v3.26.3
Fair Value of Financial Instruments - Schedule of Changes in Level 3 Portfolio Investments Rollforward (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Total        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance $ 1,632,495 $ 1,743,513 $ 1,677,033 $ 1,799,726
Investments purchased 89,520 180,866 294,824 358,815
Accretion of discount 1,907 19,445 6,441 23,654
Sales and principal repayments (299,212) (225,392) (541,784) (409,902)
Net transfers in and/or (out) of Level 3   (4,555)   (5,511)
Ending balance 1,409,732 1,714,838 1,409,732 1,714,838
Changes in net unrealized depreciation (appreciation) on investments (8,916) 21,252 (8,669) (2,600)
Total | Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation (6,347) 10,566 (422) (12,257)
Total | Location, Statement of Income, Balance [Axis]: us-gaap:RealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation (8,631) (9,605) (26,360) (39,687)
Senior Secured First Lien Debt        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 1,303,616 1,501,896 1,370,525 1,563,256
Investments purchased 62,131 128,458 256,610 293,866
Accretion of discount 1,907 19,404 6,441 23,602
Sales and principal repayments (295,852) (225,332) (530,522) (405,227)
Net transfers in and/or (out) of Level 3   0   0
Ending balance 1,053,970 1,389,814 1,053,970 1,389,814
Changes in net unrealized depreciation (appreciation) on investments (11,769) (14,931) (29,739) (38,917)
Senior Secured First Lien Debt | Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation (9,200) (28,647) (21,433) (50,167)
Senior Secured First Lien Debt | Location, Statement of Income, Balance [Axis]: us-gaap:RealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation (8,632) (5,965) (27,651) (35,516)
Senior Secured Second Lien Debt        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 0 1,011 0 2,680
Investments purchased 0 70 0 214
Accretion of discount 0 41 0 52
Sales and principal repayments 0 (35) 0 (35)
Net transfers in and/or (out) of Level 3   0   0
Ending balance 0 0 0 0
Changes in net unrealized depreciation (appreciation) on investments 0 (892) 0 (1,507)
Senior Secured Second Lien Debt | Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation 0 2,113 0 289
Senior Secured Second Lien Debt | Location, Statement of Income, Balance [Axis]: us-gaap:RealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation 0 (3,200) 0 (3,200)
Collateralized Securities And Structured Products Equity        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 0 3,027 5,028 2,682
Investments purchased 0 985 0 1,964
Accretion of discount 0 0 0 0
Sales and principal repayments 0 (25) (4,900) (537)
Net transfers in and/or (out) of Level 3   0   0
Ending balance 0 4,009 0 4,009
Changes in net unrealized depreciation (appreciation) on investments 0 462 0 340
Collateralized Securities And Structured Products Equity | Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation 0 462 (59) 340
Collateralized Securities And Structured Products Equity | Location, Statement of Income, Balance [Axis]: us-gaap:RealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation 0 (440) (69) (440)
Unsecured Debt        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 7,359 8,091 6,639 11,814
Investments purchased 51 45 147 132
Accretion of discount 0 0 0 0
Sales and principal repayments 0 0 0 (4,103)
Net transfers in and/or (out) of Level 3   0   0
Ending balance 7,668 7,398 7,668 7,398
Changes in net unrealized depreciation (appreciation) on investments 258 (738) 882 (445)
Unsecured Debt | Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation 258 (738) 882 (445)
Unsecured Debt | Location, Statement of Income, Balance [Axis]: us-gaap:RealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation 0 0 0 0
Equity        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance 321,520 229,488 294,841 219,294
Investments purchased 27,338 51,308 38,067 62,639
Accretion of discount 0 0 0 0
Sales and principal repayments (3,360) 0 (6,362) 0
Net transfers in and/or (out) of Level 3   (4,555)   (5,511)
Ending balance 348,094 313,617 348,094 313,617
Changes in net unrealized depreciation (appreciation) on investments 2,595 37,351 20,188 37,929
Equity | Location, Statement of Income, Balance [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation 2,595 37,376 20,188 37,726
Equity | Location, Statement of Income, Balance [Axis]: us-gaap:RealizedGainLossInvestmentDerivativeAndForeignCurrencyTransactionPriceChangeOperatingBeforeTax        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net realized (loss) gain and Net change in unrealized (depreciation) appreciation $ 1 $ 0 $ 1,360 $ (531)