XML 106 R179.htm IDEA: XBRL DOCUMENT
v3.20.1

26 EMPLOYEE BENEFITS (Details 9) - BRL (R$) R$ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
EmployeeBenefitsLineItems [Line Items] |  |
Allocation of plan assets | R$ 3,894,488 | R$ 3,403,906
Allocation of plan assets percent | 100.00% | 100.00%
Variable Income [Member] |  |
EmployeeBenefitsLineItems [Line Items] |  |
Allocation of plan assets | R$ 25,236 | R$ 141,705
Allocation of plan assets percent | 0.65% | 4.16%
Fixed income |  |
EmployeeBenefitsLineItems [Line Items] |  |
Allocation of plan assets | R$ 3,607,398 | R$ 3,050,099
Allocation of plan assets percent | 92.63% | 89.61%
Real estate [Member] |  |
EmployeeBenefitsLineItems [Line Items] |  |
Allocation of plan assets | R$ 183,098 | R$ 52,091
Allocation of plan assets percent | 4.70% | 1.53%
Others [Member] |  |
EmployeeBenefitsLineItems [Line Items] |  |
Allocation of plan assets | R$ 78,756 | R$ 160,011
Allocation of plan assets percent | 2.02% | 4.70%

X
- Definition The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2019-01-01 -Paragraph 57 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2019-en-r&anchor=para_57_a&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_PlanAssetsAtFairValue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Information about plan assets percentage. + References No definition available. + Details
Name: | sid_PlanAssetsPercentage
Namespace Prefix: | sid_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | sid_DefinedBenefitPlanByPlanAssetsCategoriesAxis=sid_VariableIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sid_DefinedBenefitPlanByPlanAssetsCategoriesAxis=sid_FixedIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sid_DefinedBenefitPlanByPlanAssetsCategoriesAxis=sid_RealEstatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sid_DefinedBenefitPlanByPlanAssetsCategoriesAxis=sid_OthersPlanAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |