The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Business combinations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2018-01-01
-Paragraph B67
-Subparagraph d
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-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
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-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_a&doctype=Standard
-URIDate 2018-03-16

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2018-01-01
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-Subparagraph a
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

GOODWILL - Goodwill by segment (Details) - BRL (R$) R$ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill by segment
Goodwill	R$ 9,112,390	R$ 7,891,142	R$ 9,470,016	R$ 15,124,430
Brazil
Goodwill by segment
Goodwill	373,135	373,135	380,644
Special Steel
Goodwill by segment
Goodwill	2,854,888	2,487,364	2,508,056
North America
Goodwill by segment
Goodwill	R$ 5,884,367	R$ 5,030,643	R$ 6,581,316