v3.26.1
Portfolio Investments - Schedule of Summarized Statement of Operations Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Investment Company, Nonconsolidated Subsidiary [Line Items]        
Total investment income $ 69,433 $ 75,271 $ 214,914 $ 239,486
Interest expense 24,139 31,061 76,424 89,814
Total expenses 36,609 47,093 111,004 141,453
Net investment income before taxes 32,824 33,537 103,910 117,435
Net increase (decrease) in net assets resulting from operations 30,940 38,352 17,659 9,342
SLF JV I        
Investment Company, Nonconsolidated Subsidiary [Line Items]        
Interest income 7,350 7,339 22,176 22,811
Other income/Fee income 55 13 200 19
Total investment income 7,405 7,352 22,376 22,830
Other expenses 128 234 292 427
Total expenses 5,777 7,203 19,962 21,698
Net investment income before taxes 1,628 149 2,414 1,132
Net unrealized appreciation (depreciation) 1,274 (85) 1,006 (7,016)
Realized gain (loss) (850) (693) (14,265) (669)
Net increase (decrease) in net assets resulting from operations 2,052 (629) (10,845) (6,553)
SLF JV I | Senior Credit Facility        
Investment Company, Nonconsolidated Subsidiary [Line Items]        
Interest expense 3,507 3,247 10,354 9,930
SLF JV I | SLF JV I Notes        
Investment Company, Nonconsolidated Subsidiary [Line Items]        
Interest expense 2,142 3,722 9,316 11,341
Glick JV LLC        
Investment Company, Nonconsolidated Subsidiary [Line Items]        
Interest income 2,445 2,603 7,554 8,566
Other income/Fee income 18 4 21 8
Total investment income 2,463 2,607 7,575 8,574
Other expenses 72 21 147 108
Total expenses 2,402 2,697 7,588 8,471
Net investment income before taxes 61 (90) (13) 103
Net unrealized appreciation (depreciation) 281 360 5,627 (30)
Realized gain (loss) (342) (270) (5,614) (73)
Net increase (decrease) in net assets resulting from operations 0 0 0 0
Glick JV LLC | Senior Credit Facility        
Investment Company, Nonconsolidated Subsidiary [Line Items]        
Interest expense 1,188 1,170 3,426 3,754
Glick JV LLC | Glick JV Notes        
Investment Company, Nonconsolidated Subsidiary [Line Items]        
Interest expense $ 1,142 $ 1,506 $ 4,015 $ 4,609