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Loss Contingencies, Overall Liability

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Loss Contingencies, Unpaid Service Taxes

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Loss Contingency, Amount Seeking From Other Party

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Loss Contingency, Fine Issued By Court

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Number Of Potentially Related Parties

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- Definition

Penalties

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- Definition

Total Environmental Liabilities

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Total costs accrued as of the balance sheet date for environmental loss contingencies.

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Undiscounted amount of the accrual for environmental loss contingencies.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of loss contingency liability.

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Number of claims dismissed.

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Number of pending claims pertaining to a loss contingency.

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Commitments and Contingencies (Details) € in Thousands, $ in Thousands, R$ in Millions				3 Months Ended
	Mar. 31, 2026 USD ($) claim	Mar. 31, 2026 BRL (R$)	Mar. 22, 2022 USD ($)	Mar. 31, 2026 USD ($) claim case	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Mar. 31, 2026 BRL (R$) claim	Jan. 17, 2025 company	Jul. 19, 2024 EUR (€)	Feb. 25, 2022 EUR (€)	Oct. 31, 2021 EUR (€)	Dec. 30, 2020 USD ($)
Commitments and Contingencies
Number Of Potentially Related Parties \| company								30
Reserve for loss contingencies	$ 27,000			$ 27,000
Penalties	6,000			6,000			R$ 32
Current Portion of Environmental Liabilities	12,573			12,573	$ 12,736
Environmental liabilities	38,019			38,019	38,256
Total environmental liabilities	50,592			50,592	50,992
BRAZIL
Commitments and Contingencies
Loss Contingencies, Unpaid Service Taxes												$ 2,000
Loss Contingencies, Overall Liability	$ 7,600			7,600
Loss Contingency Accrual, Provision				$ 0
Other
Commitments and Contingencies
Number of pending claims \| claim	17,000			17,000			17,000
Number of claims dismissed to date by stipulation or summary judgment prior to trial \| case				28,500
Loss Contingency Accrual, Provision				$ 0
Alleged Violation of Environmental Permit in Ijmuiden, Netherland \| Amsterdam Public Prosecutor’s Office
Commitments and Contingencies
Loss Contingency, Amount Seeking From Other Party \| €											€ 100
Loss Contingency, Fine Issued By Court \| €									€ 25	€ 5
Unfavorable Regulatory Action
Commitments and Contingencies
Loss Contingency Accrual, Provision					$ 5,000	$ 27,200
Limit and Reduce the Accumulation of Customer-Owned Slag
Commitments and Contingencies
Loss contingency, damages sought, value	$ 13,000	R$ 66
Limit and Reduce the Accumulation of Customer-Owned Slag \| Pending Litigation \| Volta Redonda vs. CSN and Enviri
Commitments and Contingencies
Loss contingency, damages sought, value	82,000	431
Limit and Reduce the Accumulation of Customer-Owned Slag \| CSN
Commitments and Contingencies
Loss contingency, damages sought, value	50,000	R$ 264
Violations of the Federal Emergency Planning and Community Right-to-Know Act \| Pending Litigation
Commitments and Contingencies
Loss contingency, damages sought, value			$ 3,000
Loss contingency reserves	$ 600			$ 600