v3.22.2.2

Credit Risk Concentrations - Additional Information (Detail) - Customer	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Concentration Risk [Line Items]
Number of tenants or common franchises	0	0	0	0

X

- Definition

Number of major customer.

+ References

No definition available.

+ Details

Name:	bnl_NumberOfMajorCustomer
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_ConcentrationRiskLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration