Name:	bbar_DepositsAbstract
Namespace Prefix:	bbar_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Savings accounts.

No definition available.

Name:	bbar_SavingsAccounts
Namespace Prefix:	bbar_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of balances in customers' current accounts held by the entity.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_BalancesOnCurrentAccountsFromCustomers
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of balances in customers' deposit accounts held by the entity that the entity does not separately disclose in the same statement or note.

Name:	ifrs-full_BalancesOnOtherDepositsFromCustomers
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of balances in customers' term deposits held by the entity.

Name:	ifrs-full_BalancesOnTermDepositsFromCustomers
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of deposit liabilities from customers held by the entity.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_55&doctype=Standard
-URIDate 2019-03-27