v3.26.1
Borrowings - Schedule of Debt Securitization (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Debt Instrument [Line Items]        
Amortization of debt issuance costs $ 983 $ 1,149 $ 2,945 $ 3,070
Cash paid for interest expense     $ 59,070 $ 44,727
Annualized average stated interest rate 5.80% 6.90% 5.80% 7.10%
Average outstanding balance     $ 1,344,035 $ 861,741
2025 Debt Securitization        
Debt Instrument [Line Items]        
Stated interest expense $ 10,818 $ 1,459 33,138 1,459
Amortization of debt issuance costs 191 23 571 23
Total interest and other debt financing expenses 11,009 1,482 33,709 1,482
Cash paid for interest expense $ 10,687 $ 0 $ 38,240 $ 0
Annualized average stated interest rate 5.40% 6.10% 5.50% 6.10%
Average outstanding balance $ 799,250 $ 96,613 $ 799,250 $ 32,204
PNC Facility        
Debt Instrument [Line Items]        
Stated interest expense 0 1,784 0 8,245
Facility fees 0 47 0 84
Amortization of debt issuance costs 0 335 0 1,004
Total interest and other debt financing expenses 0 2,166 0 9,333
Cash paid for interest expense 0 $ 4,391 0 $ 14,755
Annualized average stated interest rate   6.50%   6.70%
Average outstanding balance 0 $ 110,784 0 $ 164,495
DB Credit Facility        
Debt Instrument [Line Items]        
Stated interest expense 1,784 3,183 6,825 12,350
Facility fees 537 254 1,091 673
Amortization of debt issuance costs 312 311 935 604
Total interest and other debt financing expenses 2,633 3,748 8,851 13,627
Cash paid for interest expense $ 2,605 $ 4,055 $ 8,666 $ 14,887
Annualized average stated interest rate 5.10% 6.40% 5.30% 6.70%
Average outstanding balance $ 139,611 $ 198,687 $ 173,219 $ 246,132
BNP Credit Facility        
Debt Instrument [Line Items]        
Stated interest expense 6,114 8,367 14,751 19,966
Amortization of debt issuance costs 480 480 1,439 1,440
Total interest and other debt financing expenses 6,594 8,847 16,190 21,406
Cash paid for interest expense $ 5,000 $ 8,202 $ 12,037 $ 15,085
Annualized average stated interest rate 5.30% 6.30% 5.30% 6.40%
Average outstanding balance $ 458,874 $ 531,137 $ 371,566 $ 414,351
Adviser Revolver        
Debt Instrument [Line Items]        
Stated interest expense 0 140 0 140
Cash paid for interest expense 0 $ 0 127 $ 0
Annualized average stated interest rate   4.10%   4.10%
Average outstanding balance $ 0 $ 13,673 $ 0 $ 4,559