XML 110 R91.htm IDEA: XBRL DOCUMENT
v3.21.1

10. BASIS OF CONSOLIDATION AND INVESTMENTS IN SUBSIDIARIES AND AFFILIATES (Details 7) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Buildings and infrastructure [member] |  |
BasisOfConsolidationAndInvestmentsInSubsidiariesAndAffiliatesLineItems [Line Items] |  |
Useful lives | 27 years | 21 years

X
- Definition The useful life, measured as period of time, used for property, plant and equipment. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_UsefulLifeMeasuredAsPeriodOfTimePropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | sid_BasisOfConsolidationAndInvestmentsInSubsidiariesAndAffiliatesLineItems
Namespace Prefix: | sid_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_TypesOfInvestmentPropertyAxis=ifrs-full_BuildingsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |