Quarterly report [Sections 13 or 15(d)]

Fair Value of Financial Instruments - Summary of Reconciliation of Changes for All Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details)

v3.25.1
Fair Value of Financial Instruments - Summary of Reconciliation of Changes for All Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Significant Unobservable Inputs (Level 3) - Recurring - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance $ 3,613,959 $ 3,185,103
Net realized gains (losses) (725) 917
Net change in unrealized appreciation (depreciation) (32,252) 1,539
Purchases 435,189 502,158
Sales (749) (16,063)
Repayments (148,147) (174,035)
Gross Transfers into Level 3 17,316 0
Gross Transfers out of Level 3 12,222 0
Ending balance 3,872,369 3,499,619
Accounts payable and accrued liabilities    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance (1,012)  
Net change in unrealized appreciation (depreciation) 358  
Purchases 44  
Sales (362)  
Ending balance (972)  
Preferred Stock    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 53,802 53,038
Net change in unrealized appreciation (depreciation) (3,953) (2,326)
Purchases 2,813 1,597
Ending balance 52,662 52,309
Common Stock    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 44,593 41,790
Net realized gains (losses) (670)  
Net change in unrealized appreciation (depreciation) (2,014) (1,752)
Purchases 0  
Sales (331)  
Gross Transfers into Level 3 17,316  
Ending balance 58,894 40,038
Warrants    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 21,823 22,088
Net realized gains (losses) (63) 904
Net change in unrealized appreciation (depreciation) (1,527) (2,113)
Purchases 352 1,232
Sales 0 (2,829)
Ending balance 20,585 19,282
Senior Secured Debt    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 3,419,044 2,987,577
Net realized gains (losses) (48)  
Net change in unrealized appreciation (depreciation) (25,181) (104)
Purchases 428,830 498,787
Repayments (148,147) (174,035)
Gross Transfers out of Level 3 0  
Ending balance 3,674,498 3,312,225
Unsecured Debt    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 75,557 69,722
Net change in unrealized appreciation (depreciation) 65 481
Purchases 1,336 542
Gross Transfers out of Level 3 (12,222)  
Ending balance 64,736 70,745
Escrow and Other Investment Receivables    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 152 10,888
Net realized gains (losses) 56 13
Net change in unrealized appreciation (depreciation)   7,353
Purchases 1,814  
Sales (56) (13,234)
Ending balance $ 1,966 $ 5,020