Contingencies and Commitments - Additional Information (Details) € in Millions, Allowances in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) Facility Claim_Group Allowances Project Plaintiff	Dec. 31, 2021 EUR (€) Allowances Plaintiff	Dec. 31, 2020 USD ($) Claim_Group	Dec. 31, 2019 USD ($) Claim_Group	Dec. 31, 2018 Claim_Group
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	$ 158,000,000		$ 146,000,000	$ 186,000,000
Accrued liabilities for post-closure site monitoring and other costs	24,000,000
Accrued liability for administrative and legal costs	$ 10,000,000
Number of years of projected administrative and legal costs included in accrual	3 years	3 years
Capital expenditures	$ 27,000,000		42,000,000
Financial assurance guarantees, maximum	7,000,000
Residual value of equipment	13,000,000
Residual value liability	0
Restricted cash	78,000,000		133,000,000
Contract commitments to acquire property, plant and equipment	1,483,000,000
Total payment under take-or-pay contracts	$ 767,000,000		$ 553,000,000	$ 653,000,000
Purchase of EUA to cover Estimated 2021 Shortfall
Loss Contingencies [Line Items]
Estimated Shortfall in Emissions Allowances | Allowances	4.0	4.0
Cost of emissions allowances pre-purchased	$ 199,000,000	€ 176
Purchase of EUA to cover Estimated 2022 Shortfall
Loss Contingencies [Line Items]
Estimated Shortfall in Emissions Allowances | Allowances	1.1	1.1
Cost of emissions allowances pre-purchased	$ 77,000,000	€ 68
Gateway Energy and Coke Company, LLC
Loss Contingencies [Line Items]
Maximum default payment on termination of agreement	$ 78,000,000
Minimum
Loss Contingencies [Line Items]
Projected percentage remediation costs may exceed accrued liabilities	15.00%	15.00%
Estimated capital expenditures of complying with BAT	$ 156,000,000	€ 138
Unconditional purchase obligation term	2 years	2 years
Maximum
Loss Contingencies [Line Items]
Projected percentage remediation costs may exceed accrued liabilities	30.00%	30.00%
Unconditional purchase obligation term	15 years	15 years
Asbestos Matters
Loss Contingencies [Line Items]
Active cases brought against U.S. Steel | Claim_Group	915		855
Number of claims pending in jurisdictions | Claim_Group	2,505		2,445	2,390	2,320
Number of plaintiffs involved | Plaintiff	1,545	1,545
Percentage of claims pending in jurisdictions	61.00%
Projects with Ongoing Study and Scope Development
Loss Contingencies [Line Items]
Environmental remediation projects | Facility	4
Accrued liabilities for remediation activities	$ 1,000,000
Projects with Ongoing Study and Scope Development | Minimum
Loss Contingencies [Line Items]
Environment exit costs, possible additional loss	22,000,000
Projects with Ongoing Study and Scope Development | Maximum
Loss Contingencies [Line Items]
Environment exit costs, possible additional loss	$ 36,000,000
Other Project With Defined Scope
Loss Contingencies [Line Items]
Environmental remediation projects | Project	3
Accrued liabilities for remediation activities	$ 102,000,000
Other Project With Defined Scope | Minimum
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	5,000,000
Gary Works, Project with Defined Scope
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	24,000,000
Duluth
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	59,000,000
Geneva Project
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	$ 19,000,000
Environmental Remediation Other Projects
Loss Contingencies [Line Items]
Environmental remediation projects | Facility	3
Accrued liabilities for remediation activities	$ 6,000,000
Environmental Remediation Other Projects | Minimum
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	1,000,000
Environmental Remediation Other Projects | Maximum
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	5,000,000
Environmental Remediation Projects Less Than One Million
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	5,000,000
Environmental Remediation Projects Less Than One Million | Maximum
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	1,000,000
Surety Bonds
Loss Contingencies [Line Items]
Financial assurance guarantees, maximum	$ 216,000,000