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 2020-01-01
-Paragraph B67
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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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, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill by segment
Goodwill	R$ 12,103,519	R$ 9,469,311	R$ 9,112,390	R$ 7,891,142
Brazil
Goodwill by segment
Goodwill	373,135	373,135	373,135
Special Steel
Goodwill by segment
Goodwill	3,828,841	2,969,752	2,854,888
North America
Goodwill by segment
Goodwill	R$ 7,901,543	R$ 6,126,424	R$ 5,884,367