Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Land and depletable property	$ 213	$ 237
Buildings	1,558	1,154
Steel producing	15,968	14,417
Transportation	0	282
Other	94	92
Information technology	798	796
Assets under finance lease	160	113
Construction in process	885	613
Total	19,676	17,704
Less accumulated depreciation and depletion	12,422	12,260
Net	$ 7,254	$ 5,444
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	35 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of long-lived assets	40 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