v3.26.3
Investments and Fair Value Measurement - Schedule of Fair Value of Investments for Level III Inputs (Details) - BXINFRA Aggregator (CYM) L.P. - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance, Beginning of Period $ 3,414,771 $ 2,009,190 $ 3,025,154 $ 0
Purchases 82,482 361,184 676,757 2,200,830
Sales and Proceeds from Investments (97,385) (16,726) (139,746) (17,964)
Transfers Into Level III 1,954   5,961  
Transfers Out of Level III (1,000) (4,698) (922,565) (4,698)
Change in Gain (Loss) Included in Net Assets 421,882 27,016 1,177,143 197,798
Balance, End of Period 3,822,704 2,375,966 3,822,704 2,375,966
Changes in Unrealized Gain (Loss) Included in Earnings Related to Financial Assets Still Held at the Reporting Date 421,882 27,016 1,177,143 197,798
Equity Investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance, Beginning of Period 3,170,444 1,342,696 2,041,413 0
Purchases 73,588 70,470 596,785 1,375,570
Sales and Proceeds from Investments (93,944) 0 (108,106) (5,111)
Transfers Into Level III 0   0  
Transfers Out of Level III 0 0 0 0
Change in Gain (Loss) Included in Net Assets 421,343 54,419 1,041,339 97,126
Balance, End of Period 3,571,431 1,467,585 3,571,431 1,467,585
Changes in Unrealized Gain (Loss) Included in Earnings Related to Financial Assets Still Held at the Reporting Date 421,343 54,419 1,041,339 97,126
Debt Investments - Infrastructure        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance, Beginning of Period 239,334 190,053 207,173 0
Purchases 5,160 1,231 63,537 126,021
Sales and Proceeds from Investments (3,085) (1,500) (31,272) (1,887)
Transfers Into Level III 0   0  
Transfers Out of Level III 0 0 0 0
Change in Gain (Loss) Included in Net Assets 526 9,462 2,497 75,112
Balance, End of Period 241,935 199,246 241,935 199,246
Changes in Unrealized Gain (Loss) Included in Earnings Related to Financial Assets Still Held at the Reporting Date 526 9,462 2,497 75,112
Debt Investments - Liquids        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance, Beginning of Period 4,993 4,698 0 0
Purchases 3,734 4,012 10,768 8,710
Sales and Proceeds from Investments (356) 0 (368) 0
Transfers Into Level III 1,954   5,961  
Transfers Out of Level III (1,000) (4,698) (7,000) (4,698)
Change in Gain (Loss) Included in Net Assets 13 (4) (23) (4)
Balance, End of Period 9,338 4,008 9,338 4,008
Changes in Unrealized Gain (Loss) Included in Earnings Related to Financial Assets Still Held at the Reporting Date 13 (4) (23) (4)
Affiliated Investee Funds        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance, Beginning of Period 0 471,743 776,568 0
Purchases 0 285,471 5,667 690,529
Sales and Proceeds from Investments 0 (15,226) 0 (10,966)
Transfers Into Level III 0   0  
Transfers Out of Level III 0 0 (915,565) 0
Change in Gain (Loss) Included in Net Assets 0 (36,861) 133,330 25,564
Balance, End of Period 0 705,127 0 705,127
Changes in Unrealized Gain (Loss) Included in Earnings Related to Financial Assets Still Held at the Reporting Date $ 0 $ (36,861) $ 133,330 $ 25,564