v3.26.1
Investments - Additional Information (Details)
$ in Thousands
3 Months Ended 6 Months Ended 9 Months Ended
Jul. 26, 2023
USD ($)
Jun. 30, 2026
USD ($)
Portfolio
Jun. 30, 2025
USD ($)
Mar. 31, 2026
Jun. 30, 2026
USD ($)
Portfolio
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Sep. 30, 2025
USD ($)
Portfolio
Jul. 21, 2025
USD ($)
Dec. 23, 2024
USD ($)
Aug. 28, 2024
USD ($)
Mar. 31, 2022
USD ($)
Schedule Of Investments [Line Items]                        
Purchases of investments, including PIK interest   $ 78,900 $ 89,600   $ 306,800 $ 565,900            
Sales and repayments of investments   145,500 $ 132,200   532,100 $ 749,000            
Total assets   1,262,972     1,262,972     $ 1,349,554        
Credit facility payable   309,755     $ 309,755     425,477        
Subordinated Notes                        
Schedule Of Investments [Line Items]                        
Percentage of capital ownership in each of outstanding subordinated notes and equity interests         55.80% 55.80%            
Investments   140,300     $ 140,300     140,300        
Equity Interests in PSLF                        
Schedule Of Investments [Line Items]                        
Percentage of capital ownership in each of outstanding subordinated notes and equity interests         44.20% 44.20%            
Investments   82,400     $ 82,400     82,400        
Pantheon Funding I | Equity Interests in PSLF                        
Schedule Of Investments [Line Items]                        
Remaining commitments to fund   7,100     7,100     7,100        
Pantheon | Equity Interests in PSLF                        
Schedule Of Investments [Line Items]                        
Remaining commitments to fund   5,000     5,000     5,000        
CLO VII                        
Schedule Of Investments [Line Items]                        
Debt securitization   246,000     246,000     246,000        
CLO VII | Class A-1a [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization $ 151,000                      
Investments Basis Spread Variable Rate 2.70%                      
CLO VII | Class A1b [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Interest rate at basis points 6.50%                      
Debt securitization $ 20,000                      
CLO VII | Class A-2 [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization $ 12,000                      
Investments Basis Spread Variable Rate 3.20%                      
CLO VII | Class B [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization $ 21,000                      
Investments Basis Spread Variable Rate 4.10%                      
CLO VII | Class C [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization $ 24,000                      
CLO VII | Class C [Member] | Private Placement | SOFR                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate 4.70%                      
CLO VII | Class D [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization $ 18,000                      
CLO VII | Class D [Member] | Private Placement | SOFR                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate 7.00%                      
CLO VII | Class B (B-R) [Member]                        
Schedule Of Investments [Line Items]                        
Debt securitization                 $ 21,000      
CLO VII | Class C (C-R) [Member]                        
Schedule Of Investments [Line Items]                        
Debt securitization                 $ 24,000      
CLO VII | Class C (C-R) [Member] | SOFR                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate                 2.00%      
CLO VII | Class D (D-R) [Member]                        
Schedule Of Investments [Line Items]                        
Debt securitization                 $ 18,000      
Investments Basis Spread Variable Rate                 2.30%      
CLO VII | Class D (D-R) [Member] | SOFR                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate                 3.40%      
CLO VII | PSLF Subsidiary                        
Schedule Of Investments [Line Items]                        
Asset backed debt $ 300,000                      
CLO X                        
Schedule Of Investments [Line Items]                        
Asset backed debt   328,000     328,000     328,000        
CLO X | Class A-1 [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization             $ 158,000          
CLO X | Class A-1 [Member] | Private Placement | S O F R                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate             1.59%          
CLO X | Class A-1a [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization             $ 30,000          
Investments Basis Spread Variable Rate             1.59%          
CLO X | Class A-1W [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization             $ 40,000          
CLO X | Class A-1W [Member] | Private Placement | S O F R                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate             1.59%          
CLO X | Class A-2W [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization             $ 16,000          
CLO X | Class A-2W [Member] | Private Placement | S O F R                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate             1.75%          
CLO X | Class B [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization             $ 28,000          
CLO X | Class B [Member] | Private Placement | S O F R                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate             1.85%          
CLO X | Class C [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization             $ 32,000          
CLO X | Class C [Member] | Private Placement | S O F R                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate             2.40%          
CLO X | Class D [Member] | Private Placement                        
Schedule Of Investments [Line Items]                        
Debt securitization             $ 24,000          
CLO X | Class D [Member] | Private Placement | S O F R                        
Schedule Of Investments [Line Items]                        
Investments Basis Spread Variable Rate             3.85%          
CLO X | PSLF Subsidiary                        
Schedule Of Investments [Line Items]                        
Asset backed debt                   $ 400,500    
PSLF                        
Schedule Of Investments [Line Items]                        
Total assets   $ 1,336,374     $ 1,336,374     $ 1,315,447        
Number of portfolio companies consisted of debt investments | Portfolio   113     113     109        
Fair value of largest investment in a single portfolio company   $ 26,300     $ 26,300     $ 24,800        
Fair value of investment in five largest portfolio company   124,600     124,600     121,400        
Credit facility payable   144,900     144,900     99,600        
2034 Asset-backed debt, net par   246,000     $ 246,000     246,000        
PSLF | LLC Agreement | Maximum | PSLF and Pantheon Amendement                        
Schedule Of Investments [Line Items]                        
Ownership interest percentage                     87.50%  
PSLF | LLC Agreement | Minimum | PSLF and Pantheon Amendement                        
Schedule Of Investments [Line Items]                        
Ownership interest percentage                     25.00%  
PSLF | PSLF Subsidiary                        
Schedule Of Investments [Line Items]                        
Asset backed debt                       $ 304,000
Asset backed debt, transfer of assets, description         2034. On the closing date of the transaction, in consideration of PSLF’s transfer to PennantPark CLO IV, LLC of the initial closing date loan portfolio, which included loans distributed to PSLF by certain of its wholly owned subsidiaries and us, PennantPark CLO IV, LLC transferred to PSLF 100% of the Preferred Shares of PennantPark CLO IV, LLC and 100% of the subordinated notes issued by PennantPark CLO IV              
PSLF | PSLF Subsidiary | Senior Secured Revolving Credit Facility                        
Schedule Of Investments [Line Items]                        
Credit facility payable   325,000     $ 325,000           $ 400,000  
Credit facility interest rate description       interest rate index) plus 210 basis points reduced from plus 225 basis points in June 2026, during the investment period and is subject to leverage and borrowing base restrictions.                
Interest rate at basis points         225.00%              
PSLF | Pantheon Funding I                        
Schedule Of Investments [Line Items]                        
Remaining commitments to fund   11,700     $ 11,700     11,700        
PSLF | Pantheon                        
Schedule Of Investments [Line Items]                        
Remaining commitments to fund   $ 8,200     $ 8,200     $ 8,200