Real Estate, net - Real Estate Acquisition (Details) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2026 USD ($) property building	Dec. 31, 2025 USD ($) forwardSwap building
Real Estate [Line Items]
Purchase Price		$ 277,351
Land and Improvements		109,332
Building and Improvements		143,819
Furniture and Fixtures		11,702
Lease Intangible Assets		10,229
Other Assets		15,467
Lease Intangible Liabilities		(298)
Other Liabilities		$ (12,900)
Minimum \| Buildings
Real Estate [Line Items]
Useful life (in years)	28 years
Minimum \| Tenant Improvements
Real Estate [Line Items]
Useful life (in years)	4 years
Minimum \| Furniture and Fixtures
Real Estate [Line Items]
Useful life (in years)	4 years
Minimum \| Lease Intangibles
Real Estate [Line Items]
Useful life (in years)	1 year
Maximum \| Buildings
Real Estate [Line Items]
Useful life (in years)	40 years
Maximum \| Tenant Improvements
Real Estate [Line Items]
Useful life (in years)	15 years
Maximum \| Furniture and Fixtures
Real Estate [Line Items]
Useful life (in years)	9 years
Maximum \| Lease Intangibles
Real Estate [Line Items]
Useful life (in years)	12 years
Multifamily - Texas
Real Estate [Line Items]
Number of Buildings/Units \| building	624
Purchase Price	$ 45,400
Land and Improvements	13,486
Building and Improvements	25,944
Furniture and Fixtures	1,235
Lease Intangible Assets	4,126
Other Assets	2,876
Lease Intangible Liabilities	0
Other Liabilities	$ (2,267)
Office - Oregon
Real Estate [Line Items]
Number of Buildings/Units \| building		8
Purchase Price		$ 21,100
Land and Improvements		10,913
Building and Improvements		5,105
Furniture and Fixtures		0
Lease Intangible Assets		4,567
Other Assets		1,849
Lease Intangible Liabilities		(298)
Other Liabilities		(1,036)
Multifamily/Pre-dev - California
Real Estate [Line Items]
Purchase Price		39,760
Land and Improvements		39,760
Building and Improvements		0
Furniture and Fixtures		0
Lease Intangible Assets		0
Other Assets		0
Lease Intangible Liabilities		0
Other Liabilities		$ 0
Hotel - California
Real Estate [Line Items]
Number of Buildings/Units \| building		541
Purchase Price		$ 139,126
Land and Improvements		36,166
Building and Improvements		91,719
Furniture and Fixtures		10,197
Lease Intangible Assets		80
Other Assets		10,034
Lease Intangible Liabilities		0
Other Liabilities		$ (9,070)
Multifamily - Arizona
Real Estate [Line Items]
Number of Buildings/Units \| building		285
Purchase Price		$ 31,965
Land and Improvements		9,007
Building and Improvements		21,051
Furniture and Fixtures		270
Lease Intangible Assets		1,456
Other Assets		708
Lease Intangible Liabilities		0
Other Liabilities		$ (527)
Multifamily
Real Estate [Line Items]
Number of legal titles acquired	1	1
Office
Real Estate [Line Items]
Number of legal titles acquired \| forwardSwap		1
Hotel
Real Estate [Line Items]
Number of legal titles acquired \| forwardSwap		1

Asset Acquisition, Building and Improvements

No definition available.

Name:	brsp_AssetAcquisitionBuildingAndImprovements
Namespace Prefix:	brsp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Asset Acquisition, Furniture and Fixtures

+ References

No definition available.

+ Details

Name:	brsp_AssetAcquisitionFurnitureAndFixtures
Namespace Prefix:	brsp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Asset Acquisition, Land and Improvements

+ References

No definition available.

+ Details

Name:	brsp_AssetAcquisitionLandAndImprovements
Namespace Prefix:	brsp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Asset Acquisition, Lease Intangible Assets

+ References

No definition available.

+ Details

Name:	brsp_AssetAcquisitionLeaseIntangibleAssets
Namespace Prefix:	brsp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Asset Acquisition, Lease Intangible Liabilities

+ References

No definition available.

+ Details

Name:	brsp_AssetAcquisitionLeaseIntangibleLiabilities
Namespace Prefix:	brsp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Asset Acquisition, Other Assets

+ References

No definition available.

+ Details

Name:	brsp_AssetAcquisitionOtherAssets
Namespace Prefix:	brsp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Asset Acquisition, Other Liabilities

+ References

No definition available.

+ Details

Name:	brsp_AssetAcquisitionOtherLiabilities
Namespace Prefix:	brsp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of Assets Acquired

+ References

No definition available.

+ Details

Name:	brsp_NumberOfAssetsAcquired
Namespace Prefix:	brsp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Legal Titles Acquired

+ References

No definition available.

+ Details

Name:	brsp_NumberOfLegalTitlesAcquired
Namespace Prefix:	brsp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of consideration transferred in asset acquisition. Includes, but is not limited to, cash, liability incurred by acquirer, and equity interest issued by acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 50
-Name Accounting Standards Codification
-Section 55
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479908/805-50-55-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 50
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480060/805-50-25-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 50
-Name Accounting Standards Codification
-Section 30
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480027/805-50-30-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 50
-Name Accounting Standards Codification
-Section 30
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480027/805-50-30-2

+ Details

Name:	us-gaap_AssetAcquisitionConsiderationTransferred
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Useful life of property, plant, and equipment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, land and land improvement; building; machinery and equipment; furniture and fixture; and work of art, historical treasure, or similar asset classified as collection.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482190/360-10-35-3

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- 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 976
-SubTopic 310
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477332/976-310-50-1

+ Details

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

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=brsp_TenantImprovementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_FurnitureAndFixturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=brsp_LeaseIntangiblesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetAcquisitionAxis=brsp_MultifamilyTexasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetAcquisitionAxis=brsp_OfficeOregonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetAcquisitionAxis=brsp_MultifamilyPreDevCaliforniaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetAcquisitionAxis=brsp_HotelCaliforniaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetAcquisitionAxis=brsp_MultifamilyArizonaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=srt_MultifamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=srt_OfficeBuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=srt_HotelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: