Risk management (Details 9) - BRL (R$) R$ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Sensibilities [Abstract]
Net Interest Margin	R$ 200	R$ 378	R$ 385
Market Value of Equity	1,861	2,066	1,680
Value at Risk - Balance
VaR	R$ 1,744	R$ 1,380	R$ 804

The measure of a potential loss exposure as a result of future market movements, based on a specified confidence interval and measurement horizon.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 41
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_41&doctype=Standard
-URIDate 2017-03-09

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant