOpUnitsIssuedDuringPeriod
Namespace Prefix: | bnl_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

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