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
 3 Months Ended
Mar. 31, 2026
USD ($)
Mar. 31, 2025
USD ($)
Mar. 31, 2026
GBP (£)
Mar. 31, 2026
EUR (€)
Mar. 31, 2026
AUD ($)
Mar. 31, 2026
CAD ($)
Jan. 23, 2026
USD ($)
Dec. 31, 2025
USD ($)
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 $ 671,090             $ 407,768            
Liabilities (661,201)             (408,583)            
Unsecured debt investments | Derivatives designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Unsecured notes, carrying value 1,700,000             1,400,000            
Increase to carrying value of the notes 16,000 $ 27,800                        
Interest rate swaps | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional Amount 1,750,000             1,350,000            
Assets 14,806 [1]             18,081            
Interest rate swaps | Unsecured debt investments | Derivatives designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets 15,744             26,732            
Liabilities (938)             0            
Foreign currency forward contract GBP | Derivatives not designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets 581,299             334,694            
Liabilities (572,257)             (334,694)            
Foreign currency forward contract EUR | Derivatives not designated as hedges:                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Assets 89,791             73,074            
Liabilities (88,944)             (73,889)            
Interest rate swaps April 2029 Notes | Interest rate swaps | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional Amount 700,000 [2]             700,000 [3]           $ 700,000
Assets 8,848 [1],[2]             5,968 [3]            
Interest rate swaps April 2029 Notes | Interest rate swaps | 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 8,848             14,619            
Liabilities 0             0            
Interest rate swaps March 2028 Notes | Interest rate swaps | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional Amount               650,000 [4]         $ 650,000  
Assets [4]               12,113            
Interest rate swaps March 2028 Notes | Interest rate swaps | 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 6,896             12,113            
Liabilities 0             0            
Foreign currency forward contract GBP | Interest rate swaps | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional Amount | £     £ 147,230           £ 0          
Assets 197,076             0            
Liabilities (194,745)             0            
Interest rate swaps January 2031 Notes | Interest rate swaps | Unsecured debt investments                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional Amount 400,000 [5]           $ 400,000              
Assets [1],[5] (938)                          
Interest rate swaps January 2031 Notes | Interest rate swaps | 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 (938)             0            
Foreign currency forward contract GBP 1 | Interest rate swaps | Unsecured debt investments | Derivatives not designated as hedges: | SMBC Capital Markets, Inc.                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional Amount | £     £ 12,500           £ 0          
Assets 16,717             0            
Liabilities (16,534)             0            
Foreign currency forward contract AUD | Interest rate swaps | Unsecured debt investments | Derivatives not designated as hedges: | Goldman Sachs Bank USA                            
Derivative Instruments and Hedging Activities Disclosures [Line Items]                            
Notional Amount         $ 12,910           $ 0      
Assets 8,656             0            
Liabilities (8,905)             0            
Foreign currency forward contract CAD 1 | Interest rate swaps | 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 (1,053)             0            
Foreign currency forward contract CAD 2 | Interest rate swaps | 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 (39,590)             0            
Foreign currency forward contract EUR | Interest rate swaps | 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 (327,964)             (334,694)            
Foreign currency forward contract EUR 1 | Interest rate swaps | 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 (6,155)             (6,281)            
Foreign currency forward contract EUR 2 | Interest rate swaps | 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 $ (66,255)             $ (67,608)            
[1] Amounts are presented in accordance with Regulation S-X 17 CFR § 210.12-13C. Refer to “Note 7 — Derivative Instruments” for additional details on the Company’s interest rate swaps.
[2] The Company has an International Swaps and Derivatives Association (“ISDA”) agreement with Goldman Sachs Bank USA.
[3] The Company has an ISDA agreement with Goldman Sachs Bank USA.
[4] 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)
[5] The Company has an ISDA agreement with Regions Bank.