v3.26.1
COVER PAGE - shares
 3 Months Ended
Mar. 31, 2026
Apr. 27, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 001-40923  
Entity Registrant Name FRANKLIN BSP REALTY TRUST, INC.  
Entity Incorporation, State or Country Code MD  
Entity Tax Identification Number 46-1406086  
Entity Address, Address Line One 1 Madison Ave,  
Entity Address, Address Line Two Suite 1600  
Entity Address, City or Town New York  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 10010  
City Area Code 212  
Local Phone Number 588-6770  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   76,963,009
Entity Central Index Key 0001562528  
Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Amendment Flag false  
Common Stock    
Document Information [Line Items]    
Title of 12(b) Security Common Stock, par value $0.01 per share  
Trading Symbol FBRT  
Security Exchange Name NYSE  
Series E Preferred Stock    
Document Information [Line Items]    
Title of 12(b) Security 7.50% Series E Cumulative Redeemable Preferred Stock, par value $0.01 per share  
Trading Symbol FBRT PRE  
Security Exchange Name NYSE