v3.26.1
Fair Value of Investments - Schedule of Changes in the Fair Value of Investments (Details) - Level 3 - 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 $ 15,572,144 $ 12,567,261
Purchases of investments, net 364,416 833,968
Payment-in-kind 42,610 53,266
Proceeds from investments, net (1,496,729) (533,969)
Net amortization/accretion of discount/premium on investments 17,721 17,794
Transfers between investment types 0  
Transfers into (out of) Level 3 8,875 (18,611)
Transfers in from the OBDE Mergers   3,997,087
Fair value, end of period 14,349,099 16,995,613
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) (76,676) 193,195
Total | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (83,262) (114,378)
First-lien senior secured debt investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 12,009,907 9,796,885
Purchases of investments, net 348,644 723,797
Payment-in-kind 16,348 24,688
Proceeds from investments, net (1,286,957) (504,586)
Net amortization/accretion of discount/premium on investments 15,923 16,065
Transfers between investment types (158)  
Transfers into (out of) Level 3 8,875 (25,266)
Transfers in from the OBDE Mergers   3,450,900
Fair value, end of period 11,003,920 13,534,635
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) (53,257) 63,107
First-lien senior secured debt investments | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (55,405) (10,955)
Second-lien senior secured debt investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 801,281 660,060
Purchases of investments, net 0 0
Payment-in-kind 2,017 6,529
Proceeds from investments, net (16,723) (6,468)
Net amortization/accretion of discount/premium on investments 1,143 967
Transfers between investment types 0  
Transfers into (out of) Level 3 0 9,746
Transfers in from the OBDE Mergers   177,535
Fair value, end of period 730,176 846,978
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) (57,687) 101,400
Second-lien senior secured debt investments | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 145 (102,791)
Unsecured debt investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 399,962 301,956
Purchases of investments, net 0 0
Payment-in-kind 11,633 12,551
Proceeds from investments, net (39,358) (9,485)
Net amortization/accretion of discount/premium on investments 92 115
Transfers between investment types 0  
Transfers into (out of) Level 3 0 0
Transfers in from the OBDE Mergers   66,164
Fair value, end of period 369,374 377,711
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) (5,211) 8,263
Unsecured debt investments | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 2,256 (1,853)
Specialty Finance Debt Investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 157,297 90,735
Purchases of investments, net 0 15,780
Payment-in-kind 2,586 14
Proceeds from investments, net (285) 0
Net amortization/accretion of discount/premium on investments 11 6
Transfers between investment types 0  
Transfers into (out of) Level 3 0 0
Transfers in from the OBDE Mergers   14,779
Fair value, end of period 159,598 121,603
Specialty Finance 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) (11) 289
Specialty Finance Debt Investments | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) 0 0
Preferred equity investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 568,977 366,973
Purchases of investments, net 976 44,022
Payment-in-kind 9,748 9,227
Proceeds from investments, net (36,550) (10,376)
Net amortization/accretion of discount/premium on investments 552 641
Transfers between investment types 0  
Transfers into (out of) Level 3 0 0
Transfers in from the OBDE Mergers   128,882
Fair value, end of period 536,853 543,191
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) 13,127 3,719
Preferred equity investments | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (19,977) 103
Common equity investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 520,542 550,886
Purchases of investments, net 12,068 0
Payment-in-kind 278 257
Proceeds from investments, net (15,799) 0
Net amortization/accretion of discount/premium on investments 0 0
Transfers between investment types 158  
Transfers into (out of) Level 3 0 (3,091)
Transfers in from the OBDE Mergers   83,590
Fair value, end of period 537,854 634,300
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) 30,888 2,658
Common equity investments | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) (10,281) 0
Specialty finance    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning of period 1,114,178 799,766
Purchases of investments, net 2,728 50,369
Payment-in-kind 0 0
Proceeds from investments, net (101,057) (3,054)
Net amortization/accretion of discount/premium on investments 0 0
Transfers between investment types 0  
Transfers into (out of) Level 3 0 0
Transfers in from the OBDE Mergers   75,237
Fair value, end of period 1,011,324 937,195
Specialty finance | 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) (4,525) 13,759
Specialty finance | Net realized gain (loss)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Net change in unrealized gain (loss) / realized gains (losses) $ 0 $ 1,118