v3.26.1
Derivative Instruments - Schedule of Fair Value and Notional Value of the Derivative Assets and Liabilities (Details)
€ in Thousands, £ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Jun. 30, 2026
GBP (£)
Jun. 30, 2026
EUR (€)
Jun. 30, 2026
AUD ($)
Jun. 30, 2026
CAD ($)
Jun. 05, 2026
USD ($)
Jan. 23, 2026
USD ($)
Dec. 31, 2025
GBP (£)
Dec. 31, 2025
EUR (€)
Dec. 31, 2025
AUD ($)
Dec. 31, 2025
CAD ($)
Jan. 21, 2025
USD ($)
Apr. 04, 2024
USD ($)
Derivatives not designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets $ 738,153 $ 630,482                        
Liabilities (718,453) (632,423)                        
Unsecured debt investments | Derivatives designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Unsecured notes, carrying value 2,200,000 1,400,000                        
Increase to carrying value of the notes (1,900) 27,800                        
Interest Rate Swap | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 2,250,000 1,350,000                        
Assets (2,797) 18,081                        
Interest Rate Swap | Unsecured debt investments | Derivatives designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets 3,290 26,732                        
Liabilities (6,087) 0                        
Foreign currency forward contract GBP | Derivatives not designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets 587,633 540,869                        
Liabilities (570,828) (541,691)                        
Foreign currency forward contract EUR | Derivatives not designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets 90,008 89,613                        
Liabilities (87,870) (90,732)                        
Foreign currency forward contract AUD | Derivatives not designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets 60,512 0                        
Liabilities (59,755) 0                        
Interest rate swaps April 2029 Notes | Interest Rate Swap | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 700,000 700,000 [1]                       $ 700,000
Assets 942 5,968 [1]                        
Interest rate swaps April 2029 Notes | Interest Rate Swap | Unsecured debt investments | Derivatives designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 700,000 700,000                        
Assets 942 14,619                        
Liabilities 0 0                        
Interest rate swaps March 2028 Notes | Interest Rate Swap | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount   650,000 [2]                     $ 650,000  
Assets [2]   12,113                        
Interest rate swaps March 2028 Notes | Interest Rate Swap | Unsecured debt investments | Derivatives designated as hedges: | SMBC Capital Markets, Inc.                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 650,000 650,000                        
Assets 1,799 12,113                        
Liabilities 0 0                        
Interest rate swaps January 2031 Notes | Interest Rate Swap | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 400,000             $ 400,000            
Assets (6,087)                          
Interest rate swaps January 2031 Notes | Interest Rate Swap | Unsecured debt investments | Derivatives designated as hedges: | Regions Bank                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 400,000 0                        
Assets 0 0                        
Liabilities (6,087) 0                        
Interest rate swaps October 2029 Notes | Interest Rate Swap | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 500,000           $ 500,000              
Assets 549                          
Interest rate swaps October 2029 Notes | Interest Rate Swap | Unsecured debt investments | Derivatives designated as hedges: | Regions Bank                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 500,000 0                        
Assets 549 0                        
Liabilities 0 0                        
Foreign currency forward contract AUD | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount         $ 12,910           $ 12,910      
Assets 9,255 8,405                        
Liabilities (8,930) (8,616)                        
Foreign currency forward contract CAD 1 | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount           $ 1,454           $ 0    
Assets 1,071 0                        
Liabilities (1,029) 0                        
Foreign currency forward contract CAD 2 | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount           $ 54,652           $ 0    
Assets 39,802 0                        
Liabilities (38,690) 0                        
Foreign currency forward contract EUR | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount | €       € 282,460           € 282,460        
Assets 334,694 334,694                        
Liabilities (322,867) (334,694)                        
Foreign currency forward contract EUR | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | Royal Bank Of Canada                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount | €       51,692           0        
Assets 60,512 0                        
Liabilities (59,755) 0                        
Foreign currency forward contract EUR 1 | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | SMBC Capital Markets, Inc.                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount | €       5,301           5,301        
Assets 6,296 6,296                        
Liabilities (6,059) (6,281)                        
Foreign Currency Forward Contract USD | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount 18,281 0                        
Assets 18,281 0                        
Liabilities (18,571) 0                        
Foreign currency forward contract GBP | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount | £     £ 136,285           £ 147,230          
Assets 184,530 197,770                        
Liabilities (180,741) (198,381)                        
Foreign currency forward contract GBP | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | SMBC Capital Markets, Inc.                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount | £     £ 12,500           £ 12,500          
Assets 16,934 16,539                        
Liabilities (16,578) (16,843)                        
Foreign currency forward contract EUR 2 | Interest Rate Swap | Unsecured debt investments | Derivatives not designated as hedges: | SMBC Capital Markets, Inc.                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional amount | €       € 57,071           € 57,071        
Assets 66,778 66,778                        
Liabilities $ (65,233) $ (67,608)                        
[1] The Company has an ISDA agreement with Goldman Sachs Bank USA.
[2] The Company has an ISDA agreement with SMBC Capital Markets, Inc.
Forward Contracts as of December 31, 2025
Notional Amount to be PurchasedNotional Amount to be SoldCounterpartySettlement DateUnrealized Appreciation / (Depreciation)
Foreign currency forward contract$197,770 £147,230 Goldman Sachs Bank USA1/20/2026$(611)
Foreign currency forward contract$16,539 £12,500 SMBC Capital Markets, Inc.1/20/2026(304)
Foreign currency forward contract$6,296 €5,301 SMBC Capital Markets, Inc.7/17/202615 
Foreign currency forward contract$334,694 €282,462 Goldman Sachs Bank USA7/17/2026— 
Foreign currency forward contract$66,778 €57,070 SMBC Capital Markets, Inc.7/17/2026(830)
Foreign currency forward contract$8,405 A$12,910 Goldman Sachs Bank USA1/20/2026(211)
Total$(1,941)