Repurchase Agreements - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
BXINFRA Aggregator (CYM) L.P.
Repurchase Agreements [Line Items]
Investments pledged as collateral	$ 250.1	$ 72.0

Reported securities pledged as collateral at fair value.

No definition available.

Name:	bxinfra_ReportedSecuritiesPledgedAsCollateralAtFairvalue
Namespace Prefix:	bxinfra_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant