v3.25.3
Investments - Schedule of Investments Excluding Investments in Money Market Funds (Details) - USD ($)
$ in Thousands
Sep. 30, 2025
Dec. 31, 2024
Schedule Of Investments [Line Items]    
Cost $ 3,315,499 $ 3,673,582
Fair Value 3,196,933 3,475,258
1st Lien/Senior Secured Debt    
Schedule Of Investments [Line Items]    
Cost 3,050,865 3,301,746
Fair Value 2,998,388 3,179,820
1st Lien/Last-Out Unitranche    
Schedule Of Investments [Line Items]    
Cost 96,632 168,709
Fair Value 93,805 165,905
2nd Lien/Senior Secured Debt    
Schedule Of Investments [Line Items]    
Cost 50,237 57,161
Fair Value 47,963 46,786
Unsecured Debt    
Schedule Of Investments [Line Items]    
Cost 29,271 39,124
Fair Value 8,391 16,790
Preferred Stock    
Schedule Of Investments [Line Items]    
Cost 33,101 35,513
Fair Value 26,147 31,246
Common Stock    
Schedule Of Investments [Line Items]    
Cost 53,544 69,480
Fair Value 22,028 34,290
Warrants    
Schedule Of Investments [Line Items]    
Cost 1,849 1,849
Fair Value $ 211 $ 421