The amount of the estimated financial effect of contingent liabilities. [Refer: Contingent liabilities [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 37
-IssueDate 2018-01-01
-Paragraph 86
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=37&date=2018-03-01&anchor=para_86_a&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_EstimatedFinancialEffectOfContingentLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

Commitments - Guarantees provided (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
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Commitments
Property, plant and equipment, Net Carrying Value Pledged	$ 6	$ 15
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Guaranteed amount	331
Companhia Siderurgica do Pecem S.A.
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Guaranteed amount	$ 1,404