v3.21.2

Sale of Real Estate (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2021
Real Estate [Abstract] |
Schedule of Sale of Real Estate | The Company closed on the following sales of real estate, none of which qualified as discontinued operations:
|  | For the Three Months Ended September 30, |  |  | For the Nine Months Ended September 30, |
(in thousands, except number of properties) |  | 2021 |  |  | 2020 |  |  | 2021 |  |  | 2020 |
Number of properties disposed |  |  | 6 |  |  |  | 5 |  |  |  | 25 |  |  |  | 18 |
Aggregate sale price |  | $ | 26,567 |  |  | $ | 9,816 |  |  | $ | 71,905 |  |  | $ | 57,539 |
Aggregate carrying value |  |  | (24,244 | ) |  |  | (8,327 | ) |  |  | (58,817 | ) |  |  | (45,085 | )
Additional sales expenses |  |  | (1,103 | ) |  |  | (429 | ) |  |  | (3,297 | ) |  |  | (2,729 | )
Gain on sale of real estate |  | $ | 1,220 |  |  | $ | 1,060 |  |  | $ | 9,791 |  |  | $ | 9,725 |

X
- Definition Schedule of sale of real estate. + References No definition available. + Details
Name: | bnl_ScheduleOfSaleOfRealEstateTextBlock
Namespace Prefix: | bnl_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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