Cleveland-Cliffs Inc. Quarterly report pursuant to Section 13 or 15(d)

REVENUES - Revenues By Product Line (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 5,199	$ 5,295
Steelmaking
Disaggregation of Revenue [Line Items]
Revenues	5,027	5,126
Steelmaking \| Hot-rolled steel
Disaggregation of Revenue [Line Items]
Revenues	1,128	1,121
Steelmaking \| Cold-rolled steel
Disaggregation of Revenue [Line Items]
Revenues	749	639
Steelmaking \| Coated steel
Disaggregation of Revenue [Line Items]
Revenues	1,623	1,617
Steelmaking \| Stainless and electrical steel
Disaggregation of Revenue [Line Items]
Revenues	461	574
Steelmaking \| Plate
Disaggregation of Revenue [Line Items]
Revenues	333	331
Steelmaking \| Slab and other steel products
Disaggregation of Revenue [Line Items]
Revenues	335	327
Steelmaking \| Other
Disaggregation of Revenue [Line Items]
Revenues	398	517
Other Businesses
Disaggregation of Revenue [Line Items]
Revenues	172	169
Other Businesses \| Other
Disaggregation of Revenue [Line Items]
Revenues	$ 172	$ 169