Commitments and Contingencies (Details) - BXINFRA Aggregator (CYM) L.P. - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | 12 Months Ended | |
|---|---|---|---|---|
Sep. 30, 2026 |
Mar. 31, 2026 |
Sep. 30, 2026 |
Dec. 31, 2025 |
|
| Commitments And Contingencies Disclosure [Line Items] | ||||
| Advanced expenses reimbursement allowed duration term | 60 months | |||
| Offering expenses | $ 0.1 | $ 0.6 | $ 3.2 | |
| Unfunded investment commitments | 2,000.0 | 2,000.0 | ||
| Deferred offering costs | $ 897.0 | 897.0 | ||
| Organizational Expenses | ||||
| Commitments And Contingencies Disclosure [Line Items] | ||||
| Related party transaction, amounts of transaction | $ 3.6 | |||
| Offering Cost Payable | ||||
| Commitments And Contingencies Disclosure [Line Items] | ||||
| Related party transaction, amounts of transaction | 0.0 | $ 0.4 | ||
| Organizational Cost Payable | ||||
| Commitments And Contingencies Disclosure [Line Items] | ||||
| Related party transaction, amounts of transaction | $ 0.1 | |||