Fair Value of Financial Instruments - Schedule of Carrying and Fair Values of the Company’s Debt Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Debt Instrument [Line Items]
Net Carrying Value	$ 7,207,976	$ 6,291,450
Debt Issuance Costs	(93,204)	(84,123)
Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	7,174,233	6,288,200
Fair Value
Debt Instrument [Line Items]
Net Carrying Value	7,207,976	6,291,450
Level 1
Debt Instrument [Line Items]
Net Carrying Value	0	0
Level 2
Debt Instrument [Line Items]
Net Carrying Value	3,118,875	2,108,875
Level 3
Debt Instrument [Line Items]
Net Carrying Value	4,089,101	4,182,575
Line of Credit \| SPV Asset Facility I
Debt Instrument [Line Items]
Debt Issuance Costs	(7,760)	(8,398)
Line of Credit \| SPV Asset Facility I \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	692,240	691,602
Line of Credit \| SPV Asset Facility I \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	692,240	691,602
Line of Credit \| SPV Asset Facility II
Debt Instrument [Line Items]
Debt Issuance Costs	(3,358)	(4,536)
Line of Credit \| SPV Asset Facility II \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	321,642	320,464
Line of Credit \| SPV Asset Facility II \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	321,642	320,464
Line of Credit \| SPV Asset Facility III
Debt Instrument [Line Items]
Debt Issuance Costs	(7,064)	(11,413)
Line of Credit \| SPV Asset Facility III \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	692,936	613,087
Line of Credit \| SPV Asset Facility III \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	692,936	613,087
Line of Credit \| SPV Asset Facility IV
Debt Instrument [Line Items]
Debt Issuance Costs	(4,161)	(5,654)
Line of Credit \| SPV Asset Facility IV \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	365,839	194,346
Line of Credit \| SPV Asset Facility IV \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	365,839	194,346
Line of Credit \| SPV Asset Facility V
Debt Instrument [Line Items]
Debt Issuance Costs	(879)	0
Line of Credit \| SPV Asset Facility V \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	74,121	0
Line of Credit \| SPV Asset Facility V \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	74,121	0
Line of Credit \| SPV Asset Facility VI
Debt Instrument [Line Items]
Debt Issuance Costs	(2,768)	0
Line of Credit \| SPV Asset Facility VI \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	47,232	0
Line of Credit \| SPV Asset Facility VI \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	47,232	0
Secured Debt \| Athena CLO II
Debt Instrument [Line Items]
Debt Issuance Costs	(3,589)	(3,932)
Secured Debt \| Athena CLO II \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	371,411	371,068
Secured Debt \| Athena CLO II \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	371,411	371,068
Secured Debt \| Athena CLO IV
Debt Instrument [Line Items]
Debt Issuance Costs	(2,196)	(2,346)
Secured Debt \| Athena CLO IV \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	237,804	237,654
Secured Debt \| Athena CLO IV \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	237,804	237,654
Secured Debt \| Athena CLO V
Debt Instrument [Line Items]
Debt Issuance Costs	(1,907)	(1,928)
Secured Debt \| Athena CLO V \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	298,093	298,072
Secured Debt \| Athena CLO V \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	298,093	298,072
Unsecured debt investments \| June 2026 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	0	(713)
Unsecured debt investments \| June 2026 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	0	374,287
Unsecured debt investments \| June 2026 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	0	373,125
Unsecured debt investments \| January 2027 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	(453)	(1,621)
Unsecured debt investments \| January 2027 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	299,547	298,379
Unsecured debt investments \| January 2027 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	297,000	291,750
Unsecured debt investments \| March 2028 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	(5,228)	(7,811)
Unsecured debt investments \| March 2028 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	641,091	654,890
Unsecured debt investments \| March 2028 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	646,750	653,250
Unsecured debt investments \| September 2028 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	(360)	(495)
Unsecured debt investments \| September 2028 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	74,640	74,505
Unsecured debt investments \| September 2028 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	75,000	75,000
Unsecured debt investments \| April 2029 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	(9,028)	(11,558)
Unsecured debt investments \| April 2029 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	679,457	703,564
Unsecured debt investments \| April 2029 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	693,000	715,750
Unsecured debt investments \| Interest rate swaps October 2029 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	(8,034)	0
Unsecured debt investments \| Interest rate swaps October 2029 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	872,739	0
Unsecured debt investments \| Interest rate swaps October 2029 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	879,750	0
Unsecured debt investments \| Interest rate swaps January 2031 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	(8,348)	0
Unsecured debt investments \| Interest rate swaps January 2031 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	372,726	0
Unsecured debt investments \| Interest rate swaps January 2031 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	380,000	0
Unsecured debt investments \| September 2032 Notes
Debt Instrument [Line Items]
Debt Issuance Costs	(854)	0
Unsecured debt investments \| September 2032 Notes \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	144,932	0
Unsecured debt investments \| September 2032 Notes \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	147,375	0
Revolving loan commitments \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt Issuance Costs	(27,217)	(23,718)
Revolving loan commitments \| Line of Credit \| Revolving Credit Facility \| Net Carrying Value
Debt Instrument [Line Items]
Net Carrying Value	987,783	1,456,282
Revolving loan commitments \| Line of Credit \| Revolving Credit Facility \| Fair Value
Debt Instrument [Line Items]
Net Carrying Value	$ 987,783	$ 1,456,282