v3.26.1
Borrowings - Additional Information (Details) - USD ($)
3 Months Ended 6 Months Ended
Oct. 30, 2025
Oct. 29, 2025
Sep. 26, 2025
Jul. 10, 2025
Dec. 19, 2024
Dec. 17, 2024
Feb. 22, 2024
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Dec. 02, 2025
Aug. 13, 2025
Jun. 27, 2025
May 01, 2025
Apr. 30, 2025
Dec. 09, 2024
Dec. 08, 2024
Debt Instrument [Line Items]                                      
Minimum percentage of asset coverage                   150.00%                  
Revolving loan facility, maximum principal amount               $ 1,394,700,000   $ 1,394,700,000   $ 1,320,000,000              
Revolving credit facility amount drawn               573,200,000   573,200,000   631,000,000              
Cumulative deferred financing costs               $ 3,997,000   $ 3,997,000   $ 5,435,000              
Asset coverage percentage               192.07% 184.22% 192.07% 184.22% 187.67%              
SOFR | Fifth Amendment                                      
Debt Instrument [Line Items]                                      
Interest rate                           1.95%          
MS Revolving Credit Facility                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount             $ 300,000,000 $ 300,000,000   $ 300,000,000   $ 300,000,000              
Interest rate description                   Advances under the MS Revolving Credit Facility will initially bear interest at a per annum rate equal to an applicable benchmark (which is initially the forward-looking term rate based on the SOFR, for a tenor of three (3) months, as such rate is published by the CME Group Benchmark Administration Limited (CBA)), plus an applicable margin. As amended on July 2, 2026, the applicable margin on advances is (i) during the revolving period, which is scheduled to end on July 2, 2028, 1.95% per annum, and (ii) after the end of the revolving period, 2.45% per annum.                  
Interest rate after end of revolving period             2.45%                        
Revolving credit facility expiration date             Jul. 02, 2028                        
Revolving credit facility maturity date             Jul. 02, 2030                        
Revolving credit facility amount drawn               195,000,000   $ 195,000,000   195,000,000              
Cumulative deferred financing costs               3,339,000   $ 3,339,000                  
MS Revolving Credit Facility | Applicable Margin on Advances, Interest Rate Scheduled to End 3 Years After February 22, 2024                                      
Debt Instrument [Line Items]                                      
Interest rate per annum             1.95%                        
SMTB Credit Facility                                      
Debt Instrument [Line Items]                                      
Credit facility arrangement                   The “Borrowing Base” is calculated as an advance rate multiplied by the unfunded capital commitments of Shareholders in the Company that meet certain credit-related criteria and, in certain circumstances, have been approved for inclusion in the Borrowing Base by SMTB and/or the other lenders. The advance rate with respect to each Shareholder is 65%, 80% or 90% depending on the level of approval and criteria satisfied by such Shareholder.                  
Revolving loan facility, maximum principal amount                             $ 700,000,000 $ 275,000,000 $ 200,000,000    
Temporary increased commitment                               $ 100,000,000      
Revolving credit facility amount drawn               505,000,000   $ 505,000,000   497,000,000              
Cumulative deferred financing costs               $ 2,269,000   $ 2,269,000                  
Advance rate percentage of approval 1               65   65                  
Advance rate percentage of approval 2               80   80                  
Advance rate percentage of approval 3               90   90                  
SMTB Credit Facility | First Amendment                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount                                   $ 200,000,000 $ 100,000,000
SMTB Credit Facility | Fourth Amendment                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount                             $ 400,000,000        
SMTB Credit Facility | Fifth Amendment                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount                           $ 700,000,000          
Borrowings outstanding                           200,000,000          
SMTB Credit Facility | Sixth Amendment                                      
Debt Instrument [Line Items]                                      
Uncommitted tranche $ 500,000,000                                    
Revolving credit facility expiration date Apr. 29, 2027 Jul. 10, 2026                                  
SMTB Credit Facility | Revolving loans based on alternate base rate [Member] | Sixth Amendment                                      
Debt Instrument [Line Items]                                      
Interest rate 0.75% 1.25%                                  
SMTB Credit Facility | Revolving loans Based on Term SOFR Rate | Sixth Amendment                                      
Debt Instrument [Line Items]                                      
Interest rate 1.75% 2.25%                                  
SMTB Credit Facility | Term loans Based on Term SOFR Rate | Sixth Amendment                                      
Debt Instrument [Line Items]                                      
Interest rate 1.60% 1.95%                                  
SMTB Revolving Tranche                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount               $ 422,200,000   $ 422,200,000   420,000,000              
Uncommitted tranche               222,200,000   222,200,000                  
Revolving credit facility amount drawn               232,000,000   232,000,000   297,000,000              
SMTB Revolving Tranche | Fourth Amendment                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount                           $ 400,000,000          
SMTB Term Loan Tranche                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount               272,500,000   272,500,000   200,000,000              
Revolving credit facility amount drawn               273,000,000   273,000,000   200,000,000              
Cumulative deferred financing costs               1,320,000   1,320,000                  
BNP Revolving Credit Facility II                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount               400,000,000   $ 400,000,000   400,000,000              
BNP Revolving Credit Facility I                                      
Debt Instrument [Line Items]                                      
Commitment fee payable description                   The BNP Revolving Credit Facility I also includes a commitment fee payable each calendar quarter, at a rate per annum equal to (a) for any calendar quarter in which the average principal obligations is less than or equal to 50% of the committed facility amount, 0.70%, (b) for any calendar quarter in which the average principal obligations is greater than 50% of the committed facility amount but less than or equal to 65% of the committed facility amount, 0.30%, (c) for any calendar quarter in which the average principal obligations is greater than 65% of the committed facility amount but less than or equal to 75% of the committed facility amount, 0.20% and (d) for any calendar quarter in which the average principal obligations is greater than 75% of the committed facility amount, 0.00%.                  
Revolving credit facility maturity date     Dec. 31, 2025                                
Revolving credit facility amount drawn               0   $ 0   0              
Cumulative deferred financing costs               429,000   $ 429,000                  
BNP Revolving Credit Facility I | January 2, 2025 through March 31, 2025                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount           $ 340,000,000                          
BNP Revolving Credit Facility I | April 1, 2025 through June 30, 2025                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount           330,000,000                          
BNP Revolving Credit Facility I | July 1, 2025 through September 30, 2025                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount           270,000,000                          
BNP Revolving Credit Facility I | October 1, 2025 through December 31, 2025                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount           $ 139,000,000                          
BNP Revolving Credit Facility I | SOFR                                      
Debt Instrument [Line Items]                                      
Interest rate per annum           1.45%                          
BNP Revolving Credit Facility II                                      
Debt Instrument [Line Items]                                      
Revolving loan facility, maximum principal amount                         $ 400,000,000            
Revolving credit facility expiration date                   Dec. 02, 2028                  
Revolving credit facility maturity date                     Dec. 02, 2030                
Revolving credit facility amount drawn               146,000,000   $ 146,000,000   139,000,000              
Cumulative deferred financing costs               $ 3,382,000   $ 3,382,000                  
BNP Revolving Credit Facility II | Prior to Nine Month Anniversary                                      
Debt Instrument [Line Items]                                      
Interest rate               1.85%   1.85%                  
BNP Revolving Credit Facility II | After Nine Month Anniversary                                      
Debt Instrument [Line Items]                                      
Interest rate               1.95%   1.95%                  
BNP Revolving Credit Facility II | Minimum | Six Month Anniversary                                      
Debt Instrument [Line Items]                                      
Interest rate               1.45%   1.45%                  
BNP Revolving Credit Facility II | Maximum | Six Month Anniversary                                      
Debt Instrument [Line Items]                                      
Interest rate               1.95%   1.95%                  
Secured Borrowing Agreement                                      
Debt Instrument [Line Items]                                      
Outstanding secured borrowings               $ 0   $ 0   $ 0              
Interest expense incurred               $ 0 $ 251,000 $ 0 $ 370,000                
Secured Borrowing Agreement | SOFR                                      
Debt Instrument [Line Items]                                      
Interest rate per annum       2.95% 2.95%