Subsequent Events - Additional Information (Details)	Apr. 27, 2020
Dividend Distribution [Member]
Subsequent Events [Line Items]
Percentage Of Capital Requirement Over Exposure To Credit Card Loans	1250.00%

Percentage of capital requirement over exposure to credit card loans

No definition available.

Name:	bbar_PercentageOfCapitalRequirementOverExposureToCreditCardLoans
Namespace Prefix:	bbar_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant