v3.26.1
Investments - Schedule of Portfolio Composition by Industry at Amortization Cost and Fair Value (Details) - USD ($)
$ in Thousands
12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Schedule of Investments [Line Items]    
Amortized Cost $ 2,176,447 $ 1,291,512
Fair Value $ 2,209,174 [1] $ 1,311,001 [2]
Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Aerospace & Defense    
Schedule of Investments [Line Items]    
Amortized Cost $ 24,586 $ 15,571
Fair Value $ 24,652 $ 16,069
Aerospace & Defense | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.10% 1.20%
Aerospace & Defense | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.10% 1.20%
Air Freight & Logistics    
Schedule of Investments [Line Items]    
Amortized Cost $ 22,726 $ 0
Fair Value $ 23,033 $ 0
Air Freight & Logistics | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.00% 0.00%
Air Freight & Logistics | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.00% 0.00%
Auto Components    
Schedule of Investments [Line Items]    
Amortized Cost $ 36,496 $ 28,337
Fair Value $ 36,957 $ 28,779
Auto Components | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.70% 2.20%
Auto Components | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.70% 2.20%
Automobiles    
Schedule of Investments [Line Items]    
Amortized Cost $ 98,937 $ 72,232
Fair Value $ 101,466 $ 73,044
Automobiles | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 4.60% 5.60%
Automobiles | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 4.60% 5.60%
Banks    
Schedule of Investments [Line Items]    
Amortized Cost $ 9,356 $ 4,562
Fair Value $ 9,456 $ 4,650
Banks | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.40% 0.30%
Banks | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.40% 0.30%
Beverages    
Schedule of Investments [Line Items]    
Amortized Cost $ 25,503 $ 18,059
Fair Value $ 26,202 $ 18,388
Beverages | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.20% 1.40%
Beverages | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.20% 1.40%
Building Products    
Schedule of Investments [Line Items]    
Amortized Cost $ 677 $ 0
Fair Value $ 693 $ 0
Building Products | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.00% 0.00%
Building Products | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.00% 0.00%
Capital Markets    
Schedule of Investments [Line Items]    
Amortized Cost $ 22,977 $ 14,032
Fair Value $ 23,193 $ 14,200
Capital Markets | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.10% 1.10%
Capital Markets | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.10% 1.10%
Chemicals    
Schedule of Investments [Line Items]    
Amortized Cost $ 6,453 $ 921
Fair Value $ 6,475 $ 921
Chemicals | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.30% 0.10%
Chemicals | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.30% 0.10%
Commercial Services & Supplies    
Schedule of Investments [Line Items]    
Amortized Cost $ 95,995 $ 86,126
Fair Value $ 96,815 $ 87,416
Commercial Services & Supplies | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 4.40% 6.70%
Commercial Services & Supplies | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 4.40% 6.70%
Construction & Engineering    
Schedule of Investments [Line Items]    
Amortized Cost $ 17,379 $ 9,906
Fair Value $ 17,502 $ 10,008
Construction & Engineering | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.80% 0.80%
Construction & Engineering | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.80% 0.80%
Containers & Packaging    
Schedule of Investments [Line Items]    
Amortized Cost $ 1,715 $ 0
Fair Value $ 1,718 $ 0
Containers & Packaging | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.00%
Containers & Packaging | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.00%
Diversified Consumer Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 148,679 $ 100,926
Fair Value $ 150,189 $ 102,710
Diversified Consumer Services | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 6.80% 7.80%
Diversified Consumer Services | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 6.80% 7.80%
Diversified Financial Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 62,615 $ 22,989
Fair Value $ 63,719 $ 23,412
Diversified Financial Services | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 2.90% 1.80%
Diversified Financial Services | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 2.90% 1.80%
Electric Utilities    
Schedule of Investments [Line Items]    
Amortized Cost $ 1,903 $ 0
Fair Value $ 1,997 $ 0
Electric Utilities | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.00%
Electric Utilities | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.00%
Electrical Equipment    
Schedule of Investments [Line Items]    
Amortized Cost $ 7,028 $ 691
Fair Value $ 7,157 $ 706
Electrical Equipment | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.30% 0.00%
Electrical Equipment | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.30% 0.10%
Electronic Equipment, Instruments & Components    
Schedule of Investments [Line Items]    
Amortized Cost $ 5,184 $ 5,186
Fair Value $ 5,345 $ 5,400
Electronic Equipment, Instruments & Components | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.20% 0.40%
Electronic Equipment, Instruments & Components | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.20% 0.40%
Food Products    
Schedule of Investments [Line Items]    
Amortized Cost $ 32,759 $ 20,253
Fair Value $ 33,072 $ 20,498
Food Products | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.50% 1.60%
Food Products | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.50% 1.60%
Healthcare Equipment & Supplies    
Schedule of Investments [Line Items]    
Amortized Cost $ 51,101 $ 25,421
Fair Value $ 51,329 $ 25,691
Healthcare Equipment & Supplies | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 2.30% 2.00%
Healthcare Equipment & Supplies | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 2.30% 2.00%
Healthcare Providers & Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 106,401 $ 35,048
Fair Value $ 108,172 $ 35,903
Healthcare Providers & Services | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 4.90% 2.70%
Healthcare Providers & Services | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 4.90% 2.70%
Healthcare Technology    
Schedule of Investments [Line Items]    
Amortized Cost $ 108,643 $ 41,038
Fair Value $ 109,991 $ 41,653
Healthcare Technology | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.00% 3.20%
Healthcare Technology | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.00% 3.20%
Hotels, Restaurants & Leisure    
Schedule of Investments [Line Items]    
Amortized Cost $ 127,364 $ 52,188
Fair Value $ 128,251 $ 52,662
Hotels, Restaurants & Leisure | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.90% 4.00%
Hotels, Restaurants & Leisure | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.80% 4.00%
Household Products    
Schedule of Investments [Line Items]    
Amortized Cost $ 2,728 $ 0
Fair Value $ 2,744 $ 0
Household Products | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.00%
Household Products | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.00%
Industrial Conglomerates    
Schedule of Investments [Line Items]    
Amortized Cost $ 28,527 $ 11,492
Fair Value $ 30,631 $ 11,447
Industrial Conglomerates | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.30% 0.90%
Industrial Conglomerates | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.40% 0.90%
Insurance    
Schedule of Investments [Line Items]    
Amortized Cost $ 117,345 $ 73,366
Fair Value $ 119,150 $ 74,631
Insurance | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.40% 5.70%
Insurance | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.40% 5.70%
IT Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 44,242 $ 40,822
Fair Value $ 44,632 $ 41,300
IT Services | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 2.00% 3.20%
IT Services | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 2.00% 3.20%
Leisure Products    
Schedule of Investments [Line Items]    
Amortized Cost $ 36,537 $ 22,166
Fair Value $ 36,536 $ 22,246
Leisure Products | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.70% 1.70%
Leisure Products | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.70% 1.70%
Life Sciences Tools & Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 23,565 $ 18,343
Fair Value $ 24,992 $ 18,972
Life Sciences Tools & Services | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.10% 1.40%
Life Sciences Tools & Services | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.10% 1.40%
Machinery    
Schedule of Investments [Line Items]    
Amortized Cost $ 31,475 $ 27,540
Fair Value $ 31,741 $ 27,815
Machinery | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.40% 2.10%
Machinery | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.40% 2.10%
Media    
Schedule of Investments [Line Items]    
Amortized Cost $ 14,869 $ 7,068
Fair Value $ 14,886 $ 7,154
Media | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.70% 0.50%
Media | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.70% 0.50%
Oil, Gas & Consumable Fuels    
Schedule of Investments [Line Items]    
Amortized Cost $ 25,311 $ 15,849
Fair Value $ 25,498 $ 16,081
Oil, Gas & Consumable Fuels | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.20% 1.20%
Oil, Gas & Consumable Fuels | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.20% 1.20%
Pharmaceuticals    
Schedule of Investments [Line Items]    
Amortized Cost $ 21,811 $ 1,013
Fair Value $ 22,245 $ 1,016
Pharmaceuticals | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.00% 0.10%
Pharmaceuticals | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 1.00% 0.10%
Professional Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 79,954 $ 25,099
Fair Value $ 80,355 $ 25,225
Professional Services | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 3.70% 1.90%
Professional Services | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 3.70% 1.90%
Road & Rail    
Schedule of Investments [Line Items]    
Amortized Cost $ 13,840 $ 0
Fair Value $ 13,930 $ 0
Road & Rail | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.60% 0.00%
Road & Rail | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.60% 0.00%
Software    
Schedule of Investments [Line Items]    
Amortized Cost $ 577,485 $ 375,250
Fair Value $ 590,302 $ 382,061
Software | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 26.50% 29.10%
Software | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 26.70% 29.10%
Specialty Retail    
Schedule of Investments [Line Items]    
Amortized Cost $ 126,438 $ 118,440
Fair Value $ 126,384 $ 119,368
Specialty Retail | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.80% 9.20%
Specialty Retail | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 5.70% 9.10%
Transportation Infrastructure    
Schedule of Investments [Line Items]    
Amortized Cost $ 16,060 $ 0
Fair Value $ 15,965 $ 0
Transportation Infrastructure | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.80% 0.00%
Transportation Infrastructure | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.70% 0.00%
Water Utilities    
Schedule of Investments [Line Items]    
Amortized Cost $ 1,783 $ 1,578
Fair Value $ 1,799 $ 1,575
Water Utilities | Investments, at Amortized Cost | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.10%
Water Utilities | Investments, at Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Concentration risk, percentage 0.10% 0.10%
[1] The fair values of investments were valued using significant unobservable inputs, unless otherwise noted. See Note 7. The fair value of loan investments may include the impact of the unfunded commitment being valued below par.
[2] The fair values of investments were valued using significant unobservable inputs, unless otherwise noted. See Note 7. The fair value of loan investments may include the impact of the unfunded commitment being valued below par.