v3.26.3
Debt - Schedule of Debt (Details)
 3 Months Ended 9 Months Ended 12 Months Ended
Jul. 30, 2026
USD ($)
extension
May 27, 2026
extension
May 07, 2026
extension
Sep. 30, 2026
USD ($)
agreement
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
extension
agreement
Sep. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Jun. 30, 2025
USD ($)
Sep. 17, 2021
USD ($)
Assets Sold under Agreements to Repurchase [Line Items]                    
Realized gain/(loss) on extinguishment of debt       $ 1,699,000 $ 0 $ 766,000 $ 0      
Fixed Rate                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured notes                 $ 82,000,000.0  
Interest rate, stated percentage                 8.25%  
Floating Rate                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured notes                 $ 25,000,000.0  
Interest rate, effective percentage       4.00%   4.00%        
Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 4,525,000,000   $ 4,525,000,000   $ 4,000,000,000    
Unsecured debt, amount outstanding       $ 837,901,000   837,901,000   1,087,087,000    
Interest Expense           $ 44,654,000   $ 53,500,000    
Ending Weighted Average Interest Rate       5.68%   5.68%   5.70%    
Mortgage note payable                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured debt, amount outstanding       $ 24,186,000   $ 24,186,000   $ 23,998,000    
Interest Expense           $ 1,136,000   $ 1,783,000    
Ending Weighted Average Interest Rate       6.07%   6.07%   6.87%    
Mortgage note payable | Industrial | Jeffersonville, GA                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Principal amount                   $ 113,600,000
Mortgage note payable | September 2021 Mortgage Note Payable, Eliminated in Consolidation | Industrial | Jeffersonville, GA | Franklin BSP Realty Trust, Inc                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Principal amount                   $ 89,400,000
Other financings                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured debt, amount outstanding       $ 12,865,000   $ 12,865,000   $ 12,865,000    
Interest Expense           $ 585,000   $ 783,000    
Ending Weighted Average Interest Rate       6.00%   6.00%   6.00%    
Number of note-on-note financings | agreement       1   1        
Unsecured Debt                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured debt, amount outstanding       $ 164,500,000   $ 164,500,000   $ 189,500,000    
Interest Expense           $ 11,742,000   $ 12,808,000    
Ending Weighted Average Interest Rate       7.91%   7.91%   7.81%    
Interest paid       $ 800,000   $ 2,900,000        
Unsecured Debt | Unsecured Senior Notes I                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured debt, amount outstanding       107,000,000   107,000,000   $ 107,000,000    
Interest Expense           7,150,000   6,158,000    
Unsecured Debt | Junior Note I                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured debt, amount outstanding       $ 17,500,000   17,500,000   17,500,000    
Interest Expense           $ 1,022,000   $ 1,458,000    
Ending Weighted Average Interest Rate       7.60%   7.60%   7.60%    
Unsecured Debt | Junior Note II                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured debt, amount outstanding       $ 40,000,000   $ 40,000,000   $ 40,000,000    
Interest Expense           $ 2,230,000   $ 3,195,000    
Ending Weighted Average Interest Rate       7.46%   7.46%   7.28%    
Unsecured Debt | Junior Note III                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Unsecured debt, amount outstanding       $ 0   $ 0   $ 25,000,000    
Interest Expense           $ 1,340,000   $ 1,997,000    
Ending Weighted Average Interest Rate       0.00%   0.00%   7.28%    
Interest paid       $ 700,000   $ 1,700,000        
Realized gain/(loss) on extinguishment of debt       1,700,000            
Secured debt                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Advance rate of mortgage loan (percent)           100.00%        
Secured debt | Minimum                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Advance rate of mortgage loan (percent)           60.00%        
Secured debt | Maximum                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Advance rate of mortgage loan (percent)           75.00%        
Repo Facility | JPM Repo Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       750,000,000   $ 750,000,000   $ 500,000,000    
Unsecured debt, amount outstanding       $ 328,140,000   328,140,000   439,408,000    
Interest Expense           $ 25,440,000   $ 18,107,000    
Ending Weighted Average Interest Rate       6.11%   6.11%   6.04%    
Number of extension options | extension     1              
Extension period on initial maturity date     1 year              
Repo Facility | Atlas Repo Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 350,000,000   $ 350,000,000   $ 350,000,000    
Unsecured debt, amount outstanding       $ 76,347,000   76,347,000   150,744,000    
Interest Expense           $ 7,363,000   $ 10,598,000    
Ending Weighted Average Interest Rate       6.44%   6.44%   6.35%    
Repo Facility | WF Repo Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 250,000,000   $ 250,000,000   $ 250,000,000    
Unsecured debt, amount outstanding       $ 23,191,000   23,191,000   75,172,000    
Interest Expense           $ 2,388,000   $ 1,749,000    
Ending Weighted Average Interest Rate       5.20%   5.20%   5.22%    
Repo Facility | WF Repo Facility | Secured debt                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Number of extension options | extension           3        
Extension period on initial maturity date           1 year        
Repo Facility | Barclays Revolver Facility | Secured debt                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Number of extension options | extension           1        
Extension period on initial maturity date           1 year        
Repo Facility | Barclays Repo Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 500,000,000   $ 500,000,000   $ 500,000,000    
Unsecured debt, amount outstanding       $ 25,045,000   25,045,000   82,602,000    
Interest Expense           $ 2,117,000   $ 8,889,000    
Ending Weighted Average Interest Rate       5.36%   5.36%   5.59%    
Repo Facility | MS Repo Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 150,000,000   $ 150,000,000        
Unsecured debt, amount outstanding       $ 28,055,000   28,055,000        
Interest Expense           $ 287,000        
Ending Weighted Average Interest Rate       5.35%   5.35%        
Number of extension options | extension   2                
Extension period on initial maturity date   1 year                
Repo Facility | GS Repo Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity $ 250,000,000.0     $ 250,000,000   $ 250,000,000        
Unsecured debt, amount outstanding       0   0        
Interest Expense           0        
Number of extension options | extension 1                  
Extension period on initial maturity date 1 year                  
Initial maturity period 2 years                  
Repo Facility | Churchill Repo Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity               $ 0    
Unsecured debt, amount outstanding               0    
Interest Expense               555,000    
Repo Facility | Fifth Third Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity               100,000,000    
Unsecured debt, amount outstanding               15,000,000    
Interest Expense               1,265,000    
Repo Facility | PNC WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity               500,000,000    
Unsecured debt, amount outstanding               47,924,000    
Interest Expense               $ 1,628,000    
Ending Weighted Average Interest Rate               4.99%    
Repo Facility | ASAP WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity               $ 100,000,000    
Unsecured debt, amount outstanding               0    
Interest Expense               0    
Revolver Facility | Barclays Revolver Facility | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       0   0   100,000,000    
Unsecured debt, amount outstanding       0   0   0    
Interest Expense           74,000   438,000    
Revolver Facility | JPM WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity               700,000,000    
Unsecured debt, amount outstanding               222,831,000    
Interest Expense               $ 5,892,000    
Ending Weighted Average Interest Rate               5.04%    
Line of Credit | BAML WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       450,000,000   450,000,000   $ 500,000,000    
Unsecured debt, amount outstanding       $ 50,720,000   50,720,000   9,399,000    
Interest Expense           $ 1,671,000   $ 1,210,000    
Ending Weighted Average Interest Rate       4.98%   4.98%   5.17%    
Line of Credit | Fifth Third WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 400,000,000   $ 400,000,000   $ 400,000,000    
Unsecured debt, amount outstanding       $ 152,980,000   152,980,000   44,007,000    
Interest Expense           $ 1,095,000   $ 3,169,000    
Ending Weighted Average Interest Rate       5.20%   5.20%   5.02%    
Line of Credit | Fifth Third Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 125,000,000   $ 125,000,000        
Unsecured debt, amount outstanding       0   0        
Interest Expense           1,100,000        
Ending Weighted Average Interest Rate               6.53%    
Line of Credit | JPM WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       700,000,000   700,000,000        
Unsecured debt, amount outstanding       $ 89,560,000   89,560,000        
Interest Expense           $ 1,929,000        
Ending Weighted Average Interest Rate       5.26%   5.26%        
Line of Credit | PNC WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 500,000,000   $ 500,000,000        
Unsecured debt, amount outstanding       $ 63,863,000   63,863,000        
Interest Expense           $ 1,190,000        
Ending Weighted Average Interest Rate       5.21%   5.21%        
Line of Credit | ASAP WH Line of Credit | Line of Credit                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Repo and revolving credit facilities, commercial mortgage loans, capacity       $ 100,000,000.0   $ 100,000,000.0        
Unsecured debt, amount outstanding       $ 0   0        
Interest Expense           $ 0        
Line of Credit | ASAP WH Line of Credit | Line of Credit | Secured Overnight Financing Rate (SOFR)                    
Assets Sold under Agreements to Repurchase [Line Items]                    
Weighted Average Spread           1.50%        
Debt Instrument, Interest Rate Floor           0.25%