v3.26.1
Fair Value Measurements - Significant unobservable inputs and fair value of debt if carried at fair value (Details)
Mar. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Fair Value Measurements      
Total unobservable inputs $ 2,419,034,000 $ 2,443,312,000 $ 2,354,678,000
Level 2      
Fair Value Measurements      
Fair value of debt not carried at fair value 1,436,473 1,467,868  
Level 2 | 2019-1 Notes      
Fair Value Measurements      
Fair value of debt not carried at fair value 270,957 272,182  
Level 2 | March 2026 Notes      
Fair Value Measurements      
Fair value of debt not carried at fair value   298,926  
Level 2 | October 2026 Notes      
Fair Value Measurements      
Fair value of debt not carried at fair value 295,288 295,222  
Level 2 | March 2030 Notes      
Fair Value Measurements      
Fair value of debt not carried at fair value 339,944 350,538  
Level 2 | March 2031 Notes      
Fair Value Measurements      
Fair value of debt not carried at fair value 335,284    
Level 3      
Fair Value Measurements      
Fair value of assets 2,341,886,000 [1] 2,303,502,000 [2]  
Total unobservable inputs 2,419,034,000 2,443,312,000  
Unobservable inputs not developed 77,148,000 139,810,000  
Level 3 | Sumitomo Credit Facility      
Fair Value Measurements      
Fair value of debt not carried at fair value 195,000 251,000  
First Lien Senior Secured Loans      
Fair Value Measurements      
Total unobservable inputs 1,623,951,000 1,591,538,000 1,543,286,000
First Lien Senior Secured Loans one | Discounted cash flows | Comparative Yields | Level 3      
Fair Value Measurements      
Fair value of assets $ 1,433,213,000 [1] $ 1,425,578,000 [2]  
First Lien Senior Secured Loans one | Discounted cash flows | Comparative Yields | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.61 [3] 0.53 [4]  
First Lien Senior Secured Loans one | Discounted cash flows | Comparative Yields | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 2.84 [3] 1.95 [4]  
First Lien Senior Secured Loans one | Discounted cash flows | Comparative Yields | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.1 [5] 1.07 [6]  
First Lien Senior Secured Loans two | Comparable company multiple | EBITDA Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 96,956,000 [1] $ 74,416,000 [2]  
First Lien Senior Secured Loans two | Comparable company multiple | EBITDA Multiple | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.68 [3] 0.75 [4]  
First Lien Senior Secured Loans two | Comparable company multiple | EBITDA Multiple | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.15 [3] 1.37 [4]  
First Lien Senior Secured Loans two | Comparable company multiple | EBITDA Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.88 [5] 0.96 [6]  
First Lien Senior Secured Loans three | Comparable company multiple | Revenue Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 5,891,000 [1] $ 4,454,000 [2]  
First Lien Senior Secured Loans three | Comparable company multiple | Revenue Multiple | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input [3] 0.03    
First Lien Senior Secured Loans three | Comparable company multiple | Revenue Multiple | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input [3] 0.11    
First Lien Senior Secured Loans three | Comparable company multiple | Revenue Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.11 [5] 0.07 [6]  
First Lien Senior Secured Loans four | Collateral coverage | Recovery Rate | Level 3      
Fair Value Measurements      
Fair value of assets $ 12,052,000 [1] $ 12,052,000 [2]  
First Lien Senior Secured Loans four | Collateral coverage | Recovery Rate | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 10 [5] 10 [6]  
Second Lien Senior Secured Loans      
Fair Value Measurements      
Total unobservable inputs $ 30,069,000 $ 30,020,000 30,104,000
Second Lien Senior Secured Loans | Discounted cash flows | Comparative Yields | Level 3      
Fair Value Measurements      
Fair value of assets $ 30,069,000 [1] $ 30,020,000 [2]  
Second Lien Senior Secured Loans | Discounted cash flows | Comparative Yields | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.3 [3] 1.29 [4]  
Second Lien Senior Secured Loans | Discounted cash flows | Comparative Yields | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.36 [3] 1.31 [4]  
Second Lien Senior Secured Loans | Discounted cash flows | Comparative Yields | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.33 [5] 1.3 [6]  
Subordinated Note Investment Vehicles      
Fair Value Measurements      
Total unobservable inputs $ 357,639,000 [7] $ 348,654,000 [7] 337,224,000 [8]
Subordinated Note Investment Vehicles | Collateral coverage | Comparative Yields | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 9.69 [5] 9.68 [6]  
Subordinated Note Investment Vehicles | Collateral coverage | Recovery Rate | Level 3      
Fair Value Measurements      
Fair value of assets $ 357,639,000 [1] $ 348,654,000 [2]  
Subordinated Note Investment Vehicles | Collateral coverage | Recovery Rate | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 9.33 [3] 9.29 [4]  
Subordinated Note Investment Vehicles | Collateral coverage | Recovery Rate | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 10 [3] 10 [4]  
Subordinated Debt      
Fair Value Measurements      
Total unobservable inputs $ 81,721,000 $ 95,687,000 53,350,000
Subordinated Debt | Discounted cash flows | Comparative Yields | Level 3      
Fair Value Measurements      
Fair value of assets $ 81,721,000 [1] $ 95,086,000 [2]  
Subordinated Debt | Discounted cash flows | Comparative Yields | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.32 [3] 1.15 [4]  
Subordinated Debt | Discounted cash flows | Comparative Yields | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 2.14 [3] 2.15 [4]  
Subordinated Debt | Discounted cash flows | Comparative Yields | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.94 [5] 1.83 [6]  
Equity Interests      
Fair Value Measurements      
Total unobservable inputs $ 159,786,000 $ 219,124,000 219,210,000
Equity Interest one | Discounted cash flows | Discount Rate | Level 3      
Fair Value Measurements      
Fair value of assets $ 49,130,000 [1] $ 47,423,000 [2]  
Equity Interest one | Discounted cash flows | Discount Rate | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.34 [5] 1.34 [6]  
Equity Interest two | Comparable company multiple | EBITDA Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 95,840,000 [1] $ 97,564,000 [2]  
Equity Interest two | Comparable company multiple | EBITDA Multiple | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.38 [3] 0.4 [4]  
Equity Interest two | Comparable company multiple | EBITDA Multiple | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 2.4 [3] 2.6 [4]  
Equity Interest two | Comparable company multiple | EBITDA Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.25 [5] 1.28 [6]  
Equity Interest three | Comparable company multiple | Revenue Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 7,647,000 [1] $ 12,675,000 [2]  
Equity Interest three | Comparable company multiple | Revenue Multiple | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.38 [3] 0.5 [4]  
Equity Interest three | Comparable company multiple | Revenue Multiple | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 3.45 [3] 3.3 [4]  
Equity Interest three | Comparable company multiple | Revenue Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.27 [5] 1.1 [6]  
Equity Interest four | Comparable company multiple | Book Value Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 5,860,000 [1] $ 1,287,000 [2]  
Equity Interest four | Comparable company multiple | Book Value Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.1 [5] 0.1 [6]  
Preferred Equity      
Fair Value Measurements      
Total unobservable inputs $ 165,100,000 $ 157,244,000 170,876,000
Preferred Equity One | Comparable company multiple | EBITDA Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 26,834,000 [1] $ 27,328,000 [2]  
Preferred Equity One | Comparable company multiple | EBITDA Multiple | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.63 [3] 0.63 [4]  
Preferred Equity One | Comparable company multiple | EBITDA Multiple | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 2.3 [3] 1.65 [4]  
Preferred Equity One | Comparable company multiple | EBITDA Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.07 [5] 1.08 [6]  
Preferred Equity Two | Comparable company multiple | Revenue Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 50,092,000 [1] $ 50,135,000 [2]  
Preferred Equity Two | Comparable company multiple | Revenue Multiple | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.38 [3] 0.35 [4]  
Preferred Equity Two | Comparable company multiple | Revenue Multiple | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.01 [3] 1.09 [4]  
Preferred Equity Two | Comparable company multiple | Revenue Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.75 [5] 0.79 [6]  
Preferred Equity Three | Comparable company multiple | Book Value Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 73,309,000 [1] $ 68,748,000 [2]  
Preferred Equity Three | Comparable company multiple | Book Value Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.1 [5] 0.1 [6]  
Preferred Equity Four | Discounted cash flows | Comparative Yields | Level 3      
Fair Value Measurements      
Fair value of assets $ 11,100,000 [1] $ 7,037,000 [2]  
Preferred Equity Four | Discounted cash flows | Comparative Yields | Minimum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input [3] 1.36    
Preferred Equity Four | Discounted cash flows | Comparative Yields | Maximum | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input [3] 1.88    
Preferred Equity Four | Discounted cash flows | Comparative Yields | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 1.69 [5] 1.3 [6]  
Preferred Equity Five | Discounted cash flows | Discount Rate | Level 3      
Fair Value Measurements      
Fair value of assets [1] $ 3,765,000    
Preferred Equity Five | Discounted cash flows | Discount Rate | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input [5] 1.3    
Warrants      
Fair Value Measurements      
Total unobservable inputs $ 768,000 $ 1,045,000 $ 628,000
Warrants | Discounted cash flows | Discount Rate | Level 3      
Fair Value Measurements      
Fair value of assets $ 733,000 [1] $ 701,000 [2]  
Warrants | Discounted cash flows | Discount Rate | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 2.5 [5] 2.5 [6]  
Warrants | Comparable company multiple | Revenue Multiple | Level 3      
Fair Value Measurements      
Fair value of assets $ 35,000 [1] $ 344,000 [2]  
Warrants | Comparable company multiple | Revenue Multiple | Weighted average | Level 3      
Fair Value Measurements      
Investment owned, Measurement Input 0.35 [5] 0.38 [6]  
[1] Included within the Level 3 assets of $2,419,034 is an amount of $77,148 for which the Advisor did not develop the unobservable inputs for the determination of fair value (examples include single source quotation and prior or pending transactions such as investments originated in the quarter or imminent payoffs).
[2] Included within the Level 3 assets of $2,443,312 is an amount of $139,810 for which the Advisor did not develop the unobservable inputs for the determination of fair value (examples include single source quotation and prior or pending transactions such as investments originated in the quarter or imminent payoffs).
[3] The range for an asset category consisting of a single investment, if any, is not meaningful and therefore has been excluded.
[4] The range for an asset category consisting of a single investment, if any, is not meaningful and therefore has been excluded.
[5] Weighted average is calculated by weighing the significant unobservable input by the relative fair value of each investment in the category.
[6] Weighted average is calculated by weighing the significant unobservable input by the relative fair value of each investment in the category.
[7] Represents debt investment in ISLP and SLP.
[8] Represents debt investment in ISLP and SLP.