United States Steel (X) 10-K 14 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 10, 2020	Jun. 28, 2019
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-16811
Entity Registrant Name	United States Steel Corp
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	25-1897152
Entity Address, Address Line One	600 Grant Street
Entity Address, City or Town	Pittsburgh
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15219-2800
City Area Code	412
Local Phone Number	433-1121
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller Reporting Company	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 2.6
Entity Common Stock, Shares Outstanding		170,047,076
Documents Incorporated by Reference	Portions of the Proxy Statement for the 2020 Annual Meeting of Stockholders are incorporated into Part III.
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0001163302
Current Fiscal Year End Date	--12-31
New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	United States Steel Corporation Common Stock, par value $1.00
Trading Symbol	X
Security Exchange Name	NYSE
Chicago Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	United States Steel Corporation Common Stock, par value $1.00
Trading Symbol	X
Security Exchange Name	CHX

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net sales:
Net sales		$ 11,506	$ 12,758	$ 11,046
Net sales to related parties (Note 23)		1,431	1,420	1,204
Total (Note 6)		12,937	14,178	12,250
Operating expenses (income):
Cost of sales (excludes items shown below)		12,082	12,305	10,858
Selling, general and administrative expenses		289	336	320
Depreciation, depletion and amortization (Notes 13 and 14)		616	521	501
Earnings from investees (Note 12)		(79)	(61)	(44)
Gain on equity investee transactions (Note 12)		0	(38)	(2)
Gain associated with U. S. Steel Canada Inc. (Note 5)		0	0	(72)
Restructuring and other charges (Note 25)		275	0	31
Net gain on disposals of assets		(1)	(6)	(5)
Other income, net		(15)	(3)	(6)
Total		13,167	13,054	11,581
(Loss) earnings before interest and income taxes		(230)	1,124	669
Interest expense		142	168	226
Interest income		(17)	(23)	(17)
Loss on debt extinguishment (Note 7)		0	98	54
Other financial costs		6	0	44
Net periodic benefit cost (other than service cost) (Note 3) (a)	[1]	91	69	61
Net interest and other financial costs (Note 7)		222	312	368
(Loss) earnings before income taxes		(452)	812	301
Income tax provision (benefit) (Note 11)		178	(303)	(86)
Net (loss) earnings		(630)	1,115	387
Comprehensive income attributable to noncontrolling interest		0	0	0
(Loss) earnings attributable to United States Steel Corporation		$ (630)	$ 1,115	$ 387
(Loss) earnings per share attributable to United States Steel Corporation stockholders:
— Basic		$ (3.67)	$ 6.31	$ 2.21
— Diluted		$ (3.67)	$ 6.25	$ 2.19
[1]	Represents postretirement benefit expense as a result of the adoption of Accounting Standards Update 2017-07, Compensation - Retirement Benefits on January 1, 2018 (see Note 3 for further details).

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net (loss) earnings		$ (630)	$ 1,115	$ 387
Other comprehensive income (loss), net of tax:
Changes in foreign currency translation adjustments (a)	[1]	(22)	(60)	189
Changes in pension and other employee benefit accounts (a)	[1]	573	(107)	462
Changes in derivative financial instruments (a)	[1]	(3)	(14)	1
Total other comprehensive income (loss), net of tax		548	(181)	652
Comprehensive income including noncontrolling interest		(82)	934	1,039
Comprehensive income attributable to noncontrolling interest		0	0	0
Comprehensive income attributable to United States Steel Corporation		(82)	934	1,039
Related Income Tax Benefit (Provision):
Foreign currency translation adjustments (b)	[2],[3]	6	0	0
Pension and other benefits adjustments (b)	[2],[3]	(191)	0	0
Derivative adjustments (b)	[2],[3]	$ 1	$ 0	$ 0
[1]	Related income tax benefit (provision) Foreign currency translation adjustments (b) $ 6 $ — $ — Pension and other benefits adjustments (b) (191 ) — — Derivative adjustments (b) 1 — —
[2]	Amounts for 2018 and 2017 do not reflect a tax benefit as a result of a full valuation allowance on our domestic deferred tax assets.
[3]	Amounts for 2018 and 2017 do not reflect a tax benefit as a result of a full valuation allowance on our domestic deferred tax assets

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents (Note 9)	$ 749	$ 1,000
Receivables, less allowance of $28 and $29	956	1,435
Receivables from related parties (Note 23)	221	224
Inventories (Note 10)	1,785	2,092
Other current assets	102	79
Total current assets	3,813	4,830
Long-term restricted cash (Note 9)	188	37
Investments and long-term receivables, less allowance of $5 in both periods (Note 12)	1,466	513
Operating lease assets (Note 24)	230	0
Property, plant and equipment, net (Note 13)	5,447	4,865
Intangibles — net (Note 14)	150	158
Deferred income tax benefits (Note 11)	19	445
Other noncurrent assets	295	134
Total assets	11,608	10,982
Current liabilities:
Accounts payable and other accrued liabilities	1,970	2,454
Accounts payable to related parties (Note 23)	84	81
Payroll and benefits payable	336	440
Accrued taxes	116	118
Accrued interest	45	39
Current operating lease liabilities (Note 24)	60	0
Short-term debt and current maturities of long-term debt (Note 17)	14	65
Total current liabilities	2,625	3,197
Noncurrent operating lease liabilities (Note 24)	177	0
Long-term debt, less unamortized discount and debt issuance costs (Note 17)	3,627	2,316
Employee benefits (Note 18)	532	980
Deferred income tax liabilities (Note 11)	4	14
Deferred credits and other noncurrent liabilities	550	272
Total liabilities	7,515	6,779
Contingencies and commitments (Note 26)
Stockholders’ Equity
Common stock issued — 178,555,206 and 177,386,430 shares issued (par value $1 per share, authorized 400,000,000 shares) (Note 8)	179	177
Treasury stock, at cost (8,509,337 shares and 2,857,578 shares)	(173)	(78)
Additional paid-in capital	4,020	3,917
Retained earnings	544	1,212
Accumulated other comprehensive loss (Note 21)	(478)	(1,026)
Total United States Steel Corporation stockholders’ equity	4,092	4,202
Noncontrolling interests	1	1
Total liabilities and stockholders’ equity	$ 11,608	$ 10,982

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 28	$ 29
Other noncurrent assets, allowance	$ 5	$ 5
Common stock, par value (usd per share)	$ 1	$ 1
Common stock, shares issued	178,555,206	177,386,430
Common stock, shares authorized	400,000,000	400,000,000
Treasury stock, shares	8,509,337	2,857,578

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net (loss) earnings	$ (630)	$ 1,115	$ 387
Adjustments to reconcile net cash provided by operating activities:
Depreciation, depletion and amortization (Notes 13 and 14)	616	521	501
Gain associated with U. S. Steel Canada Inc. (Note 5)	0	0	(72)
Gain on equity investee transactions (Note 12)	0	(38)	(2)
Restructuring and other charges (Note 25)	275	0	31
Loss on debt extinguishment (Note 7)	0	98	54
Pensions and other post-employment benefits	101	77	(16)
Deferred income taxes (Note 11)	202	(329)	(72)
Net gain on disposal of assets	(1)	(6)	(5)
Equity investees earnings, net of distributions received	(74)	(47)	(32)
Changes in:
Current receivables	453	(312)	(36)
Inventories	296	(374)	(117)
Current accounts payable and accrued expenses	(473)	282	225
Income taxes receivable/payable	13	(8)	(52)
All other, net	(96)	(41)	32
Net cash provided by operating activities	682	938	826
Investing activities:
Capital expenditures	(1,252)	(1,001)	(505)
Investment in Big River Steel	(710)	0	0
Disposal of assets	4	10	5
Proceeds from sale of ownership interests in equity investees	0	30	116
Investments, net	0	(2)	(2)
Net cash used in investing activities	(1,958)	(963)	(386)
Financing activities:
Revolving credit facilities - borrowings, net of financing costs	860	228	0
Revolving credit facilities - repayments	(100)	0	0
Issuance of long-term debt, net of financing costs (Note 17)	702	640	737
Repayment of long-term debt (Note 17)	(155)	(1,299)	(1,127)
Common stock repurchased (Note 27)	(88)	(75)	0
Receipts from exercise of stock options (Note 15)	0	35	20
Taxes paid for equity compensation plans (Note 15)	(7)	(8)	(10)
Dividends paid	(35)	(36)	(35)
Net cash provided by (used in) financing activities	1,177	(515)	(415)
Effect of exchange rate changes on cash	(2)	(17)	17
Net (decrease) increase in cash, cash equivalents and restricted cash	(101)	(557)	42
Cash, cash equivalents and restricted cash at beginning of year (Note 9)	1,040	1,597	1,555
Cash, cash equivalents and restricted cash at end of year (Note 9)	$ 939	$ 1,040	$ 1,597

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions		Total		Common stock:	Treasury stock:	Additional paid-in capital:	Retained earnings:	Accumulated other comprehensive (loss) income:	Pension and other benefit adjustments (Note 18):		Foreign currency translation adjustments:		Derivative financial instruments:		Total stockholders’ equity	Noncontrolling interests:
Balance at beginning of year at Dec. 31, 2016				$ 176	$ (182)	$ 4,027	$ (250)		$ (1,771)		$ 274		$ 0			$ 1
Balance at beginning of year (in shares) at Dec. 31, 2016				(176,425,000)	(2,614,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued				$ 0
Common stock issued (in shares)				0
Common stock repurchased					$ 0
Common stock repurchased (in shares)					0
Common stock (repurchased) reissued for employee/non-employee director stock plans					$ 106
Common stock (repurchased) reissued for employee/non-employee director stock plans (in shares)					1,411,000
Dividends on common stock						(26)	(9)
Issuance of conversion option in 2026 Senior Convertible Notes, net of tax						0
Employee stock plans						(69)
Net (loss) earnings attributable to United States Steel Corporation		$ 387					387
Other							5
Changes in pension and other employee benefit accounts (a)		462	[1]						454	[2]
Changes during year, equity investee net of taxes (a)	[2]								8
Changes in foreign currency translation adjustments (a)		189	[1]								189	[2]
Changes in derivative financial instruments (a)		1	[1]										1	[2]
Net loss																0
Balance at end of year at Dec. 31, 2017				$ 176	$ (76)	3,932	133	$ (845)	(1,309)		463		1		$ 3,320	1
Balance at end of year (in shares) at Dec. 31, 2017				(176,425,000)	(1,203,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income including noncontrolling interest		1,039
Related Income Tax Benefit (Provision):
Foreign currency translation adjustments (b)	[3],[4]	0
Pension and other benefits adjustments (b)	[3],[4]	0
Derivative adjustments (b)	[3],[4]	0
Common stock issued				$ 1
Common stock issued (in shares)				961,000
Common stock repurchased		$ (75)			$ (75)
Common stock repurchased (in shares)		(2,760,112)			(2,760,000)
Common stock (repurchased) reissued for employee/non-employee director stock plans					$ 73
Common stock (repurchased) reissued for employee/non-employee director stock plans (in shares)					1,105,000
Dividends on common stock						0	(36)
Issuance of conversion option in 2026 Senior Convertible Notes, net of tax						0
Employee stock plans						(15)
Net (loss) earnings attributable to United States Steel Corporation		$ 1,115					1,115
Other							0
Changes in pension and other employee benefit accounts (a)		(107)	[1]						(108)	[2]
Changes during year, equity investee net of taxes (a)	[2]								1
Changes in foreign currency translation adjustments (a)		(60)	[1]								(60)	[2]
Changes in derivative financial instruments (a)		(14)	[1]										(14)	[2]
Net loss																0
Balance at end of year at Dec. 31, 2018		4,202		$ 177	$ (78)	3,917	1,212	(1,026)	(1,416)		403		(13)		4,202	1
Balance at end of year (in shares) at Dec. 31, 2018				(177,386,000)	(2,858,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income including noncontrolling interest		934
Related Income Tax Benefit (Provision):
Foreign currency translation adjustments (b)	[3],[4]	0
Pension and other benefits adjustments (b)	[3],[4]	0
Derivative adjustments (b)	[3],[4]	0
Common stock issued				$ 2
Common stock issued (in shares)				1,169,000
Common stock repurchased		$ (88)			$ (88)
Common stock repurchased (in shares)		(5,289,475)			(5,289,000)
Common stock (repurchased) reissued for employee/non-employee director stock plans					$ (7)
Common stock (repurchased) reissued for employee/non-employee director stock plans (in shares)					(362,000)
Dividends on common stock						0	(35)
Issuance of conversion option in 2026 Senior Convertible Notes, net of tax						77
Employee stock plans						26
Net (loss) earnings attributable to United States Steel Corporation		$ (630)					(630)
Other							(3)
Changes in pension and other employee benefit accounts (a)		573	[1]						580	[2]
Changes during year, equity investee net of taxes (a)	[2]								(7)
Changes in foreign currency translation adjustments (a)		(22)	[1]								(22)	[2]
Changes in derivative financial instruments (a)		(3)	[1]										(3)	[2]
Net loss																0
Balance at end of year at Dec. 31, 2019		4,092		$ 179	$ (173)	$ 4,020	$ 544	$ (478)	$ (843)		$ 381		$ (16)		$ 4,092	$ 1
Balance at end of year (in shares) at Dec. 31, 2019				(178,555,000)	(8,509,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income including noncontrolling interest		(82)
Related Income Tax Benefit (Provision):
Foreign currency translation adjustments (b)	[3],[4]	6
Pension and other benefits adjustments (b)	[3],[4]	(191)
Derivative adjustments (b)	[3],[4]	$ 1
[1]	Related income tax benefit (provision) Foreign currency translation adjustments (b) $ 6 $ — $ — Pension and other benefits adjustments (b) (191 ) — — Derivative adjustments (b) 1 — —
[2]	Related income tax benefit (provision): Foreign currency translation adjustments (b) $ 6 $ — $ — Pension and other benefits adjustments (b) (191 ) — — Derivative adjustments (b) 1 — —
[3]	Amounts for 2018 and 2017 do not reflect a tax benefit as a result of a full valuation allowance on our domestic deferred tax assets.
[4]	Amounts for 2018 and 2017 do not reflect a tax benefit as a result of a full valuation allowance on our domestic deferred tax assets

Nature of Business and Signific

Nature of Business and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Text Block [Abstract]
Nature of Business and Significant Accounting Policies	1. Nature of Business and Significant Accounting Policies Nature of Business U. S. Steel produces and sells steel products, including flat-rolled and tubular products, in North America and Europe. Operations in the United States also include iron ore and coke production facilities, railroad services and real estate operations. Operations in Europe also include coke production facilities. Significant Accounting Policies Principles applied in consolidation These financial statements include the accounts of U. S. Steel and its majority-owned subsidiaries. Additionally, variable interest entities for which U. S. Steel is the primary beneficiary are included in the Consolidated Financial Statements and their impacts are either partially or completely offset by noncontrolling interests. Intercompany accounts, transactions and profits have been eliminated in consolidation. Investments in entities over which U. S. Steel has significant influence are accounted for using the equity method of accounting and are carried at U. S. Steel’s share of net assets plus loans, advances and our share of earnings less distributions. Earnings or loss from investees includes U. S. Steel’s share of earnings or loss from equity method investments (and any amortization of basis differences), which are generally recorded a month in arrears, except for significant and unusual items which are recorded in the period of occurrence. Use of estimates Generally accepted accounting principles require management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at year-end and the reported amounts of revenues and expenses during the year. Significant items subject to such estimates and assumptions include the carrying value of property, plant and equipment; intangible assets; valuation allowances for receivables, inventories and deferred income tax assets and liabilities; environmental liabilities; liabilities for potential tax deficiencies; potential litigation claims and settlements; assets and obligations related to employee benefits; put and call option assets and liabilities and restructuring and other charges. Actual results could differ materially from the estimates and assumptions used. Sales recognition Sales are recognized when U. S. Steel's performance obligations are satisfied. Generally, U. S. Steel’s performance obligations are satisfied, control of our products is transferred, and revenue is recognized at a single point in time, when title transfers to our customer for product shipped or when services are provided. Revenues are recorded net of any sales incentives. Shipping and other transportation costs charged to customers are treated as fulfillment activities and are recorded in both revenue and cost of sales at the time control is transferred to the customer. See Note 6 for further details on U. S. Steel’s revenue. Inventories Inventories are carried at the lower of cost or market. Fixed costs related to abnormal production capacity are expensed in the period incurred rather than capitalized into inventory. LIFO (last-in, first-out) is the predominant method of inventory costing for inventories in the United States and FIFO (first-in, first-out) is the predominant method in Europe. The LIFO method of inventory costing was used on 75 percent and 74 percent of consolidated inventories at December 31, 2019 and 2018 , respectively. Derivative instruments From time to time, U. S. Steel may use fixed price forward physical purchase contracts to partially manage our exposure to price risk. Generally, forward physical purchase contracts qualify for the normal purchase normal sales exclusion in Accounting Standards Codification (ASC) 815, Derivatives and Hedging , and are not subject to mark-to-market accounting. U. S. Steel also uses derivatives such as commodity-based financial swaps and foreign currency exchange forward contracts to manage its exposure to purchase and sale price fluctuations and foreign currency exchange rate risk. U. S. Steel elects hedge accounting for some of its derivatives. Under hedge accounting, fluctuations in the value of the derivative are recognized in Accumulated Other Comprehensive Income (AOCI) until the associated underlying is recognized in earnings. When the associated underlying is recognized in earnings, the value of the derivative is reclassified to earnings from AOCI. We recognize fair value changes for derivatives where hedge accounting has not been elected immediately in earnings. See Note 16 for further details on U. S. Steel’s derivatives. Financial Instruments U. S. Steel's purchase of a 49.9% equity ownership interest in Big River Steel on October 31, 2019 included certain call and put options. U. S. Steel marks these options to fair value each reporting period using a Monte Carlo simulation which is considered a Level 3 valuation technique. Level 3 valuation techniques include inputs to the valuation methodology that are considered unobservable and significant to the fair value measurement. See Note 5 and Note 20 for further details. Property, plant and equipment Property, plant and equipment is carried at cost and is depreciated on a straight-line basis over the estimated useful lives of the assets. Depletion of mineral properties is based on rates which are expected to amortize cost over the estimated tonnage of minerals to be removed. When property, plant and equipment is sold or otherwise disposed of, any gains or losses are reflected in income. If a loss on disposal is expected, such losses are recognized when the assets are reclassified as assets held for sale or when impaired as part of an asset group’s impairment. U. S. Steel evaluates impairment of its property, plant and equipment whenever circumstances indicate that the carrying value may not be recoverable. We evaluate the impairment of long-lived assets at the asset group level. Our asset groups are Flat-Rolled, welded tubular, seamless tubular and U. S. Steel Europe (USSE). Asset impairments are recognized when the carrying value of an asset group exceeds its recoverable amount as determined by the asset group's aggregate projected undiscounted cash flows. During 2019, the challenging steel market environment in the U.S. that led to the idling of certain Flat-Rolled facilities, the challenging steel market in Europe that led to the temporary idling of a blast furnace and significant headcount reductions at USSE, and recent losses in the welded tubular asset group were considered triggering events for those asset groups, respectively. U. S. Steel completed a quantitative analysis of its long-lived assets for these asset groups and determined that the assets were not impaired. There were no triggering events for seamless tubular in 2019. There were no triggering events in 2018 that required fixed assets to be evaluated for impairment. Change in Accounting Estimate - Capitalization and Depreciation Method During 2017, U. S. Steel completed a review of its accounting policy for property, plant and equipment depreciated on a group basis. As a result of this review, U. S. Steel changed its accounting method for property, plant and equipment from the group method of depreciation to the unitary method of depreciation, effective as of January 1, 2017. The Company believes the change from the group method to the unitary method of depreciation is preferable under U.S. GAAP as it results in a more precise estimate of depreciation expense. Additionally, the change to the unitary method of depreciation is consistent with the depreciation method applied by our competitors, and improves the comparability of our results to the results of our competitors. Our change in the method of depreciation was considered a change in accounting estimate effected by a change in accounting principle and has been applied prospectively. Due to the application of the unitary method of depreciation and resultant change in our capitalization policy, maintenance and outage spending that had previously been expensed as well as capital investments associated with our asset revitalization program are now capitalized if the useful life of the related asset is extended. When property, plant, and equipment are disposed of by sale, retirement, or abandonment, the gross value of the property, plant and equipment and corresponding accumulated depreciation are removed from the Company’s financial accounting records. Due to the application of the unitary method of depreciation, any gain or loss resulting from an asset disposal by sale is now immediately recognized as a gain or loss on the disposal of assets line in our consolidated statement of operations. Assets that are retired or abandoned are reflected as an immediate charge to depreciation expense for any remaining book value in our consolidated statement of operations. Environmental remediation Environmental expenditures are capitalized if the costs mitigate or prevent future contamination or if the costs improve existing assets’ environmental safety or efficiency. U. S. Steel provides for remediation costs and penalties when the responsibility to remediate is probable and the amount of associated costs is reasonably estimable. The timing of remediation accruals typically coincides with completion of studies defining the scope of work to be undertaken or when it is probable that a formal plan of action will be approved by the oversight agency. Remediation liabilities are accrued based on estimates of believed environmental exposure and are discounted if the amount and timing of the cash disbursements are readily determinable. Asset retirement obligations Asset retirement obligations (AROs) are initially recorded at fair value and are capitalized as part of the cost of the related long-lived asset and depreciated in accordance with U. S. Steel’s depreciation policies for property, plant and equipment. The fair value of the obligation is determined as the discounted value of expected future cash flows. Accretion expense is recorded each month to increase this discounted obligation over time. Certain AROs related to disposal costs of the majority of assets at our integrated steel facilities are not recorded because they have an indeterminate settlement date. These AROs will be initially recognized in the period in which sufficient information exists to estimate their fair value. See Note 19 for further details on U. S. Steel's AROs. Pensions and other post-employment benefits U. S. Steel has defined contribution or multi-employer arrangements for pension benefits for more than three-quarters of its employees in the United States and defined benefit pension plans covering the remaining employees. For hires before January 1, 2016, U. S. Steel has defined benefit retiree health care and life insurance plans (Other Benefits) that cover its represented employees in North America upon their retirement. Government-sponsored programs into which U. S. Steel makes required contributions cover the majority of U. S. Steel’s European employees. For more details regarding pension and other post-employment benefits see Note 18 of the Consolidated Financial Statements. The pension and Other Benefits obligations and the related net periodic benefit costs are based on, among other things, assumptions of the discount rate, estimated return on plan assets, salary increases, the projected mortality of participants and the current level and future escalation of health care costs. Additionally, U. S. Steel recognizes an obligation to provide post-employment benefits for disability-related claims covering indemnity and medical payments for certain employees in North America. The obligation for these claims and the related periodic costs are measured using actuarial techniques and assumptions. Actuarial gains and losses occur when actual experience differs from any of the many assumptions used to value the benefit plans, or when assumptions change. For pension and Other Benefits, the Company recognizes into income on an annual basis a portion of unrecognized actuarial net gains or losses that exceed 10 percent of the larger of projected benefit obligations or plan assets (the corridor). These unrecognized amounts in excess of the corridor are amortized over the plan participants' average life expectancy or average future service, depending on the demographics of the plan. Unrecognized actuarial net gains and losses for disability-related claims are immediately recognized into income. Deferred taxes Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. The realization of deferred tax assets is assessed quarterly based on several interrelated factors. These factors include U. S. Steel’s expectation to generate sufficient future taxable income and the projected time period over which these deferred tax assets will be realized. U. S. Steel records a valuation allowance when necessary to reduce deferred tax assets to the amount that will more likely than not be realized. See Note 11 for further details of deferred taxes. Reclassifications and Adjustments Certain reclassifications of prior years' data have been made to conform to the current year presentation including the following: U. S. Steel reclassified certain prior year data as a result of the retrospective adoption on January 1, 2018 of ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash, ASU 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments and ASU 2017-07, Compensation - Retirement Benefits

New Accounting Standards

New Accounting Standards	12 Months Ended
	Dec. 31, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Standards	2. New Accounting Standards In December 2019, the Financial Accounting Standards Board (FASB) Issued Accounting Standards Update 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes (ASU 2019-12). ASU 2019-12 simplifies accounting for income taxes by removing certain exceptions from the general principles in Topic 740 including elimination of the exception to the incremental approach for intraperiod tax allocation when there is a loss from continuing operations and income or a gain from other items such as other comprehensive income. ASU 2019-12 also clarifies and amends certain guidance in Topic 740. ASU 2019-12 is effective for public companies for fiscal years beginning after December 15, 2020, including interim periods, with early adoption of all amendments in the same period permitted. U. S. Steel is currently assessing the impact of the ASU, but does not believe it will have a material impact on its Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which adds an impairment model that is based on expected losses rather than incurred losses. Under ASU 2016-13, an entity recognizes as an allowance its estimate of expected credit losses, which the FASB believes will result in more timely recognition of such losses. ASU 2016-13 is effective for public companies for fiscal years beginning after December 15, 2019 including interim reporting periods, with early adoption permitted. U. S. Steel is in the process of adopting this ASU and does not expect it to have a significant impact on its Consolidated Financial Statements.

Recently Adopted Accounting Sta

Recently Adopted Accounting Standards	12 Months Ended
	Dec. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Recently Adopted Accounting Standards	3. Recently Adopted Accounting Standards In August 2018, the FASB issued ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20), Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans (ASU 2018-14). ASU 2018-14 removes certain disclosures that the FASB no longer considers cost beneficial, adds certain disclosure requirements and clarifies others. U. S. Steel early-adopted ASU 2018-14 for purposes of its year end disclosures. Accordingly, we removed disclosure of amounts in AOCI expected to be recognized as components of net periodic benefit cost over the next year and removed the disclosure of a one-percentage-point change in assumed health care cost trend rates. In addition, we added disclosure to include an explanation of the reasons for significant gains and losses related to changes in the benefit obligation for the period. See Note 18 for further details. In February 2016, the FASB issued ASU 2016-02, Leases (ASU 2016-02). Under ASU 2016-02, for operating leases, a lessee should recognize in its statement of financial position a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term; recognize a single lease cost, which is allocated over the lease term, generally on a straight line basis, and classify all cash payments within operating activities in the statement of cash flows. For finance leases, a lessee is required to recognize a right-of-use asset and a lease liability; recognize interest on the lease liability separately from amortization of the right-of-use asset, and classify repayments of the principal portion of the lease liability within financing activities and payments of interest on the lease liability within operating activities in the statement of cash flows. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and lease liabilities. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842) -Targeted Improvements (ASU 2018-11), which provides an option to use a modified retrospective transition method at the adoption date. U. S. Steel adopted the new lease accounting standard effective January 1, 2019 using the optional modified retrospective transition method outlined in ASU 2018-11. As a result of the adoption, an operating lease asset and current and noncurrent liabilities for operating leases were recorded, and there was an insignificant reduction in prior year retained earnings for the cumulative effect of adoption for operating leases where payment started after lease commencement. See Note 24 for further details. In March 2017, the FASB issued ASU 2017-07, Compensation - Retirement Benefits (ASU 2017-07). ASU 2017-07 requires an employer who offers defined benefit and postretirement benefit plans to report the service cost component of the net periodic benefit cost in the same line item or items as other compensation cost arising from services rendered by employees during the period. The other components of net periodic benefit costs are required to be presented on a retrospective basis in the statement of operations separately from the service cost component and outside a subtotal of income from operations, if one is presented. The ASU also allows for the service cost component of net periodic benefit cost to be eligible for capitalization into inventory when applicable. ASU 2017-07 was effective for periods beginning after December 15, 2017, including interim periods within those annual periods; early adoption was permitted. U. S. Steel adopted ASU 2017-07 on January 1, 2018. U. S. Steel has historically capitalized the service cost component of net periodic benefit cost into inventory, when applicable, and will continue to do so prospectively. The effect of the retrospective presentation change related to the net periodic benefit cost of our defined benefit pension and other post-employment benefits (OPEB) plans on our consolidated statement of operations was as follows: Year Ended December 31, 2017 Statement of Operations (In millions) As Revised Previously Reported Effect of Change Higher/(Lower) Cost of Sales $ 10,858 $ 10,864 $ (6 ) Selling, general and administrative expenses 320 375 (55 ) Net periodic benefit cost (other than service cost) 61 — 61 In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18). The ASU reduced diversity in practice in the classification and presentation of changes in restricted cash on the statement of cash flows by including restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. On January 1, 2018, U. S. Steel adopted the provisions of ASU 2016-18 using a retrospective transition method. As a result, a $3 million cash outflow was removed from the investing activities section in the Consolidated Statements of Cash Flows for the year ended December 31, 2017 as changes in restricted cash are now included in the beginning-of-period and end-of-period total cash, cash equivalents and restricted cash amounts. Expanded disclosures have been included, which describe the components of cash shown on the Company's Consolidated Statements of Cash Flows. See Note 9 for further details. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments (ASU 2016-15). ASU 2016-15 reduced diversity in practice in how certain transactions are classified in the statement of cash flows by addressing eight specific cash receipt and cash payment issues. On January 1, 2018, U. S. Steel adopted the provisions of ASU 2016-15 using a retrospective transition method. As a result, all payments to extinguish debt will now be presented as cash outflows from financing activities on our Consolidated Statements of Cash Flows in accordance with ASU 2016-15. U. S. Steel has historically presented make-whole premiums as cash outflows from operating activities. There was $23 million of cash outflows for make-whole premiums that were reclassified from cash provided by operating activities to the repayment of long-term debt line within the cash used in financing activities section on the Consolidated Statements of Cash Flows for the year-ended December 31, 2017. The other cash receipt and cash payment items addressed in ASU 2016-15 did not have an impact on the Company’s Consolidated Statements of Cash Flows. Additionally, the Company has elected to use the cumulative earnings approach as defined in ASU 2016-15 to classify distributions received from equity method investees. U. S. Steel's adoption of the following ASU's did not have a material impact on U. S. Steel's financial position, results of operations or cash flows: Effective Date Accounting Standard Update January 1, 2017 2015-11 Simplifying the Measurement of Inventory January 1, 2017 2016-09 Compensation - Stock Compensation January 1, 2018 2014-09 Revenue from Contracts with Customers January 1, 2018 2017-09 Compensation - Stock Compensation: Scope of Modification Accounting January 1, 2018 2017-12 Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities July 1, 2018 2018-02 Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income January 1, 2019 2018-07 Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting January 1, 2019 2018-15 Intangibles - Goodwill and Other - Internal Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs in a Cloud Computing Arrangement That is a Service Contract

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	4. Segment Information U. S. Steel has three reportable segments: North American Flat-Rolled (Flat-Rolled), USSE and Tubular Products (Tubular). The results of Big River Steel and our railroad and real estate businesses that do not constitute reportable segments are combined and disclosed in the Other Businesses category. The majority of U. S. Steel's customers are located in North America and Europe. No single customer accounted for more than 10 percent of gross annual revenues. The Flat-Rolled segment includes the operating results of U. S. Steel’s integrated steel plants and equity investees in the United States (except for Big River Steel, which is included in Other Businesses) involved in the production of slabs, strip mill plates, sheets and tin mill products, as well as all iron ore and coke production facilities in the United States. These operations primarily serve North American customers in the service center, conversion, transportation (including automotive), construction, container, and appliance and electrical markets. The USSE segment includes the operating results of U. S. Steel Košice (USSK), U. S. Steel’s integrated steel plant and coke production facilities in Slovakia, and its subsidiaries. USSE conducts its business mainly in Central and Western Europe and primarily serves customers in the European transportation (including automotive), construction, container, appliance, electrical, service center, conversion and oil, gas and petrochemical markets. USSE produces and sells slabs, strip mill plate, sheet, tin mill products and spiral welded pipe, as well as refractory ceramic materials. The Tubular segment includes the operating results of U. S. Steel’s tubular production facilities and an equity investee in the United States. We sold our ownership interest in an equity investee in Brazil in December of 2017. These operations produce and sell seamless and electric resistance welded (welded) steel casing and tubing (commonly known as oil country tubular goods or OCTG), standard and line pipe and mechanical tubing and primarily serve customers in the oil, gas and petrochemical markets. We sold our Bellville facility in 2018. In June 2019, U. S. Steel restarted Pipe Mill #1 at our Lone Star facility. The chief operating decision maker evaluates performance and determines resource allocations based on a number of factors, the primary measure being earnings (loss) before interest and income taxes. Earnings (loss) before interest and income taxes for reportable segments and Other Businesses does not include net interest and other financial costs (income), income taxes, and certain other items that management believes are not indicative of future results. In 2018, U. S. Steel began allocating certain post-employment benefits to its segments. Prior year information was adjusted to conform with the current year presentation. The accounting principles applied at the operating segment level in determining earnings (loss) before interest and income taxes are generally the same as those applied at the consolidated financial statement level. Intersegment sales and transfers are accounted for at market-based prices and are eliminated at the corporate consolidation level. Corporate-level selling, general and administrative expenses and costs related to certain former businesses are allocated to the reportable segments and Other Businesses based on measures of activity that management believes are reasonable. The results of segment operations are as follows: (In millions) Customer Intersegment Net Earnings Earnings (Loss) before Interest and Income Taxes Depreciation, Capital 2019 Flat-Rolled $ 9,279 $ 281 $ 9,560 $ 84 $ 196 $ 456 $ 943 USSE 2,417 3 2,420 — (57 ) 92 153 Tubular 1,188 3 1,191 5 (67 ) 46 145 Total reportable segments 12,884 287 13,171 89 72 594 1,241 Other Businesses 53 115 168 (10 ) 23 22 11 Reconciling Items and Eliminations — (402 ) (402 ) — (325 ) — — Total $ 12,937 $ — $ 12,937 $ 79 $ (230 ) $ 616 $ 1,252 2018 Flat-Rolled $ 9,681 $ 231 $ 9,912 $ 54 $ 883 $ 367 $ 820 USSE 3,205 23 3,228 — 359 87 104 Tubular 1,231 5 1,236 7 (58 ) 47 45 Total reportable segments 14,117 259 14,376 61 1,184 501 969 Other Businesses 61 125 186 — 55 20 32 Reconciling Items and Eliminations — (384 ) (384 ) — (115 ) — — Total $ 14,178 $ — $ 14,178 $ 61 $ 1,124 $ 521 $ 1,001 2017 Flat-Rolled $ 8,297 $ 194 $ 8,491 $ 38 $ 375 $ 352 $ 388 USSE 2,949 25 2,974 — 327 76 83 Tubular 944 1 945 8 (99 ) 51 28 Total reportable segments 12,190 220 12,410 46 603 479 499 Other Businesses 60 119 179 (2 ) 44 22 6 Reconciling Items and Eliminations — (339 ) (339 ) — 22 — — Total $ 12,250 $ — $ 12,250 $ 44 $ 669 $ 501 $ 505 A summary of total assets by segment is as follows: December 31, (In millions) 2019 2018 Flat-Rolled (a) $ 7,267 $ 6,977 USSE (b) 5,360 5,607 Tubular 1,150 1,076 Total reportable segments $ 13,777 $ 13,660 Other Businesses $ 1,267 $ 329 Corporate, reconciling items, and eliminations (c) (3,436 ) (3,007 ) Total assets $ 11,608 $ 10,982 (a) Included in the Flat-Rolled segment assets is goodwill of $3 million as of December 31, 2018 . (b) Included in the USSE segment assets is goodwill of $4 million as of both December 31, 2019 and 2018 . (c) The majority of Corporate, reconciling items, and eliminations total assets is comprised of cash and the elimination of intersegment amounts. The detail of reconciling items to consolidated earnings (loss) before interest and income taxes is as follows: (In millions) 2019 2018 2017 Items not allocated to segments: December 24, 2018 Clairton coke making facility fire (50 ) — — United Steelworkers labor agreement signing bonus and related costs — (81 ) — Granite City Works restart and related costs — (80 ) — Loss on shutdown of certain tubular pipe mill assets (Note 25) — — (35 ) Gain associated with U. S. Steel Canada Inc. (Note 5) — — 72 Restructuring and other charges (Note 25) (275 ) — — Granite City Works temporary idling charges — 8 (17 ) Gain on equity investee transactions (Note 12) — 38 2 Total reconciling items $ (325 ) $ (115 ) $ 22 Geographic Area: The information below summarizes external sales, property, plant and equipment and equity method investments based on the location of the operating segment to which they relate. (In millions) Year External Assets North America 2019 $ 10,520 $ 5,772 (a) 2018 10,973 4,432 (a) 2017 9,301 3,831 (a) Europe 2019 2,417 947 2018 3,205 919 2017 2,949 906 Total 2019 12,937 6,719 2018 14,178 5,351 2017 12,250 4,737 (a) Assets with a book value of $5,772 million , $4,432 million and $3,817 million were located in the United States at December 31, 2019 , 2018 and 2017 , respectively.

Acquisition and Disposition

Acquisition and Disposition	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Acquisition and Disposition	5. Acquisition and Disposition Big River Steel Acquisition On October 31, 2019, a wholly owned subsidiary of U. S. Steel purchased a 49.9% ownership interest in Big River Steel at a purchase price of approximately $683 million in cash, with a call option (U. S. Steel Call Option) to acquire the remaining 50.1% within the next four years at an agreed-upon price formula, which in years three and four is based on Big River Steel’s achievement of certain metrics that include: free cash flow, product development, safety and the completion of a proposed expansion of Big River Steel's existing manufacturing line. Big River Steel currently operates a technologically advanced mini mill with approximately 1.65 million tons of steel making capacity. U. S. Steel accounts for its investment in Big River Steel under the equity method as control and risk of loss are shared among the partnership members. Big River Steel is not a variable interest entity as it qualifies for the business scope exception under ASC 810, Consolidation . Under the equity method of accounting, U. S. Steel recognizes its share of Big River Steel's after tax net income or loss as well as the amortization of any basis differences due to the step-up to fair value of certain assets attributable to Big River Steel. U. S. Steel recorded an equity investment asset for Big River Steel of $710 million that includes approximately $27 million of transaction costs and is reflected in the investments and long-term receivables line on our balance sheet. U. S. Steel’s 49.9% share of the total net assets of Big River Steel was approximately $155 million at October 31, 2019 resulting in a basis difference of approximately $550 million due to the step-up to fair value of certain assets attributable to Big River Steel. Approximately $88 million of the step-up was attributable to property, plant and equipment and approximately $460 million was attributable to goodwill. This basis difference, excluding the portion attributable to goodwill, is being amortized based on the remaining weighted average useful life of the assets of approximately 18 years . U. S. Steel’s 49.9% share of amortization expense associated with the fair value step-up was less than $1 million for 2019. The transaction to acquire Big River Steel included the U. S. Steel Call Option described above and options where the other Big River Steel equity owners can require U. S. Steel to purchase their 50.1% ownership interest (Class B Common Put Option) or require U. S. Steel to sell its ownership interest (Class B Common Call Option) at an agreed upon price if the U. S. Steel Call Option expires. The U. S. Steel Call Option, Class B Common Call Option and Class B Common Put Option are free-standing financial instruments that are marked to fair value each period using a Monte Carlo simulation which is considered a Level 3 valuation technique, see Note 20 for further details. (In millions) Consolidated Balance Sheet Classification December 31, 2019 U. S. Steel Call Option Investments and other long-term receivables $ 166 Class B Put Option Deferred credits and other long-term liabilities $ 192 Class B Call Option Deferred credits and other long-term liabilities $ 2 The transaction also included options where U. S. Steel can require the other Big River Steel equity owners to purchase U. S. Steel's ownership interest under certain conditions or if an overall cash flow target is not met for the four-year period ending September 30, 2023. These options are embedded financial instruments that are included in the Big River Steel equity investment asset. U. S. Steel Canada Inc. Retained Interest Disposition On June 30, 2017, U. S. Steel completed the restructuring and disposition of U. S. Steel Canada Inc. (USSC) through a sale and transfer of all of the issued and outstanding shares in USSC to an affiliate of Bedrock Industries LLC. In accordance with the Second Amended and Restated Plan of Compromise, Arrangement and Reorganization, approved by the Ontario Superior Court of Justice on June 9, 2017, U. S. Steel received approximately $127 million in satisfaction of its secured claims, including interest, which resulted in a gain of $72 million

Revenue

Revenue	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue	6. Revenue Revenue is generated primarily from contracts to produce, ship and deliver steel products, and to a lesser extent, to deliver raw materials such as iron ore pellets, to deliver coke by-products and for railroad services and real estate sales. Generally, U. S. Steel’s performance obligations are satisfied, control of our products is transferred, and revenue is recognized at a single point in time, when title transfers to our customer for product shipped or when services are provided. Revenues are recorded net of any sales incentives. Shipping and other transportation costs charged to customers are treated as fulfillment activities and are recorded in both revenue and cost of sales at the time control is transferred to the customer. Costs related to obtaining sales contracts are incidental and are expensed when incurred. Because customers are invoiced at the time title transfers and U. S. Steel’s right to consideration is unconditional at that time, U. S. Steel does not maintain contract asset balances. Additionally, U. S. Steel does not maintain contract liability balances, as performance obligations are satisfied prior to customer payment for product. U. S. Steel offers industry standard payment terms. U. S. Steel has three reportable segments: Flat-Rolled, USSE and Tubular. Flat-Rolled primarily generates revenue from sheet and coated product sales to North American customers. Flat-Rolled also sells iron ore pellets and coke making by-products. USSE sells slabs, sheets, strip mill plates, tin mill products and spiral welded pipe as well a refractory ceramic materials to customers primarily in the Central and Western European market. Tubular sells seamless and electric resistance welded (ERW) steel casing and tubing (commonly known as oil country tubular goods or OCTG), standard and line pipe and mechanical tubing and primarily serves customers in the oil, gas and petrochemical markets. Revenue from our railroad and real estate businesses is reported in the Other Businesses category in our segment reporting structure. The following table disaggregates our revenue by product for each of our reportable business segments for the years ended December 31, 2019 , 2018 and 2017 , respectively: Customer Sales by Product: (In millions) Year Ended December 31, 2019 Flat-Rolled USSE Tubular Other Businesses Total Semi-finished $ 305 $ 11 $ — $ — $ 316 Hot-rolled sheets 2,504 997 — — 3,501 Cold-rolled sheets 2,512 283 — — 2,795 Coated sheets 2,993 1,006 — — 3,999 Tubular products — 40 1,166 — 1,206 All Other (a) 965 80 22 53 1,120 Total $ 9,279 $ 2,417 $ 1,188 $ 53 $ 12,937 (In millions) Year Ended December 31, 2018 Flat-Rolled USSE Tubular Other Businesses Total Semi-finished $ 156 $ 174 $ — $ — $ 330 Hot-rolled sheets 2,816 1,313 — — 4,129 Cold-rolled sheets 2,709 384 — — 3,093 Coated sheets 3,090 1,164 — — 4,254 Tubular products — 48 1,195 — 1,243 All Other (a) 910 122 36 61 1,129 Total $ 9,681 $ 3,205 $ 1,231 $ 61 $ 14,178 (In millions) Year Ended December 31, 2017 Flat-Rolled USSE Tubular Other Businesses Total Semi-finished $ 72 $ 232 $ — $ — $ 304 Hot-rolled sheets 2,045 1,210 — — 3,255 Cold-rolled sheets 2,355 328 — — 2,683 Coated sheets 2,902 1,038 — — 3,940 Tubular products — 39 909 — 948 All Other (a) 923 102 35 60 1,120 Total $ 8,297 $ 2,949 $ 944 $ 60 $ 12,250 (a) Consists primarily of sales of raw materials and coke making by-products.

Net Interest and Other Financia

Net Interest and Other Financial Costs	12 Months Ended
	Dec. 31, 2019
Other Income and Expenses [Abstract]
Net Interest and Other Financial Costs	7. Net Interest and Other Financial Costs (In millions) 2019 2018 2017 Interest income: Interest income $ (17 ) $ (23 ) $ (17 ) Interest expense and other financial costs: Interest incurred 162 175 229 Less interest capitalized 20 7 3 Total interest expense 142 168 226 Loss on debt extinguishment (a) — 98 54 Net periodic benefit costs (other than service cost) (b) 91 69 61 Foreign currency net (gain) loss (c) (17 ) (19 ) 23 Financial costs on: Amended Credit Agreement 5 5 6 USSK credit facilities 1 3 3 Other (d) 10 3 2 Amortization of discounts and deferred financing costs 7 8 10 Total other financial costs 6 — 44 Net interest and other financial costs $ 222 $ 312 $ 368 (a) Represents a net pretax charge of $98 million during 2018 related to the retirement of our 2020 Senior Notes and 2021 Senior Secured Notes, and a net pretax charge of $54 million during 2017 related to the retirement of our 2018, 2021, and 2022 Senior Notes, partial redemption of our 2021 Senior Secured Notes, and redemption of the Lorain Recovery Zone Facility Bonds. (b) Represents postretirement benefit expense as a result of the adoption of Accounting Standards Update 2017-07, Compensation - Retirement Benefits on January 1, 2018. See Note 3 to the Consolidated Financial Statements. (c) The functional currency for USSE is the euro. Foreign currency net (gain) loss is a result of transactions denominated in currencies other than the euro. (d) 2019 includes a $7 million change in fair value of certain call and put options related to U. S. Steel's purchase of its 49.9%

Earnings and Dividends Per Comm

Earnings and Dividends Per Common Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings and Dividends Per Common Share	8. Earnings and Dividends Per Common Share (Loss) Earnings per Share Attributable to United States Steel Corporation Stockholders Basic (loss) earnings per common share is based on the weighted average number of common shares outstanding during the period. Diluted (loss) earnings per common share assumes the exercise of stock options, the vesting of restricted stock units and performance awards, provided in each case the effect is dilutive. The "treasury stock" method is used to calculate the dilutive effect of the Senior Convertible Notes due in 2026 (due to our current intent and policy, among other factors, to settle the principal amount of the 2026 Senior Convertible Notes in cash upon conversion). The computations for basic and diluted (loss) earnings per common share from continuing operations are as follows: (Dollars in millions, except per share amounts) 2019 2018 2017 Net (loss) earnings attributable to United States Steel Corporation stockholders $ (630 ) $ 1,115 $ 387 Weighted-average shares outstanding (in thousands): Basic 171,418 176,633 174,793 Effect of convertible notes — — — Effect of stock options, restricted stock units and performance awards — 1,828 1,727 Adjusted weighted-average shares outstanding, diluted 171,418 178,461 176,520 Basic (loss) earnings per common share $ (3.67 ) $ 6.31 $ 2.21 Diluted (loss) earnings per common share $ (3.67 ) $ 6.25 $ 2.19 The following table summarizes the securities that were antidilutive, and therefore, were not included in the computation of diluted (loss) earnings per common share: (In thousands) 2019 2018 2017 Securities granted under the 2005 Stock Incentive Plan 4,459 1,631 1,579 Securities convertible under the Senior Convertible Notes 650 — — Total 5,109 1,631 1,579 Dividends Paid per Share Quarterly dividends on common stock were five cents per share for each quarter in 2019 , 2018 and 2017 . U. S. Steel's Board of Directors approved an adjustment of the quarterly dividend to one cent

Cash, Cash Equivalents, and Res

Cash, Cash Equivalents, and Restricted Cash	12 Months Ended
	Dec. 31, 2019
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Restricted Cash	9. Cash, Cash Equivalents and Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within U. S. Steel's Consolidated Balance Sheets that sum to the total of the same amounts shown in the Consolidated Statement of Cash Flows: December 31, (In millions) 2019 2018 2017 Cash and cash equivalents $ 749 $ 1,000 $ 1,553 Restricted cash in other current assets 2 3 6 Long-term restricted cash 188 37 38 Total cash, cash equivalents and restricted cash $ 939 $ 1,040 $ 1,597 Amounts included in restricted cash represent cash balances which are legally or contractually restricted, primarily for electric arc furnace construction, environmental capital expenditure projects and insurance purposes.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories	10. Inventories (In millions) December 31, 2019 December 31, 2018 Raw materials $ 628 $ 605 Semi-finished products 720 1,021 Finished products 376 404 Supplies and sundry items 61 62 Total $ 1,785 $ 2,092 Current acquisition costs were estimated to exceed the above inventory values at December 31 by $735 million in 2019 and $1,038 million in 2018 . As a result of the liquidation of LIFO inventories, cost of sales decreased and earnings (loss) before interest and income taxes increased by $28 million in 2019 and $10 million in 2018. As a result of the liquidation of LIFO inventories, cost of sales increased and earnings (loss) before interest and income taxes decreased by $6 million in 2017 . Inventory includes $40 million and $39 million of land held for residential/commercial development as of December 31, 2019 and 2018 , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes Components of (loss) earnings (In millions) 2019 2018 2017 United States $ (381 ) $ 434 $ 75 Foreign (71 ) 378 226 (Loss) earnings before income taxes $ (452 ) $ 812 $ 301 At the end of both 2019 and 2018, U. S. Steel does not have any undistributed foreign earnings and profits for which U.S. deferred taxes have not been provided. Income tax provision (benefit) 2019 2018 2017 (In millions) Current Deferred Total Current Deferred Total Current Deferred Total Federal $ (18 ) $ 196 $ 178 $ (40 ) $ (283 ) $ (323 ) $ (66 ) $ (81 ) $ (147 ) State and local — 23 23 2 (58 ) (56 ) (1 ) — (1 ) Foreign (6 ) (17 ) (23 ) 64 12 76 53 9 62 Total $ (24 ) $ 202 $ 178 $ 26 $ (329 ) $ (303 ) $ (14 ) $ (72 ) $ (86 ) A reconciliation of the federal statutory tax rate of 21 percent ( 21 percent in 2018 and 35 percent in 2017) to total provision (benefit) follows: (In millions) 2019 2018 2017 Statutory rate applied to earnings (loss) before income taxes $ (95 ) $ 171 $ 105 Valuation allowance 334 (412 ) 36 Excess percentage depletion (46 ) (48 ) (68 ) State and local income taxes after federal income tax effects (36 ) 8 (28 ) Effects of foreign operations (23 ) 74 62 U.S. impact of foreign operations 25 (21 ) (6 ) Impact of tax credits 5 (71 ) (56 ) Effect of tax reform — — (81 ) Alternative minimum tax credit refund — — (48 ) Adjustment of prior years' federal income taxes 7 — — Other 7 (4 ) (2 ) Total provision (benefit) $ 178 $ (303 ) $ (86 ) In 2019, the tax benefit differs from the domestic statutory rate of 21 percent primarily due to the fact that it does not reflect any tax benefit in the U.S. as a valuation allowance was recorded against the Company's net domestic deferred tax asset (excluding a portion of a deferred tax liability related to an asset with an indefinite life, as well as a deferred tax asset related to refundable Alternative Minimum Tax (AMT) credits). Included in the 2018 tax benefit is a benefit of $374 million related to the reversal of a portion of the valuation allowance recorded against the Company's net domestic deferred tax asset, as well as a benefit of $38 million related to the reversal of the valuation allowance for current year activity. Included in the 2017 tax benefit is a benefit of $10 million related to corporate rate reduction provided by the Tax Cut and Jobs Act of 2017 (2017 Act), as well as a benefit of $71 million related to the reversal of the valuation allowance recorded against the remaining balance of the Company’s AMT credits, which became fully refundable pursuant to the 2017 Act. Also included in the 2017 tax benefit is a benefit of $48 million related to the Company’s election to claim a refund of AMT credits pursuant to a provision in the Protecting Americans from Tax Hikes (PATH) Act. Deferred taxes Deferred tax assets and liabilities resulted from the following: December 31, (In millions) 2019 2018 Deferred tax assets: Federal tax loss carryforwards (expiring in 2035 through 2036) $ 176 $ 220 Federal capital loss carryforwards (expiring 2021) 27 33 State tax credit carryforwards (expiring in 2020 through 2028) 18 16 State tax loss carryforwards (expiring in 2020 through 2039) 130 137 Minimum tax credit carryforwards 19 38 General business credit carryforwards (expiring in 2027 through 2039) 85 85 Foreign tax loss and credit carryforwards (expiring in 2024 through 2029) 170 173 Employee benefits 173 337 Contingencies and accrued liabilities 71 62 Investments in subsidiaries and equity investees 49 59 Inventory 32 — Other temporary differences 35 26 Valuation allowance (563 ) (214 ) Total deferred tax assets 422 972 Deferred tax liabilities: Property, plant and equipment 368 468 Inventory — 22 Receivables, payables and debt 17 33 Indefinite-lived intangible assets 19 18 Other temporary differences 3 — Total deferred tax liabilities 407 541 Net deferred tax asset $ 15 $ 431 U. S. Steel recognizes deferred tax assets and liabilities for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. The realization of deferred tax assets is assessed quarterly based on several interrelated factors. These factors include U. S. Steel’s expectation to generate sufficient future taxable income and the projected time period over which these deferred tax assets will be realized. Each quarter U. S. Steel analyzes the likelihood that our deferred tax assets will be realized. A valuation allowance is recorded if, based on the weight of all available positive and negative evidence, it is more likely than not that some portion, or all, of a deferred tax asset will not be realized. At December 31, 2019, we identified the following negative evidence concerning U. S. Steel's ability to use some or all of its domestic deferred tax assets: • U. S. Steel's domestic operations generated a significant loss in the current year and there is uncertainty regarding the Company's ability to generate domestic income in the near term, • some of our domestic deferred tax assets are carryforwards, which have expiration dates, and • the global steel industry is experiencing overcapacity, which is driving adverse economic conditions and depressed selling prices for steel products. Most positive evidence can be categorized into one of the four sources of taxable income sequentially. These are (from least to most subjective): • taxable income in prior carryback years, if carryback is permitted, • future reversal of existing taxable temporary differences, • tax planning strategies, and • future taxable income exclusive of reversing temporary differences and carryforwards. U. S. Steel utilized all available carrybacks, and therefore, our analysis at December 31, 2019 focused on the other sources of taxable income. Our projection of the reversal of our existing temporary differences generated significant taxable income. This source of taxable income, however, was not sufficient to project full utilization of U. S. Steel’s domestic deferred tax assets. To assess the realizability of the remaining domestic deferred tax assets, U. S. Steel analyzed its prudent and feasible tax planning strategies. At December 31, 2019, after weighing all the positive and negative evidence, U. S. Steel determined that it was more likely than not that the net domestic deferred tax asset (excluding a portion of a deferred tax liability related to an asset with an indefinite life, as well as a deferred tax asset related to refundable AMT credits) may not be realized. As a result, U. S. Steel recorded a $334 million non-cash charge to tax expense. In the future, if we determine that it is more likely than not that we will be able to realize all or a portion of our deferred tax assets, the valuation allowance will be reduced, and we will record a benefit to earnings. At December 31, 2019 , the net domestic deferred tax asset was $12 million , net of an established valuation allowance of $560 million . At December 31, 2018, the net domestic deferred tax asset was $445 million , net of an established valuation allowance of $211 million . At December 31, 2019 , the net foreign deferred tax asset was $3 million , net of an established valuation allowance of $3 million . At December 31, 2018, the net foreign deferred tax liability was $14 million , net of an established valuation allowance of $3 million . The net foreign deferred tax asset will fluctuate as the value of the U.S. dollar changes with respect to the euro. U. S. Steel will continue to monitor the realizability of its deferred tax assets on a quarterly basis taking into consideration, among other items, the uncertainty regarding the Company's continued ability to generate domestic income in the near term. In the future, if we determine that realization is more likely than not for a deferred tax asset with a valuation allowance, the related valuation allowance will be reduced, and we will record a non-cash benefit to earnings. Unrecognized tax benefits Unrecognized tax benefits are the differences between a tax position taken, or expected to be taken, in a tax return and the benefit recognized for accounting purposes pursuant to the guidance in ASC Topic 740 on income taxes. The total amount of unrecognized tax benefits was $3 million , $35 million and $42 million as of December 31, 2019 , 2018 and 2017 , respectively. The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate was $2 million as of both December 31, 2019 and 2018 . U. S. Steel records interest related to uncertain tax positions as a part of net interest and other financial costs in the Consolidated Statements of Operations. Any penalties are recognized as part of selling, general and administrative expenses. U. S. Steel had accrued liabilities of $2 million for interest and penalties related to uncertain tax positions as of both December 31, 2019 and 2018 . A tabular reconciliation of unrecognized tax benefits follows: (In millions) 2019 2018 2017 Unrecognized tax benefits, beginning of year $ 35 $ 42 $ 72 Increases – tax positions taken in prior years — — 1 Decreases – tax positions taken in prior years — (2 ) (26 ) Settlements (32 ) — (4 ) Lapse of statute of limitations — (5 ) (1 ) Unrecognized tax benefits, end of year $ 3 $ 35 $ 42 It is reasonably expected that during the next 12 months unrecognized tax benefits related to income tax issues will change by an immaterial amount. Tax years subject to examination Below is a summary of the tax years open to examination by major tax jurisdiction: U.S. Federal – 2014 and forward U.S. States – 2009 and forward Slovakia – 2009 and forward Status of Internal Revenue Service (IRS) examinations The IRS audit of U. S. Steel’s 2014-2016 federal consolidated tax returns began in 2018 and is ongoing. The IRS completed its audit of the Company's 2012 and 2013 tax returns in 2019. The audit report was agreed to by the Company and approved by the Congressional Joint Committee on Taxation in the fourth quarter of 2019, which resulted in a reduction to unrecognized tax benefits.

Investments, Long-Term Receivab

Investments, Long-Term Receivables and Equity Investee Transactions	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investments, Long-Term Receivables and Equity Investee Transactions	12. Investments, Long-Term Receivables and Equity Investee Transactions December 31, (In millions) 2019 2018 Equity method investments $ 1,272 $ 485 Receivables due after one year, less allowance of $5 and $11 191 24 Other 3 4 Total $ 1,466 $ 513 Summarized financial information of all investees accounted for by the equity method of accounting is as follows (amounts represent 100% of investee financial information): (In millions) 2019 2018 2017 Income data – year ended December 31: (a) Net Sales $ 2,528 $ 2,193 $ 2,485 Operating income 253 157 132 Net earnings 235 134 109 Balance sheet date – December 31: Current Assets $ 1,144 $ 642 $ 633 Noncurrent Assets 2,976 853 710 Current liabilities 573 348 441 Noncurrent Liabilities 2,542 516 335 (a) Former equity affiliates, Swan Point Development Company, Inc., Tilden Mining Company (Tilden) and Apolo Tubulars S.A. were sold on February 6, 2017, September 29, 2017 and December 22, 2017, respectively. We exited Leeds Retail Center, LLC and sold Acero Prime, S.R.L. de CV on May 31, 2018, and October 23, 2018, respectively. The former equity affiliates are included in the income data through the month prior to the date of sale. U. S. Steel's portion of the equity in net earnings for its equity investments as reported in the income from investees line on the Consolidated Statements of Operations was $79 million , $61 million and $44 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. All of our significant investees are located in the U.S. Investees accounted for using the equity method include: Investee December 31, 2019 Interest Big River Steel (a) 49.9 % Chrome Deposit Corporation 50 % Daniel Ross Bridge, LLC 50 % Double G Coatings Company, Inc. 50 % Feralloy Processing Company 49 % Hibbing Development Company 24.1 % Hibbing Taconite Company (b) 14.7 % Patriot Premium Threading Services, LLC 50 % PRO-TEC Coating Company, LLC 50 % Strategic Investment Fund Partners II (c) 5.2 % USS-POSCO Industries 50 % Worthington Specialty Processing 49 % (a) U. S. Steel's 49.9% ownership in Big River Steel consists of 47.7535% interests in Big River Steel Holdings LLC and BRS Stock Holdco LLC. U. S. Steel Blocker LLC, a wholly-owned subsidiary of U. S. Steel, holds a 2.1465% interest in both of those entities. (b) Hibbing Taconite Company (Hibbing) is an unincorporated joint venture that is owned, in part, by Hibbing Development Company (HDC), which is accounted for using the equity method. Through HDC we are able to influence the activities of HTC, and as such, its activities are accounted for using the equity method. (c) Strategic Investment Fund Partners II is a limited partnership and in accordance with ASC Topic 323, the financial activities are accounted for using the equity method. In 2018, we recognized pre-tax gains on equity investee transactions of approximately $18 million for the assignment of our ownership interest in Leeds Retail Center, LLC and $20 million from the sale of our 40 percent ownership interest in Acero Prime, S. R. L. de CV. In 2017, we recognized a total gain on equity investee transactions of $2 million primarily as a result of a gain on sale of our 15 percent ownership in Tilden Mining Company, L.C., partially offset by a loss on sale of our 50 percent ownership interest in Apolo Tubulars S.A. Dividends and partnership distributions received from equity investees were $5 million in 2019 , $13 million in 2018 and $12 million in 2017 . U. S. Steel evaluates impairment of its equity method investments whenever circumstances indicate that a decline in value below carrying value is other than temporary. Under these circumstances, we would adjust the investment down to its estimated fair value, which then becomes its new carrying value. We supply substrate to certain of our equity method investees and from time to time will extend the payment terms for their trade receivables. For discussion of transactions and related receivable and payable balances between U. S. Steel and its investees, see Note 23. Big River Steel On October 31, 2019, a wholly owned subsidiary of U. S. Steel purchased a 49.9% ownership interest in Big River Steel at a purchase price of approximately $683 million in cash. U. S. Steel recorded an equity investment asset for Big River Steel of $710 million that includes approximately $27 million of transaction costs. U. S. Steel accounts for its investment in Big River Steel under the equity method as control and risk of loss are shared among the partnership members. Big River Steel is not a variable interest entity as it qualifies for the business scope exception under ASC 810, Consolidation. See Note 5 for further details. Patriot Premium Threading Services, LLC Patriot Premium Threading Services, LLC (Patriot) is located in Midland, Texas and provides oil country threading, accessory threading, repair services and rig site services to exploration and production companies located principally in the Permian Basin. During the fourth quarter of 2019, Patriot’s 50-50 joint venture partners, a wholly owned subsidiary of U. S. Steel and Butch Gilliam Enterprises, Inc. (BGE) amended the joint venture agreement. In accordance with the amended agreement, U. S. Steel will be entitled to receive distributions of 100% of Patriot’s earnings starting January 1, 2020 and will purchase BGE’s ownership interest in Patriot after a three-year period in exchange for certain fixed payments and payments equal to ten percent of Patriot’s earnings before interest and taxes during that time period. The prepaid asset (recorded in other noncurrent assets) related to the future purchase of Patriot was $33.0 million and $27.7 million at December 31, 2019 and December 31, 2018, respectively. The liability (recorded in deferred credits and other noncurrent liabilities) related to the future purchase of Patriot was $5.7 million at December 31, 2019. There was no liability related to the purchase of Patriot at December 31, 2018. Patriot is now classified as a variable interest entity because its economics are not proportional to the equal voting interests of its two joint venture partners. U. S. Steel is not the primary beneficiary because it does not direct the decisions that most significantly impact the economic performance of Patriot. These decisions include those related to sales of Patriot’s goods and services, its production planning and scheduling and its negotiation of procurement contracts. At December 31, 2019 and 2018, U. S. Steel had other assets of approximately $29.8 million and $23.7 million

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	13. Property, Plant and Equipment December 31, (In millions) Useful Lives 2019 2018 Land and depletable property — $ 202 $ 207 Buildings 35 years 1,105 1,098 Machinery and equipment Steel producing 2-30 years 13,658 12,784 Transportation 3-40 years 280 268 Other 5-30 years 129 123 Information technology 5-6 years 787 786 Assets under finance lease 5-15 years 83 36 Construction in process — 833 706 Total 17,077 16,008 Less accumulated depreciation and depletion 11,630 11,143 Net $ 5,447 $ 4,865 Amounts in accumulated depreciation and depletion for assets acquired under finance leases (including sale-leasebacks accounted for as financings) were $27 million and $20 million at December 31, 2019 and 2018 , respectively.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	14. Intangible Assets Intangible assets are being amortized on a straight-line basis over their estimated useful lives and are detailed below: As of December 31, 2019 As of December 31, 2018 (In millions) Useful Gross Accumulated Net Gross Accumulated Net Customer relationships 22 Years $ 132 $ 76 $ 56 $ 132 $ 70 $ 62 Patents 10-15 Years 22 8 14 22 7 15 Other 4-20 Years 14 9 5 14 8 6 Total amortizable intangible assets $ 168 $ 93 $ 75 $ 168 $ 85 $ 83 Identifiable intangible assets with finite lives are reviewed for impairment whenever events or circumstances indicate that the carrying value may not be recoverable. During 2019 , steel market challenges in the U.S. and Europe, the indefinite idling of certain Flat-Rolled facilities and recent losses in the welded tubular asset groups were considered triggering events for those long-lived asset groups. Long-lived asset impairment evaluations were performed and no impairments were identified. There were no triggering events in 2018 that required a review for impairment. Amortization expense was $8 million for both years ended December 31, 2019 and December 31, 2018 . We expect a consistent level of annual amortization expense through 2024 . The carrying amount of acquired water rights with indefinite lives as of December 31, 2019 and December 31, 2018 totaled $75 million . The acquired water rights are tested for impairment annually in the third quarter, or whenever events or circumstances indicate the carrying value may not be recoverable. U. S. Steel performed a quantitative impairment evaluation of its acquired water rights during the third quarter of 2019

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	15. Stock-Based Compensation Plans U. S. Steel has outstanding stock-based compensation awards that were granted by the Compensation & Organization Committee of the Board of Directors (the Committee) under the 2005 Stock Incentive Plan (the 2005 Plan) and the 2016 Omnibus Incentive Compensation Plan (the Omnibus Plan) (collectively the Plans). On April 26, 2016, the Company's stockholders approved the Omnibus Plan and authorized the Company to issue up to 7,200,000 shares of U. S. Steel common stock under the Omnibus Plan. The Company's stockholders authorized the issuance of an additional 6,300,000 shares under the Omnibus Plan on April 25, 2017. While awards that were previously granted under the 2005 Plan remain outstanding, all future awards will be granted under the Omnibus Plan. As of December 31, 2019 , there were 7,464,779 shares available for future grants under the Omnibus Plan. Generally, a share issued under the Omnibus Plan pursuant to an award other than a stock option will reduce the number of shares available under the Stock Plan by 1.73 shares. Shares related to awards under either plan (i) that are forfeited, (ii) that terminate without shares having been issued or (iii) for which payment is made in cash or property other than shares, are again available for awards under the Omnibus Plan. Shares delivered to U. S. Steel or withheld for purposes of satisfying the exercise price or tax withholding obligations are not available for future awards. The purpose of the Plans is to attract, retain and motivate employees and non-employee directors of outstanding ability, and to align their interests with those of the stockholders of U. S. Steel. The Committee administers the Plans, and under the Omnibus Plan, may make grants of stock options, restricted stock units (RSUs), performance awards, and other stock-based awards. The following table summarizes the total stock-based compensation awards granted during the years 2019 , 2018 and 2017 : Stock Options Restricted Stock Units TSR Performance Awards ROCE Performance Awards 2019 Grants — 1,005,500 210,520 527,470 2018 Grants — 824,195 79,190 247,510 2017 Grants 647,780 348,040 169,850 — Stock-based compensation expense The following table summarizes the total compensation expense recognized for stock-based compensation awards: (In millions, except per share amounts) Year Ended December 31, 2019 Year Ended December 31, 2018 Year Ended December 31, 2017 Stock-based compensation expense recognized: Cost of sales $ 9 $ 11 $ 10 Selling, general and administrative expenses 17 21 17 Decrease in net income 26 32 27 Decrease in basic earnings per share 0.15 0.14 0.15 Decrease in diluted earnings per share 0.15 0.13 0.15 As of December 31, 2019 , total future compensation cost related to nonvested stock-based compensation arrangements was $16 million , and the average period over which this cost is expected to be recognized is approximately 18 months . Stock options Compensation expense for stock options is recorded over the vesting period based on the fair value on the date of grant, as calculated by U. S. Steel using the Black-Scholes model and the assumptions listed below. Awards generally vest ratably over a three -year service period and have a term of ten years . Stock options are generally issued at the market price of the underlying stock on the date of the grant. Upon exercise of stock options, shares of U. S. Steel stock are issued from treasury stock or from authorized, but unissued common stock. There were no stock options granted in 2019 and 2018 . Black-Scholes Assumptions (a) 2017 Grants Grant date price per share of option award $ 36.94 Exercise price per share of option award $ 36.94 Expected annual dividends per share $ 0.20 Expected life in years 5.0 Expected volatility 57 % Risk-free interest rate 2.0 % Average grant date fair value per share of unvested option awards as calculated from above $ 17.28 (a) The assumptions represent a weighted-average for all grants during the year. The expected annual dividends per share are based on the latest annualized dividend rate at the date of grant; the expected life in years is determined primarily from historical stock option exercise data; the expected volatility is based on the historical volatility of U. S. Steel stock; and the risk-free interest rate is based on the U.S. Treasury strip rate for the expected life of the option. The following table shows a summary of the status and activity of stock options for the year ended December 31, 2019 : Shares Weighted- Weighted- Aggregate Outstanding at January 1, 2019 2,746,520 $ 27.73 Granted — $ — Exercised (10,435 ) $ 16.05 Forfeited or expired (384,254 ) $ 32.00 Outstanding at December 31, 2019 2,351,831 $ 27.08 4.43 $ — Exercisable at December 31, 2019 2,209,073 $ 26.50 4.28 $ — Exercisable and expected to vest at December 31, 2019 2,323,996 $ 26.97 4.40 $ — The aggregate intrinsic value in the table above represents the total pretax intrinsic value (difference between our closing stock price on the last trading day of 2019 and the exercise price, multiplied by the number of in-the-money options). Intrinsic value changes are a function of the fair market value of our stock. The total intrinsic value of stock options exercised (i.e., the difference between the market price at exercise and the price paid by the employee to exercise the option) was immaterial during the year ended December 31, 2019 , $27 million during the year ended December 31, 2018 and $11 million during the year ended December 31, 2017 . The total amount of cash received by U. S. Steel from the exercise of options during the year ended December 31, 2019 and December 31, 2018 , was an immaterial amount and $35 million , respectively, and the related net tax benefit realized from the exercise of these options was an immaterial amount and $3 million in 2019 and 2018, respectively. Stock awards Compensation expense for nonvested stock awards is recorded over the vesting period based on the fair value at the date of grant. RSUs awarded as part of annual grants generally vest ratably over three years . Their fair value is the market price of the underlying common stock on the date of grant. RSUs granted in connection with new-hire or retention awards generally cliff vest three years from the date of the grant. Total shareholder return (TSR) performance awards may vest at varying levels at the end of a three -year performance period if U. S. Steel’s total shareholder return compared to the total shareholder return of a peer group of companies meets performance criteria during the three -year performance period. For the 2017 and 2018 awards, TSR is calculated over the full three -year performance period. For the 2019 awards, TSR is calculated as follows: 20 percent for each year in the three -year performance period and 40 percent for the full three -year period. TSR performance awards may vest and payout 50 percent at the threshold level, 100 percent at the target level and 200 percent at the maximum level for payouts. Payment for performance in between the threshold percentages will be interpolated. The fair value of the performance awards is calculated using a Monte-Carlo simulation. Performance awards based on the return on capital employed (ROCE) metric were granted in 2019 and 2018 in equity and in 2017 in cash. ROCE awards granted will be measured on a weighted average basis of the Company’s consolidated worldwide earnings (loss) before interest and income taxes, as adjusted, divided by consolidated worldwide capital employed, as adjusted, over a three year period. Weighted average ROCE is calculated based on the ROCE achieved in the first, second and third years of the performance period, weighted at 20 percent , 30 percent and 50 percent , respectively. The ROCE awards will payout 50 percent at the threshold level, 100 percent at the target level and 200 percent at the maximum level. Payouts for performance in between the threshold percentages will be interpolated. Compensation expense associated with the ROCE awards will be contingent based upon the achievement of the specified ROCE performance goals and will be adjusted on a quarterly basis to reflect the probability of achieving the ROCE metric. ROCE performance awards may vest at the end of a three -year performance period contingent upon meeting ROCE performance goals approved by the Committee. The fair value of the ROCE performance awards is the average market price of the underlying common stock on the date of grant. The following table shows a summary of the performance awards outstanding as of December 31, 2019 , and their fair market value on the respective grant date: Performance Period Fair Value Minimum Target Maximum 2019 - 2021 $ 17 — 653,194 1,306,388 2018 - 2020 $ 14 — 288,379 576,758 2017 - 2019 $ 4 — 101,587 203,174 The following table shows a summary of the status and activity of nonvested stock awards for the year ended December 31, 2019 : Restricted TSR Performance (a) ROCE Performance (a) Total Weighted- Nonvested at January 1, 2018 1,496,272 375,787 235,898 2,107,957 $ 30.92 Granted 1,005,500 210,520 527,470 1,743,490 24.46 Vested (771,677 ) (384,664 ) — (1,156,341 ) 18.26 Performance adjustment factor (b) — 192,332 — 192,332 10.02 Forfeited or expired (140,271 ) (43,658 ) (70,525 ) (254,454 ) 30.45 Nonvested at December 31, 2019 1,589,824 350,317 692,843 2,632,984 $ 30.72 (a) The number of shares shown for the performance awards is based on the target number of share awards. (b) Consists of adjustments to vested performance awards to reflect actual performance. The adjustments were required since the original grants of the awards were at 100 percent of the targeted amounts and the awards vested at greater than target. The following table presents information on RSUs and performance awards granted: 2019 2018 2017 Number of awards granted 1,743,490 1,150,895 517,890 Weighted-average grant-date fair value per share $ 24.46 $ 41.65 $ 37.68 During the years ended December 31, 2019 , 2018 , and 2017 , the total fair value of shares vested was $21 million , $14 million , and $11 million , respectively.

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	16. Derivative Instruments U. S. Steel is exposed to foreign currency exchange rate risks in our European operations. USSE’s revenues are primarily in euros and costs are primarily in euros and U.S. dollars (USD). U. S. Steel uses foreign exchange forward sales contracts (foreign exchange forwards) with maturities no longer than 12 months to exchange euros for USD to manage our currency requirements and exposure to foreign currency exchange rate fluctuations. Derivative instruments are required to be recognized at fair value in the Consolidated Balance Sheet. U. S. Steel did not designate euro foreign exchange forwards entered into prior to July 1, 2019, as hedges; therefore, changes in their fair value were recognized immediately in the Consolidated Statements of Operations (mark-to-market accounting). For those contracts, U. S. Steel will continue to recognize changes in fair value immediately through earnings until the contracts mature. U. S. Steel elected cash flow hedge accounting for euro foreign exchange forwards prospectively effective July 1, 2019. Accordingly, future gains and losses for euro foreign exchange forwards entered into after July 1, 2019 will be recorded within accumulated other comprehensive income (AOCI) until the related contract impacts earnings. We mitigate the risk of concentration of counterparty credit risk by purchasing our forwards from several counterparties. In 2018, U. S. Steel entered into long-term freight contracts in its domestic operations that require payment in Canadian dollars (CAD). We entered into foreign exchange forward contracts with remaining maturities up to 12 months to exchange USD for CAD to mitigate a portion of the related risk of exchange rate fluctuations and to manage our currency requirements. We elected to designate these contracts as cash flow hedges. U. S. Steel may use fixed-price forward physical purchase contracts to partially manage our exposure to price risk related to the purchases of natural gas, zinc and tin used in the production process. Generally, forward physical purchase contracts qualify for the normal purchase and normal sales exceptions described in ASC Topic 815 and are not subject to mark-to-market accounting. U. S. Steel also uses financial swaps to protect from the commodity price risk associated with purchases of natural gas, zinc and tin (commodity purchase swaps). We elected cash flow hedge accounting for domestic commodity purchase swaps and use mark-to-market accounting for commodity purchase swaps used in our European operations. From time to time, we enter into financial swaps that are used to partially manage the sales price of certain hot-rolled coil and iron ore pellet sales (sales swaps). We elected cash flow hedge accounting for hot-rolled coil sales swaps effective January 1, 2018 and for iron ore pellet sales swaps effective January 1, 2019. In accordance with the guidance in ASC Topic 820 on fair value measurements and disclosures, the fair value of our foreign exchange forwards, commodity purchase swaps and sales swaps was determined using Level 2 inputs, which are defined as "significant other observable" inputs. The inputs used are from market sources that aggregate data based upon market transactions. The table below shows the outstanding swap quantities used to hedge forecasted purchases and sales as of December 31, 2019 and December 31, 2018 : Hedge Contracts Classification December 31, 2019 December 31, 2018 Natural gas (in mmbtus) Commodity purchase swaps 56,613,200 33,951,016 Tin (in metric tons) Commodity purchase swaps 145 585 Zinc (in metric tons) Commodity purchase swaps 9,819 3,471 Hot-rolled coils (in tons) Sales swaps — 9,000 Foreign currency (in millions of euros) Foreign exchange forwards € 282 € 286 Foreign currency (in millions of CAD) Foreign exchange forwards C$ 25 C$ 50 The following summarizes the fair value amounts included in our Consolidated Balance Sheets as of December 31, 2019 and December 31, 2018 : (In millions) Designated as Hedging Instruments Balance Sheet Location December 31, 2019 December 31, 2018 Sales swaps Accounts payable $ — $ 1 Commodity purchase swaps Accounts receivable 1 2 Commodity purchase swaps Accounts payable 17 17 Commodity purchase swaps Investments and long-term receivables 1 — Commodity purchase swaps Other long-term liabilities 7 1 Foreign exchange forwards Accounts payable 1 1 Foreign exchange forwards Other long-term liabilities — 1 Not Designated as Hedging Instruments Foreign exchange forwards Accounts receivable 4 12 The table below summarizes the effect of hedge accounting on AOCI and amounts reclassified from AOCI into earnings for 2019 , 2018 , and 2017 : Gain (Loss) on Derivatives in AOCI Amount of Gain (Loss) Recognized in Income (In millions) 2019 2018 2017 Location of Reclassification from AOCI (a) 2019 2018 2017 Sales swaps $ 1 $ — $ — Net sales (b) $ (1 ) $ (13 ) $ — Commodity purchase swaps (6 ) (15 ) 1 Cost of sales (c) (19 ) (8 ) (2 ) Foreign exchange forwards 1 (2 ) — Cost of sales (1 ) — — (a) The earnings impact of our hedging instruments substantially offsets the earnings impact of the related hedged items since ineffectiveness is less than $1 million . (b) U. S. Steel elected cash flow hedge accounting for hot-rolled coil sales swaps effective January 1, 2018 and for iron ore pellet sales swaps effective January 1, 2019. (c) Costs for commodity purchase swaps are recognized in cost of sales as products are sold. The table below summarizes the impact of derivative activity where hedge accounting has not been elected on our Consolidated Statements of Operations for 2019 , 2018 and 2017 : Amount of Gain (Loss) Recognized in Income (In millions) Consolidated Statement of Operations Location 2019 2018 2017 Sales swaps (a) Net sales $ — $ (1 ) $ 6 Commodity purchase swaps (b) Cost of sales — — 3 Foreign exchange forwards (c) Other financial costs 17 24 (23 ) (a) U. S. Steel elected cash flow hedge accounting for hot-rolled coil sales swaps effective January 1, 2018 and for iron ore pellet sales swaps effective January 1, 2019. (b) The 2017 impacts were for de-designated zinc contracts for our domestic operations. (c) U. S. Steel has elected hedge accounting for foreign exchange forwards to exchange USD for CAD. U. S. Steel elected cash flow hedge accounting for euro foreign exchange forwards prospectively effective July 1, 2019. At current contract values, $17 million in AOCI as of December 31, 2019 will be recognized as an increase in cost of sales over the next year as related hedged items are recognized in earnings. The maximum derivative contract duration for commodity purchase swaps is 23 months and the maximum duration for foreign exchange forwards is 12 months. There are no outstanding contracts for commodity sales swaps.

Debt

Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt	17. Debt December 31, (In millions) Interest Maturity 2019 2018 2037 Senior Notes 6.650 2037 $ 350 $ 350 2026 Senior Notes 6.250 2026 650 650 2026 Senior Convertible Notes 5.000 2026 350 — 2025 Senior Notes 6.875 2025 750 750 Environmental Revenue Bonds 4.875 - 6.750 2024 - 2049 620 400 Fairfield Caster Lease 2022 18 22 Other finance leases and all other obligations 2020-2029 48 6 Amended Credit Facility, $2.0 billion Variable 2024 600 — USSK Credit Agreement Variable 2023 393 229 USSK credit facilities Variable 2021 — — Total debt 3,779 2,407 Less unamortized discount and debt issuance costs 138 26 Less short-term debt and long-term debt due within one year 14 65 Long-term debt $ 3,627 $ 2,316 2026 Senior Convertible Notes On October 21, 2019, U. S. Steel issued an aggregate principal amount of $300 million of 5.00% Senior Convertible Notes due November 1, 2026 (2026 Senior Convertible Notes), with a 30-day option to purchase up to an additional $50 million in aggregate principal amount of 2026 Senior Convertible Notes, on the same terms and conditions. On October 25, 2019, U. S. Steel issued an additional $50 million of 2026 Senior Convertible Notes after the full option was exercised. U. S. Steel received net proceeds of approximately $340 million from the sale of the 2026 Senior Convertible Notes after deducting underwriting fees and estimated offering expenses. The Company intends to use the net proceeds for general corporate purposes, including, without limitation, for previously announced strategic investments and capital expenditures. Interest on the 2026 Senior Convertible Notes is payable semi-annually on May 1 and November 1 of each year, commencing on May 1, 2020. The initial conversion rate for the 2026 Senior Convertible Notes is 74.8391 shares of U. S. Steel common stock per $1,000 principal amount, equivalent to an initial conversion price of approximately $13.36 per share of common stock, subject to adjustment as defined in the 2026 Senior Convertible Notes. On the issuance date of the 2026 Senior Convertible Notes, the market price of U. S. Steel’s common stock was below the stated conversion price of $13.36 so there was no beneficial conversion option to the holders. Based on the initial conversion rate, the 2026 Senior Convertible Notes are convertible into 26,193,685 shares of U. S. Steel common stock and we reserved for the possible issuance of 33,396,930 shares, which is the maximum amount that could be issued upon conversion. Prior to August 1, 2026, holders of notes may convert all or a portion of their notes at their option only upon the satisfaction of specified conditions and during certain periods. On or after August 1, 2026, holders may convert all or a portion of their notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date. Upon conversion, we will satisfy the obligation with cash, common stock, or a combination thereof, at our election. U. S. Steel may not redeem the 2026 Senior Convertible Notes prior to November 5, 2023. On or after November 5, 2023 and prior to August 1, 2026, if the price per share of U. S. Steel's common stock has been at least 130% of the conversion price for specified periods, U. S. Steel may redeem all or a portion of the 2026 Senior Convertible Notes at a cash redemption price of 100% of the principal amount, plus accrued and unpaid interest. If U. S. Steel undergoes a fundamental change, as defined in the 2026 Senior Convertible Notes, holders may require us to repurchase the 2026 Senior Convertible Notes in whole or in part for cash at a price equal to 100% of the principal amount of the 2026 Senior Convertible Notes to be purchased plus any accrued and unpaid interest (including additional interest, if any) up to, but excluding the repurchase date. For accounting purposes, the proceeds received from the issuance of the notes were allocated between debt and equity to reflect the fair value of the conversion option embedded in the notes and the fair value of similar debt without the conversion option. As a result, based on the aggregate principal amount of $350 million , we recorded approximately $106 million of the gross proceeds of the 2026 Senior Convertible Notes as an increase in additional paid-in capital with the offsetting amount recorded as a debt discount. The debt discount will be amortized over the term of the 2026 Senior Convertible Notes using an estimated interest rate of 10.5% (the estimated effective borrowing rate for nonconvertible debt at the time of issuance) which will accrete the carrying value of the notes to the principal amount at maturity. As of December 31, 2019, the remaining unamortized debt discount was $103 million and the net carrying amount of the 2026 Senior Convertible Notes was $247 million . Environmental Revenue Bonds On October 10, 2019, we launched offerings of two series of environmental revenue bonds in aggregate principal amount of approximately $368 million , that will mature between 2024 and 2049 (collectively, the “2019 Environmental Revenue Bonds”). Proceeds of the 2019 Environmental Revenue Bonds in the amount of approximately $93 million were used to redeem a portion of our existing outstanding environmental revenue bonds for which we issued a conditional redemption notice. Proceeds of the 2019 Environmental Revenue Bonds in the amount of $275 million will be used to finance or refinance the acquisition, construction, equipping and installation of certain solid waste disposal facilities, including an electric arc furnace and other equipment and facilities at the Company’s Fairfield Works. The 2019 Environmental Revenue Bonds closed on October 25, 2019. The Company also redeemed $55 million of outstanding Indiana Finance Authority environmental revenue bonds in December 2019. Amended and Restated Credit Agreement On October 25, 2019, we entered into a new five-year senior secured asset-based revolving credit facility in an aggregate amount of $2.0 billion (Fifth Credit Facility Agreement) to replace the prior $1.5 billion credit facility agreement. The Fifth Credit Facility Agreement has substantially the same terms as the prior credit facility agreement, except the Fifth Credit Facility Agreement will mature five years from the date of effectiveness, includes a “first-in, last-out” tranche in an amount of $150 million and includes certain other changes, including changes to the fixed charge negative covenant test allowing us to exclude (i) certain capital expenditures from the calculation of the test and (ii) certain restricted payments made pursuant to any share repurchase program from the calculation of "consolidated fixed charges." On October 30, 2019, we drew $700 million , which included $5 million in fees, on the Fifth Credit Facility Agreement to fund the closing of our acquisition of a 49.9% interest in Big River Steel. On November 14, 2019, $100 million of outstanding drawings was repaid on the facility. On January 16, 2020, U. S. Steel made an additional payment of $50 million on this facility. As of December 31, 2019 , there was $600 million drawn under the $2.0 billion Fifth Credit Facility Agreement. U. S. Steel must maintain a fixed charge coverage ratio of at least 1.00 to 1.00 for the most recent four consecutive quarters when availability under the Fifth Credit Facility Agreement is less than the greater of 10 percent of the total aggregate commitments and $200 million . Based on the most recent four quarters as of December 31, 2019 , we would have met the fixed charge negative covenant test. However, since the value of our accounts receivable and inventory less specified reserves do not support the full amount of the facility at December 31, 2019, the amount available to the Company under this facility was reduced by $20 million . The availability under the Fifth Credit Facility Agreement was $1.38 billion as of December 31, 2019 . The Fifth Credit Facility Agreement provides for borrowings at interest rates based on defined, short-term market rates plus a spread based on availability and includes other customary terms and conditions including restrictions on our ability to create certain liens and to consolidate, merge or transfer all, or substantially all, of our assets. The Fifth Credit Facility Agreement expires in October 2024. Maturity may be accelerated 91 days prior to the stated maturity of any outstanding senior debt if excess cash and credit facility availability do not meet the liquidity conditions set forth in the Fifth Credit Facility Agreement. Borrowings are secured by liens on substantially all inventory and trade accounts receivable of the Company and subsidiary guarantors. U. S. Steel Košice ( USSK) credit facilities At December 31, 2019 , USSK had borrowings of €350 million (approximately $393 million ) under its €460 million (approximately $517 million ) revolving credit facility. At December 31, 2018 , USSK had borrowings of €200 million (approximately $229 million ) under its €460 million (approximately $527 million ) revolving credit facility. The USSK Credit Agreement contains certain USSK specific financial covenants including a minimum stockholders' equity to assets ratio and net debt to EBITDA ratio. The covenants are measured semi-annually at June and December each year for the period covering the last twelve calendar months, with the first net debt to EBITDA measurement occurring at June 2021. If USSK does not comply with the USSK Credit Agreement financial covenants, it would constitute an event of default under the USSK Credit Agreement, under which USSK may not draw upon the facility, and the majority lenders, as defined in the USSK Credit Agreement, may cancel any and all commitments, and/or accelerate full repayment of any or all amounts outstanding under the USSK Credit Agreement. On December 23, 2019, USSK entered into a supplemental agreement that amended the USSK Credit Agreement leverage covenant and pledged certain USSK trade receivables and inventory as collateral in support of USSK's obligations. At December 31, 2019 , USSK had availability of €110 million (approximately $124 million ) under the USSK Credit Agreement. At December 31, 2019 , USSK had no borrowings under its €20 million and €10 million credit facilities (collectively approximately $33 million ) and the availability was approximately $31 million due to approximately $2 million of customs and other guarantees outstanding. Each of these facilities bear interest at the applicable inter-bank offer rate plus a margin and contain customary terms and conditions. Export Credit Agreement On December 10, 2019, U. S. Steel entered into an Export Credit Agreement (ECA) with KfW IPEX-Bank GMBH (Facility Agent) and certain other lenders (Lenders). Funding of the ECA is expected to occur during the first quarter of 2020. The purpose of the ECA is to finance equipment purchased for the endless casting and rolling facility under construction at our Mon Valley Works facility in Braddock, Pennsylvania. Loans available under the ECA total approximately $288 million and are made up of a Commercial Facility of approximately $38 million and a Covered Facility of approximately $250 million . The Covered Facility was entered into in conjunction with a guarantee agreement between the Lenders and Oesterreichische Kontrollbank AG (OeKB Guarantor) which provides certain guarantees (OeKB Guarantee) to the Lenders and the project equipment supplier (Supplier). Payment of loans will be due every six months from the earlier of the date on which the relevant goods and services are accepted from the Supplier or April 30, 2023 (Starting Point of Credit). Each loan granted from the Covered Facility must be repaid in full within eight years from the Starting Point of Credit. Each loan granted from the Commercial Facility must be repaid in full within five years from the Starting Point of Credit. If at any time, any portion of the OeKB Guarantee becomes unlawful or invalid, or if at any time the OeKB Guarantor attempts to rescind, suspend, or terminate any portion of the OeKB Guarantee, each Lender’s Covered Facility commitments are reduced to zero and each Covered Facility amount outstanding becomes fully due within 30 days . If at any time performance under the agreement with the Supplier becomes impaired the Facility Agent may request that U. S. Steel prepay outstanding loans within 30 days . If the costs under the agreement with the Supplier against which loans may be drawn are reduced, the Facility Agent may request prepayment in an amount corresponding with the reduction within 30 days . The Company is required to comply with a number of customary covenants and there are customary events of default and remedies for credit facilities of this nature. Change in control event If there is a change in control of U. S. Steel: (a) debt obligations totaling $3,093 million as of December 31, 2019 may be declared due and payable; (b) the Credit Facility Agreement and the USSK credit facilities may be terminated and any amounts outstanding declared due and payable; and (c) U. S. Steel may be required to either repurchase the leased Fairfield Works slab caster for $19 million or provide a letter of credit to secure the remaining obligation. Debt Maturities – Aggregate maturities of debt are as follows (in millions): 2020 2021 2022 2023 2024 Later Total $ 14 $ 12 $ 17 $ 399 $ 664 $ 2,673 $ 3,779

Pensions and Other Benefits

Pensions and Other Benefits	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Pensions and Other Benefits	18. Pensions and Other Benefits U. S. Steel has defined contribution or multi-employer retirement benefits for more than three-quarters of its employees in the United States and non-contributory defined benefit pension plans covering the remaining employees. Benefits under the defined benefit pension plans are based upon years of service and final average pensionable earnings, or a minimum benefit based upon years of service, whichever is greater. In addition, pension benefits for most non-represented employees under these plans are based upon a percent of total career pensionable earnings. Effective December 31, 2015, non-represented participants in the defined benefit plan no longer accrue additional benefits under the plan. For those without defined benefit coverage (defined benefit pension plan was closed to new participants in 2003) and those for which the defined benefit plan was frozen, the Company also provides in the defined contribution plans (401(k) plans) a retirement account benefit based on salary and attained age. Most non-represented employees also participate in the 401(k) plans whereby the Company matches a certain percentage of salary based on the amount contributed by the participant. At December 31, 2019 , more than two-thirds of U. S. Steel’s represented employees in the United States are covered by the Steelworkers Pension Trust (SPT), a multi-employer pension plan, to which U. S. Steel contributes on the basis of a fixed dollar amount for each hour worked. On November 13, 2018, the USW ratified successor four year Collective Bargaining Agreements with U. S. Steel and its U. S. Steel Tubular Products, Inc. subsidiary (the 2018 Labor Agreements). The 2018 Labor Agreements were effective as of September 1, 2018 and expire on September 1, 2022. As a result of the 2018 Labor Agreements, the defined benefit pension liability increased $26 million after considering higher wages on final average pay formulas and higher flat rate minimum multipliers. U. S. Steel’s defined benefit retiree health care and life insurance plans (Other Benefits) cover the majority of its represented employees in the United States upon their retirement. Health care benefits are provided for Medicare and pre-Medicare retirees, with Medicare retirees largely enrolled in Medicare Advantage Plans. Both are subject to various cost sharing features, and in most cases domestically, an employer cap on total costs. The Other Benefits plan was closed to represented employees hired or rehired under certain conditions on or after January 1, 2016. Per an amendment effective June 30, 2014 to the retiree medical and retiree life insurance plan, benefits for non-represented employees who retired after December 31, 2017 were eliminated. The majority of U. S. Steel’s European employees are covered by government-sponsored programs into which U. S. Steel makes required contributions. Also, U. S. Steel sponsors defined benefit plans for most European employees covering benefit payments due to employees upon their retirement, some of which are government mandated. These same employees receive service awards throughout their careers based on stipulated service and, in some cases, age and service. U. S. Steel uses a December 31 measurement date for its plans and may have an interim measurement date if significant events occur. Details relating to pension benefits and Other Benefits are below. Pension Benefits Other Benefits (In millions) 2019 2018 2019 2018 Change in benefit obligations Benefit obligations at January 1 $ 5,626 $ 6,107 $ 2,121 $ 2,379 Service cost 44 49 13 17 Interest cost 237 233 91 92 Plan amendments — 26 — — Actuarial (gains) losses 416 (223 ) (195 ) (185 ) Exchange rate loss 1 (3 ) — — Settlements, curtailments and termination benefits — (18 ) — — Benefits paid (502 ) (545 ) (154 ) (182 ) Benefit obligations at December 31 $ 5,822 $ 5,626 $ 1,876 $ 2,121 Change in plan assets Fair value of plan at January 1 $ 4,960 $ 5,732 $ 1,860 $ 2,042 Actual return on plan assets 948 (228 ) 274 (49 ) Employer contributions — — — — Benefits paid from plan assets (502 ) (544 ) (109 ) (133 ) Fair value of plan assets at December 31 $ 5,406 $ 4,960 $ 2,025 $ 1,860 Funded status of plans at December 31 (416 ) (666 ) 149 (261 ) For Pension Benefits, the largest contributor to the actuarial loss in 2019 was the decrease in discount rate from 4.41% at December 31, 2018 to 3.35% at December 31, 2019. This loss was partially offset by a change in mortality assumptions. In 2018, the largest contributor of actuarial gain was the increase in the discount rate from 4.00% at December 31, 2017 to 4.41% at December 31, 2018. For Other Benefits, the largest contributor to the actuarial gain in 2019 was attributable to reductions in future health care costs and assumptions on future participant enrollment in the plan. The gain was partially offset by a decrease in the discount rate from 4.47% at December 31, 2018 to 3.43% at December 31, 2019. In 2018, the largest contributor of actuarial gain was the increase in discount rate from 4.03% at December 31, 2017 to 4.47% at December 31, 2018. Reductions to future health care costs at December 31, 2018 also contributed to the actuarial gain. Amounts recognized in accumulated other comprehensive loss: 2019 (In millions) 12/31/2018 Amortization Activity 12/31/2019 Pensions Prior Service Cost $ 18 $ (2 ) $ — $ 16 Actuarial Losses 2,442 (134 ) (207 ) 2,101 Other Benefits Prior Service Cost (80 ) (29 ) — (109 ) Actuarial Gains (17 ) (3 ) (391 ) (411 ) As of December 31, 2019 and 2018 , the following amounts were recognized in the Consolidated Balance Sheet: Pension Benefits Other Benefits (In millions) 2019 2018 2019 2018 Noncurrent assets (a) — — 158 — Current liabilities (3 ) (2 ) (1 ) (52 ) Noncurrent liabilities (413 ) (664 ) (8 ) (209 ) Accumulated other comprehensive loss (b) 2,117 2,460 (520 ) (97 ) Net amount recognized $ 1,701 $ 1,794 $ (371 ) $ (358 ) (a) Included in Noncurrent assets are $49 million of expected retiree medical and life insurance payments for the next twelve months. (b) Accumulated other comprehensive loss effects associated with accounting for pensions and other benefits in accordance with ASC Topic 715 at December 31, 2019 and December 31, 2018 , respectively, are reflected net of tax of $800 million and $991 million respectively, on the Consolidated Statements of Stockholders’ Equity. The Accumulated Benefit Obligation (ABO) for all defined benefit pension plans was $5,636 million and $5,454 million at December 31, 2019 and 2018 , respectively. December 31, (In millions) 2019 2018 Information for pension plans with an accumulated benefit obligation in excess of plan assets: Aggregate accumulated benefit obligations (ABO) $ (5,636 ) $ (5,454 ) Aggregate projected benefit obligations (PBO) (5,822 ) (5,626 ) Aggregate fair value of plan assets 5,406 4,960 The aggregate PBO in excess of plan assets reflected above is included in the payroll and benefits payable and employee benefits lines on the Consolidated Balance Sheet. Following are the details of net periodic benefit costs related to Pension and Other Benefits: Pension Benefits Other Benefits (In millions) 2019 2018 2017 2019 2018 2017 Components of net periodic benefit cost: Service cost $ 44 $ 49 $ 50 $ 13 $ 17 $ 17 Interest cost 237 233 235 91 92 94 Expected return on plan assets (324 ) (361 ) (390 ) (79 ) (82 ) (65 ) Amortization - prior service costs 2 — — 29 29 29 - actuarial losses 132 152 148 3 4 3 Net periodic benefit cost, excluding below 91 73 43 57 60 78 Multiemployer plans (a) 77 60 59 — — — Settlement, termination and curtailment losses 11 10 7 — — — Net periodic benefit cost $ 179 $ 143 $ 109 $ 57 $ 60 $ 78 (a) Primarily represents pension expense for the SPT covering USW employees hired from National Steel Corporation and new USW employees hired after May 21, 2003. Net periodic benefit cost for pensions and Other Benefits is projected to be approximately $141 million and approximately $(29) million , respectively, in 2020 . The pension cost projection includes approximately $79 million of contributions to the SPT. Weighted average assumptions used to determine the benefit obligation at December 31 and net periodic benefit cost for the year ended December 31 are detailed below. Pension Benefits Other Benefits 2019 2018 2019 2018 U.S. and Europe U.S. and Europe U.S. U.S. Actuarial assumptions used to determine benefit obligations at December 31: Discount rate 3.35 % 4.41 % 3.43 % 4.47 % Increase in compensation rate 2.60 % 2.60 % N/A N/A Pension Benefits 2019 2018 2017 U.S. and Europe U.S. and Europe U.S. and Europe Actuarial assumptions used to determine net periodic benefit cost for the year ended December 31: Discount rate 4.41 % 4.00 % 4.00 % Expected annual return on plan assets 6.50 % 6.85 % 7.25 % Increase in compensation rate 2.60 % 2.60 % 2.60 % Other Benefits 2019 2018 2017 U.S. U.S. U.S. Discount rate 4.47 % 4.03 % 4.00 % Expected annual return on plan assets 4.25 % 4.25 % 3.25 % Increase in compensation rate N/A N/A 3.50 % The discount rate reflects the current rate at which the pension and Other Benefit liabilities could be effectively settled at the measurement date. In 2017, we refined our discount rate determination process for our U.S. plans by using a bond matching approach to select specific bonds that would satisfy our projected benefit payments. We believe the bond matching approach more closely reflects the process we would employ to settle our pension and other benefits obligations. For our European pension plan, the discount rate is determined using a yield curve methodology based on European bonds. The discount rate assumptions are updated annually. 2019 2018 Assumed health care cost trend rates at December 31: U.S. U.S. Health care cost trend rate assumed for next year 6.50% 7.00% Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 4.50% 5.00% Year that the rate reaches the ultimate trend rate 2028 2023 U. S. Steel reviews its actual historical rate experience and expectations of future health care cost trends to determine the escalation of per capita health care costs under U. S. Steel’s benefit plans. About three quarters of our costs for the domestic USW participants’ retiree health benefits in the Company’s main domestic benefit plan are limited to a per capita dollar maximum calculation based on 2006 base year actual costs incurred under the main U. S. Steel benefit plan for USW participants (cost cap). The full effect of the cost cap is expected to be realized around 2028. After 2028, the Company’s costs for a majority of USW retirees and their dependents are expected to remain fixed and as a result, the cost impact of health care escalation for the Company is projected to be limited for this group. Plan Assets ASC Topic 820 establishes a single definition of fair value, creates a three-tier hierarchy as a framework for measuring fair value based on inputs used to value the Plan's investments, and requires additional disclosure about fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (level 1) and the lowest priority to unobservable inputs (level 3). The three levels of the fair value hierarchy are summarized below: • Level 1 – Inputs to the valuation methodology are unadjusted quoted prices for identical assets or liabilities in active markets that the Plan has the ability to access. • Level 2 – Inputs to the valuation methodology include: ◦ Quoted prices for similar assets or liabilities in active markets; ◦ Quoted prices for identical or similar assets or liabilities in inactive markets; ◦ Inputs other than quoted prices that are observable for the asset or liability; ◦ Inputs that are derived principally from or corroborated by observable market data by correlation or other means If the asset or liability has a specified (contractual) term, the level 2 input must be observable for substantially the full term of the asset or liability. • Level 3 – Inputs to the valuation methodology are unobservable and significant to the fair value measurement. U. S. Steel’s Pension plan and Other Benefits plan assets are classified as follows: Level 1 Level 2 Level 3 Short-term Investments Corporate Bonds - U.S. & Non U.S. Private Equities Equity Securities - U.S. & Non U.S. Government Bonds - U.S. & Non U.S. Real Estate Exchange-traded Funds Mortgage and asset-backed securities Mineral Interests Investment Trusts Timberlands An instrument’s level is based on the lowest level of any input that is significant to the fair value measurement. Valuation techniques maximize the use of relevant observable inputs and minimize the use of unobservable inputs. The following is a description of the valuation methodologies used for assets measured at fair value. There have been no changes in the methodologies used at December 31, 2019 and 2018 . Short-term investments are valued at amortized cost which approximates fair value due to the short-term maturity of the instruments. Equity securities - U.S. & Non U.S., investments in investment trusts and exchange-traded funds are valued at the closing price reported on the active exchange on which the individual securities are traded. U.S. & Non U.S. government bonds are valued using pricing models maximizing the use of observable inputs for similar securities. Corporate U.S. & Non U.S. bonds are also valued using pricing models maximizing the use of observable inputs for similar securities, which includes basing value on yields currently available on comparable securities of issuers with similar credit ratings. When quoted prices are not available for identical or similar bonds, the bond is valued under a discounted cash flow approach that maximizes observable inputs, such as current yields of similar instruments, but includes adjustments for certain risks that may not be observable, such as credit and liquidity risks. Mortgage and asset-backed securities are valued using quotes from a broker dealer. Private equities and real estate are valued using information provided by external managers for each individual investment held in the fund or using NAV as a practical expedient. Timberland investments are valued at their appraised value. Mineral Interests are valued at the present value of estimated future cash flows discounted at estimated market rates for assets of similar quality and duration. The following is a summary of U. S. Steel’s Pension plan assets carried at fair value at December 31, 2019 and 2018 : Fair Value Measurements at December 31, 2019 (in millions) Total Quoted Prices in Other Significant Observable Inputs Significant Asset Classes Equity Securities (a) 130 130 — — Corporate & Government Bonds (b) 2,277 — 2,277 — Mineral Interests 2 — — 2 Timberlands 283 — — 283 Real Estate (c) 32 — — 32 All Other (d) 34 34 — — Total assets in the fair value hierarchy $ 2,758 $ 164 $ 2,277 $ 317 Investments measured at net asset value (e) 2,648 Investments at fair value $ 5,406 (a) Includes $123 million of U.S. equity securities and $7 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 1,004 Corporate Bonds - Non U.S. 160 Government Bonds – U.S. 771 Government Bonds - Non U.S. 77 Mortgage and asset-backed securities 265 Total $ 2,277 (c) Includes investments in the Avanti Funds and the Mariano Ranch properties. (d) Includes $26 million of cash, $19 million of accrued income, $(8) million of investment purchases and $(3) million of miscellaneous payables. (e) In accordance with ASC Topic 820, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2019 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 238 $ 48 Not redeemable N/A Real Estate Funds (a) 240 62 Not redeemable N/A Commingled Funds 2,170 N/A N/A N/A Investments measured at net asset value $ 2,648 (a) The remaining lives of such investments range from approximately less than 1 year to up to 9 years. Fair Value Measurements at December 31, 2018 (in millions) Total Quoted Prices in Other Significant Observable Inputs (Level 2) Significant Asset Classes Short-term investments $ 7 $ 7 $ — $ — Equity Securities (a) 101 101 — — Corporate & Government Bonds (b) 2,143 — 2,143 — Mineral Interests 2 — — 2 Timberlands 294 — — 294 Private equities (c) 2 — — 2 Real Estate (d) 33 — — 33 All Other (e) 14 14 — — Total assets in the fair value hierarchy $ 2,596 $ 122 2,143 $ 331 Investments measured at net asset value (f) 2,364 Investments at fair value $ 4,960 (a) Includes $95 million of U.S. equity securities and $6 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 933 Corporate Bonds – Non U.S. 149 Government Bonds – U.S. 858 Government Bonds – Non U.S. 67 Mortgage and asset-backed securities 136 Total $ 2,143 (c) Includes investments in CAI Partners and Company III LP, Clayton Dubilier Rice Fund VI and Epiris Club 2007. (d) Includes investments in the Avanti Funds and the Mariano Ranch properties. (e) Includes $32 million of cash, $57 million of investment sales, $21 million of accrued income, and $(80) million of investment purchases and $(16) million of miscellaneous payables. (f) In accordance with ASC Topic 820, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2018 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 254 $ 68 Not redeemable N/A Real Estate Funds (a) 236 93 Not redeemable N/A Commingled Funds 1,874 N/A N/A N/A Investments measured at net asset value $ 2,364 (a) The remaining lives of such investments range from approximately less than 1 year to up to 10 years. The following table sets forth a summary of changes in the fair value of U. S. Steel’s Pension plan Level 3 assets for the years ended December 31, 2019 and 2018 : (In millions) 2019 2018 Balance at beginning of period $ 331 $ 340 Transfers in and/or out of Level 3 — — Actual return on plan assets: Realized gain 8 11 Net unrealized loss (21 ) (8 ) Purchases, sales, issuances and settlements: Purchases 1 — Sales (2 ) (12 ) Balance at end of period $ 317 $ 331 The following is a summary of U. S. Steel’s Other Benefits plan assets carried at fair value at December 31, 2019 and 2018 . Fair Value Measurements at December 31, 2019 (in millions) Total Quoted Prices in Other Significant Observable Inputs (Level 2) Significant Asset Classes Short-term investments $ 31 $ 31 — $ — Equity Securities (a) 49 49 — — Corporate & Government Bonds (b) 1,799 — 1,799 — Timberlands 35 — — 35 All Other (c) 25 25 — — Total assets in the fair value hierarchy $ 1,939 $ 105 $ 1,799 $ 35 Investments measured at net asset value (d) 86 Investments at fair value $ 2,025 (a) Includes $30 million of U.S. equity securities and $19 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 1,132 Corporate Bonds - Non U.S. 287 Government Bonds – U.S. 329 Government Bonds - Non U.S. 13 Mortgage and asset-backed Securities 38 Total $ 1,799 (c) Includes $12 million of cash, $16 million of accrued income, $2 million of investments sales and $(5) million of miscellaneous payables. (d) In accordance with Subtopic 820-10, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2019 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 54 $ 8 Not redeemable NA Real Estate Funds (a) 32 10 Not redeemable NA Investments measured at net asset value $ 86 (a) The remaining lives of such investments range from approximately less than 1 year up to 9 years. Fair Value Measurements at December 31, 2018 (in millions) Total Quoted Prices in Other Significant Observable Inputs (Level 2) Significant Asset Classes Short-term investments 42 42 — — Equity Securities (a) 45 45 — — Corporate & Government Bonds (b) 1,631 — 1,631 — Timberlands 35 — — 35 All Other (c) 13 13 — — Total assets in the fair value hierarchy $ 1,766 $ 100 1,631 $ 35 Investments measured at net asset value (d) 94 Investments at fair value $ 1,860 (a) Includes $27 million of U.S. equity securities and $18 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 1,052 Corporate Bonds - Non U.S. 271 Government Bonds – U.S. 270 Government Bonds - Non U.S. 8 Mortgage and asset-backed Securities 30 Total $ 1,631 (c) Includes $16 million of accrued income and $(3) million of investment purchase payables. (d) In accordance with Subtopic 820-10, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2018 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 61 $ 10 Not redeemable N/A Real Estate Funds (a) 33 12 Not redeemable N/A Investments measured at net asset value $ 94 (a) The remaining lives of such investments range from approximately less than 1 year to up to 10 years. The following table sets forth a summary of changes in the fair value of U. S. Steel’s Other Benefits plan Level 3 assets for the years ended December 31, 2019 and 2018 : (In millions) 2019 2018 Balance at beginning of period $ 35 $ 35 Transfers in and/or out of Level 3 — — Actual return on plan assets: Realized gain — 1 Net unrealized loss — (1 ) Purchases, sales, issuances and settlements: Sales — — Balance at end of period $ 35 $ 35 U. S. Steel’s investment strategy for its U.S. pension and Other Benefits plan assets provides for a diversified mix of high quality bonds, public equities and selected smaller investments in private equities, timber and mineral interests. For its U.S. pension, U. S. Steel has a target allocation for plan assets of 45 percent in corporate bonds, government bonds and mortgage and asset-backed securities. The balance is invested in equity securities, timber, private equity and real estate partnerships. U. S. Steel believes that returns on equities over the long term will be higher than returns from fixed-income securities as actual historical returns from U. S. Steel’s trusts have shown. Returns on bonds tend to offset some of the short-term volatility of stocks. Both equity and fixed-income investments are made across a broad range of industries and companies (both domestic and foreign) to provide protection against the impact of volatility in any single industry as well as company specific developments. U. S. Steel will use a 6.50 percent assumed rate of return on assets for the development of net periodic cost for the main defined benefit pension plan in 2020 . The 2020 assumed rate of return is consistent with the rate of return used for 2019 domestic expense and was determined by taking into account the intended asset mix and some moderation of the historical premiums that fixed-income and equity investments have yielded above government bonds. Actual returns since the inception of the plan have exceeded this 6.50 percent rate and while recent annual returns have been volatile, it is U. S. Steel’s expectation that rates will achieve this level in future periods. For its Other Benefits plan, U. S. Steel is employing a liability driven investment strategy. The plan assets are allocated to match the plan cash flows with maturing investments. To achieve this strategy, U. S. Steel has a target allocation for plan assets of 90 percent in high quality bonds with the balance primarily invested in equity securities, timber, private equity and real estate partnerships. U. S. Steel will use a 4.25 percent assumed rate of return on assets for the development of net periodic cost for its Other Benefits plan for 2020. The 2020 assumed rate of return is consistent with the rate of return used for 2019 and has been conservatively set, taking into account the intended asset mix. Steelworkers Pension Trust For most bargaining unit employees participating in the SPT, U. S. Steel contributes to the SPT a fixed dollar amount for each hour worked of $3.15 through December 31, 2019 . SPT contributions per hour worked increase to $3.35 and $3.50 effective January 1, 2020 and January 1, 2021, respectively. U. S. Steel’s contributions to the SPT represented greater than 5% of the total combined contributions of all employers participating in the plan for the years ended December 31, 2019 , 2018 and 2017 . Participation in a multi-employer pension plan agreed to under the terms of a collective bargaining agreement differ from a traditional qualified single employer defined benefit pension plan. The SPT shares risks associated with the plan in the following respects: a. Contributions to the SPT by U. S. Steel may be used to provide benefits to employees of other participating employers; b. If a participating employer stops contributing to the SPT, the unfunded obligations of the plan may be borne by the remaining participating employers; c. If U. S. Steel chooses to stop participating in the SPT, U. S. Steel may be required to pay an amount based on the underfunded status of the plan, referred to as a withdrawal liability. On March 21, 2011 the Board of Trustees of the SPT elected funding relief which has the effect of decreasing the amount of required minimum contributions in near-term years, but will increase the minimum funding requirements during later plan years. As a result of the election of funding relief, the SPT’s zone funding under the Pension Protection Act may be impacted. In addition to the funding relief election, the Board of Trustees also elected a special amortization rule, which allows the SPT to separately amortize investment losses incurred during the SPT’s December 31, 2008 plan year-end over a 29 year period, whereas they were previously required to be amortized over a 15 year period. U. S. Steel’s participation in the SPT for the annual periods ended December 31, 2019 , 2018 and 2017 is outlined in the table below. Employer Pension Protection Act Zone (a) FIP/RP Status (b) U.S. Steel Surcharge (c) Expiration Date Pension Fund 2019 2018 2019 2018 2017 2019 2018 Steelworkers Pension Trust 23-6648508/499 Green Green No $ 77 $ 60 $ 59 No No September 1, 2022 (a) The zone status is based on information that U. S. Steel received from the plan and is certified by the plan’s actuary. Among other factors, plans in the green zone are at least 80 percent funded, while plans in the yellow zone are less than 80 percent funded and plans in the red zone are less than 65 percent funded. (b) Indicates if a financial improvement plan (FIP) or a rehabilitation plan (RP) is either pending or has been implemented. (c) Indicates whether there were charges to U. S. Steel from the plan. Cash Flows The following information is in addition to the contributions to the SPT noted in the table above. Employer Contributions – U. S. Steel did not make any voluntary or mandatory contributions to the U. S. Steel Retirement Plan Trust in 2019 or 2018. The U. S. Steel Retirement Plan Trust is the funding vehicle for the Company's main defined benefit pension plan. U. S. Steel did make a voluntary contribution of $75 million to the main pension plan on November 20, 2017. For pension plans not funded by trusts, U. S. Steel made $8 million , $20 million and $13 million of pension payments not funded by trusts in 2019 , 2018 and 2017 , respectively. Cash payments totaling $45 million , $48 million and $59 million were made for other post-employment benefit payments not funded by trusts in 2019 , 2018 and 2017 , respectively. In 2019, 2018 and 2017, U. S. Steel continued to use assets from our VEBA trust for represented retiree health care and life insurance benefits to pay USW post-employment benefit claims. Estimated Future Benefit Payments – The following benefit payments, which reflect expected future service as appropriate, are expected to be paid from U. S. Steel’s defined benefit plans: (In millions) Pension Other 2020 $ 483 $ 153 2021 465 152 2022 442 151 2023 418 149 2024 406 146 Years 2025 - 2028 1,850 680 Defined contribution plans U. S. Steel also contributes to several defined contribution plans for its salaried employees. Effective December 31, 2015, all non-represented salaried employees in North America receive pension benefits in the form of a separate retirement account through a defined contribution plan with contribution percentages based upon age, for which company contributions totaled $23 million , $23 million and $22 million in 2019 , 2018 and 2017 , respectively. U. S. Steel’s matching contributions to salaried employees’ defined contribution plans, which are 100 percent of the employees’ contributions up to six percent of their eligible salary, totaled $18 million in 2019 and $17 million in 2018 and 2017 . U. S. Steel also maintains non-qualified defined contribution plans to provide benefits which are otherwise limited by the Internal Revenue Code for qualified plans. U. S. Steel’s contributions under these defined contribution plans totaled $1 million , $4 million , and $1 million in 2019 , 2018 and 2017 , respectively. Most represented employees are eligible to participate in a defined contribution plan where there is no company match on savings except for certain Tubular hourly employees. Effective with the 2015 Labor Agreement, represented hires on or after January 1, 2016 are eligible for a $0.50 per hour savings account contribution. As a result of the 2018 Labor Agreements, the savings account contribution for each hour worked will increase to $0.55 effective January 1, 2019, $0.60 effective January 1, 2020, and $0.65 effective January 1, 2021. These Company contributions for represented employees totaled $ 3 million , $2 million and $1 million in 2019 , 2018 and 2017 , respectively. Other post-employment benefits The Company provides benefits to former or inactive employees after employment but before retirement. Certain benefits including workers’ compensation and black lung benefits represent material obligations to the Company and under the guidance for nonretirement post-employment benefits, have historically been treated as accrued benefit obligations. Liabilities for these benefits recorded at December 31, 2019 , totaled $111 million as compared to $110 million at December 31, 2018 . Liability amounts were developed assuming a discount rate of 3.40% and 4.36% at December 31, 2019 and 2018 . Net periodic benefit cost for these benefits is projected to be $15 million in 2020 compared to $21 million in 2019 and $10 million in 2018 . Pension Funding In November 2015, pension stabilization legislation further extended a revised interest rate formula to be used to measure defined benefit pension obligations for calculating minimum annual contributions. The new interest rate formula results in higher interest rates for minimum funding calculations as compared to prior law over the next few years, which will improve the funded status of our main defined benefit pension plan and reduce minimum required contributions.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2019
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	19. Asset Retirement Obligations U. S. Steel’s asset retirement obligations (AROs) primarily relate to mine, landfill closure and post-closure costs. The following table reflects changes in the carrying values of AROs for the years ended December 31, 2019 and 2018 : December 31, (In millions) 2019 2018 Balance at beginning of year $ 60 $ 69 Additional obligations incurred 4 — Obligations settled (9 ) (12 ) Accretion expense 3 3 Balance at end of period $ 58 $ 60 Certain AROs related to disposal costs of the majority of fixed assets at our integrated steel facilities have not been recorded because they have an indeterminate settlement date. These AROs will be initially recognized in the period in which sufficient information exists to estimate their fair value.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	20. Fair Value of Financial Instruments The carrying value of cash and cash equivalents, current accounts and notes receivable, accounts payable, bank checks outstanding, and accrued interest included in the Consolidated Balance Sheet approximate fair value. See Note 16 for disclosure of U. S. Steel’s derivative instruments, which are accounted for at fair value on a recurring basis. On October 31, 2019, a wholly owned subsidiary of U. S. Steel purchased a 49.9% ownership interest in Big River Steel. The transaction included a call option (U. S. Steel Call Option) to acquire the remaining 50.1% within the next four years at an agreed-upon price formula, which in years three and four is based on Big River Steel’s achievement of certain metrics that include: free cash flow, product development, safety and the completion of a proposed expansion of Big River Steel's existing manufacturing line. The transaction also included options where the other Big River Steel equity owners can require U. S. Steel to purchase their 50.1% ownership interest (Class B Common Put Option) or require U. S. Steel to sell its ownership interest (Class B Common Call Option) after the U. S. Steel Call Option expires. All of the options are marked to fair value each period using a Monte Carlo simulation which is considered a Level 3 valuation technique. Level 3 valuation techniques include inputs to the valuation methodology that are considered unobservable and significant to the fair value measurement. The simulation relies on assumptions that include Big River Steel's future equity value, volatility, the risk free interest rate and U. S. Steel's credit spread. The net change in fair value of the options during 2019 resulted in a $7 million increase to net interest and other financial costs. See Note 5 and Note 7 for further details. The following table shows the change in fair value by option from purchase date through December 31, 2019 . (In millions) Balance Sheet Location Fair Value asset/(liability) (a) Fair Value Fair Value asset/(liability) U. S. Steel Call Option Investments and Long-Term Receivables $ 162 $ 4 $ 166 Class B Common Deferred credits and other noncurrent liabilities $ (181 ) $ (11 ) $ (192 ) Class B Common Deferred credits and other noncurrent liabilities $ (2 ) $ — $ (2 ) Net Mark to Market Impact $ (7 ) (a) On October 31, 2019, a wholly owned subsidiary of U. S. Steel purchased a 49.9% ownership interest in Big River Steel The following table shows the net fair values of the options at December 31, 2019 and the effect on these amounts of a hypothetical change in the market prices or rates that existed as of December 31, 2019 . Fair Value asset/(liability) Big River Steel Equity Value Volatility Risk Free Interest Rate U. S. Steel's Credit Spread (In millions) 5% (5)% 10% (10)% 1% (1)% 1% (1)% U. S. Steel Call Option $166 $19 $(17) $34 $(34) $3 $(3) N/A N/A Class B Common Put Option $(192) $15 $(16) $(25) $25 $13 $(14) $7 $(8) Class B Common Call Option $(2) $— $— $— $— $— $— N/A N/A The following tables shows the assumptions used in the calculations shown in the table directly above. At December 31, 2019 Big River Steel Equity Value (in approximate billions) $ 1.4 Volatility 54.1 % Risk Free Interest Rate 1.6 % Credit Spread 7.9 % The following table summarizes U. S. Steel’s financial assets and liabilities that were not carried at fair value at December 31, 2019 and 2018 . December 31, 2019 December 31, 2018 (In millions) Fair Value Carrying Fair Value Carrying Financial liabilities: Long-term debt (a) $ 3,576 $ 3,575 $ 2,182 $ 2,353 (a) Excludes finance lease obligations. The fair value of long-term debt was determined using Level 2 inputs which were derived from quoted market prices and is based on the yield on public debt where available or current borrowing rates available for financings with similar terms and maturities. Fair value of the financial assets and liabilities disclosed herein is not necessarily representative of the amount that could be realized or settled, nor does the fair value amount consider the tax consequences of realization or settlement. Financial guarantees are U. S. Steel’s only unrecognized financial instrument. For details relating to financial guarantees see Note 26.

Reclassifications from Accumula

Reclassifications from Accumulated Other Comprehensive Income (AOCI)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Reclassifications from Accumulated Other Comprehensive Income (AOCI)	21. Reclassifications from Accumulated Other Comprehensive Income (AOCI) (In millions) Pension and Other Benefit Items Foreign Currency Items Unrealized Gain (Loss) on Derivatives Total Balance at December 31, 2017 $ (1,309 ) $ 463 $ 1 $ (845 ) Other comprehensive loss before reclassifications (b) (255 ) (60 ) — (315 ) Amounts reclassified from AOCI (a)(b) 148 — (14 ) 134 Net current-period other comprehensive loss (107 ) (60 ) (14 ) (181 ) Balance at December 31, 2018 $ (1,416 ) $ 403 $ (13 ) $ (1,026 ) Other comprehensive income (loss) before reclassifications 446 (22 ) (19 ) 405 Amounts reclassified from AOCI (a) 127 — 16 143 Net current-period other comprehensive income (loss) 573 (22 ) (3 ) 548 Balance at December 31, 2019 $ (843 ) $ 381 $ (16 ) $ (478 ) (a) See table below for further details. (b) The Company previously disclosed in Note 21 to the Consolidated Financial Statements in its Annual Report on Form 10-K for the period ended December 31, 2018, an increase to AOCI of $41 million in the Other comprehensive income before reclassifications line item and a decrease to AOCI of $148 million in the Amounts reclassified from AOCI line item for the twelve months ended December 31, 2018 amounts for Pension and Other Benefit Items. These amounts should have been disclosed as a decrease to AOCI of $255 million and an increase to AOCI of $148 million , respectively, which have been corrected in the table above. The Company concluded that the errors were not material to the financial statements of any prior annual or interim period and therefore, amendments of previously filed reports are not required. The revision had no impact on the Consolidated Balance Sheets, Consolidated Statements of Operations, Consolidated Statements of Cash Flows or the Consolidated Statements of Comprehensive Income (Loss). Quarterly periods not presented herein will be revised, as applicable, in future filings. Amount reclassified from AOCI (c) (In millions) (a) Details about AOCI components 2019 2018 2017 Amortization of pension and other benefit items Prior service costs (a) $ 31 $ 29 $ 29 Actuarial losses (a) 135 156 151 Settlements, termination and curtailment losses (a) 3 10 7 Total pensions and other benefits items 169 195 187 Derivative reclassifications to Consolidated Statements of Operations 22 (19 ) (4 ) Total before tax 191 176 183 Tax provision (b) (48 ) (42 ) — Net of tax $ 143 $ 134 $ 183 (a) These AOCI components are included in the computation of net periodic benefit cost (see Note 18 for additional details). (b) Amounts in 2017 do not reflect a tax benefit as a result of a full valuation allowance on our domestic deferred tax assets. (c) The corrections noted in footnote (b) to the table above are consistently reflected in this table.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	22. Supplemental Cash Flow Information Year Ended December 31, (In millions) 2019 2018 2017 Net cash (used in) provided by operating activities included: Interest and other financial costs paid (net of amount capitalized) $ (151 ) $ (207 ) $ (242 ) Income taxes refunded (paid) $ 38 $ (39 ) $ (40 ) Non-cash investing and financing activities: Change in accrued capital expenditures $ (70 ) $ 135 $ 208 U. S. Steel common stock issued for employee/non-employee director stock plans $ 19 $ 21 $ 49 Capital expenditures funded by finance lease borrowings $ 46 $ — $ — Big River Steel put and call options (a) $ 21 $ — $ — (a) The Big River Steel put and call options amount represents the excess of the Class B Common Put Option and the Class B Common Call Option liabilities over the U. S. Steel Call Option asset from U. S. Steel's acquisition of its 49.9% ownership interest in Big River Steel on October 31, 2019. See Note 20 for further details.

Transactions with Related Parti

Transactions with Related Parties	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Transactions with Related Parties	23. Transactions with Related Parties Net sales to related parties and receivables from related parties primarily reflect sales of raw materials and steel products to equity investees. Generally, transactions are conducted under long-term contractual arrangements. Related party sales and service transactions were $1,431 million , $1,420 million and $1,204 million in 2019 , 2018 and 2017 , respectively. As of December 31, 2019, the related party receivable included a short-term note receivable of $10 million to PRO-TEC. Payment on the note receivable is anticipated in the first quarter of 2020. Purchases from related parties for outside processing services provided by equity investees amounted to $31 million , $29 million and $70 million during 2019 , 2018 and 2017 , respectively. Purchases of iron ore pellets from related parties amounted to $104 million , $91 million and $140 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. Accounts payable to related parties include balances due to PRO-TEC Coating Company (PRO-TEC) of $82 million and $80 million at December 31, 2019 and 2018 , respectively for invoicing and receivables collection services provided by U. S. Steel on PRO-TEC's behalf. U. S. Steel, as PRO-TEC’s exclusive sales agent, is responsible for credit risk related to those receivables. U. S. Steel also provides PRO-TEC marketing, selling and customer service functions. Payables to other related parties totaled $2 million and $1 million at December 31, 2019 and 2018 , respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases Effective January 1, 2019, U. S. Steel adopted ASU 2016-02 using the optional modified retrospective transition method outlined in ASU 2018-11 which permitted application of ASU 2016-02 on January 1, 2019 using a cumulative effect adjustment to the opening balance of retained earnings. As of December 31, 2019 , an operating lease asset of $230 million and current and noncurrent liabilities for operating leases of $60 million and $177 million , respectively, were recorded (see below tabular disclosure for further details). There was an insignificant cumulative effect of adoption for operating lease liabilities that exceeded their related asset values for leases where payment started after lease commencement. Operating lease assets consist primarily of office space, heavy mobile equipment used in our mining operations and facilities and equipment under operating service agreements for electricity generation and scrap processing. We also have operating lease assets for light mobile equipment and information technology assets. Significant finance leases include the Fairfield slab caster lease and heavy mobile equipment used in our mining operations (see Note 17 for further details). Variable lease payments are primarily related to operating service agreements where payment is solely dependent on consumption of certain services, such as raw material and by-product processing. Most long-term leases include renewal options and, in certain leases, purchase options. Generally, we are not reasonably certain that these options will be exercised. We have residual value guarantees under certain light mobile equipment leases. There is no impact to our leased assets for residual value guarantees as the potential loss is not probable (see “Other Contingencies” in Note 26 for further details). We do not have material restrictive covenants associated with our leases or material amounts of sublease income. From time to time, U. S. Steel may enter into arrangements for the construction or purchase of an asset and then enter into a financing arrangement to lease the asset. U. S. Steel recognizes leased assets and liabilities under these arrangements when it obtains control of the asset. U. S. Steel elected the option within ASU 2016-02 to straight-line expense and not record assets or liabilities for leases with an initial term of 12 months or less. For leases beginning in 2019 and later, we separate non-lease components from lease components for leases under operating service agreements. We do not separate non-lease components for other lease types as they are not significant. The Company does not have secured notes outstanding; therefore, we use an estimated secured borrowing rate as the discount rate for most of our leases. In accordance with the practical expedients outlined in ASU 2016-02, we did not use hindsight in determining the lease term for existing leases and elected not to reassess the following for existing leases: whether contracts contain a lease, lease classification, and initial direct costs. The following table summarizes the lease amounts included in our Consolidated Balance Sheet as of December 31, 2019 . (In millions) Balance Sheet Location December 31, 2019 Assets Operating Operating lease assets (a) (c) $ 230 Finance Property, plant and equipment (b) 56 Total Lease Assets $ 286 Liabilities Current Operating Current operating lease liabilities (c) $ 60 Finance Current portion of long-term debt 11 Non-Current Operating Noncurrent operating lease liabilities (c) 177 Finance Long-term debt less unamortized discount and issue costs 51 Total Lease Liabilities $ 299 (a) Operating lease assets are recorded net of accumulated amortization of $50 million . (b) Finance lease assets are recorded net of accumulated depreciation of $27 million . (c) Operating lease assets and noncurrent operating lease liabilities were reduced by $7 million for an amendment to a building lease and $4 million for retirements. The impact on the current operating lease liabilities was immaterial. The following table summarizes lease costs included in our Consolidated Statement of Operations for the twelve month periods ended December 31, 2019 . (In millions) Classification Year Ended December 31, 2019 Operating Lease Cost (a) Cost of sales $ 81 Operating Lease Cost Selling, general and administrative expenses 11 Finance Lease Cost Amortization Depreciation, depletion and amortization 7 Interest Interest expense 3 Total Lease Cost $ 102 (a) Operating lease cost recorded in cost of sales includes $15 million of variable lease cost for the year ended December 31, 2019 . An immaterial amount of variable lease cost is included in selling, general and administrative expenses and immaterial amounts of short-term lease cost are included in cost of sales and selling, general and administrative expenses. Lease liability maturities as of December 31, 2019 are shown below (In millions) Operating Finance Total 2020 $ 74 $ 15 $ 89 2021 58 14 72 2022 46 18 64 2023 34 7 41 2024 26 6 32 After 2024 51 12 63 Total Lease Payments $ 289 $ 72 $ 361 Less: Interest 52 10 62 Present value of lease liabilities $ 237 $ 62 $ 299 Future minimum commitments for capital and operating leases having non-cancelable lease terms in excess of one year as of the year ended December 31, 2018 were as follows. (In millions) Capital Operating 2019 $ 5 $ 66 2020 5 55 2021 5 45 2022 11 37 2023 — 28 After 2023 — 72 Total minimum lease payments $ 26 $ 303 Less imputed interest costs 4 Present value of net minimum lease payments included in long-term debt $ 22 Lease terms and discount rates are shown below. December 31, 2019 Weighted average lease term Finance 5 years Operating 5 years Weighted average discount rate Finance 6.05 % Operating 7.76 % Supplemental cash flow information related to leases follows. (In millions) Year Ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 72 Operating cash flows from finance leases 3 Financing cash flows from finance leases 7 Right-of-use assets exchanged for lease liabilities: Operating leases 53 Finance leases 46

Restructuring and Other Charges

Restructuring and Other Charges	12 Months Ended
	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring and Other Charges	25. Restructuring and Other Charges During 2019, U. S. Steel recorded restructuring and other charges of $275 million , which consists of charges of $25 million at USSK for headcount reductions and plant exit costs, $227 million for the indefinite idling of our East Chicago Tin operations, our finishing facility in Dearborn, Michigan, and the intended indefinite idling of a significant portion of Great Lakes Works and $23 million for Company-wide headcount reductions. Cash payments were made related to severance and exit costs of $35 million . During 2018, restructuring and other charges recorded were immaterial. Cash payments were made related to severance and exit costs of $21 million . During 2017, U. S. Steel recorded net restructuring and other charges of approximately $31 million , which consists of charges of $37 million primarily related to the permanent shutdown and relocation of the No. 6 Quench & Temper Mill at Lorain Tubular Operations and a favorable adjustment of $6 million primarily associated with a change in estimate for previously recorded costs for environmental obligations and Company-wide headcount reductions. Cash payments were made related to severance and exit costs of $32 million . Charges for restructuring and ongoing cost reduction initiatives are recorded in the period U. S. Steel commits to a restructuring or cost reduction plan, or executes specific actions contemplated by the plan and all criteria for liability recognition have been met. Charges related to the restructuring and cost reductions are reported in restructuring and other charges in the Consolidated Statements of Operations. The activity in the accrued balances incurred in relation to restructuring and other cost reduction programs during the years ended December 31, 2019 and December 31, 2018 were as follows: (in millions) Employee Related Costs Exit Costs Non-cash Charges (a) Total Balance at December 31, 2017 $ 4 $ 34 $ — $ 38 Cash payments/utilization (4 ) (17 ) — (21 ) Balance at December 31, 2018 $ — $ 17 $ — $ 17 Additional charges 111 119 45 275 Cash payments/utilization (24 ) (11 ) (45 ) (80 ) Balance at December 31, 2019 $ 87 $ 125 $ — $ 212 (a) Non-cash charges primarily relate to accelerated depreciation associated with the intended indefinite idling of our ECT operations and Dearborn, Michigan, finishing facility. Accrued liabilities for restructuring and other cost reduction programs are included in the following balance sheet lines: (in millions) December 31, 2019 December 31, 2018 Accounts payable $ 46 $ 11 Payroll and benefits payable 64 — Employee benefits 23 — Deferred credits and other noncurrent liabilities 79 6 Total $ 212 $ 17

Contingencies and Commitments

Contingencies and Commitments	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Commitments	26. Contingencies and Commitments U. S. Steel is the subject of, or party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. Certain of these matters are discussed below. The ultimate resolution of these contingencies could, individually or in the aggregate, be material to the Consolidated Financial Statements. However, management believes that U. S. Steel will remain a viable and competitive enterprise even though it is possible that these contingencies could be resolved unfavorably. U. S. Steel accrues for estimated costs related to existing lawsuits, claims and proceedings when it is probable that it will incur these costs in the future and the costs are reasonably estimable. Asbestos matters – As of December 31, 2019 , U. S. Steel was a defendant in approximately 800 active cases involving approximately 2,390 plaintiffs. The vast majority of these cases involve multiple defendants. About 1,540 , or approximately 65 percent , of these plaintiff claims are currently pending in jurisdictions which permit filings with massive numbers of plaintiffs. At December 31, 2018 , U. S. Steel was a defendant in approximately 755 cases involving approximately 2,320 plaintiffs. Based upon U. S. Steel’s experience in such cases, it believes that the actual number of plaintiffs who ultimately assert claims against U. S. Steel will likely be a small fraction of the total number of plaintiffs. The following table shows the number of asbestos claims in the current year and the prior two years: Period ended Opening Claims (a) New Closing December 31, 2017 3,340 275 250 3,315 December 31, 2018 3,315 1,285 290 2,320 December 31, 2019 2,320 195 265 2,390 (a) The period ending December 31, 2018 includes approximately 1,000 dismissed cases previously pending in the State of Texas. Historically, asbestos-related claims against U. S. Steel fall into three groups: (1) claims made by persons who allegedly were exposed to asbestos on the premises of U. S. Steel facilities; (2) claims made by persons allegedly exposed to products manufactured by U. S. Steel; and (3) claims made under certain federal and maritime laws by employees of former operations of U. S. Steel. The amount U. S. Steel accrues for pending asbestos claims is not material to U. S. Steel’s financial condition. However, U. S. Steel is unable to estimate the ultimate outcome of asbestos-related claims due to a number of uncertainties, including: (1) the rates at which new claims are filed, (2) the number of and effect of bankruptcies of other companies traditionally defending asbestos claims, (3) uncertainties associated with the variations in the litigation process from jurisdiction to jurisdiction, (4) uncertainties regarding the facts, circumstances and disease process with each claim, and (5) any new legislation enacted to address asbestos-related claims. Further, U. S. Steel does not believe that an accrual for unasserted claims is required. At any given reporting date, it is probable that there are unasserted claims that will be filed against the Company in the future. In 2018 and 2019 , the Company engaged an outside valuation consultant to assist in assessing its ability to estimate an accrual for unasserted claims. This assessment was based on the Company's settlement experience, including recent claims trends. The analysis focused on settlements made over the last several years as these claims are likely to best represent future claim characteristics. After review by the valuation consultant and U. S. Steel management, it was determined that the Company could not estimate an accrual for unasserted claims. Despite these uncertainties, management believes that the ultimate resolution of these matters will not have a material adverse effect on U. S. Steel’s financial condition. Environmental Matters – U. S. Steel is subject to federal, state, local and foreign laws and regulations relating to the environment. These laws generally provide for control of pollutants released into the environment and require responsible parties to undertake remediation of hazardous waste disposal sites. Penalties may be imposed for noncompliance. Changes in accrued liabilities for remediation activities where U. S. Steel is identified as a named party are summarized in the following table: Year Ended December 31, (In millions) 2019 2018 Beginning of period $ 187 $ 179 Accruals for environmental remediation deemed probable and reasonably estimable 20 14 Obligations settled (21 ) (6 ) End of period $ 186 $ 187 Accrued liabilities for remediation activities are included in the following Consolidated Balance Sheet lines: (In millions) December 31, 2019 December 31, 2018 Accounts payable $ 53 $ 37 Deferred credits and other noncurrent liabilities 133 150 Total $ 186 $ 187 Expenses related to remediation are recorded in cost of sales and were immaterial for the years ended December 31, 2019 , December 31, 2018 and December 31, 2017 . It is not currently possible to estimate the ultimate amount of all remediation costs that might be incurred or the penalties that may be imposed. Due to uncertainties inherent in remediation projects and the associated liabilities, it is reasonably possible that total remediation costs for active matters may exceed the accrued liabilities by as much as 15 to 30 percent . Remediation Projects U. S. Steel is involved in environmental remediation projects at or adjacent to several current and former U. S. Steel facilities and other locations that are in various stages of completion ranging from initial characterization through post-closure monitoring. Based on the anticipated scope and degree of uncertainty of projects, we categorize projects as follows: (1) Projects with Ongoing Study and Scope Development – Projects which are still in the development phase. For these projects, the extent of remediation that may be required is not yet known, the remediation methods and plans are not yet developed, and/or cost estimates cannot be determined. Therefore, significant costs, in addition to the accrued liabilities for these projects, are reasonably possible. There are six environmental remediation projects where additional costs for completion are not currently estimable, but could be material. These projects are at Fairfield Works, Lorain Tubular, USS-POSCO Industries (UPI), the Fairless Plant, Gary Works and the former steelmaking plant at Joliet, Illinois. As of December 31, 2019 , accrued liabilities for these projects totaled $2 million for the costs of studies, investigations, interim measures, design and/or remediation. It is reasonably possible that additional liabilities associated with future requirements regarding studies, investigations, design and remediation for these projects could be as much as $30 million to $45 million . (2) Significant Projects with Defined Scope – Projects with significant accrued liabilities with a defined scope. As of December 31, 2019 , there are four significant projects with defined scope greater than or equal to $5 million each, with a total accrued liability of $128 million . These projects are: Gary Resource Conservation and Recovery Act (RCRA) (accrued liability of $25 million ), the former Geneva facility (accrued liability of $48 million ), the Cherryvale Zinc site (accrued liability of $10 million ) and the former Duluth facility St. Louis River Estuary (accrued liability of $45 million ). (3) Other Projects with a Defined Scope – Projects with relatively small accrued liabilities for which we believe that, while additional costs are possible, they are not likely to be significant, and also include those projects for which we do not yet possess sufficient information to estimate potential costs to U. S. Steel. There are two other environmental remediation projects which each had an accrued liability of between $1 million and $5 million . The total accrued liability for these projects at December 31, 2019 was $4 million . These projects have progressed through a significant portion of the design phase and material additional costs are not expected. The remaining environmental remediation projects each have an accrued liability of less than $1 million each. The total accrued liability for these projects at December 31, 2019 was approximately $2 million . We do not foresee material additional liabilities for any of these sites. Post-Closure Costs – Accrued liabilities for post-closure site monitoring and other costs at various closed landfills totaled $23 million at December 31, 2019 and were based on known scopes of work. Administrative and Legal Costs – As of December 31, 2019 , U. S. Steel had an accrued liability of $11 million for administrative and legal costs related to environmental remediation projects. These accrued liabilities were based on projected administrative and legal costs for the next three years and do not change significantly from year to year. Capital Expenditures – For a number of years, U. S. Steel has made substantial capital expenditures to comply with various regulations, laws, and other requirements relating to the environment. In 2019 and 2018 , such capital expenditures totaled $123 million and $125 million , respectively. U. S. Steel anticipates making additional such expenditures in the future, which may be material; however, the exact amounts and timing of such expenditures are uncertain because of the continuing evolution of specific regulatory requirements. EU Environmental Requirements – Under the Emissions Trading Scheme (ETS), USSK's final allocation of allowances for the Phase III period, which covers the years 2013 through 2020 is 48 million allowances. Based on projected total production levels, we started to purchase allowances in the third quarter of 2017 to meet the annual compliance submission in the future. As of December 31, 2019 , we have purchased approximately 11.7 million European Union Allowances (EUA) totaling €132 million (approximately $148 million ) to cover the estimated shortfall of emission allowances. We estimate that the total shortfall will be approximately 12.5 million allowances for the Phase III period. The full cost of complying with the ETS regulations will depend on future production levels and future emissions intensity levels. The EU's Industrial Emissions Directive requires implementation of EU determined best available techniques (BAT) for Iron and Steel production to reduce environmental impacts as well as compliance with BAT associated emission levels. Our most recent estimate of total capital expenditures for projects to comply with or go beyond BAT requirements is €138 million (approximately $155 million ) over the 2017 to 2020 program period. These costs may be mitigated if USSK complies with certain financial covenants, which are assessed annually. USSK complied with these covenants as of December 31, 2019 . If we are unable to meet these covenants in the future, USSK might be required to provide additional collateral (e.g. bank guarantee) to secure the full value of estimated expenditures. There could be increased operating costs associated with these projects, such as increased energy and maintenance costs. We are currently unable to reliably estimate what the increase in operating costs will be as many projects are in the development stage. Environmental indemnifications – Throughout its history, U. S. Steel has sold numerous properties and businesses and many of these sales included indemnifications and cost sharing agreements related to the assets that were divested. These indemnifications and cost sharing agreements have included provisions related to the condition of the property, the approved use, certain representations and warranties, matters of title, and environmental matters. While most of these provisions have not specifically dealt with environmental issues, there have been transactions in which U. S. Steel indemnified the buyer for clean-up or remediation costs relating to the business sold or its then existing conditions or past practices related to non-compliance with environmental laws. Most of the recent indemnification and cost sharing agreements are of a limited nature, only applying to non-compliance with past and/or current laws. Some indemnifications and cost sharing agreements only run for a specified period of time after the transactions close and others run indefinitely. In addition, current owners or operators of property formerly owned or operated by U. S. Steel may have common law claims and cost recovery and contribution rights against U. S. Steel related to environmental matters. The amount of potential environmental liability associated with these transactions and properties is not estimable due to the nature and extent of the unknown conditions related to the properties divested and deconsolidated. Aside from the environmental liabilities already recorded as a result of these transactions due to specific environmental remediation activities and cases (included in the $186 million of accrued liabilities for remediation discussed above), there are no other known probable and estimable environmental liabilities related to these transactions. Guarantees – The maximum guarantees of the indebtedness of unconsolidated entities of U. S. Steel totaled $4 million at December 31, 2019 . Other contingencies – Under certain operating lease agreements covering various equipment, U. S. Steel has the option to renew the lease or to purchase the equipment at the end of the lease term. If U. S. Steel does not exercise the purchase option by the end of the lease term, U. S. Steel guarantees a residual value of the equipment as determined at the lease inception date (totaling approximately $23 million at December 31, 2019 ). No liability has been recorded for these guarantees as the potential loss is not probable. Insurance – U . S. Steel maintains insurance for certain property damage, equipment, business interruption and general liability exposures; however, insurance is applicable only after certain deductibles and retainages. U. S. Steel is self-insured for certain other exposures including workers’ compensation (where permitted by law) and auto liability. Liabilities are recorded for workers’ compensation and personal injury obligations. Other costs resulting from losses under deductible or retainage amounts or not otherwise covered by insurance are charged against income upon occurrence. U. S. Steel uses surety bonds, trusts and letters of credit to provide whole or partial financial assurance for certain obligations such as workers’ compensation. The total amount of active surety bonds, trusts and letters of credit being used for financial assurance purposes was approximately $164 million as of December 31, 2019 , which reflects U. S. Steel’s maximum exposure under these financial guarantees, but not its total exposure for the underlying obligations. A significant portion of our trust arrangements and letters of credit are collateralized by our Credit Facility Agreement. The remaining trust arrangements and letters of credit are collateralized by restricted cash. Restricted cash, which is recorded in other current and noncurrent assets, totaled $190 million and $40 million at December 31, 2019 and December 31, 2018 respectively. Capital Commitments – At December 31, 2019 , U. S. Steel’s contractual commitments to acquire property, plant and equipment totaled $880 million . Contractual Purchase Commitments – U. S. Steel is obligated to make payments under contractual purchase commitments, including unconditional purchase obligations. Payments for contracts with remaining terms in excess of one year are summarized below (in millions): 2020 2021 2022 2023 2024 Later years Total $430 $404 $337 $338 $107 $611 $2,227 The majority of U. S. Steel’s unconditional purchase obligations relate to the supply of industrial gases, and certain energy and utility services with terms ranging from two to 16 years . Unconditional purchase obligations also include coke and steam purchase commitments related to a coke supply agreement with Gateway Energy & Coke Company LLC (Gateway) under which Gateway is obligated to supply a minimum volume of the expected targeted annual production of the heat recovery coke plant, and U. S. Steel is obligated to purchase the coke from Gateway at the contract price. As of December 31, 2019 , if U. S. Steel were to terminate the agreement, it may be obligated to pay in excess of $138 million . Total payments relating to unconditional purchase obligations were approximately $653 million in 2019 , $600 million in 2018 and $576 million in 2017 .

Common Stock Repurchase Program

Common Stock Repurchase Program	12 Months Ended
	Dec. 31, 2019
Common Stock Repurchase Program [Abstract]
Common Stock Repurchase Program and Common Stock Issuance	27. Common Stock Repurchase Program In November 2018, U. S. Steel announced a common stock repurchase program that allowed for the repurchase of up to $300 million of its outstanding common stock from time to time in the open market or privately negotiated transactions through 2020 at the discretion of management. U. S. Steel repurchased 5,289,475 and 2,760,112 shares of common stock for approximately $88 million and $75 million under this program during 2019 and 2018

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On January 23, 2020, U. S. Steel and POSCO-California Corporation, a subsidiary of POSCO (POSCAL), entered into an agreement under which U. S. Steel will acquire POSCAL’s 50% ownership interest in USS-POSCO Industries (UPI). UPI is located in Pittsburg, California and markets sheet and tin mill products, principally in the western United States. UPI produces hot rolled pickled and oiled, cold-rolled sheets, galvanized sheets and tin mill products made from hot bands principally provided by U. S. Steel. UPI’s annual production capability is approximately 1.5 million

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts and Reserves	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts and Reserves	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS AND RESERVES YEARS ENDED DECEMBER 31, 2019 , 2018 AND 2017 (Millions of Dollars) Additions Deductions Description Balance at Charged to Charged Charged to Charged Balance Year ended December 31, 2019: Reserves deducted in the balance sheet from the assets to which they apply: Allowance for doubtful accounts $ 29 $ — $ — $ — $ 1 $ 28 Investments and long-term receivables reserve 5 — — — — 5 Deferred tax valuation allowance: Domestic 211 349 — — — 560 Foreign 3 — — — — 3 Year ended December 31, 2018: Reserves deducted in the balance sheet from the assets to which they apply: Allowance for doubtful accounts $ 28 $ 5 $ — $ — $ 4 $ 29 Investments and long-term receivables reserve 11 — — — 6 5 Deferred tax valuation allowance: Domestic 604 — — 393 — 211 Foreign 4 — — 1 — 3 Year ended December 31, 2017: Reserves deducted in the balance sheet from the assets to which they apply: Allowance for doubtful accounts $ 25 $ 2 $ 2 $ — $ 1 $ 28 Allowance for related party doubtful accounts 265 — — — 265 — Investments and long-term receivables reserve 10 — 1 — — 11 Long-term receivables from related parties reserve 1,627 — — — 1,627 — Deferred tax valuation allowance: Domestic 1,109 42 — 373 174 604 Foreign 4 — — — — 4

Nature of Business and Signif_2

Nature of Business and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Text Block [Abstract]
Principles applied in consolidation	Principles applied in consolidation These financial statements include the accounts of U. S. Steel and its majority-owned subsidiaries. Additionally, variable interest entities for which U. S. Steel is the primary beneficiary are included in the Consolidated Financial Statements and their impacts are either partially or completely offset by noncontrolling interests. Intercompany accounts, transactions and profits have been eliminated in consolidation. Investments in entities over which U. S. Steel has significant influence are accounted for using the equity method of accounting and are carried at U. S. Steel’s share of net assets plus loans, advances and our share of earnings less distributions. Earnings or loss from investees includes U. S. Steel’s share of earnings or loss from equity method investments (and any amortization of basis differences), which are generally recorded a month in arrears, except for significant and unusual items which are recorded in the period of occurrence.
Use of estimates	Use of estimates Generally accepted accounting principles require management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at year-end and the reported amounts of revenues and expenses during the year. Significant items subject to such estimates and assumptions include the carrying value of property, plant and equipment; intangible assets; valuation allowances for receivables, inventories and deferred income tax assets and liabilities; environmental liabilities; liabilities for potential tax deficiencies; potential litigation claims and settlements; assets and obligations related to employee benefits; put and call option assets and liabilities and restructuring and other charges. Actual results could differ materially from the estimates and assumptions used.
Sales recognition	Sales recognition Sales are recognized when U. S. Steel's performance obligations are satisfied. Generally, U. S. Steel’s performance obligations are satisfied, control of our products is transferred, and revenue is recognized at a single point in time, when title transfers to our customer for product shipped or when services are provided. Revenues are recorded net of any sales incentives. Shipping and other transportation costs charged to customers are treated as fulfillment activities and are recorded in both revenue and cost of sales at the time control is transferred to the customer. See Note 6 for further details on U. S. Steel’s revenue.
Inventories	Inventories Inventories are carried at the lower of cost or market. Fixed costs related to abnormal production capacity are expensed in the period incurred rather than capitalized into inventory. LIFO (last-in, first-out) is the predominant method of inventory costing for inventories in the United States and FIFO (first-in, first-out) is the predominant method in Europe. The LIFO method of inventory costing was used on 75 percent and 74 percent of consolidated inventories at December 31, 2019 and 2018 , respectively.
Derivative instruments	Derivative instruments From time to time, U. S. Steel may use fixed price forward physical purchase contracts to partially manage our exposure to price risk. Generally, forward physical purchase contracts qualify for the normal purchase normal sales exclusion in Accounting Standards Codification (ASC) 815, Derivatives and Hedging , and are not subject to mark-to-market accounting. U. S. Steel also uses derivatives such as commodity-based financial swaps and foreign currency exchange forward contracts to manage its exposure to purchase and sale price fluctuations and foreign currency exchange rate risk. U. S. Steel elects hedge accounting for some of its derivatives. Under hedge accounting, fluctuations in the value of the derivative are recognized in Accumulated Other Comprehensive Income (AOCI) until the associated underlying is recognized in earnings. When the associated underlying is recognized in earnings, the value of the derivative is reclassified to earnings from AOCI. We recognize fair value changes for derivatives where hedge accounting has not been elected immediately in earnings. See Note 16 for further details on U. S. Steel’s derivatives.
Financial Instruments	Financial Instruments U. S. Steel's purchase of a 49.9% equity ownership interest in Big River Steel on October 31, 2019 included certain call and put options. U. S. Steel marks these options to fair value each reporting period using a Monte Carlo simulation which is considered a Level 3 valuation technique. Level 3 valuation techniques include inputs to the valuation methodology that are considered unobservable and significant to the fair value measurement. See Note 5 and Note 20 for further details.
Property, plant and equipment	Property, plant and equipment Property, plant and equipment is carried at cost and is depreciated on a straight-line basis over the estimated useful lives of the assets. Depletion of mineral properties is based on rates which are expected to amortize cost over the estimated tonnage of minerals to be removed. When property, plant and equipment is sold or otherwise disposed of, any gains or losses are reflected in income. If a loss on disposal is expected, such losses are recognized when the assets are reclassified as assets held for sale or when impaired as part of an asset group’s impairment. U. S. Steel evaluates impairment of its property, plant and equipment whenever circumstances indicate that the carrying value may not be recoverable. We evaluate the impairment of long-lived assets at the asset group level. Our asset groups are Flat-Rolled, welded tubular, seamless tubular and U. S. Steel Europe (USSE). Asset impairments are recognized when the carrying value of an asset group exceeds its recoverable amount as determined by the asset group's aggregate projected undiscounted cash flows. During 2019, the challenging steel market environment in the U.S. that led to the idling of certain Flat-Rolled facilities, the challenging steel market in Europe that led to the temporary idling of a blast furnace and significant headcount reductions at USSE, and recent losses in the welded tubular asset group were considered triggering events for those asset groups, respectively. U. S. Steel completed a quantitative analysis of its long-lived assets for these asset groups and determined that the assets were not impaired. There were no triggering events for seamless tubular in 2019. There were no triggering events in 2018 that required fixed assets to be evaluated for impairment.
Change in accounting estimate - capitalization and depreciation method	Change in Accounting Estimate - Capitalization and Depreciation Method During 2017, U. S. Steel completed a review of its accounting policy for property, plant and equipment depreciated on a group basis. As a result of this review, U. S. Steel changed its accounting method for property, plant and equipment from the group method of depreciation to the unitary method of depreciation, effective as of January 1, 2017. The Company believes the change from the group method to the unitary method of depreciation is preferable under U.S. GAAP as it results in a more precise estimate of depreciation expense. Additionally, the change to the unitary method of depreciation is consistent with the depreciation method applied by our competitors, and improves the comparability of our results to the results of our competitors. Our change in the method of depreciation was considered a change in accounting estimate effected by a change in accounting principle and has been applied prospectively. Due to the application of the unitary method of depreciation and resultant change in our capitalization policy, maintenance and outage spending that had previously been expensed as well as capital investments associated with our asset revitalization program are now capitalized if the useful life of the related asset is extended. When property, plant, and equipment are disposed of by sale, retirement, or abandonment, the gross value of the property, plant and equipment and corresponding accumulated depreciation are removed from the Company’s financial accounting records. Due to the application of the unitary method of depreciation, any gain or loss resulting from an asset disposal by sale is now immediately recognized as a gain or loss on the disposal of assets line in our consolidated statement of operations. Assets that are retired or abandoned are reflected as an immediate charge to depreciation expense for any remaining book value in our consolidated statement of operations.
Environmental remediation	Environmental remediation Environmental expenditures are capitalized if the costs mitigate or prevent future contamination or if the costs improve existing assets’ environmental safety or efficiency. U. S. Steel provides for remediation costs and penalties when the responsibility to remediate is probable and the amount of associated costs is reasonably estimable. The timing of remediation accruals typically coincides with completion of studies defining the scope of work to be undertaken or when it is probable that a formal plan of action will be approved by the oversight agency. Remediation liabilities are accrued based on estimates of believed environmental exposure and are discounted if the amount and timing of the cash disbursements are readily determinable.
Asset retirement obligations	Asset retirement obligations Asset retirement obligations (AROs) are initially recorded at fair value and are capitalized as part of the cost of the related long-lived asset and depreciated in accordance with U. S. Steel’s depreciation policies for property, plant and equipment. The fair value of the obligation is determined as the discounted value of expected future cash flows. Accretion expense is recorded each month to increase this discounted obligation over time. Certain AROs related to disposal costs of the majority of assets at our integrated steel facilities are not recorded because they have an indeterminate settlement date. These AROs will be initially recognized in the period in which sufficient information exists to estimate their fair value. See Note 19 for further details on U. S. Steel's AROs.
Pensions and postemployment benefits	Pensions and other post-employment benefits U. S. Steel has defined contribution or multi-employer arrangements for pension benefits for more than three-quarters of its employees in the United States and defined benefit pension plans covering the remaining employees. For hires before January 1, 2016, U. S. Steel has defined benefit retiree health care and life insurance plans (Other Benefits) that cover its represented employees in North America upon their retirement. Government-sponsored programs into which U. S. Steel makes required contributions cover the majority of U. S. Steel’s European employees. For more details regarding pension and other post-employment benefits see Note 18 of the Consolidated Financial Statements. The pension and Other Benefits obligations and the related net periodic benefit costs are based on, among other things, assumptions of the discount rate, estimated return on plan assets, salary increases, the projected mortality of participants and the current level and future escalation of health care costs. Additionally, U. S. Steel recognizes an obligation to provide post-employment benefits for disability-related claims covering indemnity and medical payments for certain employees in North America. The obligation for these claims and the related periodic costs are measured using actuarial techniques and assumptions. Actuarial gains and losses occur when actual experience differs from any of the many assumptions used to value the benefit plans, or when assumptions change. For pension and Other Benefits, the Company recognizes into income on an annual basis a portion of unrecognized actuarial net gains or losses that exceed 10 percent of the larger of projected benefit obligations or plan assets (the corridor). These unrecognized amounts in excess of the corridor are amortized over the plan participants' average life expectancy or average future service, depending on the demographics of the plan. Unrecognized actuarial net gains and losses for disability-related claims are immediately recognized into income.
Deferred taxes	Deferred taxes
Reclassifications	Reclassifications and Adjustments Certain reclassifications of prior years' data have been made to conform to the current year presentation including the following: U. S. Steel reclassified certain prior year data as a result of the retrospective adoption on January 1, 2018 of ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash, ASU 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments and ASU 2017-07, Compensation - Retirement Benefits . See Note 3 for further details.

Recently Adopted Accounting S_2

Recently Adopted Accounting Standards (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Schedule of Changes Related to Net Periodic Benefit Cost	The effect of the retrospective presentation change related to the net periodic benefit cost of our defined benefit pension and other post-employment benefits (OPEB) plans on our consolidated statement of operations was as follows: Year Ended December 31, 2017 Statement of Operations (In millions) As Revised Previously Reported Effect of Change Higher/(Lower) Cost of Sales $ 10,858 $ 10,864 $ (6 ) Selling, general and administrative expenses 320 375 (55 ) Net periodic benefit cost (other than service cost) 61 — 61

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Results of Segment Operations	The results of segment operations are as follows: (In millions) Customer Intersegment Net Earnings Earnings (Loss) before Interest and Income Taxes Depreciation, Capital 2019 Flat-Rolled $ 9,279 $ 281 $ 9,560 $ 84 $ 196 $ 456 $ 943 USSE 2,417 3 2,420 — (57 ) 92 153 Tubular 1,188 3 1,191 5 (67 ) 46 145 Total reportable segments 12,884 287 13,171 89 72 594 1,241 Other Businesses 53 115 168 (10 ) 23 22 11 Reconciling Items and Eliminations — (402 ) (402 ) — (325 ) — — Total $ 12,937 $ — $ 12,937 $ 79 $ (230 ) $ 616 $ 1,252 2018 Flat-Rolled $ 9,681 $ 231 $ 9,912 $ 54 $ 883 $ 367 $ 820 USSE 3,205 23 3,228 — 359 87 104 Tubular 1,231 5 1,236 7 (58 ) 47 45 Total reportable segments 14,117 259 14,376 61 1,184 501 969 Other Businesses 61 125 186 — 55 20 32 Reconciling Items and Eliminations — (384 ) (384 ) — (115 ) — — Total $ 14,178 $ — $ 14,178 $ 61 $ 1,124 $ 521 $ 1,001 2017 Flat-Rolled $ 8,297 $ 194 $ 8,491 $ 38 $ 375 $ 352 $ 388 USSE 2,949 25 2,974 — 327 76 83 Tubular 944 1 945 8 (99 ) 51 28 Total reportable segments 12,190 220 12,410 46 603 479 499 Other Businesses 60 119 179 (2 ) 44 22 6 Reconciling Items and Eliminations — (339 ) (339 ) — 22 — — Total $ 12,250 $ — $ 12,250 $ 44 $ 669 $ 501 $ 505
Schedule of Assets by Segment	A summary of total assets by segment is as follows: December 31, (In millions) 2019 2018 Flat-Rolled (a) $ 7,267 $ 6,977 USSE (b) 5,360 5,607 Tubular 1,150 1,076 Total reportable segments $ 13,777 $ 13,660 Other Businesses $ 1,267 $ 329 Corporate, reconciling items, and eliminations (c) (3,436 ) (3,007 ) Total assets $ 11,608 $ 10,982 (a) Included in the Flat-Rolled segment assets is goodwill of $3 million as of December 31, 2018 . (b)
Schedule of Reconciling Items to EBIT	detail of reconciling items to consolidated earnings (loss) before interest and income taxes is as follows: (In millions) 2019 2018 2017 Items not allocated to segments: December 24, 2018 Clairton coke making facility fire (50 ) — — United Steelworkers labor agreement signing bonus and related costs — (81 ) — Granite City Works restart and related costs — (80 ) — Loss on shutdown of certain tubular pipe mill assets (Note 25) — — (35 ) Gain associated with U. S. Steel Canada Inc. (Note 5) — — 72 Restructuring and other charges (Note 25) (275 ) — — Granite City Works temporary idling charges — 8 (17 ) Gain on equity investee transactions (Note 12) — 38 2 Total reconciling items $ (325 ) $ (115 ) $ 22
Net Sales, Property, Plant and Equipment and Equity Method Investments Based on Location of Operating Segment	raphic Area: The information below summarizes external sales, property, plant and equipment and equity method investments based on the location of the operating segment to which they relate. (In millions) Year External Assets North America 2019 $ 10,520 $ 5,772 (a) 2018 10,973 4,432 (a) 2017 9,301 3,831 (a) Europe 2019 2,417 947 2018 3,205 919 2017 2,949 906 Total 2019 12,937 6,719 2018 14,178 5,351 2017 12,250 4,737 (a) Assets with a book value of $5,772 million , $4,432 million and $3,817 million were located in the United States at December 31, 2019 , 2018 and 2017 , respectively.

Acquisition and Disposition (Ta

Acquisition and Disposition (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Schedule of Options Recorded as Embedded Financial Instruments included in Equity Investment Asset	(In millions) Consolidated Balance Sheet Classification December 31, 2019 U. S. Steel Call Option Investments and other long-term receivables $ 166 Class B Put Option Deferred credits and other long-term liabilities $ 192 Class B Call Option Deferred credits and other long-term liabilities $ 2

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Sales by Product	The following table disaggregates our revenue by product for each of our reportable business segments for the years ended December 31, 2019 , 2018 and 2017 , respectively: Customer Sales by Product: (In millions) Year Ended December 31, 2019 Flat-Rolled USSE Tubular Other Businesses Total Semi-finished $ 305 $ 11 $ — $ — $ 316 Hot-rolled sheets 2,504 997 — — 3,501 Cold-rolled sheets 2,512 283 — — 2,795 Coated sheets 2,993 1,006 — — 3,999 Tubular products — 40 1,166 — 1,206 All Other (a) 965 80 22 53 1,120 Total $ 9,279 $ 2,417 $ 1,188 $ 53 $ 12,937 (In millions) Year Ended December 31, 2018 Flat-Rolled USSE Tubular Other Businesses Total Semi-finished $ 156 $ 174 $ — $ — $ 330 Hot-rolled sheets 2,816 1,313 — — 4,129 Cold-rolled sheets 2,709 384 — — 3,093 Coated sheets 3,090 1,164 — — 4,254 Tubular products — 48 1,195 — 1,243 All Other (a) 910 122 36 61 1,129 Total $ 9,681 $ 3,205 $ 1,231 $ 61 $ 14,178 (In millions) Year Ended December 31, 2017 Flat-Rolled USSE Tubular Other Businesses Total Semi-finished $ 72 $ 232 $ — $ — $ 304 Hot-rolled sheets 2,045 1,210 — — 3,255 Cold-rolled sheets 2,355 328 — — 2,683 Coated sheets 2,902 1,038 — — 3,940 Tubular products — 39 909 — 948 All Other (a) 923 102 35 60 1,120 Total $ 8,297 $ 2,949 $ 944 $ 60 $ 12,250 (a) Consists primarily of sales of raw materials and coke making by-products.

Net Interest and Other Financ_2

Net Interest and Other Financial Costs (Tables)	12 Months Ended
	Dec. 31, 2019
Other Income and Expenses [Abstract]
Net Interest and Other Financial Costs	(In millions) 2019 2018 2017 Interest income: Interest income $ (17 ) $ (23 ) $ (17 ) Interest expense and other financial costs: Interest incurred 162 175 229 Less interest capitalized 20 7 3 Total interest expense 142 168 226 Loss on debt extinguishment (a) — 98 54 Net periodic benefit costs (other than service cost) (b) 91 69 61 Foreign currency net (gain) loss (c) (17 ) (19 ) 23 Financial costs on: Amended Credit Agreement 5 5 6 USSK credit facilities 1 3 3 Other (d) 10 3 2 Amortization of discounts and deferred financing costs 7 8 10 Total other financial costs 6 — 44 Net interest and other financial costs $ 222 $ 312 $ 368 (a) Represents a net pretax charge of $98 million during 2018 related to the retirement of our 2020 Senior Notes and 2021 Senior Secured Notes, and a net pretax charge of $54 million during 2017 related to the retirement of our 2018, 2021, and 2022 Senior Notes, partial redemption of our 2021 Senior Secured Notes, and redemption of the Lorain Recovery Zone Facility Bonds. (b) Represents postretirement benefit expense as a result of the adoption of Accounting Standards Update 2017-07, Compensation - Retirement Benefits on January 1, 2018. See Note 3 to the Consolidated Financial Statements. (c) The functional currency for USSE is the euro. Foreign currency net (gain) loss is a result of transactions denominated in currencies other than the euro. (d) 2019 includes a $7 million change in fair value of certain call and put options related to U. S. Steel's purchase of its 49.9%

Earnings and Dividends Per Co_2

Earnings and Dividends Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Computations for Basic and Diluted Earnings Per Common Share from Continuing Operations	The computations for basic and diluted (loss) earnings per common share from continuing operations are as follows: (Dollars in millions, except per share amounts) 2019 2018 2017 Net (loss) earnings attributable to United States Steel Corporation stockholders $ (630 ) $ 1,115 $ 387 Weighted-average shares outstanding (in thousands): Basic 171,418 176,633 174,793 Effect of convertible notes — — — Effect of stock options, restricted stock units and performance awards — 1,828 1,727 Adjusted weighted-average shares outstanding, diluted 171,418 178,461 176,520 Basic (loss) earnings per common share $ (3.67 ) $ 6.31 $ 2.21 Diluted (loss) earnings per common share $ (3.67 ) $ 6.25 $ 2.19
Antidilutive Securities that were Not Included in Computations of Diluted Loss Per Common Share	The following table summarizes the securities that were antidilutive, and therefore, were not included in the computation of diluted (loss) earnings per common share: (In thousands) 2019 2018 2017 Securities granted under the 2005 Stock Incentive Plan 4,459 1,631 1,579 Securities convertible under the Senior Convertible Notes 650 — — Total 5,109 1,631 1,579

Cash, Cash Equivalents, and R_2

Cash, Cash Equivalents, and Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2019
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within U. S. Steel's Consolidated Balance Sheets that sum to the total of the same amounts shown in the Consolidated Statement of Cash Flows: December 31, (In millions) 2019 2018 2017 Cash and cash equivalents $ 749 $ 1,000 $ 1,553 Restricted cash in other current assets 2 3 6 Long-term restricted cash 188 37 38 Total cash, cash equivalents and restricted cash $ 939 $ 1,040 $ 1,597
Schedule of Restrictions on Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within U. S. Steel's Consolidated Balance Sheets that sum to the total of the same amounts shown in the Consolidated Statement of Cash Flows: December 31, (In millions) 2019 2018 2017 Cash and cash equivalents $ 749 $ 1,000 $ 1,553 Restricted cash in other current assets 2 3 6 Long-term restricted cash 188 37 38 Total cash, cash equivalents and restricted cash $ 939 $ 1,040 $ 1,597

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories	(In millions) December 31, 2019 December 31, 2018 Raw materials $ 628 $ 605 Semi-finished products 720 1,021 Finished products 376 404 Supplies and sundry items 61 62 Total $ 1,785 $ 2,092

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Earnings (Loss)	Components of (loss) earnings (In millions) 2019 2018 2017 United States $ (381 ) $ 434 $ 75 Foreign (71 ) 378 226 (Loss) earnings before income taxes $ (452 ) $ 812 $ 301
(Benefit) Provision for Income Taxes	Components of (loss) earnings (In millions) 2019 2018 2017 United States $ (381 ) $ 434 $ 75 Foreign (71 ) 378 226 (Loss) earnings before income taxes $ (452 ) $ 812 $ 301 At the end of both 2019 and 2018, U. S. Steel does not have any undistributed foreign earnings and profits for which U.S. deferred taxes have not been provided. Income tax provision (benefit) 2019 2018 2017 (In millions) Current Deferred Total Current Deferred Total Current Deferred Total Federal $ (18 ) $ 196 $ 178 $ (40 ) $ (283 ) $ (323 ) $ (66 ) $ (81 ) $ (147 ) State and local — 23 23 2 (58 ) (56 ) (1 ) — (1 ) Foreign (6 ) (17 ) (23 ) 64 12 76 53 9 62 Total $ (24 ) $ 202 $ 178 $ 26 $ (329 ) $ (303 ) $ (14 ) $ (72 ) $ (86 )
Reconciliation of Federal Statutory Tax to Total Provisions	reconciliation of the federal statutory tax rate of 21 percent ( 21 percent in 2018 and 35 percent in 2017) to total provision (benefit) follows: (In millions) 2019 2018 2017 Statutory rate applied to earnings (loss) before income taxes $ (95 ) $ 171 $ 105 Valuation allowance 334 (412 ) 36 Excess percentage depletion (46 ) (48 ) (68 ) State and local income taxes after federal income tax effects (36 ) 8 (28 ) Effects of foreign operations (23 ) 74 62 U.S. impact of foreign operations 25 (21 ) (6 ) Impact of tax credits 5 (71 ) (56 ) Effect of tax reform — — (81 ) Alternative minimum tax credit refund — — (48 ) Adjustment of prior years' federal income taxes 7 — — Other 7 (4 ) (2 ) Total provision (benefit) $ 178 $ (303 ) $ (86 )
Deferred Tax Assets and Liabilities	Deferred tax assets and liabilities resulted from the following: December 31, (In millions) 2019 2018 Deferred tax assets: Federal tax loss carryforwards (expiring in 2035 through 2036) $ 176 $ 220 Federal capital loss carryforwards (expiring 2021) 27 33 State tax credit carryforwards (expiring in 2020 through 2028) 18 16 State tax loss carryforwards (expiring in 2020 through 2039) 130 137 Minimum tax credit carryforwards 19 38 General business credit carryforwards (expiring in 2027 through 2039) 85 85 Foreign tax loss and credit carryforwards (expiring in 2024 through 2029) 170 173 Employee benefits 173 337 Contingencies and accrued liabilities 71 62 Investments in subsidiaries and equity investees 49 59 Inventory 32 — Other temporary differences 35 26 Valuation allowance (563 ) (214 ) Total deferred tax assets 422 972 Deferred tax liabilities: Property, plant and equipment 368 468 Inventory — 22 Receivables, payables and debt 17 33 Indefinite-lived intangible assets 19 18 Other temporary differences 3 — Total deferred tax liabilities 407 541 Net deferred tax asset $ 15 $ 431
Reconciliation of Unrecognized Tax Benefits	A tabular reconciliation of unrecognized tax benefits follows: (In millions) 2019 2018 2017 Unrecognized tax benefits, beginning of year $ 35 $ 42 $ 72 Increases – tax positions taken in prior years — — 1 Decreases – tax positions taken in prior years — (2 ) (26 ) Settlements (32 ) — (4 ) Lapse of statute of limitations — (5 ) (1 ) Unrecognized tax benefits, end of year $ 3 $ 35 $ 42

Investments, Long-Term Receiv_2

Investments, Long-Term Receivables and Equity Investee Transactions (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investments and Long-Term Receivables	Investments, Long-Term Receivables and Equity Investee Transactions December 31, (In millions) 2019 2018 Equity method investments $ 1,272 $ 485 Receivables due after one year, less allowance of $5 and $11 191 24 Other 3 4 Total $ 1,466 $ 513
Summarized Financial Information of Investees Accounted for by Equity Method of Accounting	Summarized financial information of all investees accounted for by the equity method of accounting is as follows (amounts represent 100% of investee financial information): (In millions) 2019 2018 2017 Income data – year ended December 31: (a) Net Sales $ 2,528 $ 2,193 $ 2,485 Operating income 253 157 132 Net earnings 235 134 109 Balance sheet date – December 31: Current Assets $ 1,144 $ 642 $ 633 Noncurrent Assets 2,976 853 710 Current liabilities 573 348 441 Noncurrent Liabilities 2,542 516 335 (a) Former equity affiliates, Swan Point Development Company, Inc., Tilden Mining Company (Tilden) and Apolo Tubulars S.A. were sold on February 6, 2017, September 29, 2017 and December 22, 2017, respectively. We exited Leeds Retail Center, LLC and sold Acero Prime, S.R.L. de CV on May 31, 2018, and October 23, 2018, respectively. The former equity affiliates are included in the income data through the month prior to the date of sale.
Investees Accounted for using Equity Method	Investees accounted for using the equity method include: Investee December 31, 2019 Interest Big River Steel (a) 49.9 % Chrome Deposit Corporation 50 % Daniel Ross Bridge, LLC 50 % Double G Coatings Company, Inc. 50 % Feralloy Processing Company 49 % Hibbing Development Company 24.1 % Hibbing Taconite Company (b) 14.7 % Patriot Premium Threading Services, LLC 50 % PRO-TEC Coating Company, LLC 50 % Strategic Investment Fund Partners II (c) 5.2 % USS-POSCO Industries 50 % Worthington Specialty Processing 49 % (a) U. S. Steel's 49.9% ownership in Big River Steel consists of 47.7535% interests in Big River Steel Holdings LLC and BRS Stock Holdco LLC. U. S. Steel Blocker LLC, a wholly-owned subsidiary of U. S. Steel, holds a 2.1465% interest in both of those entities. (b) Hibbing Taconite Company (Hibbing) is an unincorporated joint venture that is owned, in part, by Hibbing Development Company (HDC), which is accounted for using the equity method. Through HDC we are able to influence the activities of HTC, and as such, its activities are accounted for using the equity method. (c) Strategic Investment Fund Partners II is a limited partnership and in accordance with ASC Topic 323, the financial activities are accounted for using the equity method.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	December 31, (In millions) Useful Lives 2019 2018 Land and depletable property — $ 202 $ 207 Buildings 35 years 1,105 1,098 Machinery and equipment Steel producing 2-30 years 13,658 12,784 Transportation 3-40 years 280 268 Other 5-30 years 129 123 Information technology 5-6 years 787 786 Assets under finance lease 5-15 years 83 36 Construction in process — 833 706 Total 17,077 16,008 Less accumulated depreciation and depletion 11,630 11,143 Net $ 5,447 $ 4,865

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortizable Intangible Assets	Intangible assets are being amortized on a straight-line basis over their estimated useful lives and are detailed below: As of December 31, 2019 As of December 31, 2018 (In millions) Useful Gross Accumulated Net Gross Accumulated Net Customer relationships 22 Years $ 132 $ 76 $ 56 $ 132 $ 70 $ 62 Patents 10-15 Years 22 8 14 22 7 15 Other 4-20 Years 14 9 5 14 8 6 Total amortizable intangible assets $ 168 $ 93 $ 75 $ 168 $ 85 $ 83

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Total Stock-Based Compensation Awards Granted	The following table summarizes the total stock-based compensation awards granted during the years 2019 , 2018 and 2017 : Stock Options Restricted Stock Units TSR Performance Awards ROCE Performance Awards 2019 Grants — 1,005,500 210,520 527,470 2018 Grants — 824,195 79,190 247,510 2017 Grants 647,780 348,040 169,850 —
Total Compensation Expense Recognized for Stock-Based Compensation Awards	The following table summarizes the total compensation expense recognized for stock-based compensation awards: (In millions, except per share amounts) Year Ended December 31, 2019 Year Ended December 31, 2018 Year Ended December 31, 2017 Stock-based compensation expense recognized: Cost of sales $ 9 $ 11 $ 10 Selling, general and administrative expenses 17 21 17 Decrease in net income 26 32 27 Decrease in basic earnings per share 0.15 0.14 0.15 Decrease in diluted earnings per share 0.15 0.13 0.15
Black-Scholes Assumptions	Compensation expense for stock options is recorded over the vesting period based on the fair value on the date of grant, as calculated by U. S. Steel using the Black-Scholes model and the assumptions listed below. Awards generally vest ratably over a three -year service period and have a term of ten years . Stock options are generally issued at the market price of the underlying stock on the date of the grant. Upon exercise of stock options, shares of U. S. Steel stock are issued from treasury stock or from authorized, but unissued common stock. There were no stock options granted in 2019 and 2018 . Black-Scholes Assumptions (a) 2017 Grants Grant date price per share of option award $ 36.94 Exercise price per share of option award $ 36.94 Expected annual dividends per share $ 0.20 Expected life in years 5.0 Expected volatility 57 % Risk-free interest rate 2.0 % Average grant date fair value per share of unvested option awards as calculated from above $ 17.28 (a) The assumptions represent a weighted-average for all grants during the year.
Status and Activity of Stock Options	The following table shows a summary of the status and activity of stock options for the year ended December 31, 2019 : Shares Weighted- Weighted- Aggregate Outstanding at January 1, 2019 2,746,520 $ 27.73 Granted — $ — Exercised (10,435 ) $ 16.05 Forfeited or expired (384,254 ) $ 32.00 Outstanding at December 31, 2019 2,351,831 $ 27.08 4.43 $ — Exercisable at December 31, 2019 2,209,073 $ 26.50 4.28 $ — Exercisable and expected to vest at December 31, 2019 2,323,996 $ 26.97 4.40 $ —
Performance Awards Outstanding and their Fair Market Value on Respective Grant Date	The following table shows a summary of the performance awards outstanding as of December 31, 2019 , and their fair market value on the respective grant date: Performance Period Fair Value Minimum Target Maximum 2019 - 2021 $ 17 — 653,194 1,306,388 2018 - 2020 $ 14 — 288,379 576,758 2017 - 2019 $ 4 — 101,587 203,174
Status and Activity of Nonvested Stock Awards	The following table shows a summary of the status and activity of nonvested stock awards for the year ended December 31, 2019 : Restricted TSR Performance (a) ROCE Performance (a) Total Weighted- Nonvested at January 1, 2018 1,496,272 375,787 235,898 2,107,957 $ 30.92 Granted 1,005,500 210,520 527,470 1,743,490 24.46 Vested (771,677 ) (384,664 ) — (1,156,341 ) 18.26 Performance adjustment factor (b) — 192,332 — 192,332 10.02 Forfeited or expired (140,271 ) (43,658 ) (70,525 ) (254,454 ) 30.45 Nonvested at December 31, 2019 1,589,824 350,317 692,843 2,632,984 $ 30.72 (a) The number of shares shown for the performance awards is based on the target number of share awards. (b) Consists of adjustments to vested performance awards to reflect actual performance. The adjustments were required since the original grants of the awards were at 100 percent of the targeted amounts and the awards vested at greater than target.
Restricted Stock Units and Performance Awards Granted	The following table presents information on RSUs and performance awards granted: 2019 2018 2017 Number of awards granted 1,743,490 1,150,895 517,890 Weighted-average grant-date fair value per share $ 24.46 $ 41.65 $ 37.68

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions	The table below shows the outstanding swap quantities used to hedge forecasted purchases and sales as of December 31, 2019 and December 31, 2018 : Hedge Contracts Classification December 31, 2019 December 31, 2018 Natural gas (in mmbtus) Commodity purchase swaps 56,613,200 33,951,016 Tin (in metric tons) Commodity purchase swaps 145 585 Zinc (in metric tons) Commodity purchase swaps 9,819 3,471 Hot-rolled coils (in tons) Sales swaps — 9,000 Foreign currency (in millions of euros) Foreign exchange forwards € 282 € 286 Foreign currency (in millions of CAD) Foreign exchange forwards C$ 25 C$ 50
Location and Amounts of Fair Values Related to Derivatives in Financial Statements	The following summarizes the fair value amounts included in our Consolidated Balance Sheets as of December 31, 2019 and December 31, 2018 : (In millions) Designated as Hedging Instruments Balance Sheet Location December 31, 2019 December 31, 2018 Sales swaps Accounts payable $ — $ 1 Commodity purchase swaps Accounts receivable 1 2 Commodity purchase swaps Accounts payable 17 17 Commodity purchase swaps Investments and long-term receivables 1 — Commodity purchase swaps Other long-term liabilities 7 1 Foreign exchange forwards Accounts payable 1 1 Foreign exchange forwards Other long-term liabilities — 1 Not Designated as Hedging Instruments Foreign exchange forwards Accounts receivable 4 12
Schedule of Effect of Hedge Accounting on Accumulated Other Comprehensive Income	The table below summarizes the effect of hedge accounting on AOCI and amounts reclassified from AOCI into earnings for 2019 , 2018 , and 2017 : Gain (Loss) on Derivatives in AOCI Amount of Gain (Loss) Recognized in Income (In millions) 2019 2018 2017 Location of Reclassification from AOCI (a) 2019 2018 2017 Sales swaps $ 1 $ — $ — Net sales (b) $ (1 ) $ (13 ) $ — Commodity purchase swaps (6 ) (15 ) 1 Cost of sales (c) (19 ) (8 ) (2 ) Foreign exchange forwards 1 (2 ) — Cost of sales (1 ) — — (a) The earnings impact of our hedging instruments substantially offsets the earnings impact of the related hedged items since ineffectiveness is less than $1 million . (b) U. S. Steel elected cash flow hedge accounting for hot-rolled coil sales swaps effective January 1, 2018 and for iron ore pellet sales swaps effective January 1, 2019. (c) Costs for commodity purchase swaps are recognized in cost of sales as products are sold.
Location and Amounts of Gains and Losses Related to Derivatives in Financial Instruments	The table below summarizes the impact of derivative activity where hedge accounting has not been elected on our Consolidated Statements of Operations for 2019 , 2018 and 2017 : Amount of Gain (Loss) Recognized in Income (In millions) Consolidated Statement of Operations Location 2019 2018 2017 Sales swaps (a) Net sales $ — $ (1 ) $ 6 Commodity purchase swaps (b) Cost of sales — — 3 Foreign exchange forwards (c) Other financial costs 17 24 (23 ) (a) U. S. Steel elected cash flow hedge accounting for hot-rolled coil sales swaps effective January 1, 2018 and for iron ore pellet sales swaps effective January 1, 2019. (b) The 2017 impacts were for de-designated zinc contracts for our domestic operations.

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt	December 31, (In millions) Interest Maturity 2019 2018 2037 Senior Notes 6.650 2037 $ 350 $ 350 2026 Senior Notes 6.250 2026 650 650 2026 Senior Convertible Notes 5.000 2026 350 — 2025 Senior Notes 6.875 2025 750 750 Environmental Revenue Bonds 4.875 - 6.750 2024 - 2049 620 400 Fairfield Caster Lease 2022 18 22 Other finance leases and all other obligations 2020-2029 48 6 Amended Credit Facility, $2.0 billion Variable 2024 600 — USSK Credit Agreement Variable 2023 393 229 USSK credit facilities Variable 2021 — — Total debt 3,779 2,407 Less unamortized discount and debt issuance costs 138 26 Less short-term debt and long-term debt due within one year 14 65 Long-term debt $ 3,627 $ 2,316
Aggregate Maturities of Debt	Debt Maturities – Aggregate maturities of debt are as follows (in millions): 2020 2021 2022 2023 2024 Later Total $ 14 $ 12 $ 17 $ 399 $ 664 $ 2,673 $ 3,779

Pensions and Other Benefits (Ta

Pensions and Other Benefits (Tables)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Details Relating to Pension Benefits and Other Benefits	Details relating to pension benefits and Other Benefits are below. Pension Benefits Other Benefits (In millions) 2019 2018 2019 2018 Change in benefit obligations Benefit obligations at January 1 $ 5,626 $ 6,107 $ 2,121 $ 2,379 Service cost 44 49 13 17 Interest cost 237 233 91 92 Plan amendments — 26 — — Actuarial (gains) losses 416 (223 ) (195 ) (185 ) Exchange rate loss 1 (3 ) — — Settlements, curtailments and termination benefits — (18 ) — — Benefits paid (502 ) (545 ) (154 ) (182 ) Benefit obligations at December 31 $ 5,822 $ 5,626 $ 1,876 $ 2,121 Change in plan assets Fair value of plan at January 1 $ 4,960 $ 5,732 $ 1,860 $ 2,042 Actual return on plan assets 948 (228 ) 274 (49 ) Employer contributions — — — — Benefits paid from plan assets (502 ) (544 ) (109 ) (133 ) Fair value of plan assets at December 31 $ 5,406 $ 4,960 $ 2,025 $ 1,860 Funded status of plans at December 31 (416 ) (666 ) 149 (261 )
Amounts Recognized in Accumulated Other Comprehensive Loss	Amounts recognized in accumulated other comprehensive loss: 2019 (In millions) 12/31/2018 Amortization Activity 12/31/2019 Pensions Prior Service Cost $ 18 $ (2 ) $ — $ 16 Actuarial Losses 2,442 (134 ) (207 ) 2,101 Other Benefits Prior Service Cost (80 ) (29 ) — (109 ) Actuarial Gains (17 ) (3 ) (391 ) (411 ) Amount reclassified from AOCI (c) (In millions) (a) Details about AOCI components 2019 2018 2017 Amortization of pension and other benefit items Prior service costs (a) $ 31 $ 29 $ 29 Actuarial losses (a) 135 156 151 Settlements, termination and curtailment losses (a) 3 10 7 Total pensions and other benefits items 169 195 187 Derivative reclassifications to Consolidated Statements of Operations 22 (19 ) (4 ) Total before tax 191 176 183 Tax provision (b) (48 ) (42 ) — Net of tax $ 143 $ 134 $ 183 (a) These AOCI components are included in the computation of net periodic benefit cost (see Note 18 for additional details). (b) Amounts in 2017 do not reflect a tax benefit as a result of a full valuation allowance on our domestic deferred tax assets. (c) The corrections noted in footnote (b) to the table above are consistently reflected in this table.
Pension and Other Benefits Recognized in Balance Sheet	As of December 31, 2019 and 2018 , the following amounts were recognized in the Consolidated Balance Sheet: Pension Benefits Other Benefits (In millions) 2019 2018 2019 2018 Noncurrent assets (a) — — 158 — Current liabilities (3 ) (2 ) (1 ) (52 ) Noncurrent liabilities (413 ) (664 ) (8 ) (209 ) Accumulated other comprehensive loss (b) 2,117 2,460 (520 ) (97 ) Net amount recognized $ 1,701 $ 1,794 $ (371 ) $ (358 ) (a) Included in Noncurrent assets are $49 million of expected retiree medical and life insurance payments for the next twelve months. (b) Accumulated other comprehensive loss effects associated with accounting for pensions and other benefits in accordance with ASC Topic 715 at December 31, 2019 and December 31, 2018 , respectively, are reflected net of tax of $800 million and $991 million respectively, on the Consolidated Statements of Stockholders’ Equity.
Information for Pension Plans with Accumulated Benefit Obligation in Excess of Plan Assets	The Accumulated Benefit Obligation (ABO) for all defined benefit pension plans was $5,636 million and $5,454 million at December 31, 2019 and 2018 , respectively. December 31, (In millions) 2019 2018 Information for pension plans with an accumulated benefit obligation in excess of plan assets: Aggregate accumulated benefit obligations (ABO) $ (5,636 ) $ (5,454 ) Aggregate projected benefit obligations (PBO) (5,822 ) (5,626 ) Aggregate fair value of plan assets 5,406 4,960
Details of Net Periodic Benefit Costs Related to Pension and Other Benefits	Following are the details of net periodic benefit costs related to Pension and Other Benefits: Pension Benefits Other Benefits (In millions) 2019 2018 2017 2019 2018 2017 Components of net periodic benefit cost: Service cost $ 44 $ 49 $ 50 $ 13 $ 17 $ 17 Interest cost 237 233 235 91 92 94 Expected return on plan assets (324 ) (361 ) (390 ) (79 ) (82 ) (65 ) Amortization - prior service costs 2 — — 29 29 29 - actuarial losses 132 152 148 3 4 3 Net periodic benefit cost, excluding below 91 73 43 57 60 78 Multiemployer plans (a) 77 60 59 — — — Settlement, termination and curtailment losses 11 10 7 — — — Net periodic benefit cost $ 179 $ 143 $ 109 $ 57 $ 60 $ 78 (a) Primarily represents pension expense for the SPT covering USW employees hired from National Steel Corporation and new USW employees hired after May 21, 2003.
Assumptions used to Determine Benefit Obligation and Net Periodic Benefit Cost	Weighted average assumptions used to determine the benefit obligation at December 31 and net periodic benefit cost for the year ended December 31 are detailed below. Pension Benefits Other Benefits 2019 2018 2019 2018 U.S. and Europe U.S. and Europe U.S. U.S. Actuarial assumptions used to determine benefit obligations at December 31: Discount rate 3.35 % 4.41 % 3.43 % 4.47 % Increase in compensation rate 2.60 % 2.60 % N/A N/A Pension Benefits 2019 2018 2017 U.S. and Europe U.S. and Europe U.S. and Europe Actuarial assumptions used to determine net periodic benefit cost for the year ended December 31: Discount rate 4.41 % 4.00 % 4.00 % Expected annual return on plan assets 6.50 % 6.85 % 7.25 % Increase in compensation rate 2.60 % 2.60 % 2.60 % Other Benefits 2019 2018 2017 U.S. U.S. U.S. Discount rate 4.47 % 4.03 % 4.00 % Expected annual return on plan assets 4.25 % 4.25 % 3.25 % Increase in compensation rate N/A N/A 3.50 %
Assumed Health Care Cost Trend Rates	2019 2018 Assumed health care cost trend rates at December 31: U.S. U.S. Health care cost trend rate assumed for next year 6.50% 7.00% Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 4.50% 5.00% Year that the rate reaches the ultimate trend rate 2028 2023
Schedule of Defined Benefit Plans Disclosures	U. S. Steel’s Pension plan and Other Benefits plan assets are classified as follows: Level 1 Level 2 Level 3 Short-term Investments Corporate Bonds - U.S. & Non U.S. Private Equities Equity Securities - U.S. & Non U.S. Government Bonds - U.S. & Non U.S. Real Estate Exchange-traded Funds Mortgage and asset-backed securities Mineral Interests Investment Trusts Timberlands
Multiemployer Pension Plans	U. S. Steel’s participation in the SPT for the annual periods ended December 31, 2019 , 2018 and 2017 is outlined in the table below. Employer Pension Protection Act Zone (a) FIP/RP Status (b) U.S. Steel Surcharge (c) Expiration Date Pension Fund 2019 2018 2019 2018 2017 2019 2018 Steelworkers Pension Trust 23-6648508/499 Green Green No $ 77 $ 60 $ 59 No No September 1, 2022 (a) The zone status is based on information that U. S. Steel received from the plan and is certified by the plan’s actuary. Among other factors, plans in the green zone are at least 80 percent funded, while plans in the yellow zone are less than 80 percent funded and plans in the red zone are less than 65 percent funded. (b) Indicates if a financial improvement plan (FIP) or a rehabilitation plan (RP) is either pending or has been implemented. (c) Indicates whether there were charges to U. S. Steel from the plan.
Benefit Payments Expected to be Paid from Defined Benefit Plans	Estimated Future Benefit Payments – The following benefit payments, which reflect expected future service as appropriate, are expected to be paid from U. S. Steel’s defined benefit plans: (In millions) Pension Other 2020 $ 483 $ 153 2021 465 152 2022 442 151 2023 418 149 2024 406 146 Years 2025 - 2028 1,850 680
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Benefits Plan Assets Carried at Fair Value	The following is a summary of U. S. Steel’s Pension plan assets carried at fair value at December 31, 2019 and 2018 : Fair Value Measurements at December 31, 2019 (in millions) Total Quoted Prices in Other Significant Observable Inputs Significant Asset Classes Equity Securities (a) 130 130 — — Corporate & Government Bonds (b) 2,277 — 2,277 — Mineral Interests 2 — — 2 Timberlands 283 — — 283 Real Estate (c) 32 — — 32 All Other (d) 34 34 — — Total assets in the fair value hierarchy $ 2,758 $ 164 $ 2,277 $ 317 Investments measured at net asset value (e) 2,648 Investments at fair value $ 5,406 (a) Includes $123 million of U.S. equity securities and $7 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 1,004 Corporate Bonds - Non U.S. 160 Government Bonds – U.S. 771 Government Bonds - Non U.S. 77 Mortgage and asset-backed securities 265 Total $ 2,277 (c) Includes investments in the Avanti Funds and the Mariano Ranch properties. (d) Includes $26 million of cash, $19 million of accrued income, $(8) million of investment purchases and $(3) million of miscellaneous payables. (e) In accordance with ASC Topic 820, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.	Fair Value Measurements at December 31, 2018 (in millions) Total Quoted Prices in Other Significant Observable Inputs (Level 2) Significant Asset Classes Short-term investments $ 7 $ 7 $ — $ — Equity Securities (a) 101 101 — — Corporate & Government Bonds (b) 2,143 — 2,143 — Mineral Interests 2 — — 2 Timberlands 294 — — 294 Private equities (c) 2 — — 2 Real Estate (d) 33 — — 33 All Other (e) 14 14 — — Total assets in the fair value hierarchy $ 2,596 $ 122 2,143 $ 331 Investments measured at net asset value (f) 2,364 Investments at fair value $ 4,960 (a) Includes $95 million of U.S. equity securities and $6 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 933 Corporate Bonds – Non U.S. 149 Government Bonds – U.S. 858 Government Bonds – Non U.S. 67 Mortgage and asset-backed securities 136 Total $ 2,143 (c) Includes investments in CAI Partners and Company III LP, Clayton Dubilier Rice Fund VI and Epiris Club 2007. (d) Includes investments in the Avanti Funds and the Mariano Ranch properties. (e) Includes $32 million of cash, $57 million of investment sales, $21 million of accrued income, and $(80) million of investment purchases and $(16) million of miscellaneous payables. (f) In accordance with ASC Topic 820, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.
Investments Based on Net Asset Value	The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2019 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 238 $ 48 Not redeemable N/A Real Estate Funds (a) 240 62 Not redeemable N/A Commingled Funds 2,170 N/A N/A N/A Investments measured at net asset value $ 2,648 (a) The remaining lives of such investments range from approximately less than 1 year to up to 9 years.	The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2018 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 254 $ 68 Not redeemable N/A Real Estate Funds (a) 236 93 Not redeemable N/A Commingled Funds 1,874 N/A N/A N/A Investments measured at net asset value $ 2,364 (a) The remaining lives of such investments range from approximately less than 1 year to up to 10 years.
Changes in Fair Value of Pension and Other Benefits Plan Level 3 Assets	The following table sets forth a summary of changes in the fair value of U. S. Steel’s Pension plan Level 3 assets for the years ended December 31, 2019 and 2018 : (In millions) 2019 2018 Balance at beginning of period $ 331 $ 340 Transfers in and/or out of Level 3 — — Actual return on plan assets: Realized gain 8 11 Net unrealized loss (21 ) (8 ) Purchases, sales, issuances and settlements: Purchases 1 — Sales (2 ) (12 ) Balance at end of period $ 317 $ 331
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Benefits Plan Assets Carried at Fair Value	The following is a summary of U. S. Steel’s Other Benefits plan assets carried at fair value at December 31, 2019 and 2018 . Fair Value Measurements at December 31, 2019 (in millions) Total Quoted Prices in Other Significant Observable Inputs (Level 2) Significant Asset Classes Short-term investments $ 31 $ 31 — $ — Equity Securities (a) 49 49 — — Corporate & Government Bonds (b) 1,799 — 1,799 — Timberlands 35 — — 35 All Other (c) 25 25 — — Total assets in the fair value hierarchy $ 1,939 $ 105 $ 1,799 $ 35 Investments measured at net asset value (d) 86 Investments at fair value $ 2,025 (a) Includes $30 million of U.S. equity securities and $19 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 1,132 Corporate Bonds - Non U.S. 287 Government Bonds – U.S. 329 Government Bonds - Non U.S. 13 Mortgage and asset-backed Securities 38 Total $ 1,799 (c) Includes $12 million of cash, $16 million of accrued income, $2 million of investments sales and $(5) million of miscellaneous payables. (d) In accordance with Subtopic 820-10, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.	Fair Value Measurements at December 31, 2018 (in millions) Total Quoted Prices in Other Significant Observable Inputs (Level 2) Significant Asset Classes Short-term investments 42 42 — — Equity Securities (a) 45 45 — — Corporate & Government Bonds (b) 1,631 — 1,631 — Timberlands 35 — — 35 All Other (c) 13 13 — — Total assets in the fair value hierarchy $ 1,766 $ 100 1,631 $ 35 Investments measured at net asset value (d) 94 Investments at fair value $ 1,860 (a) Includes $27 million of U.S. equity securities and $18 million of Non U.S. equity securities. (b) Underlying investments include: Corporate Bonds – U.S. $ 1,052 Corporate Bonds - Non U.S. 271 Government Bonds – U.S. 270 Government Bonds - Non U.S. 8 Mortgage and asset-backed Securities 30 Total $ 1,631 (c) Includes $16 million of accrued income and $(3) million of investment purchase payables. (d) In accordance with Subtopic 820-10, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.
Investments Based on Net Asset Value	The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2019 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 54 $ 8 Not redeemable NA Real Estate Funds (a) 32 10 Not redeemable NA Investments measured at net asset value $ 86 (a) The remaining lives of such investments range from approximately less than 1 year up to 9 years.	The following table represents investments based on net asset value and the significant unobservable inputs and the ranges of values for those inputs (in millions): Net Asset Value at December 31, 2018 Unfunded Commitments Redemption Frequency Redemption Notice Period Private Equity Funds (a) $ 61 $ 10 Not redeemable N/A Real Estate Funds (a) 33 12 Not redeemable N/A Investments measured at net asset value $ 94 (a) The remaining lives of such investments range from approximately less than 1 year to up to 10 years.
Changes in Fair Value of Pension and Other Benefits Plan Level 3 Assets	The following table sets forth a summary of changes in the fair value of U. S. Steel’s Other Benefits plan Level 3 assets for the years ended December 31, 2019 and 2018 : (In millions) 2019 2018 Balance at beginning of period $ 35 $ 35 Transfers in and/or out of Level 3 — — Actual return on plan assets: Realized gain — 1 Net unrealized loss — (1 ) Purchases, sales, issuances and settlements: Sales — — Balance at end of period $ 35 $ 35

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2019
Asset Retirement Obligation Disclosure [Abstract]
Changes in Carrying Values of Asset Retirement Obligations	The following table reflects changes in the carrying values of AROs for the years ended December 31, 2019 and 2018 : December 31, (In millions) 2019 2018 Balance at beginning of year $ 60 $ 69 Additional obligations incurred 4 — Obligations settled (9 ) (12 ) Accretion expense 3 3 Balance at end of period $ 58 $ 60

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Change in Fair Value by Option from Purchase Date	The following table shows the change in fair value by option from purchase date through December 31, 2019 . (In millions) Balance Sheet Location Fair Value asset/(liability) (a) Fair Value Fair Value asset/(liability) U. S. Steel Call Option Investments and Long-Term Receivables $ 162 $ 4 $ 166 Class B Common Deferred credits and other noncurrent liabilities $ (181 ) $ (11 ) $ (192 ) Class B Common Deferred credits and other noncurrent liabilities $ (2 ) $ — $ (2 ) Net Mark to Market Impact $ (7 ) (a) On October 31, 2019, a wholly owned subsidiary of U. S. Steel purchased a 49.9% ownership interest in Big River Steel
Fair Value Measurement Inputs and Valuation Techniques	The following table shows the net fair values of the options at December 31, 2019 and the effect on these amounts of a hypothetical change in the market prices or rates that existed as of December 31, 2019 . Fair Value asset/(liability) Big River Steel Equity Value Volatility Risk Free Interest Rate U. S. Steel's Credit Spread (In millions) 5% (5)% 10% (10)% 1% (1)% 1% (1)% U. S. Steel Call Option $166 $19 $(17) $34 $(34) $3 $(3) N/A N/A Class B Common Put Option $(192) $15 $(16) $(25) $25 $13 $(14) $7 $(8) Class B Common Call Option $(2) $— $— $— $— $— $— N/A N/A The following tables shows the assumptions used in the calculations shown in the table directly above. At December 31, 2019 Big River Steel Equity Value (in approximate billions) $ 1.4 Volatility 54.1 % Risk Free Interest Rate 1.6 % Credit Spread 7.9 %
Financial Assets and Liabilities Not Carried at Fair Value	The following table summarizes U. S. Steel’s financial assets and liabilities that were not carried at fair value at December 31, 2019 and 2018 . December 31, 2019 December 31, 2018 (In millions) Fair Value Carrying Fair Value Carrying Financial liabilities: Long-term debt (a) $ 3,576 $ 3,575 $ 2,182 $ 2,353 (a) Excludes finance lease obligations.

Reclassifications from Accumu_2

Reclassifications from Accumulated Other Comprehensive Income (AOCI) (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	(In millions) Pension and Other Benefit Items Foreign Currency Items Unrealized Gain (Loss) on Derivatives Total Balance at December 31, 2017 $ (1,309 ) $ 463 $ 1 $ (845 ) Other comprehensive loss before reclassifications (b) (255 ) (60 ) — (315 ) Amounts reclassified from AOCI (a)(b) 148 — (14 ) 134 Net current-period other comprehensive loss (107 ) (60 ) (14 ) (181 ) Balance at December 31, 2018 $ (1,416 ) $ 403 $ (13 ) $ (1,026 ) Other comprehensive income (loss) before reclassifications 446 (22 ) (19 ) 405 Amounts reclassified from AOCI (a) 127 — 16 143 Net current-period other comprehensive income (loss) 573 (22 ) (3 ) 548 Balance at December 31, 2019 $ (843 ) $ 381 $ (16 ) $ (478 ) (a) See table below for further details. (b) The Company previously disclosed in Note 21 to the Consolidated Financial Statements in its Annual Report on Form 10-K for the period ended December 31, 2018, an increase to AOCI of $41 million in the Other comprehensive income before reclassifications line item and a decrease to AOCI of $148 million in the Amounts reclassified from AOCI line item for the twelve months ended December 31, 2018 amounts for Pension and Other Benefit Items. These amounts should have been disclosed as a decrease to AOCI of $255 million and an increase to AOCI of $148 million , respectively, which have been corrected in the table above. The Company concluded that the errors were not material to the financial statements of any prior annual or interim period and therefore, amendments of previously filed reports are not required. The revision had no impact on the Consolidated Balance Sheets, Consolidated Statements of Operations, Consolidated Statements of Cash Flows or the Consolidated Statements of Comprehensive Income (Loss). Quarterly periods not presented herein will be revised, as applicable, in future filings.
Amounts Recognized in Accumulated Other Comprehensive Loss	Amounts recognized in accumulated other comprehensive loss: 2019 (In millions) 12/31/2018 Amortization Activity 12/31/2019 Pensions Prior Service Cost $ 18 $ (2 ) $ — $ 16 Actuarial Losses 2,442 (134 ) (207 ) 2,101 Other Benefits Prior Service Cost (80 ) (29 ) — (109 ) Actuarial Gains (17 ) (3 ) (391 ) (411 ) Amount reclassified from AOCI (c) (In millions) (a) Details about AOCI components 2019 2018 2017 Amortization of pension and other benefit items Prior service costs (a) $ 31 $ 29 $ 29 Actuarial losses (a) 135 156 151 Settlements, termination and curtailment losses (a) 3 10 7 Total pensions and other benefits items 169 195 187 Derivative reclassifications to Consolidated Statements of Operations 22 (19 ) (4 ) Total before tax 191 176 183 Tax provision (b) (48 ) (42 ) — Net of tax $ 143 $ 134 $ 183 (a) These AOCI components are included in the computation of net periodic benefit cost (see Note 18 for additional details). (b) Amounts in 2017 do not reflect a tax benefit as a result of a full valuation allowance on our domestic deferred tax assets. (c) The corrections noted in footnote (b) to the table above are consistently reflected in this table.

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Year Ended December 31, (In millions) 2019 2018 2017 Net cash (used in) provided by operating activities included: Interest and other financial costs paid (net of amount capitalized) $ (151 ) $ (207 ) $ (242 ) Income taxes refunded (paid) $ 38 $ (39 ) $ (40 ) Non-cash investing and financing activities: Change in accrued capital expenditures $ (70 ) $ 135 $ 208 U. S. Steel common stock issued for employee/non-employee director stock plans $ 19 $ 21 $ 49 Capital expenditures funded by finance lease borrowings $ 46 $ — $ — Big River Steel put and call options (a) $ 21 $ — $ — (a) The Big River Steel put and call options amount represents the excess of the Class B Common Put Option and the Class B Common Call Option liabilities over the U. S. Steel Call Option asset from U. S. Steel's acquisition of its 49.9% ownership interest in Big River Steel on October 31, 2019. See Note 20 for further details.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Schedule of Operating and Finance Leases by Balance Sheet Location	The following table summarizes the lease amounts included in our Consolidated Balance Sheet as of December 31, 2019 . (In millions) Balance Sheet Location December 31, 2019 Assets Operating Operating lease assets (a) (c) $ 230 Finance Property, plant and equipment (b) 56 Total Lease Assets $ 286 Liabilities Current Operating Current operating lease liabilities (c) $ 60 Finance Current portion of long-term debt 11 Non-Current Operating Noncurrent operating lease liabilities (c) 177 Finance Long-term debt less unamortized discount and issue costs 51 Total Lease Liabilities $ 299 (a) Operating lease assets are recorded net of accumulated amortization of $50 million . (b) Finance lease assets are recorded net of accumulated depreciation of $27 million .
Schedule of Operating and Finance Lease Costs by Income Statement Location	The following table summarizes lease costs included in our Consolidated Statement of Operations for the twelve month periods ended December 31, 2019 . (In millions) Classification Year Ended December 31, 2019 Operating Lease Cost (a) Cost of sales $ 81 Operating Lease Cost Selling, general and administrative expenses 11 Finance Lease Cost Amortization Depreciation, depletion and amortization 7 Interest Interest expense 3 Total Lease Cost $ 102 (a) Operating lease cost recorded in cost of sales includes $15 million of variable lease cost for the year ended December 31, 2019 . An immaterial amount of variable lease cost is included in selling, general and administrative expenses and immaterial amounts of short-term lease cost are included in cost of sales and selling, general and administrative expenses.
Schedule of Operating Lease Maturities	Lease liability maturities as of December 31, 2019 are shown below (In millions) Operating Finance Total 2020 $ 74 $ 15 $ 89 2021 58 14 72 2022 46 18 64 2023 34 7 41 2024 26 6 32 After 2024 51 12 63 Total Lease Payments $ 289 $ 72 $ 361 Less: Interest 52 10 62 Present value of lease liabilities $ 237 $ 62 $ 299
Schedule of Financing Lease Maturities	Lease liability maturities as of December 31, 2019 are shown below (In millions) Operating Finance Total 2020 $ 74 $ 15 $ 89 2021 58 14 72 2022 46 18 64 2023 34 7 41 2024 26 6 32 After 2024 51 12 63 Total Lease Payments $ 289 $ 72 $ 361 Less: Interest 52 10 62 Present value of lease liabilities $ 237 $ 62 $ 299
Schedule Of Future Minimum Obligations Under Operating And Capital Lease Commitments Table [Text Block]	Future minimum commitments for capital and operating leases having non-cancelable lease terms in excess of one year as of the year ended December 31, 2018 were as follows. (In millions) Capital Operating 2019 $ 5 $ 66 2020 5 55 2021 5 45 2022 11 37 2023 — 28 After 2023 — 72 Total minimum lease payments $ 26 $ 303 Less imputed interest costs 4 Present value of net minimum lease payments included in long-term debt $ 22
Schedule of Lease Terms and Discount Rates	Lease terms and discount rates are shown below. December 31, 2019 Weighted average lease term Finance 5 years Operating 5 years Weighted average discount rate Finance 6.05 % Operating 7.76 %
Schedule of Cash Amounts Paid for Lease Liabilities	Supplemental cash flow information related to leases follows. (In millions) Year Ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 72 Operating cash flows from finance leases 3 Financing cash flows from finance leases 7 Right-of-use assets exchanged for lease liabilities: Operating leases 53 Finance leases 46

Restructuring and Other Charg_2

Restructuring and Other Charges (Tables)	12 Months Ended
	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Activity in Accrued Balances for Restructuring and Other Cost Reduction Programs	The activity in the accrued balances incurred in relation to restructuring and other cost reduction programs during the years ended December 31, 2019 and December 31, 2018 were as follows: (in millions) Employee Related Costs Exit Costs Non-cash Charges (a) Total Balance at December 31, 2017 $ 4 $ 34 $ — $ 38 Cash payments/utilization (4 ) (17 ) — (21 ) Balance at December 31, 2018 $ — $ 17 $ — $ 17 Additional charges 111 119 45 275 Cash payments/utilization (24 ) (11 ) (45 ) (80 ) Balance at December 31, 2019 $ 87 $ 125 $ — $ 212 (a) Non-cash charges primarily relate to accelerated depreciation associated with the intended indefinite idling of our ECT operations and Dearborn, Michigan, finishing facility.
Balance Sheet Location of Accrued Liabilities for Restructuring and Other Cost Reduction Programs	Accrued liabilities for restructuring and other cost reduction programs are included in the following balance sheet lines: (in millions) December 31, 2019 December 31, 2018 Accounts payable $ 46 $ 11 Payroll and benefits payable 64 — Employee benefits 23 — Deferred credits and other noncurrent liabilities 79 6 Total $ 212 $ 17

Contingencies and Commitments (

Contingencies and Commitments (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Asbestos Litigation Activity	The following table shows the number of asbestos claims in the current year and the prior two years: Period ended Opening Claims (a) New Closing December 31, 2017 3,340 275 250 3,315 December 31, 2018 3,315 1,285 290 2,320 December 31, 2019 2,320 195 265 2,390
Changes in Accrued Liabilities for Remediation Activities	Changes in accrued liabilities for remediation activities where U. S. Steel is identified as a named party are summarized in the following table: Year Ended December 31, (In millions) 2019 2018 Beginning of period $ 187 $ 179 Accruals for environmental remediation deemed probable and reasonably estimable 20 14 Obligations settled (21 ) (6 ) End of period $ 186 $ 187
Accrued Liabilities for Remediation Activities Included in Balance Sheet	Accrued liabilities for remediation activities are included in the following Consolidated Balance Sheet lines: (In millions) December 31, 2019 December 31, 2018 Accounts payable $ 53 $ 37 Deferred credits and other noncurrent liabilities 133 150 Total $ 186 $ 187
Payments for Contracts with Remaining Terms in Excess of One Year	Payments for contracts with remaining terms in excess of one year are summarized below (in millions): 2020 2021 2022 2023 2024 Later years Total $430 $404 $337 $338 $107 $611 $2,227

Nature of Business and Signif_3

Nature of Business and Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019	Oct. 31, 2019	Oct. 30, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Percentage of LIFO (last in first out) inventory to total inventory	75.00%			74.00%
Portion of salaried employees that receive pension benefits through a defined contribution pension plan	three-quarters
Pension corridor percentage	10.00%
Big River Steel
Significant Accounting Policies [Line Items]
Ownership interest		49.90%	49.90%

Recently Adopted Accounting S_3

Recently Adopted Accounting Standards - Changes Related to Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Sales	$ 12,082	$ 12,305	$ 10,858
Selling, general and administrative expenses	289	336	320
Cash removed from investing activities	1,958	963	386
Decrease in net cash provided by operating activities	$ (682)	$ (938)	(826)
Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Sales			10,858
Selling, general and administrative expenses			320
Net periodic benefit cost (other than service cost)			61
Accounting Standards Update 2017-07 | Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Sales			10,864
Selling, general and administrative expenses			375
Net periodic benefit cost (other than service cost)			0
Accounting Standards Update 2017-07 | Effect of Change Higher/(Lower)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Sales			(6)
Selling, general and administrative expenses			(55)
Net periodic benefit cost (other than service cost)			61
Accounting Standards Update 2016-18 | Effect of Change Higher/(Lower)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash removed from investing activities			3
Accounting Standards Update 2016-15 | Effect of Change Higher/(Lower)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in net cash provided by operating activities			$ 23

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019Segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Information - Results o

Segment Information - Results of Segment Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 12,937	$ 14,178	$ 12,250
Earnings (loss) from investees	79	61	44
Earnings (Loss) before Interest and Income Taxes	(230)	1,124	669
Depreciation, depletion & amortization	616	521	501
Capital expenditures	1,252	1,001	505
Flat-Rolled
Segment Reporting Information [Line Items]
Net sales	9,279	9,681	8,297
Earnings (loss) from investees	84	54	38
Earnings (Loss) before Interest and Income Taxes	196	883	375
Depreciation, depletion & amortization	456	367	352
Capital expenditures	943	820	388
USSE
Segment Reporting Information [Line Items]
Net sales	2,417	3,205	2,949
Earnings (loss) from investees	0	0	0
Earnings (Loss) before Interest and Income Taxes	(57)	359	327
Depreciation, depletion & amortization	92	87	76
Capital expenditures	153	104	83
Tubular
Segment Reporting Information [Line Items]
Net sales	1,188	1,231	944
Earnings (loss) from investees	5	7	8
Earnings (Loss) before Interest and Income Taxes	(67)	(58)	(99)
Depreciation, depletion & amortization	46	47	51
Capital expenditures	145	45	28
Total reportable segments
Segment Reporting Information [Line Items]
Net sales	12,884	14,117	12,190
Earnings (loss) from investees	89	61	46
Earnings (Loss) before Interest and Income Taxes	72	1,184	603
Depreciation, depletion & amortization	594	501	479
Capital expenditures	1,241	969	499
Other Businesses
Segment Reporting Information [Line Items]
Net sales	53	61	60
Earnings (loss) from investees	(10)	0	(2)
Earnings (Loss) before Interest and Income Taxes	23	55	44
Depreciation, depletion & amortization	22	20	22
Capital expenditures	11	32	6
Reconciling Items and Eliminations
Segment Reporting Information [Line Items]
Net sales	0	0	0
Earnings (loss) from investees	0	0	0
Earnings (Loss) before Interest and Income Taxes	(325)	(115)	22
Depreciation, depletion & amortization	0	0	0
Capital expenditures	0	0	0
Net Sales
Segment Reporting Information [Line Items]
Net sales	12,937	14,178	12,250
Net Sales | Flat-Rolled
Segment Reporting Information [Line Items]
Net sales	9,560	9,912	8,491
Net Sales | USSE
Segment Reporting Information [Line Items]
Net sales	2,420	3,228	2,974
Net Sales | Tubular
Segment Reporting Information [Line Items]
Net sales	1,191	1,236	945
Net Sales | Total reportable segments
Segment Reporting Information [Line Items]
Net sales	13,171	14,376	12,410
Net Sales | Other Businesses
Segment Reporting Information [Line Items]
Net sales	168	186	179
Net Sales | Reconciling Items and Eliminations
Segment Reporting Information [Line Items]
Net sales	(402)	(384)	(339)
Intersegment Sales
Segment Reporting Information [Line Items]
Net sales	0	0	0
Intersegment Sales | Flat-Rolled
Segment Reporting Information [Line Items]
Net sales	281	231	194
Intersegment Sales | USSE
Segment Reporting Information [Line Items]
Net sales	3	23	25
Intersegment Sales | Tubular
Segment Reporting Information [Line Items]
Net sales	3	5	1
Intersegment Sales | Total reportable segments
Segment Reporting Information [Line Items]
Net sales	287	259	220
Intersegment Sales | Other Businesses
Segment Reporting Information [Line Items]
Net sales	115	125	119
Intersegment Sales | Reconciling Items and Eliminations
Segment Reporting Information [Line Items]
Net sales	$ (402)	$ (384)	$ (339)

Segment Information - Schedule

Segment Information - Schedule of Assets by Segment (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 11,608	$ 10,982
Flat-Rolled
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	7,267	6,977
Goodwill		3
USSE
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	5,360	5,607
Goodwill	4	4
Tubular
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,150	1,076
Total reportable segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	13,777	13,660
Other Businesses
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,267	329
Corporate, reconciling items, and eliminations(c)
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ (3,436)	$ (3,007)

Segment Information - Schedul_2

Segment Information - Schedule of Reconciling Items to EBIT (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	$ (230)	$ 1,124	$ 669
Reconciling Items and Eliminations
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	(325)	(115)	22
Reconciling Items and Eliminations | United Steelworkers Labor Agreement
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	0	(81)	0
Reconciling Items and Eliminations | Restructuring Charges
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	(275)	0	0
Reconciling Items and Eliminations | Gain (loss) on Equity Investee Transactions
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	0	38	2
Reconciling Items and Eliminations | Clairton | Fire
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	(50)	0	0
Reconciling Items and Eliminations | Granite City | Restart and Related Costs
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	0	(80)	0
Reconciling Items and Eliminations | Granite City | Temporary Idling Charges
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	0	8	(17)
Reconciling Items and Eliminations | Tubular products | Restructuring Charges
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	0	0	(35)
Reconciling Items and Eliminations | U.S. Steel Canada | Gain associated with USSC
Other items not allocated to segments:
(Loss) earnings before interest and income taxes	$ 0	$ 0	$ 72

Segment Information - Net Sales

Segment Information - Net Sales, Property, Plant and Equipment and Equity Method Investments Based on Location of Operating Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
External Sales	$ 12,937	$ 14,178	$ 12,250
Assets	6,719	5,351	4,737
North America
Segment Reporting Information [Line Items]
External Sales	10,520	10,973	9,301
Assets	5,772	4,432	3,831
Europe
Segment Reporting Information [Line Items]
External Sales	2,417	3,205	2,949
Assets	947	919	906
U.S.
Segment Reporting Information [Line Items]
Assets	$ 5,772	$ 4,432	$ 3,817

Acquisition and Disposition - A

Acquisition and Disposition - Additional Information (Details) T in Thousands, $ in Millions	Oct. 31, 2019USD ($)T	Jun. 30, 2017USD ($)	Dec. 31, 2019USD ($)	Oct. 30, 2019
Big River Steel(a)
Business Acquisition [Line Items]
Ownership interest	49.90%			49.90%
Remaining ownership interest	50.10%
Purchase price	$ 683
Term option to purchase remaining equity interest	4 years
Number of tons of steel making capacity | T	1,650
Equity investment asset	$ 710
Transaction costs	27
Net asset value of interest acquired	155
Step up adjustments related to various assets	550
Step up adjustments related to property, plant and equipment	88
Step up adjustment for goodwill	$ 460
Amortization period of assets acquired	18 years
Amortization expenses recognized in acquisition (less than)			$ 1
U. S. Steel Canada Inc.
Business Acquisition [Line Items]
Proceeds in Satisfaction of Secured Claims		$ 127
Gain (Loss) on Disposition of Stock in Subsidiary		$ 72

Acquisition and Disposition - S

Acquisition and Disposition - Schedule of Options Recorded as Embedded Financial Instruments included in Equity Investment Asset (Details) $ in Millions	Dec. 31, 2019USD ($)
Call Option
Open Option Contracts Written [Line Items]
Value of options	$ 166
Common Class B | Call Option
Open Option Contracts Written [Line Items]
Value of options	2
Common Class B | Put Option
Open Option Contracts Written [Line Items]
Value of options	$ 192

Revenue - Additional Informatio

Revenue - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019Segment
Revenue from Contract with Customer [Abstract]
Number of reportable segments	3

Revenue - Disaggregation of Sal

Revenue - Disaggregation of Sales by Product (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 12,937	$ 14,178	$ 12,250
Semi-finished
Disaggregation of Revenue [Line Items]
Net sales	316	330	304
Hot-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	3,501	4,129	3,255
Cold-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	2,795	3,093	2,683
Coated sheets
Disaggregation of Revenue [Line Items]
Net sales	3,999	4,254	3,940
Tubular products
Disaggregation of Revenue [Line Items]
Net sales	1,206	1,243	948
All Other (a)
Disaggregation of Revenue [Line Items]
Net sales	1,120	1,129	1,120
Flat-Rolled
Disaggregation of Revenue [Line Items]
Net sales	9,279	9,681	8,297
Flat-Rolled | Semi-finished
Disaggregation of Revenue [Line Items]
Net sales	305	156	72
Flat-Rolled | Hot-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	2,504	2,816	2,045
Flat-Rolled | Cold-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	2,512	2,709	2,355
Flat-Rolled | Coated sheets
Disaggregation of Revenue [Line Items]
Net sales	2,993	3,090	2,902
Flat-Rolled | Tubular products
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Flat-Rolled | All Other (a)
Disaggregation of Revenue [Line Items]
Net sales	965	910	923
USSE
Disaggregation of Revenue [Line Items]
Net sales	2,417	3,205	2,949
USSE | Semi-finished
Disaggregation of Revenue [Line Items]
Net sales	11	174	232
USSE | Hot-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	997	1,313	1,210
USSE | Cold-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	283	384	328
USSE | Coated sheets
Disaggregation of Revenue [Line Items]
Net sales	1,006	1,164	1,038
USSE | Tubular products
Disaggregation of Revenue [Line Items]
Net sales	40	48	39
USSE | All Other (a)
Disaggregation of Revenue [Line Items]
Net sales	80	122	102
Tubular
Disaggregation of Revenue [Line Items]
Net sales	1,188	1,231	944
Tubular | Semi-finished
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Tubular | Hot-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Tubular | Cold-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Tubular | Coated sheets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Tubular | Tubular products
Disaggregation of Revenue [Line Items]
Net sales	1,166	1,195	909
Tubular | All Other (a)
Disaggregation of Revenue [Line Items]
Net sales	22	36	35
Other Businesses
Disaggregation of Revenue [Line Items]
Net sales	53	61	60
Other Businesses | Semi-finished
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Other Businesses | Hot-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Other Businesses | Cold-rolled sheets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Other Businesses | Coated sheets
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Other Businesses | Tubular products
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Other Businesses | All Other (a)
Disaggregation of Revenue [Line Items]
Net sales	$ 53	$ 61	$ 60

Net Interest and Other Financ_3

Net Interest and Other Financial Costs - Net Interest and Other Financial Costs (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 31, 2019	Oct. 30, 2019
Interest income:
Interest income		$ (17)	$ (23)	$ (17)
Interest expense and other financial costs:
Interest incurred		162	175	229
Less interest capitalized		20	7	3
Total interest expense		142	168	226
Loss on debt extinguishment (Note 7)		0	98	54
Net periodic benefit costs (other than service cost) (b)	[1]	91	69	61
Foreign currency net (gain) loss (c)		(17)	(19)	23
Financial costs on:
Amended Credit Agreement		5	5	6
USSK credit facilities		1	3	3
Other (d)		10	3	2
Amortization of discounts and deferred financing costs		7	8	10
Total other financial costs		6	0	44
Net interest and other financial costs		222	$ 312	$ 368
Change in fair value of put and call options		$ 7
Big River Steel
Business Acquisition [Line Items]
Ownership interest					49.90%	49.90%
[1]	Represents postretirement benefit expense as a result of the adoption of Accounting Standards Update 2017-07, Compensation - Retirement Benefits on January 1, 2018 (see Note 3 for further details).

Earnings and Dividends Per Co_3

Earnings and Dividends Per Common Share - Computations for Basic and Diluted Income (Loss) Per Common Share from Continuing Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net (loss) earnings attributable to United States Steel Corporation stockholders	$ (630)	$ 1,115	$ 387
Weighted-average shares outstanding (in thousands):
Basic	171,418	176,633	174,793
Effect of convertible notes	0	0	0
Effect of stock options, restricted stock units and performance awards	0	1,828	1,727
Adjusted weighted-average shares outstanding, diluted	171,418	178,461	176,520
Basic (loss) earnings per common share	$ (3.67)	$ 6.31	$ 2.21
Diluted (loss) earnings per common share	$ (3.67)	$ 6.25	$ 2.19

Earnings and Dividends Per Co_4

Earnings and Dividends Per Common Share - Antidilutive Securities that were Not Included in Computation of Diluted Loss Per Common Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per common share	5,109	1,631	1,579
Securities granted under the 2005 Stock Incentive Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per common share	4,459	1,631	1,579
Securities convertible under the Senior Convertible Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per common share	650	0	0

Earnings and Dividends Per Co_5

Earnings and Dividends Per Common Share - Additional Information (Details) - $ / shares	3 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017
Dividends Payable [Line Items]
Quarterly dividends per common share					$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05
Subsequent Event
Dividends Payable [Line Items]
Quarterly dividends per common share	$ 0.01	$ 0.01	$ 0.01	$ 0.01

Cash, Cash Equivalents, and R_3

Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 749	$ 1,000	$ 1,553
Restricted cash in other current assets	2	3	6
Long-term restricted cash	188	37	38
Total cash, cash equivalents and restricted cash	$ 939	$ 1,040	$ 1,597	$ 1,555

Inventories Inventory balances

Inventories Inventory balances (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 628	$ 605
Semi-finished products	720	1,021
Finished products	376	404
Supplies and sundry items	61	62
Total	$ 1,785	$ 2,092

Inventories - Additional Inform

Inventories - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Estimate in excess of current acquisition costs over stated inventory values	$ 735	$ 1,038
Change in income from operations as a result of liquidations of LIFO inventories	28	10	$ 6
Land held for residential or commercial development	$ 40	$ 39

Income Taxes - Components of Ea

Income Taxes - Components of Earnings (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
(Loss) earnings before income taxes	$ (452)	$ 812	$ 301
United States
Income Taxes [Line Items]
(Loss) earnings before income taxes	(381)	434	75
Foreign
Income Taxes [Line Items]
(Loss) earnings before income taxes	$ (71)	$ 378	$ 226

Income Taxes - (Benefit) Provis

Income Taxes - (Benefit) Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current (Benefit) Provision for Income Taxes
Current Federal income tax (benefit) provision	$ (18)	$ (40)	$ (66)
Current state and local Income tax (benefit) provision	0	2	(1)
Current foreign income tax (benefit) provision	(6)	64	53
Current income tax (benefit) provision	(24)	26	(14)
Deferred (Benefit) Provision for Income Taxes
Deferred Federal income tax (benefit) provision	196	(283)	(81)
Deferred state and local Income tax (benefit) provision	23	(58)	0
Deferred foreign income tax (benefit) provision	(17)	12	9
Deferred income tax (benefit) provision	202	(329)	(72)
(Benefit) Provision for Income Taxes, Total
Federal income tax (benefit) provision	178	(323)	(147)
State and local Income tax (benefit) provision	23	(56)	(1)
Foreign income tax (benefit) provision	(23)	76	62
Total provision (benefit)	$ 178	$ (303)	$ (86)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Federal Statutory Tax to Total Provisions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory rate applied to earnings (loss) before income taxes	$ (95)	$ 171	$ 105
Valuation allowance	334	(412)	36
Excess percentage depletion	(46)	(48)	(68)
State and local income taxes after federal income tax effects	(36)	8	(28)
Effects of foreign operations	(23)	74	62
U.S. impact of foreign operations	25	(21)	(6)
Impact of tax credits	5	(71)	(56)
Effect of tax reform	0	0	(81)
Alternative minimum tax credit refund	0	0	(48)
Adjustment of prior years' federal income taxes	7	0	0
Other	7	(4)	(2)
Total provision (benefit)	$ 178	$ (303)	$ (86)

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets
Federal tax loss carryforwards (expiring in 2035 through 2036)	$ 176	$ 220
State tax credit carryforwards (expiring in 2020 through 2028)	18	16
Minimum tax credit carryforwards	19	38
General business credit carryforwards (expiring in 2027 through 2039)	85	85
Foreign tax loss and credit carryforwards (expiring in 2024 through 2029)	170	173
Employee benefits	173	337
Contingencies and accrued liabilities	71	62
Investments in subsidiaries and equity investees	49	59
Inventory	32	0
Other temporary differences	35	26
Valuation allowance	(563)	(214)
Total deferred tax assets	422	972
Deferred Tax Liabilities
Property, plant and equipment	368	468
Inventory	0	22
Receivables, payables and debt	17	33
Indefinite-lived intangible assets	19	18
Other temporary differences	3	0
Total deferred tax liabilities	407	541
Net deferred tax asset	15	431
Federal
Deferred Tax Assets
Capital loss carryforwards	27	33
Valuation allowance	(560)	(211)
Deferred Tax Liabilities
Net deferred tax asset	12	445
State
Deferred Tax Assets
Capital loss carryforwards	$ 130	$ 137

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of unrecognized tax benefits [Roll Forward]:
Unrecognized tax benefits, beginning of year	$ 35	$ 42	$ 72
Increases – tax positions taken in prior years	0	0	1
Decreases – tax positions taken in prior years	0	(2)	(26)
Settlements	(32)	0	(4)
Lapse of statute of limitations	0	(5)	(1)
Unrecognized tax benefits, end of year	$ 3	$ 35	$ 42

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Statutory tax rate	21.00%
Tax benefit related to partial reversal of valuation allowance		$ 374
Tax benefit related to reversal of the valuation allowance related to current year activity		38
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount			$ 10
Tax benefit related to reversal of valuation allowance on AMT credits			71
Effective Income Tax Rate Reconciliation, Deduction, Amount			48
Non-cash tax expense	$ 334
Net deferred tax asset	15	431
Valuation allowance on net deferred tax asset	563	214
Unrecognized tax benefits	3	35	$ 42	$ 72
Total amount of unrecognized tax benefits that, if recognized, would affect effective tax rate	2	2
Accrued liabilities, interest on unrecognized tax benefits	2	2
Domestic Country
Income Taxes [Line Items]
Net deferred tax asset	12	445
Valuation allowance on net deferred tax asset	560	211
Foreign
Income Taxes [Line Items]
Net deferred tax asset	3
Valuation allowance on net deferred tax asset	$ 3
Deferred Tax Liabilities, Net		14
Deferred Tax Liabilities, Valuation Allowance		$ 3

Investments, Long-Term Receiv_3

Investments, Long-Term Receivables and Equity Investee Transactions - Schedule of Investments and Long-Term Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity method investments	$ 1,272	$ 485
Receivables due after one year, less allowance of $5 and $11	191	24
Receivables due after one year, allowance	5	11
Other	3	4
Total	$ 1,466	$ 513

Investments, Long-Term Receiv_4

Investments, Long-Term Receivables and Equity Investee Transactions - Summarized Financial Information of Investees Accounted for by Equity Method of Accounting (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income data:
Net Sales	$ 2,528	$ 2,193	$ 2,485
Operating income	253	157	132
Net earnings	235	134	109
Balance sheet data:
Current Assets	1,144	642	633
Noncurrent Assets	2,976	853	710
Current liabilities	573	348	441
Noncurrent Liabilities	$ 2,542	$ 516	$ 335

Investments, Long-Term Receiv_5

Investments, Long-Term Receivables and Equity Investee Transactions - Investees Accounted for using Equity Method (Details) - U.S.	Dec. 31, 2019
Big River Steel(a)
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	49.90%
Big River Steel Holdings LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	47.7535%
Chrome Deposit Corporation
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	50.00%
Daniel Ross Bridge, LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	50.00%
Double G Coatings Company, Inc.
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	50.00%
Feralloy Processing Company
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	49.00%
Hibbing Development Company
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	24.10%
Hibbing Taconite Company(b)
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	14.70%
Patriot Premium Threading Services, LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	50.00%
PRO-TEC Coating Company, LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	50.00%
Strategic Investment Fund Partners II(c)
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	5.20%
USS-POSCO Industries
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	50.00%
Worthington Specialty Processing
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	49.00%
BRS Stock Holdco LLC. U.S. Steel Blocker LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity investees	2.1465%

Investments, Long-Term Receiv_6

Investments, Long-Term Receivables and Equity Investee Transactions - Additional Information (Details) - USD ($) $ in Millions	Jan. 01, 2020	Oct. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 30, 2019
Schedule of Investments [Line Items]
Income from investees			$ 79	$ 61	$ 44
Dividends and partnership distributions received from equity investees			5	13	12
Other noncurrent assets			295	134
Deferred credits and other noncurrent liabilities			550	272
Assets within equity method investments			1,272	485
Leeds Retail Center, LLC
Schedule of Investments [Line Items]
Gain (loss) on sale of equity investments				18
Acero Prime, S.R.L. de CV
Schedule of Investments [Line Items]
Gain (loss) on sale of equity investments				$ 20
Ownership percentage				40.00%
Tilden Mining Company, L.C.
Schedule of Investments [Line Items]
Gain (loss) on sale of equity investments					$ 2
Ownership percentage					1500.00%
Apolo Tubulars, S.A.
Schedule of Investments [Line Items]
Ownership percentage					5000.00%
Patriot Premium Threading Services, LLC
Schedule of Investments [Line Items]
Other noncurrent assets			33	$ 27.7
Deferred credits and other noncurrent liabilities			5.7
Assets within equity method investments			$ 29.8	$ 23.7
Big River Steel
Schedule of Investments [Line Items]
Ownership interest		49.90%				49.90%
Purchase price		$ 683
Equity investment asset		710
Transaction costs		$ 27
Subsequent Event | Patriot Premium Threading Services, LLC
Schedule of Investments [Line Items]
Earnings distribution percentage	100.00%
Period for exchange of certain fixed payments	3 years
Fixed payment earnings distribution percentage before taxes and interest	10.00%

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Land and depletable property	$ 202	$ 207
Buildings	1,105	1,098
Steel producing	13,658	12,784
Transportation	280	268
Other	129	123
Information technology	787	786
Assets under finance lease	83	36
Construction in process	833	706
Total	17,077	16,008
Less accumulated depreciation and depletion	11,630	11,143
Net	$ 5,447	$ 4,865
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	35 years
Steel producing | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	2 years
Steel producing | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	30 years
Transportation | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	3 years
Transportation | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	40 years
Other | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	5 years
Other | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	30 years
Information technology | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	5 years
Information technology | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	6 years
Assets under finance lease | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	5 years
Assets under finance lease | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	15 years

Property, Plant and Equipment_2

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Finance Lease and Sale Leaseback Transactions, Accumulated Depreciation and Depletion	$ 27	$ 20

Intangible Assets - Amortizable

Intangible Assets - Amortizable Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 168	$ 168
Accumulated Amortization	93	85
Net Amount	75	83
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	132	132
Accumulated Amortization	76	70
Net Amount	56	62
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	22	22
Accumulated Amortization	8	7
Net Amount	14	15
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	14	14
Accumulated Amortization	9	8
Net Amount	$ 5	$ 6

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Indefinite-lived Intangible Assets [Line Items]
Amortization expense	$ 8	$ 8
Water Rights
Indefinite-lived Intangible Assets [Line Items]
Carrying amount of acquired water rights with indefinite lives	$ 75	$ 75
Customer relationships
Indefinite-lived Intangible Assets [Line Items]
Useful Lives (in years)	22 years
Minimum | Patents
Indefinite-lived Intangible Assets [Line Items]
Useful Lives (in years)	10 years
Minimum | Other
Indefinite-lived Intangible Assets [Line Items]
Useful Lives (in years)	4 years
Maximum | Patents
Indefinite-lived Intangible Assets [Line Items]
Useful Lives (in years)	15 years
Maximum | Other
Indefinite-lived Intangible Assets [Line Items]
Useful Lives (in years)	20 years

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans - Total Stock-Based Compensation Awards Granted (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Stock Options, Grants	0	0	647,780
Restricted Stock Units and Performance Awards, Grants	1,743,490
Restricted Stock Units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted Stock Units and Performance Awards, Grants	1,005,500	824,195	348,040
TSR Performance Awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted Stock Units and Performance Awards, Grants	210,520	79,190	169,850
ROCE Performance Awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted Stock Units and Performance Awards, Grants	527,470	247,510	0

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Total Compensation Expense Recognized for Stock-Based Compensation Awards (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-based compensation expense recognized:
Stock-based compensation expense recognized:	$ 26	$ 32	$ 27
Decrease in basic earnings per share	$ 0.15	$ 0.14	$ 0.15
Decrease in diluted earnings per share	$ 0.15	$ 0.13	$ 0.15
Cost of sales
Stock-based compensation expense recognized:
Stock-based compensation expense recognized:	$ 9	$ 11	$ 10
Selling, general and administrative expenses
Stock-based compensation expense recognized:
Stock-based compensation expense recognized:	$ 17	$ 21	$ 17

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans - Black-Scholes Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2017
Share-based Payment Arrangement [Abstract]
Grant date price per share of option award		$ 36.94
Exercise price per share of option award	$ 0	$ 36.94
Expected life in years		5 years
Expected volatility		57.00%
Risk-free interest rate		2.00%
Average grant date fair value per share of unvested option awards as calculated from above		$ 17.28
Measurement Input, Expected Dividend Rate
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected annual dividends per share		$ 0.20

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Status and Activity of Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2017
Shares [Roll Forward]
Outstanding at beginning of period	2,746,520
Granted	0
Exercised	(10,435)
Forfeited or expired	(384,254)
Outstanding at end of period	2,351,831
Exercisable at end of period	2,209,073
Exercisable and expected to vest at end of period	2,323,996
Weighted- Average Exercise Price (per share)
Outstanding at beginning of period	$ 27.73
Granted	0	$ 36.94
Exercised	16.05
Forfeited or expired	32
Outstanding at end of period	27.08
Exercisable at end of period	26.50
Exercisable and expected to vest at end of a period	$ 26.97
Weighted- Average Remaining Contractual Term (in years)
Outstanding at end of period	4 years 5 months 4 days
Exercisable at end of period	4 years 3 months 10 days
Exercisable and expected to vest at end of period	4 years 4 months 24 days
Aggregate Intrinsic Value
Outstanding at end of period	$ 0
Exercisable at end of period	0
Exercisable and expected to vest at end of period	$ 0

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans - Performance Awards Outstanding and their Fair Market Value on Respective Grant Date (Details) - TSR Awards $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)shares
2019 - 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value | $	$ 17
Minimum Shares	0
Target Shares	653,194
Maximum Shares	1,306,388
2018 - 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value | $	$ 14
Minimum Shares	0
Target Shares	288,379
Maximum Shares	576,758
2017 - 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value | $	$ 4
Minimum Shares	0
Target Shares	101,587
Maximum Shares	203,174

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans - Status and Activity of Nonvested Stock Awards (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Nonvested Stock Awards [Roll Forward]
Nonvested, beginning of period	2,107,957
Granted	1,743,490
Vested	(1,156,341)
Performance adjustment factor (b)	192,332
Forfeited or expired	(254,454)
Nonvested, end of period	2,632,984	2,107,957
Weighted- Average Grant-Date Fair Value
Beginning of period	$ 30.92
Granted	24.46
Vested	18.26
Performance adjustment factor (b)	10.02
Forfeited or expired	30.45
End of period	$ 30.72	$ 30.92
Percentage of original grants of awards to targeted amounts	100.00%
Restricted Stock Units
Nonvested Stock Awards [Roll Forward]
Nonvested, beginning of period	1,496,272
Granted	1,005,500	824,195	348,040
Vested	(771,677)
Performance adjustment factor (b)	0
Forfeited or expired	(140,271)
Nonvested, end of period	1,589,824	1,496,272
TSR Performance Awards
Nonvested Stock Awards [Roll Forward]
Nonvested, beginning of period	375,787
Granted	210,520	79,190	169,850
Vested	(384,664)
Performance adjustment factor (b)	192,332
Forfeited or expired	(43,658)
Nonvested, end of period	350,317	375,787
ROCE Performance Awards
Nonvested Stock Awards [Roll Forward]
Nonvested, beginning of period	235,898
Granted	527,470
Vested	0
Performance adjustment factor (b)	0
Forfeited or expired	(70,525)
Nonvested, end of period	692,843	235,898

Stock-Based Compensation Plan_8

Stock-Based Compensation Plans - Restricted Stock Units and Performance Awards Granted (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted	1,743,490
Weighted-average grant-date fair value per share	$ 30.72	$ 30.92
Restricted Stock Units and Performance Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted	1,743,490	1,150,895	517,890
Weighted-average grant-date fair value per share	$ 24.46	$ 41.65	$ 37.68

Stock-Based Compensation Plan_9

Stock-Based Compensation Plans - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Apr. 25, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to nonvested stocks	$ 16
Weighted average period for recognizing nonvested stock based compensation costs	18 months
Stock options exercised, total intrinsic value		$ 27	$ 11
Receipts from exercise of stock options (Note 15)	$ 0	35	20
Net benefit realized from exercise of options	(178)	303	86
Shares vested, fair value	$ 21	14	$ 11
2005 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future grant	7,464,779
Reduction in number of shares available under Stock Plan for each share issued under Plan pursuant to award other than stock option	1.73
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation plans, term	10 years
Net benefit realized from exercise of options		$ 3
Share-based compensation plans, vesting period	3 years
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation plans, vesting period	3 years
TSR Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation plans, vesting period	3 years
Performance Period Weighting Year One, Year Two, Year Three (Individually)	20.00%
Performance Period Weighting All Three Years	40.00%
Vesting of performance awards as percentage to threshold award	50.00%
Vesting of performance awards as percentage to target award	100.00%
Vesting of performance awards as percentage to maximum award	200.00%
ROCE Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation plans, vesting period	3 years
Vesting of performance awards as percentage to threshold award	50.00%
Vesting of performance awards as percentage to target award	100.00%
Vesting of performance awards as percentage to maximum award	200.00%
Performance period weighting year one	20.00%
Performance period weighting year two	30.00%
Performance period weighting year three	50.00%
Omnibus Incentive Compensation Plan 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares to be issued					7,200,000
Additional shares authorized				6,300,000
Cliff Vesting | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation plans, vesting period	3 years

Derivative Instruments - Schedu

Derivative Instruments - Schedule of Notional Amounts of Outstanding Derivative Positions (Details) € in Millions, $ in Millions	Dec. 31, 2019EUR (€)TMMBTU	Dec. 31, 2019CAD ($)TMMBTU	Dec. 31, 2018EUR (€)TMMBTU	Dec. 31, 2018CAD ($)TMMBTU
Foreign exchange forwards
Derivative [Line Items]
Notional amount of derivatives	€ 282	$ 25	€ 286	$ 50
Cash Flow Hedges | Natural Gas | Commodity purchase swaps
Derivative [Line Items]
Quantities of derivatives held | MMBTU	56,613,200	56,613,200	33,951,016	33,951,016
Cash Flow Hedges | Tin | Commodity purchase swaps
Derivative [Line Items]
Quantities of derivatives held	145	145	585	585
Cash Flow Hedges | Zinc | Commodity purchase swaps
Derivative [Line Items]
Quantities of derivatives held	9,819	9,819	3,471	3,471
Cash Flow Hedges | Hot-rolled Coil | Sales swaps
Derivative [Line Items]
Quantities of derivatives held	0	0	9,000	9,000

Derivative Instruments - Locati

Derivative Instruments - Location and Amounts of Fair Values Related to Derivatives in Financial Statements (Details) - Cash Flow Hedges - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts payable | Sales swaps
Derivative [Line Items]
Derivatives designated as hedging instruments, liabilities	$ 0	$ 1
Accounts payable | Commodity purchase swaps
Derivative [Line Items]
Derivatives designated as hedging instruments, liabilities	17	17
Accounts payable | Foreign exchange forwards
Derivative [Line Items]
Derivatives designated as hedging instruments, liabilities	1	1
Accounts receivable | Commodity purchase swaps
Derivative [Line Items]
Derivatives designated as hedging instruments, assets	1	2
Accounts receivable | Foreign exchange forwards
Derivative [Line Items]
Derivatives not designated as hedging instruments, assets	4	12
Investments and long-term receivables | Commodity purchase swaps
Derivative [Line Items]
Derivatives designated as hedging instruments, assets	1	0
Other long-term liabilities | Commodity purchase swaps
Derivative [Line Items]
Derivatives designated as hedging instruments, liabilities	7	1
Other long-term liabilities | Foreign exchange forwards
Derivative [Line Items]
Derivatives designated as hedging instruments, liabilities	$ 0	$ 1

Derivative Instruments - Sche_2

Derivative Instruments - Schedule of Effect of Hedge Accounting on Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Sales swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives in AOCI	$ 1	$ 0	$ 0
Sales swaps | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income	(1)	(13)	0
Commodity purchase swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives in AOCI	(6)	(15)	1
Commodity purchase swaps | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income	(19)	(8)	(2)
Foreign exchange forwards
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives in AOCI	1	(2)	0
Foreign exchange forwards | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income	$ (1)	$ 0	$ 0

Derivative Instruments - Loca_2

Derivative Instruments - Location and Amounts of Gains or Losses Related to Derivatives in Financial Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Sales swaps | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income	$ 0	$ (1)	$ 6
Commodity purchase swaps | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income	0	0	3
Foreign exchange forwards | Other financial costs
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income	$ 17	$ 24	$ (23)

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative, Remaining Maturity		12 months
Ineffectiveness of hedging related items	$ 1	$ 1	$ 1
Cost of sales
Derivative [Line Items]
Current contract values of derivative instruments	$ 17
Foreign exchange forwards | Maximum
Derivative [Line Items]
Term of derivative contract	12 months
Commodity purchase swaps | Maximum
Derivative [Line Items]
Term of derivative contract	23 months

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($)	Dec. 31, 2019	Oct. 25, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total debt	$ 3,779,000,000		$ 2,407,000,000
Less unamortized discount and debt issuance costs	138,000,000		26,000,000
Less short-term debt and long-term debt due within one year	14,000,000		65,000,000
Long-term debt	$ 3,627,000,000		2,316,000,000
2037 Senior Notes
Debt Instrument [Line Items]
Interest rates percentages	6.65%
Total debt	$ 350,000,000		350,000,000
2026 Senior Notes
Debt Instrument [Line Items]
Interest rates percentages	6.25%
Total debt	$ 650,000,000		650,000,000
2026 Senior Convertible Notes
Debt Instrument [Line Items]
Interest rates percentages	5.00%
Total debt	$ 350,000,000		0
2025 Senior Notes
Debt Instrument [Line Items]
Interest rates percentages	6.875%
Total debt	$ 750,000,000		750,000,000
Environmental Revenue Bonds
Debt Instrument [Line Items]
Total debt	620,000,000		400,000,000
Fairfield Caster Lease
Debt Instrument [Line Items]
Total debt	18,000,000		22,000,000
Other finance leases and all other obligations
Debt Instrument [Line Items]
Total debt	48,000,000		6,000,000
Amended Credit Facility, $2.0 billion
Debt Instrument [Line Items]
Total debt	600,000,000		0
Maximum borrowing capacity under credit facility	2,000,000,000	$ 2,000,000,000
USSK Credit Agreement
Debt Instrument [Line Items]
Total debt	393,000,000		229,000,000
USSK credit facilities
Debt Instrument [Line Items]
Total debt	$ 0		$ 0
Minimum | Environmental Revenue Bonds
Debt Instrument [Line Items]
Interest rates percentages	4.875%
Maximum | Environmental Revenue Bonds
Debt Instrument [Line Items]
Interest rates percentages	6.75%

Debt - Aggregate Maturities of

Debt - Aggregate Maturities of Debt (Details) $ in Millions	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
2020	$ 14
2021	12
2022	17
2023	399
2024	664
Later Years	2,673
Total	$ 3,779

Debt - Additional Information (

Debt - Additional Information (Details) $ / shares in Units, € in Millions	Jan. 16, 2020USD ($)	Dec. 10, 2019EUR (€)	Nov. 14, 2019USD ($)	Oct. 30, 2019USD ($)	Oct. 25, 2019USD ($)	Oct. 21, 2019USD ($)$ / sharesshares	Oct. 10, 2019USD ($)environmental_revenue_bond	Dec. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2019EUR (€)	Oct. 31, 2019	Dec. 31, 2018EUR (€)
Debt Instrument [Line Items]
Repayments of Long-term Debt									$ 155,000,000	$ 1,299,000,000	$ 1,127,000,000
Repayments of Long-term Lines of Credit									$ 100,000,000	0	$ 0
2026 Senior Convertible Notes
Debt Instrument [Line Items]
Stated interest rate								5.00%	5.00%			5.00%
2026 Senior Convertible Notes | Convertible Debt
Debt Instrument [Line Items]
Debt Instrument, Original Face Amount						$ 300,000,000
Stated interest rate						5.00%
Debt Instrument, Additional Face Amount					$ 50,000,000	$ 50,000,000
Proceeds from Issuance of Debt					340,000,000
Debt Instrument, Convertible, Conversion Ratio						0.0748391
Debt Instrument, Convertible, Conversion Price | $ / shares						$ 13.36
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger						130.00%
Debt Instrument, Redemption Price, Percentage						100.00%
Debt Instrument, Face Amount						$ 350,000,000
Debt Instrument, Interest Rate, Effective Percentage						10.50%
Debt Instrument, Unamortized Discount (Premium), Net								$ 103,000,000	$ 103,000,000
Carrying value								247,000,000	247,000,000
Environmental Revenue Bonds
Debt Instrument [Line Items]
Debt Instrument, Face Amount							$ 368,000,000
Debt Instrument, Number Of Loans | environmental_revenue_bond							2
Indiana Finance Authority Environmental Revenue Bonds
Debt Instrument [Line Items]
Repayments of Long-term Debt								55,000,000
Amended Credit Facility, $2.0 billion
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility					$ 2,000,000,000			2,000,000,000	2,000,000,000
Debt Instrument, Term					5 years
Line of Credit Facility, First In Last Out Tranche					$ 150,000,000
Long-term Line of Credit, Borrowings under credit facility				$ 700,000,000				600,000,000	600,000,000
Payments of Debt Issuance Costs				$ 5,000,000
Repayments of Long-term Lines of Credit			$ 100,000,000
Decrease in borrowing capacity under credit facility									20,000,000
Available borrowing capacity								$ 1,380,000,000	$ 1,380,000,000
Length debt maturity could be extended if liquidity conditions are not met									91 days
Amended Credit Facility, $2.0 billion | Covenant Requirement
Debt Instrument [Line Items]
Fixed coverage charge ratio, minimum								1	1			1
Fixed Charge Coverage Ratio Maximum								1	1			1
Percentage of total debt								10.00%	10.00%			10.00%
Credit agreement, upper range of outstanding debt								$ 200,000,000	$ 200,000,000
Fourth Amended and Restated Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility					$ 1,500,000,000
USSK Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility								517,000,000	517,000,000	527,000,000		€ 460		€ 460
Long-term Line of Credit, Borrowings under credit facility								393,000,000	393,000,000	$ 229,000,000		350		€ 200
Available borrowing capacity								124,000,000	124,000,000			110
USSK credit facilities | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility								33,000,000	33,000,000
Long-term Line of Credit, Borrowings under credit facility								0	0
Available borrowing capacity								31,000,000	31,000,000
Customs and other guarantees outstanding								$ 2,000,000	$ 2,000,000
USSK €20 Million Unsecured Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility | €												20
USSK €10 Million Unsecured Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facility | €												€ 10
Export Credit Agreement
Debt Instrument [Line Items]
Long-term Line of Credit, Borrowings under credit facility | €		€ 288
Long-term Line Of Credit, Payment Period		6 months
Export Credit Agreement | Commercial Facility
Debt Instrument [Line Items]
Long-term Line of Credit, Borrowings under credit facility | €		€ 38
Long-term Line Of Credit, Payment Period		5 years
Export Credit Agreement | Covered Facility
Debt Instrument [Line Items]
Long-term Line of Credit, Borrowings under credit facility | €		€ 250
Long-term Line Of Credit, Payment Period		8 years
Additional Paid-in Capital | 2026 Senior Convertible Notes | Convertible Debt
Debt Instrument [Line Items]
Debt Instrument, Convertible, Carrying Amount of Equity Component						$ 106,000,000
Big River Steel
Debt Instrument [Line Items]
Ownership interest				49.90%									49.90%
Redemption of Existing Outstanding Debt | Environmental Revenue Bonds
Debt Instrument [Line Items]
Proceeds from Issuance of Debt							$ 93,000,000
Acquisitions, Construction, Equipping and Installation | Environmental Revenue Bonds
Debt Instrument [Line Items]
Proceeds from Issuance of Debt							$ 275,000,000
Maximum | Environmental Revenue Bonds
Debt Instrument [Line Items]
Stated interest rate								6.75%	6.75%			6.75%
Maximum | Change in Control Debt Obligations
Debt Instrument [Line Items]
Obligations under financing arrangements								$ 3,093,000,000	$ 3,093,000,000
Maximum | Change In Control Fairfield Lease
Debt Instrument [Line Items]
Obligations under financing arrangements								$ 19,000,000	$ 19,000,000
Common Stock | 2026 Senior Convertible Notes | Convertible Debt
Debt Instrument [Line Items]
Debt Conversion, Converted Instrument, Shares Authorized To Be Converted | shares						26,193,685
Common Stock, Capital Shares Reserved for Future Issuance | shares						33,396,930
Subsequent Event | Amended Credit Facility, $2.0 billion
Debt Instrument [Line Items]
Repayments of Long-term Lines of Credit	$ 50,000,000

Pensions and Other Benefits - D

Pensions and Other Benefits - Details Relating to Pension Benefits and Other Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Change in benefit obligations [Roll Forward]
Benefit obligations, Beginning Balance	$ 5,626	$ 6,107
Service cost	44	49	$ 50
Interest cost	237	233	235
Plan amendments	0	26
Actuarial (gains) losses	416	(223)
Exchange rate loss	1	(3)
Settlements, curtailments and termination benefits	0	(18)
Benefits paid	(502)	(545)
Benefit obligations, Ending Balance	5,822	5,626	6,107
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan Beginning Balance	4,960	5,732
Actual return on plan assets	948	(228)
Employer contributions	0	0
Benefits paid from plan assets	(502)	(544)
Fair value of plan assets, Ending Balance	5,406	4,960	5,732
Funded status of plans, Ending Balance	(416)	(666)
Other Benefits
Change in benefit obligations [Roll Forward]
Benefit obligations, Beginning Balance	2,121	2,379
Service cost	13	17	17
Interest cost	91	92	94
Plan amendments	0	0
Actuarial (gains) losses	(195)	(185)
Exchange rate loss	0	0
Settlements, curtailments and termination benefits	0	0
Benefits paid	(154)	(182)
Benefit obligations, Ending Balance	1,876	2,121	2,379
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan Beginning Balance	1,860	2,042
Actual return on plan assets	274	(49)
Employer contributions	0	0
Benefits paid from plan assets	(109)	(133)
Fair value of plan assets, Ending Balance	2,025	1,860	$ 2,042
Funded status of plans, Ending Balance	$ 149	$ (261)

Pensions and Other Benefits - A

Pensions and Other Benefits - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income [Roll Forward]
Amortization	$ 405	$ (315)
Activity	143	134
Prior Service Cost | Pension Benefits
Accumulated Other Comprehensive Income [Roll Forward]
Defined Benefit Plan costs in Accumulated Other Comprehensive, beginning balance	18
Amortization	(2)
Activity	0
Defined Benefit Plan costs in Accumulated Other Comprehensive, ending balance	16	18
Prior Service Cost | Other Benefits
Accumulated Other Comprehensive Income [Roll Forward]
Defined Benefit Plan costs in Accumulated Other Comprehensive, beginning balance	(80)
Amortization	(29)
Activity	0
Defined Benefit Plan costs in Accumulated Other Comprehensive, ending balance	(109)	(80)
Actuarial (gains) losses | Pension Benefits
Accumulated Other Comprehensive Income [Roll Forward]
Defined Benefit Plan costs in Accumulated Other Comprehensive, beginning balance	2,442
Amortization	(134)
Activity	(207)
Defined Benefit Plan costs in Accumulated Other Comprehensive, ending balance	2,101	2,442
Actuarial (gains) losses | Other Benefits
Accumulated Other Comprehensive Income [Roll Forward]
Defined Benefit Plan costs in Accumulated Other Comprehensive, beginning balance	(17)
Amortization	(3)
Activity	(391)
Defined Benefit Plan costs in Accumulated Other Comprehensive, ending balance	$ (411)	$ (17)

Pensions and Other Benefits - P

Pensions and Other Benefits - Pension and Other Benefits Recognized in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Pension and Other Postretirement Benefits Disclosure [Line Items]
Accumulated other comprehensive loss effects associated with accounting for pensions and other benefits in accordance with ASC Topic 715	$ 800	$ 991
Pension Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Noncurrent assets (a)	0	0
Current liabilities	(3)	(2)
Noncurrent liabilities	(413)	(664)
Accumulated other comprehensive loss (b)	2,117	2,460
Net amount recognized	1,701	1,794
Other Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Noncurrent assets (a)	158	0
Current liabilities	(1)	(52)
Noncurrent liabilities	(8)	(209)
Accumulated other comprehensive loss (b)	(520)	(97)
Net amount recognized	(371)	$ (358)
Retiree medical and life insurance | Other Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Noncurrent assets (a)	$ 49

Pensions and Other Benefits - I

Pensions and Other Benefits - Information for Pension Plans with Accumulated Benefit Obligation in Excess of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Information for pension plans with an accumulated benefit obligation in excess of plan assets:
Aggregate accumulated benefit obligations (ABO)	$ (5,636)	$ (5,454)
Aggregate projected benefit obligations (PBO)	(5,822)	(5,626)
Aggregate fair value of plan assets	$ 5,406	$ 4,960

Pensions and Other Benefits -_2

Pensions and Other Benefits - Details of Net Periodic Benefit Costs Related to Pension and Other Benefits (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of net periodic benefit cost:
Net periodic benefit cost	[1]	$ 91	$ 69	$ 61
Pension Benefits
Components of net periodic benefit cost:
Service cost		44	49	50
Interest cost		237	233	235
Expected return on plan assets		(324)	(361)	(390)
Amortization - prior service costs		2	0	0
Amortization - actuarial losses		132	152	148
Net periodic benefit cost, excluding below		91	73	43
Multiemployer plans (a)		77	60	59
Settlement, termination and curtailment losses		11	10	7
Net periodic benefit cost		179	143	109
Other Benefits
Components of net periodic benefit cost:
Service cost		13	17	17
Interest cost		91	92	94
Expected return on plan assets		(79)	(82)	(65)
Amortization - prior service costs		29	29	29
Amortization - actuarial losses		3	4	3
Net periodic benefit cost, excluding below		57	60	78
Multiemployer plans (a)		0	0	0
Settlement, termination and curtailment losses		0	0	0
Net periodic benefit cost		$ 57	$ 60	$ 78
[1]	Represents postretirement benefit expense as a result of the adoption of Accounting Standards Update 2017-07, Compensation - Retirement Benefits on January 1, 2018 (see Note 3 for further details).

Pensions and Other Benefits -_3

Pensions and Other Benefits - Assumptions used to Determine Benefit Obligation and Net Periodic Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Actuarial assumptions used to determine benefit obligations at December 31:
Discount rate	3.35%	4.41%
Increase in compensation rate	2.60%	2.60%
Actuarial assumptions used to determine net periodic benefit cost for the year ended December 31:
Discount rate	4.41%	4.00%	4.00%
Expected annual return on plan assets	6.50%	6.85%	7.25%
Increase in compensation rate	2.60%	2.60%	2.60%
Other Benefits
Actuarial assumptions used to determine benefit obligations at December 31:
Discount rate	3.43%	4.47%
Actuarial assumptions used to determine net periodic benefit cost for the year ended December 31:
Discount rate	4.47%	4.03%	4.00%
Expected annual return on plan assets	4.25%	4.25%	3.25%
Increase in compensation rate			3.50%

Pensions and Other Benefits -_4

Pensions and Other Benefits - Assumed Health Care Cost Trend Rates (Details)	Dec. 31, 2019	Dec. 31, 2018
Assumed health care cost trend rates
Health care cost trend rate assumed for next year	6.50%	7.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50%	5.00%

Pensions and Other Benefits -_5

Pensions and Other Benefits - Pension Plan and Other Plan Assets Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	$ 5,406	$ 4,960	$ 5,732
Investments measured in the fair value hierarchy	2,758	2,596
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	2,648	2,364
Pension Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		7
Pension Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	130	101
Pension Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	2,277	2,143
Pension Benefits | Mineral Interests
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	2	2
Pension Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	283	294
Pension Benefits | Private equities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		2
Pension Benefits | Real estate
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	32	33
Pension Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	34	14
Pension Benefits | Defined Benefit Plan, Equity Securities, US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	123	95
Pension Benefits | Defined Benefit Plan, Equity Securities, Non-US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	7	6
Other Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	2,025	1,860	$ 2,042
Investments measured in the fair value hierarchy	1,939	1,766
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	86	94
Other Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	31	42
Other Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	49	45
Other Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	1,799	1,631
Other Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	35	35
Other Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	25	13
Other Benefits | Defined Benefit Plan, Equity Securities, US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	30	27
Other Benefits | Defined Benefit Plan, Equity Securities, Non-US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	19	18
Quoted Prices in Active Markets (Level 1) | Pension Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	164	122
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		7
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	130	101
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Mineral Interests
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Private equities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		0
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Real estate
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Pension Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	34	14
Quoted Prices in Active Markets (Level 1) | Other Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	105	100
Quoted Prices in Active Markets (Level 1) | Other Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	31	42
Quoted Prices in Active Markets (Level 1) | Other Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	49	45
Quoted Prices in Active Markets (Level 1) | Other Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Other Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Quoted Prices in Active Markets (Level 1) | Other Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	25	13
Other Significant Observable Inputs (Level 2) | Pension Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	2,277	2,143
Other Significant Observable Inputs (Level 2) | Pension Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		0
Other Significant Observable Inputs (Level 2) | Pension Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Pension Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	2,277	2,143
Other Significant Observable Inputs (Level 2) | Pension Benefits | Mineral Interests
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Pension Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Pension Benefits | Private equities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		0
Other Significant Observable Inputs (Level 2) | Pension Benefits | Real estate
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Pension Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Other Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	1,799	1,631
Other Significant Observable Inputs (Level 2) | Other Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Other Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Other Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	1,799	1,631
Other Significant Observable Inputs (Level 2) | Other Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Other Significant Observable Inputs (Level 2) | Other Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	317	331
Significant Unobservable Inputs (Level 3) | Pension Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Mineral Interests
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	2	2
Significant Unobservable Inputs (Level 3) | Pension Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	283	294
Significant Unobservable Inputs (Level 3) | Pension Benefits | Private equities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		2
Significant Unobservable Inputs (Level 3) | Pension Benefits | Real estate
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	32	33
Significant Unobservable Inputs (Level 3) | Pension Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Significant Unobservable Inputs (Level 3) | Other Benefits
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	35	35
Significant Unobservable Inputs (Level 3) | Other Benefits | Short-term Investments
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Significant Unobservable Inputs (Level 3) | Other Benefits | Equity Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Significant Unobservable Inputs (Level 3) | Other Benefits | Corporate and Government Bonds
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Significant Unobservable Inputs (Level 3) | Other Benefits | Timberlands
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	35	35
Significant Unobservable Inputs (Level 3) | Other Benefits | Other securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	0	0
Corporate Bond Securities | Pension Benefits | Debt Security, Corporate, US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	1,004	933
Corporate Bond Securities | Pension Benefits | Debt Security, Corporate, Non-US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	160	149
Corporate Bond Securities | Other Benefits | Debt Security, Corporate, US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	1,132	1,052
Corporate Bond Securities | Other Benefits | Debt Security, Corporate, Non-US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	287	271
Government Bonds | Pension Benefits | Debt Security, Government - U.S.
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	771	858
Government Bonds | Pension Benefits | Debt Security, Government, Non-US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	77	67
Government Bonds | Other Benefits | Debt Security, Government - U.S.
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	329	270
Government Bonds | Other Benefits | Debt Security, Government, Non-US
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	13	8
Mortgage and asset-backed securities | Pension Benefits | Equity Securities – U.S.
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	265	136
Mortgage and asset-backed securities | Other Benefits | Equity Securities – U.S.
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	38	30
Other securities | Pension Benefits | Cash
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	26	32
Other securities | Pension Benefits | Accrued income
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	19	21
Other securities | Pension Benefits | Investment purchases
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	(8)	(80)
Other securities | Pension Benefits | Miscellaneous Payables
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	(3)	(16)
Other securities | Pension Benefits | Investment sales
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		57
Other securities | Other Benefits | Cash
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	12
Other securities | Other Benefits | Accrued income
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	16	16
Other securities | Other Benefits | Miscellaneous Payables
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	(5)
Other securities | Other Benefits | Investment sales
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value	$ 2
Other securities | Other Benefits | Investment purchase payables
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Investments measured at fair value		$ (3)

Pensions and Other Benefits - F

Pensions and Other Benefits - Fair Value, Investments, Entities that Calculate Net Asset Value per Share (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	$ 2,648	$ 2,364
Other Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	86	94
Private Equity Funds | Pension Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	238	254
Unfunded commitments	48	68
Private Equity Funds | Other Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	54	61
Unfunded commitments	8	10
Real Estate Funds | Pension Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	240	236
Unfunded commitments	62	93
Real Estate Funds | Other Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	32	33
Unfunded commitments	10	12
Commingled Funds | Pension Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Defined Benefit Plan, Alternative Investments, Fair Value of Plan Assets	$ 2,170	$ 1,874
Minimum | Pension Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Remaining life of investments	1 year	1 year
Minimum | Other Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Remaining life of investments	1 year	1 year
Maximum | Pension Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Remaining life of investments	9 years	10 years
Maximum | Other Benefits
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Remaining life of investments	9 years	10 years

Pensions and Other Benefits - C

Pensions and Other Benefits - Changes in Fair Value of Pension Plan and Other Benefit Plan Level 3 Assets (Details) - USD ($)	Jan. 01, 2019	Dec. 31, 2019	Dec. 31, 2018
Purchases, sales, issuances and settlements:
Employees eligible savings account contribution amount	$ 0.55	$ 0.50
Pension Benefits
Pension Plan Assets [Roll Forward]
Balance at beginning of period	331,000,000	331,000,000	$ 340,000,000
Transfers in and/or out of Level 3		0	0
Actual return on plan assets:
Realized gain		8,000,000	11,000,000
Net unrealized loss		(21,000,000)	(8,000,000)
Purchases, sales, issuances and settlements:
Purchases		1,000,000	0
Sales		(2,000,000)	(12,000,000)
Balance at end of period		317,000,000	331,000,000
Other Benefits
Pension Plan Assets [Roll Forward]
Balance at beginning of period	$ 35,000,000	35,000,000	35,000,000
Transfers in and/or out of Level 3		0	0
Actual return on plan assets:
Realized gain		0	(1,000,000)
Net unrealized loss		0	(1,000,000)
Purchases, sales, issuances and settlements:
Sales		0	0
Balance at end of period		$ 35,000,000	$ 35,000,000

Pensions and Other Benefits - M

Pensions and Other Benefits - Multiemployer Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Employer Identification Number/ Pension Plan Number	23-6648508/499
Pension Protection Act Zone Status	Green	Green
FIP/RP Status Pending/Implemented	No
U.S. Steel Contributions	$ 77	$ 60	$ 59
Surcharged Imposed	No	No
Expiration Date of Collective Bargaining Agreement	Sep. 1, 2022
Minimum | Steelworkers Pension Trust | Green Zone
Defined Benefit Plan Disclosure [Line Items]
Funded Percentage Under Pension Protection Act	80.00%
Maximum | Steelworkers Pension Trust | Yellow Zone
Defined Benefit Plan Disclosure [Line Items]
Funded Percentage Under Pension Protection Act	80.00%
Maximum | Steelworkers Pension Trust | Red Zone
Defined Benefit Plan Disclosure [Line Items]
Funded Percentage Under Pension Protection Act	65.00%

Pensions and Other Benefits - B

Pensions and Other Benefits - Benefit Payments Expected to be Paid from Defined Benefit Plans (Details) $ in Millions	Dec. 31, 2019USD ($)
Pension Benefits
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
2020	$ 483
2021	465
2022	442
2023	418
2024	406
Years 2025 - 2028	1,850
Other Benefits
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
2020	153
2021	152
2022	151
2023	149
2024	146
Years 2025 - 2028	$ 680

Pensions and Other Benefits -_6

Pensions and Other Benefits - Additional Information (Details) - USD ($)	Jan. 01, 2021	Jan. 01, 2020	Jan. 01, 2019	Nov. 13, 2018	Nov. 20, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2007
Defined Benefit Plan Disclosure [Line Items]
Portion of employees included In multiemployer plan						three-quarters
Portion of represented employees covered by SPT						two-thirds
Collective bargaining agreement term				4 years
Increase to defined benefit plan pension liability due to 2018 labor agreements				$ 26,000,000
Defined benefit plans, accumulated benefit obligation						$ 5,636,000,000	$ 5,454,000,000
Portion of costs for retiree health benefits limited to a per capital dollar maximum						three quarters
Defined Contribution Plan, Eligible Amount Contributed Per Hour			$ 0.55			$ 0.50
Discount rate used for calculating benefit obligation						3.40%	4.36%
Future projected benefit cost, other postretirement benefit plans						$ 15,000,000
Net periodic benefit cost, other postretirement benefit plans						21,000,000	$ 10,000,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plans, expected net periodic benefit cost						$ 141,000,000
Expected annual return on plan assets						6.50%	6.85%	7.25%
Employer contributions						$ 0	$ 0
Discount rate used for calculating benefit obligation						3.35%	4.41%	4.00%
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plans, expected net periodic benefit cost						$ (29,000,000)
Target allocation for plan assets						90.00%
Expected annual return on plan assets						4.25%	4.25%	3.25%
Employer contributions						$ 0	$ 0
Discount rate used for calculating benefit obligation						3.43%	4.47%	4.03%
Steelworkers Pension Trust
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plans, expected net periodic benefit cost						$ 79,000,000
Employer contribution amount for each employee hour worked						$ 3.15
Total amortization period of losses						29 years			15 years
U. S. Steel Retirement Plan Trust
Defined Benefit Plan Disclosure [Line Items]
Target allocation for plan assets						45.00%
Employer contributions					$ 75,000,000
Unfunded Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Payments for pension benefits						$ 8,000,000	$ 20,000,000	$ 13,000,000
Unfunded Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Payments for pension benefits						45,000,000	48,000,000	59,000,000
Defined Contribution Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense						$ 23,000,000	23,000,000	22,000,000
Percentage of employee's percentage contributions, matched by employer						100.00%
Percentage of employee's pay matched by employer						6.00%
Defined Contribution Pension Matching Contribution
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense						$ 18,000,000	17,000,000	17,000,000
Supplemental Thrift Plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense						1,000,000	4,000,000	1,000,000
Canadian Hourly Employees Savings Match
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense						3,000,000	2,000,000	$ 1,000,000
Other Postemployment Benefit
Defined Benefit Plan Disclosure [Line Items]
Accrued employee benefits						$ 111,000,000	$ 110,000,000
Minimum | Steelworkers Pension Trust
Defined Benefit Plan Disclosure [Line Items]
Proportion of single plan contribution as to total combined contribution						5.00%	5.00%	5.00%
Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Eligible Amount Contributed Per Hour	$ 0.65	$ 0.60
Subsequent Event | Steelworkers Pension Trust
Defined Benefit Plan Disclosure [Line Items]
Employer contribution amount for each employee hour worked	$ 3.50	$ 3.35

Asset Retirement Obligations -

Asset Retirement Obligations - Changes in Carrying Values of Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Asset Retirement Obligations [Roll Forward]
Balance at beginning of year	$ 60	$ 69
Additional obligations incurred	4	0
Obligations settled	(9)	(12)
Accretion expense	3	3
Balance at end of period	$ 58	$ 60

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Schedule of Change in Fair Value by Option from Purchase Date (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair Value Mark to Market gain/(loss)	$ (7)
Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, beginning balance	162
Fair Value Mark to Market gain/(loss)	4
Fair value asset/liability, ending balance	166
Common Class B | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, beginning balance	(2)
Fair Value Mark to Market gain/(loss)	0
Fair value asset/liability, ending balance	(2)
Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, beginning balance	(181)
Fair Value Mark to Market gain/(loss)	(11)
Fair value asset/liability, ending balance	(192)
Big River Steel Equity Value
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Big River Steel Equity Value	$ 1,400
Volatility
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Measurement input	0.541
Risk Free Interest Rate
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Measurement input	0.016
Credit Spread
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Measurement input	0.079
Maximum | Big River Steel Equity Value | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	$ 19
Maximum | Big River Steel Equity Value | Common Class B | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	0
Maximum | Big River Steel Equity Value | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	15
Maximum | Volatility | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	34
Maximum | Volatility | Common Class B | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	0
Maximum | Volatility | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	(25)
Maximum | Risk Free Interest Rate | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	3
Maximum | Risk Free Interest Rate | Common Class B | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	0
Maximum | Risk Free Interest Rate | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	13
Maximum | Credit Spread | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	7
Minimum | Big River Steel Equity Value | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	(17)
Minimum | Big River Steel Equity Value | Common Class B | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	0
Minimum | Big River Steel Equity Value | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	(16)
Minimum | Volatility | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	(34)
Minimum | Volatility | Common Class B | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	0
Minimum | Volatility | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	25
Minimum | Risk Free Interest Rate | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	(3)
Minimum | Risk Free Interest Rate | Common Class B | Call Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	0
Minimum | Risk Free Interest Rate | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	(14)
Minimum | Credit Spread | Common Class B | Put Option
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value asset/liability, ending balance	$ (8)

Fair Value of Financial Instr_4

Fair Value of Financial Instruments -Financial Assets and Liabilities Not Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financial liabilities:
Long-term debt (a)	$ 3,779
Fair Value
Financial liabilities:
Long-term debt (a)	3,576	$ 2,182
Carrying Amount
Financial liabilities:
Long-term debt (a)	$ 3,575	$ 2,353

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	Oct. 31, 2019	Dec. 31, 2019	Oct. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Other noncurrent assets		$ 295		$ 134
Change in fair value of put and call options		7
Big River Steel
Business Acquisition [Line Items]
Ownership interest	49.90%		49.90%
Remaining ownership interest	50.10%
Term option to purchase remaining equity interest	4 years
Patriot Premium Threading Services, LLC
Business Acquisition [Line Items]
Other noncurrent assets		$ 33		$ 27.7

Reclassifications from Accumu_3

Reclassifications from Accumulated Other Comprehensive Income (AOCI) - Schedule of Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	$ (1,026)	$ (845)
Other comprehensive loss before reclassifications (b)	405	(315)
Amounts reclassified from AOCI (a)(b)	143	134
Total other comprehensive income (loss), net of tax	548	(181)	$ 652
Balance, end of period	(478)	(1,026)	(845)
Pension and Other Benefit Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	(1,416)	(1,309)
Other comprehensive loss before reclassifications (b)	446	(255)
Amounts reclassified from AOCI (a)(b)	127	148
Total other comprehensive income (loss), net of tax	573	(107)
Balance, end of period	(843)	(1,416)	(1,309)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	403	463
Other comprehensive loss before reclassifications (b)	(22)	(60)
Amounts reclassified from AOCI (a)(b)	0	0
Total other comprehensive income (loss), net of tax	(22)	(60)
Balance, end of period	381	403	463
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	(13)	1
Other comprehensive loss before reclassifications (b)	(19)	0
Amounts reclassified from AOCI (a)(b)	16	(14)
Total other comprehensive income (loss), net of tax	(3)	(14)
Balance, end of period	$ (16)	$ (13)	$ 1

Reclassifications from Accumu_4

Reclassifications from Accumulated Other Comprehensive Income (AOCI) - Detail of Amounts Reclassified From Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) earnings before income taxes	$ (452)	$ 812	$ 301
Tax provision (b)	(178)	303	86
Net of tax	(630)	1,115	387
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
(Loss) earnings before income taxes	191	176	183
Tax provision (b)	(48)	(42)	0
Net of tax	143	134	183
Pension and Other Benefit Items | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Prior service costs (a)	31	29	29
Actuarial losses (a)	135	156	151
Settlements, termination and curtailment losses (a)	3	10	7
Total pensions and other benefits items	169	195	187
Unrealized Gain (Loss) on Derivatives | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Derivative reclassifications to Consolidated Statements of Operations	$ 22	$ (19)	$ (4)

Reclassifications from Accumu_5

Reclassifications from Accumulated Other Comprehensive Income (AOCI) - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Increase (decrease) in AOCI for other comprehensive income before reclassification	$ 405	$ (315)
Increase (decrease) in AOCI	(143)	(134)
Pension and Other Benefit Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Increase (decrease) in AOCI for other comprehensive income before reclassification	446	(255)
Increase (decrease) in AOCI	(127)	$ (148)
Previously Reported | Pension and Other Benefit Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Increase (decrease) in AOCI for other comprehensive income before reclassification	41
Increase (decrease) in AOCI	(148)
Restatement Adjustment | Pension and Other Benefit Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Increase (decrease) in AOCI for other comprehensive income before reclassification	(255)
Increase (decrease) in AOCI	$ 148

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information -Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 31, 2019	Oct. 30, 2019
Net cash used in operating activities included:
Interest and other financial costs paid (net of amount capitalized)	$ 151	$ 207	$ 242
Income taxes refunded (paid)	(38)	39	40
Non-cash investing and financing activities:
Change in accrued capital expenditures	(70)	135	208
U. S. Steel common stock issued for employee/non-employee director stock plans	19	21	49
Capital expenditures funded by finance lease borrowings	46	0	0
Big River Steel put and call options	$ 21	$ 0	$ 0
Big River Steel
Business Acquisition [Line Items]
Ownership interest				49.90%	49.90%

Transactions with Related Par_2

Transactions with Related Parties - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Related party sales and service transactions	$ 1,431	$ 1,420	$ 1,204
Receivables from related parties	221	224
Accounts payable to related parties	84	81
Outside processing services
Related Party Transaction [Line Items]
Purchases from related parties	31	29	70
Taconite pellets
Related Party Transaction [Line Items]
Purchases from related parties	104	91	$ 140
PRO-TEC Coating Company, LLC
Related Party Transaction [Line Items]
Receivables from related parties	10
Accounts payable to related parties	82	80
Other related parties
Related Party Transaction [Line Items]
Accounts payable to related parties	$ 2	$ 1

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease assets	$ 230	$ 0
Current operating lease liabilities	60	0
Noncurrent operating lease liabilities	$ 177	$ 0

Leases - Schedule of Leases by

Leases - Schedule of Leases by Balance Sheet Location (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease assets	$ 230	$ 0
Assets under finance lease	56
Total Lease Assets	286
Current operating lease liabilities	60	0
Current finance lease liabilities	11
Noncurrent operating lease liabilities	177	$ 0
Noncurrent finance lease liabilities	51
Total Lease Liabilities	299
Operating Lease, Right-of-Use Asset, Accumulated Amortization	50
Finance lease, Accumulated Depreciation	27
Operating Lease, Right-of-Use Asset (Liability), Adjustments	7
Operating Lease, Right-of-Use Asset (Liability), Retirements	$ 4

Leases - Schedule of Operating

Leases - Schedule of Operating and Finance Lease Costs by Income Statement Location (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Finance Lease, Right-Of-Use Asset, Depreciation, Depletion And Amortization	$ 7
Finance Lease, Right-Of-Use Asset, Interest	3
Total Lease Cost	102
Variable Lease, Cost	15
Cost of sales
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	81
Selling, general and administrative expenses
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	$ 11

Leases - Schedule of Operatin_2

Leases - Schedule of Operating and Finance Lease Maturities (Details) $ in Millions	Dec. 31, 2019USD ($)
Operating
2020	$ 74
2021	58
2022	46
2023	34
2024	26
After 2024	51
Total Lease Payments	289
Less: Interest	52
Present value of lease liabilities	237
Finance
2020	15
2021	14
2022	18
2023	7
2024	6
After 2024	12
Total Lease Payments	72
Less: Interest	10
Present value of lease liabilities	62
Total
2020	89
2021	72
2022	64
2023	41
2024	32
After 2024	63
Total Lease Payments	361
Less: Interest	62
Present value of lease liabilities	$ 299

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Commitments for Capital Leases and Operating Leases (Details) $ in Millions	Dec. 31, 2018USD ($)
Capital Leases
Capital leases future minimum payment in 2019	$ 5
Capital leases future minimum payment in 2020	5
Capital leases future minimum payment in 2021	5
Capital leases future minimum payment in 2022	11
Capital leases future minimum payment in 2023	0
Capital leases future minimum payment, later years	0
Total minimum lease payments	26
Less imputed interest costs	4
Present value of net minimum lease payments included in long-term debt	22
Operating Leases
Operating leases future minimum payment in 2019	66
Operating leases future minimum payment in 2020	55
Operating leases future minimum payment in 2021	45
Operating leases future minimum payment in 2022	37
Operating leases future minimum payment in 2023	28
Operating leases future minimum payment, later years	72
Total minimum lease payments	$ 303

Leases - Schedule of Lease Term

Leases - Schedule of Lease Terms and Discount Rates (Details)	Dec. 31, 2019
Weighted Average Lease Term [Abstract]
Finance - Weighted average lease term	5 years
Operating - Weighted average lease term	5 years
Weighted Average Discount Rate [Abstract]
Finance - Weighted average discount rate	6.05%
Operating - Weighted average discount rate	7.76%

Leases - Schedule of Cash Amoun

Leases - Schedule of Cash Amounts Paid for Lease Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Operating cash flows from operating leases	$ 72
Operating cash flows from finance leases	3
Financing cash flows from finance leases	7
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	53
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 46	$ 0	$ 0

Restructuring and Other Charg_3

Restructuring and Other Charges - Activity in Accrued Balances for Restructuring and Other Cost Reduction Programs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	$ 80	$ 21
Restructuring and other charges (Note 25)	275	0	$ 31
Restructuring Reserve [Roll Forward]
Balance at beginning of period	17	38
Balance at end of period	212	17	38
Employee Related Costs
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	24	4
Restructuring and other charges (Note 25)	111
Restructuring Reserve [Roll Forward]
Balance at beginning of period	0	4
Balance at end of period	87	0	4
Exit Costs
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	11	17
Restructuring and other charges (Note 25)	119
Restructuring Reserve [Roll Forward]
Balance at beginning of period	17	34
Balance at end of period	125	17	34
Non-cash Charges
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	45	0
Restructuring and other charges (Note 25)	45
Restructuring Reserve [Roll Forward]
Balance at beginning of period	0	0
Balance at end of period	$ 0	$ 0	$ 0

Restructuring and Other Charg_4

Restructuring and Other Charges - Balance Sheet Location of Accrued Liabilities for Restructuring and Other Cost Reduction Programs (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Accrued liabilities for restructuring and other reduction programs	$ 212	$ 17	$ 38
Accounts payable
Restructuring Cost and Reserve [Line Items]
Accrued liabilities for restructuring and other reduction programs	46	11
Payroll and benefits payable
Restructuring Cost and Reserve [Line Items]
Accrued liabilities for restructuring and other reduction programs	64	0
Employee benefits
Restructuring Cost and Reserve [Line Items]
Accrued liabilities for restructuring and other reduction programs	23	0
Deferred credits and other noncurrent liabilities
Restructuring Cost and Reserve [Line Items]
Accrued liabilities for restructuring and other reduction programs	$ 79	$ 6

Restructuring and Other Charg_5

Restructuring and Other Charges -Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 275	$ 0	$ 31
Business Exit And Severance Costs	35	$ 21	32
Other adjustments and reclasses			(6)
Tubular
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			$ 37
U.S. Steel Kosice Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	25
Idling
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	119
Idling | East Chicago Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	227
Headcount Reductions
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 23

Contingencies and Commitments -

Contingencies and Commitments - Asbestos Litigation Activity (Details) - Asbestos Matters - Claim_Group	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Loss Contingency Accrual [Roll Forward]
Opening Number of Claims	2,320	3,315	3,340
Claims Dismissed, Settled and Resolved (a)	195	1,285	275
New Claims	265	290	250
Closing Number of Claims	2,390	2,320	3,315

Contingencies and Commitments_2

Contingencies and Commitments - Changes in Accrued Liabilities for Remediation Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Change in Accrued Liabilities for Remediation Activities [Roll Forward]
Beginning of period	$ 187	$ 179
Accruals for environmental remediation deemed probable and reasonably estimable	20	14
Obligations settled	(21)	(6)
End of period	$ 186	$ 187

Contingencies and Commitments_3

Contingencies and Commitments - Accrued Liabilities for Remediation Activities Included in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Line Items]
Accrued liabilities for remediation activities	$ 186	$ 187	$ 179
Accounts payable
Commitments and Contingencies Disclosure [Line Items]
Accrued liabilities for remediation activities	53	37
Deferred credits and other noncurrent liabilities
Commitments and Contingencies Disclosure [Line Items]
Accrued liabilities for remediation activities	$ 133	$ 150

Contingencies and Commitments_4

Contingencies and Commitments - Payments for Contracts with Remaining Terms in Excess of One Year (Details) $ in Millions	Dec. 31, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
2020	$ 430
2021	404
2022	337
2023	338
2024	107
Later years	611
Total	$ 2,227

Contingencies and Commitments_5

Contingencies and Commitments - Additional Information (Details) € in Millions, Allowances in Millions	12 Months Ended
	Dec. 31, 2019USD ($)PlaintiffFacilityAllowancesClaim_GroupProject	Dec. 31, 2019EUR (€)PlaintiffAllowances	Dec. 31, 2018USD ($)Claim_Group	Dec. 31, 2017USD ($)Claim_Group	Dec. 31, 2016Claim_Group
Loss Contingencies [Line Items]
Number of cases dismissed			1,000
Accrued liabilities for remediation activities	$ 186,000,000		$ 187,000,000	$ 179,000,000
Accrued liabilities for post-closure site monitoring and other costs	23,000,000
Accrued liability for administrative and legal costs	$ 11,000,000
Number of years of projected administrative and legal costs included in accrual	3 years	3 years
Capital expenditures	$ 123,000,000		125,000,000
Final allocation for emissions allowances during NAP III period | Allowances	48	48
Emissions allowances purchased | Allowances	11.7
Cost of emissions allowances purchased	$ 148,000,000	€ 132
Total Shortfall Of Allowances | Allowances	12.5	12.5
Financial assurance guarantees, maximum	$ 4,000,000
Residual value of equipment	23,000,000
Residual value liability	0
Restricted cash	190,000,000		40,000,000
Contract commitments to acquire property, plant and equipment	880,000,000
Total payment under take-or-pay contracts	653,000,000		$ 600,000,000	$ 576,000,000
Gateway Energy and Coke Company, LLC
Loss Contingencies [Line Items]
Maximum default payment on termination of agreement	$ 138,000,000
Minimum
Loss Contingencies [Line Items]
Projected percentage remediation costs may exceed accrued liabilities	15.00%	15.00%
Estimated capital expenditures of complying with BAT over 2017 to 2020 period	$ 155,000,000	€ 138
Unconditional purchase obligation term	0 years	0 years
Maximum
Loss Contingencies [Line Items]
Projected percentage remediation costs may exceed accrued liabilities	30.00%	30.00%
Unconditional purchase obligation term	16 years	16 years
Asbestos Matters
Loss Contingencies [Line Items]
Active cases brought against U.S. Steel | Claim_Group	800		755
Number of claims pending in jurisdictions | Claim_Group	2,390		2,320	3,315	3,340
Number of plaintiffs involved | Plaintiff	1,540	1,540
Percentage of claims pending in jurisdictions	65.00%
Projects with Ongoing Study and Scope Development
Loss Contingencies [Line Items]
Environmental remediation projects | Facility	6
Accrued liabilities for remediation activities	$ 2,000,000
Projects with Ongoing Study and Scope Development | Minimum
Loss Contingencies [Line Items]
Environment exit costs, possible additional loss	30,000,000
Projects with Ongoing Study and Scope Development | Maximum
Loss Contingencies [Line Items]
Environment exit costs, possible additional loss	$ 45,000,000
Other Project With Defined Scope
Loss Contingencies [Line Items]
Environmental remediation projects | Project	4
Accrued liabilities for remediation activities	$ 128,000,000
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	25,000,000
Geneva Project
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	48,000,000
Cherryvale Zinc Site
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	10,000,000
St Louis Estuary Project
Loss Contingencies [Line Items]
Accrued liabilities for remediation activities	$ 45,000,000
Environmental Remediation Other Projects
Loss Contingencies [Line Items]
Environmental remediation projects | Facility	2
Accrued liabilities for remediation activities	$ 4,000,000
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	2,000,000
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	$ 164,000,000

Common Stock Repurchase Progr_2

Common Stock Repurchase Program - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Common Stock Repurchase Program [Abstract]
Stock repurchase program, authorized amount		$ 300
Shares repurchased (in shares)	5,289,475	2,760,112
Value of shares repurchased	$ 88	$ 75

Subsequent Event (Details)

Subsequent Event (Details) - USS-POSCO Industries - Subsequent Event T in Millions	Jan. 23, 2020T
Subsequent Event [Line Items]
Ownership interest	50.00%
Number of tons of steel making capacity	1.5

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 29	$ 28	$ 25
Additions, Charged to Costs and Expenses	0	5	2
Additions, Charged to Other Accounts	0	0	2
Deductions, Charged to Costs and Expenses	0	0	0
Deductions, Charged to Other Accounts	1	4	1
Balance at End of Period	28	29	28
Allowance for related party doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		0	265
Additions, Charged to Costs and Expenses			0
Additions, Charged to Other Accounts			0
Deductions, Charged to Costs and Expenses			0
Deductions, Charged to Other Accounts			265
Balance at End of Period			0
Investments and long-term receivables reserve
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	5	11	10
Additions, Charged to Costs and Expenses	0	0	0
Additions, Charged to Other Accounts	0	0	1
Deductions, Charged to Costs and Expenses	0	0	0
Deductions, Charged to Other Accounts	0	6	0
Balance at End of Period	5	5	11
Long-term receivables from related parties reserve
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		0	1,627
Additions, Charged to Costs and Expenses			0
Additions, Charged to Other Accounts			0
Deductions, Charged to Costs and Expenses			0
Deductions, Charged to Other Accounts			1,627
Balance at End of Period			0
Domestic deferred tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	211	604	1,109
Additions, Charged to Costs and Expenses	349	0	42
Additions, Charged to Other Accounts	0	0	0
Deductions, Charged to Costs and Expenses	0	393	373
Deductions, Charged to Other Accounts	0	0	174
Balance at End of Period	560	211	604
Foreign deferred tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	3	4	4
Additions, Charged to Costs and Expenses	0	0	0
Additions, Charged to Other Accounts	0	0	0
Deductions, Charged to Costs and Expenses	0	1	0
Deductions, Charged to Other Accounts	0	0	0
Balance at End of Period	$ 3	$ 3	$ 4