v3.26.1
Investments - Investments at Fair Value and Amortized Cost (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Schedule of Investments [Line Items]    
Amortized Cost [1],[2] $ 15,002,793 $ 14,127,213
Fair Value 14,680,538 14,286,039
First-lien senior secured debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 11,674,158 10,983,810
Fair Value 11,444,661 10,979,070
Second-lien senior secured debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 597,545 601,494
Fair Value 478,763 568,641
Unsecured debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 460,040 467,464
Fair Value 464,478 477,128
Specialty finance debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 40,772 37,449
Fair Value 40,774 37,452
Preferred equity investments    
Schedule of Investments [Line Items]    
Amortized Cost 1,155,595 1,127,105
Fair Value 951,696 1,072,481
Common equity investments    
Schedule of Investments [Line Items]    
Amortized Cost 545,784 504,733
Fair Value 747,669 722,100
Specialty finance equity investments    
Schedule of Investments [Line Items]    
Amortized Cost 488,433 351,675
Fair Value 515,617 375,812
Joint ventures    
Schedule of Investments [Line Items]    
Amortized Cost 40,466 53,483
Fair Value $ 36,880 $ 53,355
[1] The amortized cost represents the original cost adjusted for the amortization or accretion of premium or discount, as applicable, on debt investments using the effective interest method.
[2] As of June 30, 2026, the net estimated unrealized loss for U.S. federal income tax purposes was $108.4 million based on a tax cost basis of $14.8 billion. As of June 30, 2026, the estimated aggregate gross unrealized loss for U.S. federal income tax purposes was $807.0 million and the estimated aggregate gross unrealized gain for U.S. federal income tax purposes was $698.6 million.