v3.26.1
Debt - Schedule of Outstanding Debt Obligations (Details) - USD ($)
Jun. 30, 2026
Jun. 05, 2026
May 21, 2026
Jan. 23, 2026
Dec. 31, 2025
Oct. 08, 2025
Jan. 21, 2025
Dec. 20, 2024
Oct. 30, 2024
Aug. 15, 2024
Apr. 04, 2024
Dec. 13, 2023
Sep. 27, 2023
Dec. 22, 2022
Nov. 08, 2022
Jul. 15, 2022
Nov. 16, 2021
Jun. 14, 2021
Dec. 17, 2020
Debt Instrument [Line Items]                                      
Total Debt $ 9,065,000,000       $ 8,390,000,000                            
Outstanding Principal 7,254,500,000       6,344,500,000                            
Unused portion 1,807,483,000       2,042,483,000                            
Total Debt 1,377,907,000       1,447,969,000                            
Unamortized Debt Issuance Costs (95,067,000)       (84,123,000)                            
Net Carrying Value 7,157,528,000       6,288,200,000                            
Outstanding letters of credit 3,000,000.0       3,000,000.0                            
SPV Asset Facility I | Line of Credit                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 700,000,000       700,000,000                 $ 700,000,000.0          
Outstanding Principal 700,000,000       700,000,000                            
Unused portion 0       0                            
Amount available 0       0                            
Unamortized Debt Issuance Costs (7,975,000)       (8,398,000)                            
Net Carrying Value 692,025,000       691,602,000                            
SPV Asset Facility II | Line of Credit                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 400,000,000       400,000,000       $ 300,000,000.0               $ 400,000,000    
Outstanding Principal 325,000,000       325,000,000                            
Unused portion 75,000,000       75,000,000                            
Amount available 38,832,000       75,000,000                            
Unamortized Debt Issuance Costs (3,755,000)       (4,536,000)                            
Net Carrying Value 321,245,000       320,464,000                            
SPV Asset Facility III | Line of Credit                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 1,100,000,000       1,100,000,000                     $ 1,100,000,000      
Outstanding Principal 624,500,000       624,500,000                            
Unused portion 475,500,000       475,500,000                            
Amount available 119,093,000       64,924,000                            
Unamortized Debt Issuance Costs (8,554,000)       (11,413,000)                            
Net Carrying Value 615,946,000       613,087,000                            
SPV Asset Facility IV | Line of Credit                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 500,000,000       500,000,000                   $ 500,000,000.0        
Outstanding Principal 370,000,000       200,000,000                            
Unused portion 130,000,000       300,000,000                            
Amount available 92,999,000       116,062,000                            
Unamortized Debt Issuance Costs (4,664,000)       (5,654,000)                            
Net Carrying Value 365,336,000       194,346,000                            
SPV Asset Facility V | Line of Credit                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 150,000,000   $ 150,000,000.0                                
Outstanding Principal 75,000,000                                    
Unused portion 75,000,000                                    
Amount available 75,000,000                                    
Unamortized Debt Issuance Costs (685,000)                                    
Net Carrying Value 74,315,000                                    
Athena CLO II | Secured Debt                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 375,000,000       375,000,000             $ 475,300,000              
Outstanding Principal 375,000,000       375,000,000                            
Unamortized Debt Issuance Costs (3,799,000)       (3,932,000)                            
Net Carrying Value 371,201,000       371,068,000                            
Athena CLO IV | Secured Debt                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 240,000,000       240,000,000         $ 399,700,000                  
Outstanding Principal 240,000,000       240,000,000                            
Unamortized Debt Issuance Costs (2,247,000)       (2,346,000)                            
Net Carrying Value 237,753,000       237,654,000                            
Athena CLO V | Secured Debt                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 300,000,000       300,000,000 $ 501,300,000                          
Outstanding Principal 300,000,000       300,000,000                            
Unamortized Debt Issuance Costs (2,026,000)       (1,928,000)                            
Net Carrying Value 297,974,000       298,072,000                            
June 2026 Notes | Unsecured debt investments                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed         375,000,000                           $ 375,000,000
Outstanding Principal         375,000,000                            
Unamortized Debt Issuance Costs         (713,000)                            
Net Carrying Value         374,287,000                            
January 2027 Notes | Unsecured debt investments                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 300,000,000       300,000,000                         $ 300,000,000  
Outstanding Principal 300,000,000       300,000,000                            
Unamortized Debt Issuance Costs (847,000)       (1,621,000)                            
Net Carrying Value 299,153,000       298,379,000                            
Interest rate swaps March 2028 Notes | Unsecured debt investments                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 650,000,000       650,000,000   $ 650,000,000.0                        
Outstanding Principal 650,000,000       650,000,000                            
Unamortized Debt Issuance Costs (6,109,000)       (7,811,000)                            
Net Carrying Value 646,097,000       654,890,000                            
September 2028 Notes | Unsecured debt investments                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 75,000,000       75,000,000               $ 75,000,000.0            
Outstanding Principal 75,000,000       75,000,000                            
Unamortized Debt Issuance Costs (405,000)       (495,000)                            
Net Carrying Value 74,595,000       74,505,000                            
Interest rate swaps April 2029 Notes | Unsecured debt investments                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 700,000,000       700,000,000           $ 700,000,000.0                
Outstanding Principal 700,000,000       700,000,000                            
Unamortized Debt Issuance Costs (9,880,000)       (11,558,000)                            
Net Carrying Value 691,569,000       703,564,000                            
Interest rate swaps October 2029 Notes | Unsecured debt investments                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 500,000,000 $ 500,000,000                                  
Outstanding Principal 500,000,000                                    
Unamortized Debt Issuance Costs (7,396,000)                                    
Net Carrying Value 493,124,000                                    
Interest rate swaps January 2031 Notes | Unsecured debt investments                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 400,000,000     $ 400,000,000.0                              
Outstanding Principal 400,000,000                                    
Unamortized Debt Issuance Costs (8,171,000)                                    
Net Carrying Value 385,749,000                                    
Revolving loan commitments | Revolving Credit Facility                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 5,500,000,000       5,570,000,000                            
Revolving loan commitments | Revolving Credit Facility | Line of Credit                                      
Debt Instrument [Line Items]                                      
Aggregate Principal Committed 2,675,000,000       2,675,000,000     $ 2,580,000,000                      
Outstanding Principal 1,620,000,000       1,480,000,000                            
Unused portion 1,051,983,000       1,191,983,000                            
Amount available 1,051,983,000       1,191,983,000                            
Unamortized Debt Issuance Costs (28,554,000)       (23,718,000)                            
Net Carrying Value $ 1,591,446,000       $ 1,456,282,000