v3.26.3
Financial Highlights (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
Per share data                
Net asset value at beginning of period (in dollars per share)     $ 12.13 $ 11.66        
Net investment income (in dollars per share)     1.45 1.45        
Net realized gain (loss) (in dollars per share)     0.03 (0.35)        
Net unrealized appreciation (depreciation) (in dollars per share)     (0.04) 0.31        
Total from investment operations (in dollars per share)     1.44 1.41        
Net increase (decrease) in net assets from capital share transactions (in dollars per share)     0.05 0.33        
Distributions of net investment income (in dollars per share)     (1.42) (1.36)        
Distributions of capital gains (in dollars per share)     0 (0.06)        
Stock-based compensation expense included in net investment income and other movements (in dollars per share)     0.06 0.07        
Net asset value at ending of period (in dollars per share) $ 12.26 $ 12.05 12.26 12.05        
Ratios and supplemental data:                
Per share market value at end of period (in dollars per share) $ 16.81 $ 18.91 $ 16.81 $ 18.91        
Total return     (2.69%) 1.22%        
Shares outstanding at end of period (in shares) 189,597 181,776 189,597 181,776        
Weighted average shares outstanding (in shares) 185,989 180,360 184,767 175,633        
Net assets at end of period $ 2,324,713 $ 2,189,865 $ 2,324,713 $ 2,189,865 $ 2,274,330 $ 2,216,053 $ 2,151,075 $ 1,989,581
Ratio of total expense to average net assets     9.69% 9.01%        
Ratio of net investment income before investment gains and losses to average net assets     16.01% 16.36%        
Portfolio turnover rate     22.06% 19.01%        
Weighted average debt outstanding $ 2,457,332 $ 2,128,248 $ 2,429,053 $ 2,029,422        
Weighted average debt per common share (in dollars per share)     $ 13.15 $ 11.55