XML 51 R87.htm IDEA: XBRL DOCUMENT
v3.20.1

8. INVESTMENTS (Details 8) | 12 Months Ended
--- | ---
Dec. 31, 2019
Estimated Costs |
InvestmentsLineItems [Line Items] |
Main assumptions (Until 2057) | Costs based on studies and market trends.
Growth rate in perpetuity |
InvestmentsLineItems [Line Items] |
Main assumptions (Until 2057) | Growth rate was not considered due to the projection model until the end of the concession.
Discount rate |
InvestmentsLineItems [Line Items] |
Main assumptions (Until 2057) | Between 5.09% to 6.98% in real terms.
Gross Margin |
InvestmentsLineItems [Line Items] |
Main assumptions (Until 2057) | Based on market studies to capture operations costs and loads, based on studies of market trends.

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

X
- Definition The amount refers to main assumptions. + References No definition available. + Details
Name: | sid_MainAssumptions
Namespace Prefix: | sid_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | sid_CashFlowProjectionAxis=sid_EstimatedCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sid_CashFlowProjectionAxis=sid_GrowthRateInPerpetuityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sid_CashFlowProjectionAxis=sid_DiscountRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sid_CashFlowProjectionAxis=sid_GrossMarginMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |