Commitments and Contingencies (Details)		1 Months Ended	3 Months Ended
	Jun. 04, 2018 USD ($)	Aug. 31, 2005 USD ($)	Mar. 31, 2021 USD ($) claim case enforcementAction defendant	Dec. 31, 2020 USD ($)	Dec. 30, 2020 USD ($)	Jan. 27, 2020 party	Nov. 01, 2019 USD ($)	Nov. 01, 2019 BRL (R$)	Mar. 18, 2019 USD ($)	Mar. 18, 2019 BRL (R$)
Commitments and Contingencies
Number Of Potentially Related Parties | party						18
Reserve for loss contingencies			$ 7,000,000.0
Penalties per day							$ 4,300	R$ 25,000	$ 900	R$ 5,000
Penalties							1,732,000	10,000,000
Current Portion of Environmental Liabilities			6,791,000	$ 6,933,000
Environmental liabilities			29,044,000	29,424,000
Total environmental liabilities			$ 35,835,000	36,357,000
Enforcement Actions | enforcementAction			3
Netherlands
Commitments and Contingencies
Damages sought - interest, penalties and fees			$ 700,000
BRAZIL
Commitments and Contingencies
Loss Contingencies, Unpaid Service Taxes					$ 1,800,000
Loss Contingencies, Overall Liability				3,000,000.0
Brazilian Tax Disputes - Jan 2004 through May 2005 | Sao Paulo State Revenue Authority
Commitments and Contingencies
Damages sought - interest, penalties and fees			14,700,000
Damages sought - principal			1,100,000
Loss contingency, reduced penalty	$ 1,100,000
Amount of damages sought	$ 6,000,000
Brazilian Tax Disputes - Jan 2002 through Dec 2003 | Sao Paulo State Revenue Authority
Commitments and Contingencies
Damages sought - interest, penalties and fees		$ 3,300,000
Damages sought - principal		1,000,000.0
Loss contingency, reduced penalty		700,000
Amount of damages sought		4,400,000
Loss contingency, reduced penalty, including interest		$ 5,000,000.0
Brazilian Labor Claims
Commitments and Contingencies
Loss contingency reserves			$ 3,700,000	$ 4,300,000
Other
Commitments and Contingencies
Approximate number of defendants that includes the company named in legal actions | defendant			90
Number of pending claims | claim			17,192
Number of claims dismissed to date by stipulation or summary judgment prior to trial | case			28,324
Other | Active or In Extremis docket
Commitments and Contingencies
Number of pending claims | claim			53
Other | Minimum
Commitments and Contingencies
Amount of damages sought			$ 20,000,000
Other | Maximum
Commitments and Contingencies
Amount of damages sought			$ 25,000,000
Other | New York County as managed by the New York Supreme Court
Commitments and Contingencies
Number of pending claims | case			16,602
Other | New York County as managed by the New York Supreme Court | Pending And Future Litigation, Deferred Or Inactive Docket
Commitments and Contingencies
Number of pending claims | claim			16,549
Other | New York State Supreme Court, Counties Excluding New York County
Commitments and Contingencies
Number of pending claims | case			119
Other | Courts Located In States Other Than New York
Commitments and Contingencies
Number of pending claims | case			471
CSN
Commitments and Contingencies
Penalties per day							$ 17,300	R$ 100,000	$ 3,500	R$ 20,000