v3.26.3
Condensed Schedules of Investments (Unaudited) (Parenthetical) - USD ($)
Sep. 30, 2026
Dec. 31, 2025
Schedule of Investments [Line Items]    
Investment owned, cost $ 5,529,843,000 $ 3,324,540
Investment, Identifier [Axis]: Investments | BXINFRA Aggregator (CYM) L.P.    
Schedule of Investments [Line Items]    
Investment owned, balance, shares (in shares) [1] 204,506,119 129,060,376
[1] Refer to Note 3. “Investment in the Aggregator” for details on BXINFRA U.S.’s proportional share of investments through investees.