v3.26.1
Fair Value Measurements - Schedule of Investments that Use Level 3 Inputs (Details) - Level 3 [Member] - USD ($)
$ in Thousands
 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Schedule of Investments that Use Level 3 Inputs [Line Items]    
Balance at beginning $ 224,187 $ 140,290
Purchases and other adjustments to cost 41,894 143,044
Sales (including repayments or maturities) (18,317) (48,172)
Net realized gains/(losses) from investments 698 (13,388)
Net unrealized gains/(losses) (2,897) 6,545
Transfer in/(out) (7,995)
Balance at ending 245,565 220,324
Senior Secured First Lien Term Loans [Member]    
Schedule of Investments that Use Level 3 Inputs [Line Items]    
Balance at beginning 88,981 68,987
Purchases and other adjustments to cost 26,302 66,391
Sales (including repayments or maturities) (11,143) (35,192)
Net realized gains/(losses) from investments 19 (11,617)
Net unrealized gains/(losses) (5,962) 9,617
Transfer in/(out) (7,883)
Balance at ending 98,197 90,303
Senior Secured Notes [Member]    
Schedule of Investments that Use Level 3 Inputs [Line Items]    
Balance at beginning 6,997 7,422
Purchases and other adjustments to cost
Sales (including repayments or maturities)
Net realized gains/(losses) from investments
Net unrealized gains/(losses)
Transfer in/(out)
Balance at ending 6,997 7,422
Equities/ Warrants [Member]    
Schedule of Investments that Use Level 3 Inputs [Line Items]    
Balance at beginning 128,209 63,881
Purchases and other adjustments to cost 15,592 76,653
Sales (including repayments or maturities) (7,174) (12,983)
Net realized gains/(losses) from investments 679 (1,771)
Net unrealized gains/(losses) 3,065 (3,069)
Transfer in/(out) (112)
Balance at ending $ 140,371 $ 122,599