v3.26.3
Related Party Transactions - Additional Information (Detail) - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended
Aug. 11, 2026
Sep. 30, 2026
Aug. 31, 2026
Jul. 31, 2026
Jun. 30, 2026
May 31, 2026
Apr. 30, 2026
Mar. 31, 2026
Feb. 28, 2026
Jan. 31, 2026
Sep. 30, 2025
Aug. 31, 2025
Jul. 31, 2025
Jun. 30, 2025
May 31, 2025
Apr. 30, 2025
Mar. 31, 2025
Feb. 28, 2025
Jan. 31, 2025
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Related Party Transaction [Line Items]                                                
General and administration expenses                                       $ 1,350 $ 711 $ 3,502 $ 2,062  
Investment company expense offset arrangement                                       0 0 $ 0 $ (778)  
Stock issued during the period shares new issues   5,035,671 1,134,111 8,865,731 10,650,045 5,680,855 10,381,667 3,361,013 438,709 5,164,340 3,624,185 3,886,374 2,115,437 3,052,634 849,290 3,273,944 2,030,616 2,949,039 1,191,393     50,712,142 22,972,912  
Proceeds from the issuance of common stock                                           $ 1,269,297 $ 563,028  
Management fee expense                                       7,776 3,580 19,226 9,111  
Income incentive fee                                       $ 5,434 $ 2,812 $ 13,103 $ 7,289  
Stock issued during the period shares dividend reinvestment plan 551,335     675,220     608,290                         675,220 589,003 1,952,334 1,525,234  
Capital gain incentive fees operating                                       $ 87 $ 191 $ 41 $ 146  
Mass Mutual SPV I Revolving Credit Facility [Member]                                                
Related Party Transaction [Line Items]                                                
Line of credit additional percentage of fees payable unused commitement                                           0.175%    
Massacheuts Mutual Life Insurance Company [Member] | Mass Mutual SPV I Revolving Credit Facility [Member]                                                
Related Party Transaction [Line Items]                                                
Line of credit additional percentage of fees payable unused commitement                                           0.20%    
Investment Income Expense [Member]                                                
Related Party Transaction [Line Items]                                                
Waived amount of management fees                                       5,434 2,812 $ 13,103 7,289  
Stepstone Private Credit Fund SP [Member]                                                
Related Party Transaction [Line Items]                                                
Capital Units   $ 2,639,193                                   $ 2,639,193   $ 2,639,193   $ 1,818,930
Percentage of company voting securities   83.60%                                   83.60%   83.60%   97.60%
Enhanced Segregated Portfolio [Member]                                                
Related Party Transaction [Line Items]                                                
Capital Units   $ 458,169                                   $ 458,169   $ 458,169   $ 0
Percentage of company voting securities   14.50%                                   14.50%   14.50%   0.00%
Advisory agreement [Member]                                                
Related Party Transaction [Line Items]                                                
Percentage of excess preincentive fee net investment income that is eligible to be applied towards incentive fee when hurdle rate is exceeded                                           100.00%    
Income incentive fee percentage on preincentive fee net inestment income when the hurdle rate is exceeded                                           7.50%    
Percentage of net assets quarterly basis maximum                                           1.3514%    
Percentage of net assets annual basis maximum                                           5.4056%    
Percentage of net assets quarterly basis minimum                                           5.4056%    
Percentage of net assets annual basis minimum                                           1.3514%    
Capital gain incentive fee payable as a percentage of net capital gains   7.50%                                   7.50%   7.50%    
Capital gain incentive fees operating                                       $ 87 191 $ 41 146  
Advisory agreement [Member] | Subsdiary of swiss capital alternative investments AG [Member]                                                
Related Party Transaction [Line Items]                                                
Base management fee percentage                                           1.00%    
Quarterly hurdle rate for calculation of income incentive fees                                           1.25%    
Annual hurdle rate for calculation of income incentive fees                                           5.00%    
Expenses limitation and reimbursement agreement [Member]                                                
Related Party Transaction [Line Items]                                                
Recoupments incurred                                         0   778  
Expenses limitation and reimbursement agreement [Member] | Subsdiary of swiss capital alternative investments AG [Member]                                                
Related Party Transaction [Line Items]                                                
Other operating expenses as percentage of net assets on an annualized basis maximum                                           1.00%    
Minimum gross proceeds from the sale of shares for payment to the advisor towards expenses                                           $ 100,000    
Administration agreement [Member] | Subsdiary of swiss capital alternative investments AG [Member]                                                
Related Party Transaction [Line Items]                                                
Administration fees as a percentage of net assets                                           0.30%    
General and administration expenses                                       $ 1,350 $ 711 $ 3,502 $ 2,062