v3.26.1
Fair Value of Investments - Schedule of Changes in the Fair Value of Investments (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Total    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period $ 5,295,125 $ 4,010,081
Purchases of investments, net 51,536 500,498
Payment-in-kind 10,045 8,420
Proceeds from investments, net (641,246) (259,852)
Net accretion/amortization of discount/premium on investments 3,324 5,837
Transfers into (out of) Level 3 (44,675) (34,542)
Fair Value, End of Period 4,578,924 4,231,626
Total | Net change in unrealized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (96,075) 920
Total | Net realized gains (losses)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 890 264
First-lien senior secured debt investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 4,802,901 3,601,677
Purchases of investments, net 44,676 479,306
Payment-in-kind 5,432 2,772
Proceeds from investments, net (635,381) (233,940)
Net accretion/amortization of discount/premium on investments 3,192 5,282
Transfers into (out of) Level 3 (4,166) (26,813)
Fair Value, End of Period 4,142,341 3,830,095
First-lien senior secured debt investments | Net change in unrealized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (75,174) 1,804
First-lien senior secured debt investments | Net realized gains (losses)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 861 7
Second-lien senior secured debt investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 161,254 122,347
Purchases of investments, net 33 12,438
Payment-in-kind 1,141 2,113
Proceeds from investments, net 0 0
Net accretion/amortization of discount/premium on investments 18 61
Transfers into (out of) Level 3 (40,509) 0
Fair Value, End of Period 117,845 135,061
Second-lien senior secured debt investments | Net change in unrealized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (4,092) (1,898)
Second-lien senior secured debt investments | Net realized gains (losses)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 0 0
Unsecured debt investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 66,531 59,333
Purchases of investments, net 0 0
Payment-in-kind 1,031 950
Proceeds from investments, net (4,780) 0
Net accretion/amortization of discount/premium on investments 6 7
Transfers into (out of) Level 3 0 0
Fair Value, End of Period 62,454 60,284
Unsecured debt investments | Net change in unrealized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (363) (6)
Unsecured debt investments | Net realized gains (losses)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 29 0
Preferred equity investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 173,230 171,478
Purchases of investments, net 4,000 0
Payment-in-kind 2,441 2,585
Proceeds from investments, net (1,085) (25,912)
Net accretion/amortization of discount/premium on investments 108 487
Transfers into (out of) Level 3 0 0
Fair Value, End of Period 171,367 148,221
Preferred equity investments | Net change in unrealized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (7,327) (674)
Preferred equity investments | Net realized gains (losses)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 0 257
Common equity investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 88,586 52,144
Purchases of investments, net 2,827 8,754
Payment-in-kind 0 0
Proceeds from investments, net 0 0
Net accretion/amortization of discount/premium on investments 0 0
Transfers into (out of) Level 3 0 (7,729)
Fair Value, End of Period 82,255 54,917
Common equity investments | Net change in unrealized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (9,158) 1,748
Common equity investments | Net realized gains (losses)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 0 0
Specialty finance equity investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 2,623 3,102
Purchases of investments, net 0 0
Payment-in-kind 0 0
Proceeds from investments, net 0 0
Net accretion/amortization of discount/premium on investments 0 0
Transfers into (out of) Level 3 0 0
Fair Value, End of Period 2,662 3,048
Specialty finance equity investments | Net change in unrealized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 39 (54)
Specialty finance equity investments | Net realized gains (losses)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) $ 0 $ 0