8 Trade receivables (Details 2) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Trade and other receivables [abstract]
Balance at the beginning of the year	R$ (7,537)	R$ (3,794)	R$ (1,100)
Additions	(15,040)	(7,714)	(2,914)
Write-offs	7,814	3,971	220
Balance at the end of the year	R$ (14,763)	R$ (7,537)	R$ (3,794)

The amount of additional allowance for credit losses of financial assets recognised in profit or loss. [Refer: Allowance account for credit losses of financial assets]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2021-01-01
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 16
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_16&doctype=Standard&book=b
-URIDate 2019-03-27

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