Quarterly report [Sections 13 or 15(d)]

Investments - Schedule of Realized Gains and Losses and Changes in Unrealized Appreciation and Depreciation on Control and Affiliate investments (Details)

v3.25.2
Investments - Schedule of Realized Gains and Losses and Changes in Unrealized Appreciation and Depreciation on Control and Affiliate investments (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Dec. 31, 2023
Schedule Of Investments [Line Items]            
Fair value of investments (in millions) $ 4,176,486   $ 4,176,486   $ 3,659,978  
Interest & Dividend Income 129,571 $ 117,529 245,143 $ 233,308    
Fee Income 7,888 7,477 11,827 13,251    
Net Change in Unrealized Appreciation (Depreciation) 47,790 (34,722) 22,225 (31,088)    
Control investments            
Schedule Of Investments [Line Items]            
Fair value of investments (in millions) 114,896 111,259 114,896 111,259 $ 113,179 $ 115,004
Interest & Dividend Income 3,368 3,457 7,005 6,414    
Fee Income 41 36 80 72    
Net Change in Unrealized Appreciation (Depreciation) (836) (1,506) 1,141 (4,335)    
Realized Gain (Loss) 0 0 0 0    
Control investments | Coronado Aesthetics, LLC            
Schedule Of Investments [Line Items]            
Fair value of investments (in millions) 313 186 313 186    
Interest & Dividend Income 0 0 0 0    
Fee Income 0 0 0 0    
Net Change in Unrealized Appreciation (Depreciation) 267 (97) 244 (76)    
Realized Gain (Loss) 0 0 0 0    
Control investments | Gibraltar Business Capital, LLC            
Schedule Of Investments [Line Items]            
Fair value of investments (in millions) 60,343 56,811 60,343 56,811    
Interest & Dividend Income 1,096 1,534 2,663 2,567    
Fee Income 41 36 80 72    
Net Change in Unrealized Appreciation (Depreciation) 1,444 (1,670) 504 (6,291)    
Realized Gain (Loss) 0 0 0 0    
Control investments | Hercules Adviser LLC            
Schedule Of Investments [Line Items]            
Fair value of investments (in millions) 44,222 42,728 44,222 42,728    
Interest & Dividend Income 2,100 1,751 4,000 3,503    
Fee Income 0 0 0 0    
Net Change in Unrealized Appreciation (Depreciation) (795) 844 2,032 2,015    
Realized Gain (Loss) 0 0 0 0    
Control investments | Tectura Corporation            
Schedule Of Investments [Line Items]            
Fair value of investments (in millions) 10,018 11,534 10,018 11,534    
Interest & Dividend Income 172 172 342 344    
Fee Income 0 0 0 0    
Net Change in Unrealized Appreciation (Depreciation) (1,752) (583) (1,639) 17    
Realized Gain (Loss) $ 0 $ 0 $ 0 $ 0