v3.26.1
Fair Value of Investments - Fair value hierarchy (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Fair value hierarchy    
Fair Value $ 2,960,692 $ 2,882,954 [1],[2],[3],[4]
Level 2    
Fair value hierarchy    
Fair Value 179,678 187,390
Level 3    
Fair value hierarchy    
Fair Value 2,763,239 2,684,098
NAV    
Fair value hierarchy    
Fair Value 17,775 11,466
Interest rate swaps    
Fair value hierarchy    
Fair Value (2,124)  
Interest rate swaps | Level 2    
Fair value hierarchy    
Fair Value (2,124)  
First Lien Loans    
Fair value hierarchy    
Fair Value 2,617,370 2,549,002
First Lien Loans | Level 2    
Fair value hierarchy    
Fair Value 110,347 111,646
First Lien Loans | Level 3    
Fair value hierarchy    
Fair Value 2,507,023 2,437,356
Second Lien Loans    
Fair value hierarchy    
Fair Value 129,726 133,093
Second Lien Loans | Level 2    
Fair value hierarchy    
Fair Value 48,032 59,663
Second Lien Loans | Level 3    
Fair value hierarchy    
Fair Value 81,694 73,430
Unsecured Note    
Fair value hierarchy    
Fair Value 155,317 138,583
Unsecured Note | Level 2    
Fair value hierarchy    
Fair Value 23,423 16,081
Unsecured Note | Level 3    
Fair value hierarchy    
Fair Value 131,894 122,502
Preferred Equity    
Fair value hierarchy    
Fair Value 31,484 40,166
Preferred Equity | Level 3    
Fair value hierarchy    
Fair Value 31,484 40,166
Common Equity & Warrants    
Fair value hierarchy    
Fair Value 11,144 10,644
Common Equity & Warrants | Level 3    
Fair value hierarchy    
Fair Value 11,144 10,644
Securities Investment | Level 2    
Fair value hierarchy    
Fair Value 181,802 187,390
Securities Investment | Level 3    
Fair value hierarchy    
Fair Value 2,763,239 2,684,098
Securities Investment | Level 1 2 3    
Fair value hierarchy    
Fair Value $ 2,945,041 $ 2,871,488
[1] All investments were qualifying assets as defined under Section 55(a) of the Investment Company Act of 1940, as amended (the "1940 Act"), except for ALP CFO LP 2024-1, Apex Group Treasury LLC, Barings Middle Market CLO Ltd., Best Egg Asset Structured Pass Through Master Trust, Churchill Middle Market CLO Ltd., Claros Mortgage Trust, Inc., Coller Capital, Exeter Short Term Funding LLC, Inizio Group Limited, Ivy Hill Asset Management, Ivy Hill Middle Market Credit Fund XII Ltd, LD Holdings Group LLC., MC CIF Wealth Management (UK) Ltd. New Mountain Guardian IV Income Rated Feeder II, Ltd., New Mountain Guardian IV Rated Feeder III, LTD., and Syntax Systems Limited.
[2] All of the Company’s investments are domiciled in the United States except for Apex Group Treasury LLC, Barings Middle Market CLO Ltd., Inizio Group Limited, MC CIF Wealth Management Ltd, Flow Traders Holding LLC, New Mountain Guardian IV Income Rated Feeder II Ltd & New Mountain Guardian IV Rated Feeder III Ltd, and Syntax Systems Limited, which are domiciled in Ireland, the Cayman Islands, United Kingdom, United Kingdom, Bermuda, Bermuda, and Canada, respectively.
[3] As of December 31, 2025, all investments are pledged as collateral unless otherwise stated.
[4] Unless otherwise indicated, all securities are valued using significant unobservable inputs, which are categorized as Level 3 assets under the definition of ASC 820 fair value hierarchy.