v3.26.1
Fair Value Measurements - Investments - Schedule of Fair Value Measurements of Investments by Major Class (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Mar. 31, 2026
Fair Value Disclosures [Abstract]    
Asset transferred into Level 3 $ 193,230  
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Infrastructure Assets 5,563,528 $ 6,185,617
Unrealized appreciation on foreign currency forward contracts 13,310 77,023
Unrealized depreciation on foreign currency forward contracts (3,225) (2,175)
Investments in Money Market Funds 977,437 1,051,371
Total Investments and Cash Equivalents 6,551,050 7,311,836
Level I    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Infrastructure Assets 0 0
Unrealized appreciation on foreign currency forward contracts 0 0
Unrealized depreciation on foreign currency forward contracts 0 0
Investments in Money Market Funds 977,437 1,051,371
Total Investments and Cash Equivalents 977,437 1,051,371
Level II    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Infrastructure Assets 0 0
Unrealized appreciation on foreign currency forward contracts 13,310 77,023
Unrealized depreciation on foreign currency forward contracts (3,225) (2,175)
Investments in Money Market Funds 0 0
Total Investments and Cash Equivalents 10,085 74,848
Level III    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Infrastructure Assets 5,382,280 5,972,089
Unrealized appreciation on foreign currency forward contracts 0 0
Unrealized depreciation on foreign currency forward contracts 0 0
Investments in Money Market Funds 0 0
Total Investments and Cash Equivalents 5,382,280 5,972,089
Net Asset Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Infrastructure Assets 181,248 213,528
Unrealized appreciation on foreign currency forward contracts 0 0
Unrealized depreciation on foreign currency forward contracts 0 0
Investments in Money Market Funds 0 0
Total Investments and Cash Equivalents $ 181,248 $ 213,528