Minimum cash and minimum capital - Narrative (Details)	12 Months Ended
Dec. 31, 2025
Minimum Cash And Minimum Capital [Abstract]
Percentage of sum of credit-risk-weighted asset transactions	8.00%

The amount of minimum capital requirement for credit risk, percent of the sum of credit-risk-weighted asset transactions without delivery against payment.

No definition available.

Name:	bbar_ItemOfMinimumCapitalRequirementForCreditRisk
Namespace Prefix:	bbar_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration