v3.25.2
Fair Value of Financial Instruments - Schedule of Changes in the Fair Value of Investments (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net change in unrealized gain (loss) / Net realized gains (losses) $ 73,395 $ (77,236) $ 67,214 $ (87,103)
First-lien senior secured debt investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Fair value, beginning of period 9,120,915 3,947,332 4,346,309 3,975,147
Purchases of investments, net 684,131 601,138 1,062,322 776,023
Payment-in-kind 13,127 16,958 20,348 27,528
Proceeds from investments, net (231,957) (356,871) (469,084) (562,953)
Net change in unrealized gain (loss) / Net realized gains (losses) 30,350 (58,531) 25,112 (66,519)
Net amortization/accretion of premium/discount on investments 6,271 8,864 10,753 12,717
Transfers into (out of) Level 3 (74,514) 0 0 0
Transfers in from the Mergers     4,552,286  
Fair value, end of period 9,548,767 4,156,539 9,548,767 4,156,539
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) / Net realized gains (losses) 27,299 (60,861) 22,305 (71,902)
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) / Net realized gains (losses) 3,495 (21) 3,528 (21)
Second-lien senior secured debt investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Fair value, beginning of period 291,217 255,724 166,159 235,292
Purchases of investments, net 61,324 0 61,323 0
Payment-in-kind 5,360 3,367 9,065 4,576
Proceeds from investments, net (32,717) (68,548) (41,117) (68,548)
Net change in unrealized gain (loss) / Net realized gains (losses) 2,078 (3,120) (446) (1,917)
Net amortization/accretion of premium/discount on investments 1,505 610 1,565 684
Transfers into (out of) Level 3 (17,413) (18,008) 0 0
Transfers in from the Mergers     116,990  
Fair value, end of period 310,288 169,510 310,288 169,510
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) / Net realized gains (losses) 1,012 (2,829) 8,501 (1,688)
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) / Net realized gains (losses) 0 (806) (12,198) (806)
Unsecured debt investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Fair value, beginning of period 460,216 401,445 336,635 407,407
Purchases of investments, net (2) 51,464 (1) 51,464
Payment-in-kind 6,210 6,393 13,713 16,960
Proceeds from investments, net (30,661) (136,107) (33,358) (154,085)
Net change in unrealized gain (loss) / Net realized gains (losses) 8,932 6,812 11,330 6,225
Net amortization/accretion of premium/discount on investments 5,914 3,929 10,516 7,623
Transfers into (out of) Level 3 0 0 0 0
Transfers in from the Mergers     111,857  
Fair value, end of period 451,319 322,371 451,319 322,371
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) / Net realized gains (losses) 8,932 6,812 11,872 6,225
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) / Net realized gains (losses) 710 (11,565) 85 (13,223)
Preferred equity investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Fair value, beginning of period 956,331 837,243 689,952 861,779
Purchases of investments, net 31,565 5,890 31,565 5,891
Payment-in-kind 23,295 11,649 33,158 18,803
Proceeds from investments, net (8,694) (1,076) (12,581) (1,319)
Net change in unrealized gain (loss) / Net realized gains (losses) 18,653 (32,128) 12,218 (63,123)
Net amortization/accretion of premium/discount on investments 971 117 1,210 231
Transfers into (out of) Level 3 0 0 0 0
Transfers in from the Mergers     266,560  
Fair value, end of period 1,022,197 821,664 1,022,197 821,664
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) / Net realized gains (losses) 18,653 (32,159) 12,218 (63,721)
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) / Net realized gains (losses) 76 0 115 0
Common equity investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Fair value, beginning of period 706,192 358,489 535,467 310,585
Purchases of investments, net 10,643 9,660 27,037 29,087
Payment-in-kind 0 0 0 0
Proceeds from investments, net 13,555 (1,224) 13,479 (1,247)
Net change in unrealized gain (loss) / Net realized gains (losses) 13,382 9,731 19,000 38,231
Net amortization/accretion of premium/discount on investments 0 0 0 0
Transfers into (out of) Level 3 0 (1,000) (3,092) (1,000)
Transfers in from the Mergers     151,980  
Fair value, end of period 743,758 376,656 743,758 376,656
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) / Net realized gains (losses) 13,368 10,731 18,887 39,231
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) / Net realized gains (losses) 0 0 0 0
Total        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Fair value, beginning of period 11,534,871 5,800,233 6,074,522 5,790,210
Purchases of investments, net 787,661 668,152 1,182,246 862,465
Payment-in-kind 47,992 38,367 76,284 67,867
Proceeds from investments, net (290,474) (563,826) (542,661) (788,152)
Net amortization/accretion of premium/discount on investments 14,661 13,520 24,044 21,255
Transfers into (out of) Level 3 (91,927) (19,008) (3,092) (1,000)
Transfers in from the Mergers     5,199,673  
Fair value, end of period 12,076,329 5,846,740 12,076,329 5,846,740
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) / Net realized gains (losses) 69,264 (78,306) 73,783 (91,855)
Total | Net realized gains (losses)        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Net change in unrealized gain (loss) / Net realized gains (losses) $ 4,281 $ (12,392) $ (8,470) $ (14,050)