11. Contract Assets (Details) - BRL (R$) R$ in Thousands	Dec. 31, 2018	Dec. 31, 2017
SummaryOfContractAssetsLineItems [Line Items]
Contract Assets	R$ 3,433,230	R$ 0
Current	85,019	0
Noncurrent	3,348,211	0
Power distribution service concession
SummaryOfContractAssetsLineItems [Line Items]
Contract Assets	640,500	0
Piped gas distribution service concession
SummaryOfContractAssetsLineItems [Line Items]
Contract Assets	25,718	0
Power transmission concession
SummaryOfContractAssetsLineItems [Line Items]
Contract Assets	R$ 2,767,012	R$ 0

The amount of an entity’s right to consideration in exchange for goods or services that the entity has transferred to a customer, when that right is conditioned on something other than the passage of time (for example, the entity’s future performance).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2018-01-01
-Paragraph 105
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=15&date=2018-03-01&anchor=para_105&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2018-01-01
-Paragraph 116
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=15&date=2018-03-01&anchor=para_116_a&doctype=Standard
-URIDate 2018-03-16

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