Net Interest and Other Financial Costs - Net Interest and Other Financial Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 31, 2019
Interest income:
Interest income	$ (4)	$ (7)	$ (17)
Interest expense and other financial costs:
Interest incurred	342	306	162
Less interest capitalized	29	26	20
Total interest expense	313	280	142
Loss on debt extinguishment (Note 7)	292	0	0
Net periodic benefit (income) costs (other than service cost)	(45)	(25)	91
Foreign currency net gain (b)	17	(15)	(17)
Financial costs on:
Other (c)	5	(21)	10
Amortization of discounts and deferred financing costs	14	15	7
Total other financial costs	46	(16)	6
Net interest and other financial costs	602	232	222
Change in fair value of put and call options		(39)	7
Big River Steel
Financial costs on:
Ownership interest				49.90%
Amended Credit Agreement
Financial costs on:
Credit facilities	6	3	5
USSK credit facilities
Financial costs on:
Credit facilities	$ 4	$ 2	$ 1