PROPERTY, PLANT AND EQUIPMENT - Impairment (Details) - BRL (R$) R$ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Land, buildings and construction
PROPERTY, PLANT AND EQUIPMENT
Carrying value of impaired assets	R$ 118,348	R$ 112,438
Machines, equipment, and installations
PROPERTY, PLANT AND EQUIPMENT
Carrying value of impaired assets	783,183	642,592
Property, plant and equipment under construction
PROPERTY, PLANT AND EQUIPMENT
Carrying value of impaired assets	R$ 543,726	R$ 543,726

The amount of property, plant and equipment stated at revalued amounts. [Refer: Property, plant and equipment]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2017-01-01
-Paragraph 77
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=16&date=2017-03-01&anchor=para_77&doctype=Standard
-URIDate 2017-03-09

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