v3.26.1
Investments - Investments at Fair Value and Amortized Cost (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Schedule of Investments [Line Items]    
Amortized Cost [1],[2] $ 14,415,609 $ 14,127,213
Fair Value 14,068,239 14,286,039
First-lien senior secured debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 11,120,112 10,983,810
Fair Value 10,917,188 10,979,070
Second-lien senior secured debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 593,785 601,494
Fair Value 498,121 568,641
Unsecured debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 452,138 467,464
Fair Value 456,403 477,128
Specialty finance debt investments    
Schedule of Investments [Line Items]    
Amortized Cost 37,999 37,449
Fair Value 38,000 37,452
Preferred equity investments    
Schedule of Investments [Line Items]    
Amortized Cost 1,154,990 1,127,105
Fair Value 982,150 1,072,481
Common equity investments    
Schedule of Investments [Line Items]    
Amortized Cost 516,899 504,733
Fair Value 615,910 722,100
Specialty finance equity investments    
Schedule of Investments [Line Items]    
Amortized Cost 503,939 351,675
Fair Value 527,414 375,812
Joint ventures    
Schedule of Investments [Line Items]    
Amortized Cost 35,747 53,483
Fair Value $ 33,053 $ 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 March 31, 2026, the net estimated unrealized loss for U.S. federal income tax purposes was $147.6 million based on a tax cost basis of $14.2 billion. As of March 31, 2026, the estimated aggregate gross unrealized loss for U.S. federal income tax purposes was $689.2 million and the estimated aggregate gross unrealized gain for U.S. federal income tax purposes was $541.6 million.