Derivatives - Narrative (Details)	Jun. 30, 2023 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash collateral for the derivative contracts	$ 0

Cash Collateral For Derivatives Held By Counterparties

No definition available.

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