v3.26.3
Agreements and Related Party Transactions - Additional Information (Details) - USD ($)
 1 Months Ended 3 Months Ended 9 Months Ended
Mar. 31, 2020
Apr. 15, 2011
Nov. 30, 2026
Nov. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Related Party Transaction [Line Items]                
Management fees         $ 13,268,000 $ 13,081,000 $ 38,821,000 $ 39,082,000
Administration Agreement                
Related Party Transaction [Line Items]                
Agreement termination period       60 days        
Administration Agreement | Adviser | Location, Statement of Income, Balance [Axis]: us-gaap:OtherGeneralAndAdministrativeExpense                
Related Party Transaction [Line Items]                
Expenses incurred         900,000 1,000,000 3,000,000 2,800,000
Investment Advisory Agreement                
Related Party Transaction [Line Items]                
Percentage of management fee on gross assets   1.50%            
Management fees         13,200,000 13,100,000 38,800,000 39,100,000
Percentage of excess pre-incentive fee net investment income for immediate preceding calendar quarter   100.00%            
Percentage of hurdle rate   1.50%            
Percentage of total pre-Incentive fee net investment income payable quarterly   17.50%            
Percentage of excess pre-Incentive Fee net investment income quarterly   1.82%            
Percentage of all remaining pre-Incentive Fee net investment income quarterly   17.50%            
Percentage of excess catch-up provision for pre-Incentive Fee net investment income   100.00%            
Percentage of all pre-Incentive Fee net investment income   17.50%            
Percentage of pre-Incentive Fee net investment income annualized   7.28%            
Percentage of excess pre-Incentive Fee net investment income   17.50%            
Percentage of pre-Incentive Fee net investment income payable in any quarter   1.82%            
Percentage of weighted cumulative realized capital gains less cumulative realized capital losses and unrealized capital losses   15.00%            
Incentive fees         8,800,000 9,500,000 25,900,000 29,800,000
Incentive fees realized and payable to advisor         8,800,000 10,500,000 25,900,000 33,100,000
Incentive fees accrued related to expense (reversal) of capital gains fees         0 (1,100,000) 0 (3,300,000)
Investment Advisory Agreement | Forecast                
Related Party Transaction [Line Items]                
Agreement termination period     60 days          
Investment Advisory Agreement | Capital Gains Accrue Following March 31, 2014                
Related Party Transaction [Line Items]                
Percentage of incentive fee rate   17.50%            
Investment Advisory Agreement | Realized Capital Gains Accrued Prior to March 31, 2014                
Related Party Transaction [Line Items]                
Percentage of incentive fee rate   15.00%            
Investment Advisory Agreement | Realized Capital Gains Accrued Beginning April 1, 2014                
Related Party Transaction [Line Items]                
Percentage of incentive fee rate   17.50%            
Investment Advisory Agreement | Future Realized Capital Gains Prior to April 1, 2014                
Related Party Transaction [Line Items]                
Remaining investments $ 0              
Incentive fee rate 17.50%              
Investment Advisory Agreement | Leverage Waiver                
Related Party Transaction [Line Items]                
Management fees         $ 500,000 $ 300,000 $ 1,300,000 $ 1,000,000
Percentage of asset coverage   200.00%            
Percentage of management fee in excess of annual rate on gross assets   1.00%            
Percentage of management fee in excess of quarter rate on gross assets   0.25%