v3.25.3
SLR Business Credit - Additional Information (Details)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 27, 2024
USD ($)
Jun. 03, 2021
USD ($)
Sep. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Sep. 30, 2025
USD ($)
Issuers
Sep. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Issuers
Jun. 28, 2019
USD ($)
May 01, 2018
Oct. 20, 2017
USD ($)
SLR Business Credit [Line Items]                    
Line of credit facility, maximum borrowing capacity $ 30,000                  
Commitments and contingencies              
Assets     2,529,892   $ 2,529,892   $ 2,449,417      
Number of issuers in business credit | Issuers         191   188      
Line of credit facility, expiration date         Nov. 13, 2028          
Net Income (Loss)     23,305 $ 22,049 $ 67,463 $ 73,148        
SLR Business Credit [Member]                    
SLR Business Credit [Line Items]                    
Long-term line of credit     2,894   2,894   $ 2,598      
Net Income (Loss)     2,545 824 8,026 6,329        
Gross income     15,417 $ 9,567 41,568 $ 31,172        
Senior Secured Commitments [Member]                    
SLR Business Credit [Line Items]                    
Commitments and contingencies     298,750   298,750   288,250      
Commitment funded amount     151,790   151,790   130,207      
Senior Secured Commitments [Member] | SLR Business Credit [Member]                    
SLR Business Credit [Line Items]                    
Commitments and contingencies     994,776   994,776   857,953      
Commitment funded amount     552,668   552,668   488,402      
Assets     597,455   597,455   527,077      
Fast Pay Partners LLC [Member]                    
SLR Business Credit [Line Items]                    
Percentage of voting interests acquired   100.00%                
Business combination, consideration transferred   $ 66,671                
Webster Bank, N.A.'s Commercial Services Division [Member]                    
SLR Business Credit [Line Items]                    
Business combination, consideration transferred 127,000                  
NMCs Credit Facility [Member]                    
SLR Business Credit [Line Items]                    
Line of credit facility, maximum borrowing capacity $ 97,000 47,671           $ 15,500    
SUNS [Member]                    
SLR Business Credit [Line Items]                    
Line of credit facility, maximum borrowing capacity   $ 19,000                
NMC Senior Credit Facility [Member]                    
SLR Business Credit [Line Items]                    
Line of credit facility, maximum borrowing capacity     367,000   367,000          
Long-term line of credit     $ 290,335   $ 290,335   $ 231,034      
NM Holdco [Member]                    
SLR Business Credit [Line Items]                    
Percentage of equity interest contributed to another entity               99.00%    
North Mill Capital LLC [Member]                    
SLR Business Credit [Line Items]                    
Equity method investment, ownership percentage                 99.00% 100.00%
Equity method investments                   $ 51,000
ESP SSC Corporation [Member]                    
SLR Business Credit [Line Items]                    
Equity method investment, ownership percentage                 1.00% 1.00%
Summit Financial Resources [Member]                    
SLR Business Credit [Line Items]                    
Equity method investment, ownership percentage               100.00%