v3.25.0.1
Consolidated Statements of Changes in Net Assets (unaudited) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Investment Company, Net Assets [Roll Forward]    
Beginning balance (in shares) 264,277,128  
Beginning balance $ 4,014,529 $ 2,547,878
Net increase (decrease) in net assets resulting from operations    
Net investment income after taxes 96,590 83,535
Net realized gain (loss) on investment transactions (27,855) 1,096
Net realized gain (loss) on extinguishment of debt (48) 0
Net change in unrealized appreciation (depreciation) on investment transactions 42,575 (8,832)
(Provision) benefit for taxes on unrealized appreciation on investments 52 (23)
Distributions to stockholders:    
Stock issued in connection with dividend reinvestment plan 18,554 14,886
Distributions from distributable earnings (126,853) (74,622)
Total increase (decrease) common stock, outstanding $ 3,015 $ 16,040
Ending balance (in shares) 265,498,597 170,585,795
Ending balance $ 4,017,544 $ 2,563,918
Common Stock    
Investment Company, Net Assets [Roll Forward]    
Beginning balance (in shares) 264,277,128 169,594,742
Beginning balance $ 264 $ 170
Distributions to stockholders:    
Stock issued in connection with dividend reinvestment plan (in shares) 1,221,469 991,053
Stock issued in connection with dividend reinvestment plan $ 1 $ 1
Total increase (decrease) common stock, outstanding (in shares) 1,221,469 991,053
Total increase (decrease) common stock, outstanding $ 1 $ 1
Ending balance (in shares) 265,498,597 170,585,795
Ending balance $ 265 $ 171
Paid in Capital in Excess of Par    
Investment Company, Net Assets [Roll Forward]    
Beginning balance 4,167,258 2,646,912
Distributions to stockholders:    
Stock issued in connection with dividend reinvestment plan 18,553 14,885
Total increase (decrease) common stock, outstanding 18,553 14,885
Ending balance 4,185,811 2,661,797
Distributable Earnings (Losses)    
Investment Company, Net Assets [Roll Forward]    
Beginning balance (152,993) (99,204)
Net increase (decrease) in net assets resulting from operations    
Net investment income after taxes 96,590 83,535
Net realized gain (loss) on investment transactions (27,855) 1,096
Net realized gain (loss) on extinguishment of debt (48)  
Net change in unrealized appreciation (depreciation) on investment transactions 42,575 (8,832)
(Provision) benefit for taxes on unrealized appreciation on investments 52 (23)
Distributions to stockholders:    
Distributions from distributable earnings (126,853) (74,622)
Total increase (decrease) common stock, outstanding (15,539) 1,154
Ending balance $ (168,532) $ (98,050)