XML 31 R184.htm IDEA: XBRL DOCUMENT v3.20.1

26 EMPLOYEE BENEFITS (Details 14) - Post-employment Healthcare Benefits [Member] - BRL (R$) R$ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
EmployeeBenefitsLineItems [Line Items]
Actuarial gain /(loss) on obligation	R$ 7,433	R$ 16,237	R$ 170,445
Gain/(loss) recognized in shareholders' equity	R$ 7,433	R$ 16,237	R$ 170,445

X

- Definition

The decrease (increase) in a net defined benefit liability (asset) resulting from the remeasurement of that net defined benefit liability (asset). [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2019-01-01
-Paragraph 141
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2019-en-r&anchor=para_141_c&doctype=Standard
-URIDate 2019-03-27

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount refers to actuarial gains losses defined benefit liability asset.

+ References

No definition available.

+ Details

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Namespace Prefix:	sid_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	sid_EmployeeBenefitsLineItems
Namespace Prefix:	sid_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=sid_PostEmploymentHealthcareBenefitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: