v3.26.1
Fair Value of Financial Instruments - Schedule of Investment Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Total        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance $ 3,954,010 $ 3,860,220 $ 3,998,057 $ 3,851,424
Purchases and other adjustments to cost 128,571 357,066 368,269 646,728
Sales and repayments (83,823) (193,866) (330,070) (515,799)
Transfers in 7,320 (14,617) 7,555 51,211
Transfers out     (16,600) (7,980)
Ending balance 4,000,024 3,997,407 4,000,024 3,997,407
Net change in unrealized appreciation (depreciation) for the period relating to those Level 3 assets that were still held by the Company at the end of the period: (5,550) (11,891) (29,569) (29,337)
Total | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) (791) (11,508) (33,464) (8,043)
Total | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) (5,263) 112 6,277 (20,134)
Senior Secured First Lien Debt        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 3,051,735 2,985,186 3,121,003 2,886,706
Purchases and other adjustments to cost 92,880 336,787 250,642 572,974
Sales and repayments (39,988) (195,873) (241,563) (393,520)
Transfers in 7,320 (14,617) 7,555 51,211
Transfers out     0 0
Ending balance 3,105,812 3,098,775 3,105,812 3,098,775
Net change in unrealized appreciation (depreciation) for the period relating to those Level 3 assets that were still held by the Company at the end of the period: (5,913) (13,168) (33,668) (20,690)
Senior Secured First Lien Debt | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) 121 (11,542) (33,822) (8,046)
Senior Secured First Lien Debt | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) (6,256) (1,166) 1,997 (10,550)
Senior Secured Second Lien Debt        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 101,855 92,885 110,594 103,368
Purchases and other adjustments to cost 4,789 1,954 56,611 3,843
Sales and repayments (9,504) 4,608 (54,155) 2,483
Transfers in 0 0 0 0
Transfers out     (16,600) (7,980)
Ending balance 97,785 100,297 97,785 100,297
Net change in unrealized appreciation (depreciation) for the period relating to those Level 3 assets that were still held by the Company at the end of the period: 1,004 851 874 (620)
Senior Secured Second Lien Debt | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) (1,274) 0 (4) 0
Senior Secured Second Lien Debt | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) 1,919 850 1,339 (1,417)
Subordinated Debt        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 285,017 220,889 259,132 196,418
Purchases and other adjustments to cost 27,442 18,301 55,515 63,124
Sales and repayments (32,500) (7,025) (32,515) (26,729)
Transfers in 0 0 0 0
Transfers out     0 0
Ending balance 276,251 232,792 276,251 232,792
Net change in unrealized appreciation (depreciation) for the period relating to those Level 3 assets that were still held by the Company at the end of the period: (3,699) 627 (5,872) (21)
Subordinated Debt | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) (9) 0 (9) 0
Subordinated Debt | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) (3,699) 627 (5,872) (21)
Collateralized Securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 4,098 7,486 4,861 10,893
Purchases and other adjustments to cost 15 24 33 57
Sales and repayments (28) (476) (40) (2,949)
Transfers in 0 0 0 0
Transfers out     0 0
Ending balance 3,898 6,564 3,898 6,564
Net change in unrealized appreciation (depreciation) for the period relating to those Level 3 assets that were still held by the Company at the end of the period: (144) (505) (916) (1,469)
Collateralized Securities | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) (204) 34 (204) 172
Collateralized Securities | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) 17 (504) (752) (1,609)
Equity/Other        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 511,305 553,774 502,467 654,039
Purchases and other adjustments to cost 3,445 0 5,468 6,730
Sales and repayments (1,803) 4,900 (1,797) (95,084)
Transfers in 0 0 0 0
Transfers out     0 0
Ending balance 516,278 558,979 516,278 558,979
Net change in unrealized appreciation (depreciation) for the period relating to those Level 3 assets that were still held by the Company at the end of the period: 3,202 304 10,013 (6,537)
Equity/Other | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) 575 0 575 (169)
Equity/Other | Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized gain (loss) $ 2,756 $ 305 $ 9,565 $ (6,537)