Note 10 - Financial Assets at Amortised Cost (Details) - ARS ($)	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
Fair Value of Finacial Assets Accepted as Collateral Abstract
Fair Value of Finacial Assets Accepted as Collateral	$ 26,150,141,000	$ 17,201,658,000	$ 119,530,000

The fair value of financial assets accepted as collateral that the Group is permitted to sell or repledge in the absence of default.

No definition available.

Name:	bfr_Fairvalueoffinacialassetsacceptedascollateral
Namespace Prefix:	bfr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant