Quarterly report [Sections 13 or 15(d)]

BORROWINGS - Revolving Credit Facility Narrative (Details)

v3.26.1
BORROWINGS - Revolving Credit Facility Narrative (Details) - Credit Facility - Revolving Line of Credit - Line of Credit
 6 Months Ended 12 Months Ended
Feb. 03, 2026
USD ($)
Nov. 25, 2025
USD ($)
Mar. 31, 2026
USD ($)
obligor
Sep. 30, 2025
USD ($)
Debt Instrument [Line Items]        
Increase in borrowing capacity $ 25,000,000.0 $ 20,000,000.0    
Commitment amount     $ 365,000,000 $ 320,000,000
Line of credit facility, accordion feature maximum borrowing capacity     $ 400,000,000.0  
Debt instrument, basis spread on variable rate     2.60% 2.60%
Debt instrument, covenant, borrowing base, minimum number of obligors | obligor     25  
Covenant, required minimum net worth of mandatory redeemable term preferred stock     $ 500,000,000.0  
Covenant, required minimum net worth of mandatory redeemable term preferred stock, plus percent of all equity and subordinated debt raised     50.00%  
Covenant, required minimum net worth of mandatory redeemable term preferred stock, minus percent of any equity or subordinated debt redeemed or retired     50.00%  
Covenant, required minimum net worth of mandatory redeemable term preferred stock, plus percent of all equity and subordinated debt raised, minus percent of any equity or subordinated debt redeemed or retired     $ 486,500,000  
Debt instrument, covenant, senior security, indebtedness, required minimum asset coverage ratio     150.00%  
Senior security, indebtedness, asset coverage amount     $ 674,000,000.0  
Indebtedness asset coverage on our senior securities     225.70%  
Investment company, number of obligor | obligor     37  
Secured Overnight Financing Rate (SOFR), Tranche One        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate     2.60%  
Secured Overnight Financing Rate (SOFR), Thereafter        
Debt Instrument [Line Items]        
Debt instrument, basis spread on variable rate     3.10%