v3.25.2
Financial Highlights (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 27, 2024
Oct. 30, 2020
Aug. 03, 2020
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2022
Jun. 30, 2021
Investment Company, Financial Highlights [Roll Forward]                
Net asset value, beginning balance (in dollars per share)       $ 8.74 $ 9.24 $ 10.48 $ 9.81 $ 8.18
Net investment income (in dollars per share)       0.77 1.02 1.06 0.88 0.75
Net realized and change in unrealized gains (losses) (in dollars per share)       (1.87) (0.42) (1.31) 0.61 1.77
Net increase (decrease) from operations (in dollars per share)       (1.11) 0.60 (0.25) 1.49 2.51
Net increase (decrease) from operations applicable to common stockholders (in dollars per share)       (1.35) 0.36 (0.43) 1.43 2.51
Common stock transactions (in dollars per share)       (0.25) (0.15) (0.10) (0.05) (0.11)
Offering costs from issuance of preferred stock (in dollars per share)       0 0 0 (0.03) (0.04)
Reclassification of preferred stock issuance costs (in dollars per share)       0 0 0 0.03 0
Net asset value, ending balance (in dollars per share)       6.56 8.74 9.24 10.48 9.81
Per common share market value (in dollars per share)       $ 3.18 $ 5.53 $ 6.20 $ 6.99 $ 8.39
Total return based on market value       (33.71%) 1.47% (1.37%) (8.59%) 85.53%
Total return based on net asset value       (13.47%) 7.61% (1.96%) 17.21% 35.52%
Shares of common stock outstanding at end of period (in shares)       455,902,826 424,846,963 404,033,549 393,164,437 388,419,573
Weighted average shares of common stock outstanding (in shares)       440,314,909 412,703,365 398,514,965 390,571,648 382,705,106
Ratios/Supplemental Data                
Net assets at end of year       $ 2,988,772 $ 3,711,733 $ 3,732,665 $ 4,119,123 $ 3,945,517
Portfolio turnover rate       12.43% 7.56% 6.05% 15.92% 14.64%
Annualized ratio of operating expenses to average net assets applicable to common shares       11.26% 11.84% 11.01% 9.00% 9.98%
Annualized ratio of net investment income to average net assets applicable to common shares       10.03% 11.25% 10.75% 8.44% 8.24%
5.50% Preferred Stock                
Ratios/Supplemental Data                
Dividend rate 5.50% 5.50% 5.50% 5.50% 5.50%      
6.50% Preferred Stock                
Ratios/Supplemental Data                
Dividend rate     6.50% 6.50% 6.50%      
Preferred Stock                
Investment Company, Financial Highlights [Roll Forward]                
Distributions of net investment income (in dollars per share)       $ (0.24) $ (0.24) $ (0.17) $ (0.05) $ 0
Distributions of capital gains (in dollars per share)       0 0 0 (0.01) 0
Total distributions (in dollars per share)       (0.24) (0.24) (0.17) (0.06) 0
Common Stock                
Investment Company, Financial Highlights [Roll Forward]                
Distributions of net investment income (in dollars per share)       (0.58) (0.56) (0.60) (0.60) (0.63)
Distributions of capital gains (in dollars per share)       0 0 (0.02) (0.11) 0
Return of Capital to common stockholders (in dollars per share)       (0.02) (0.16) (0.10) (0.01) (0.09)
Total distributions (in dollars per share)       $ (0.60) $ (0.72) $ (0.72) $ (0.72) $ (0.72)
Shares of common stock outstanding at end of period (in shares)       455,902,826 424,846,963 404,033,549 393,164,437  
Ratios/Supplemental Data                
Net assets at end of year       $ 456 $ 425 $ 404 $ 393