Statements Of Unaudited Condensed Consolidated Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 165	$ 1,282	$ 1,580	$ 2,134
Other comprehensive income (loss):
Changes in pension and OPEB, net of tax	93	6	94	20
Changes in foreign currency translation	(2)	0	(4)	(1)
Changes in derivative financial instruments, net of tax	61	83	102	137
Total other comprehensive income	152	89	192	156
Comprehensive income	317	1,371	1,772	2,290
Comprehensive income attributable to noncontrolling interests	(13)	(8)	(31)	(39)
Comprehensive income attributable to Cliffs shareholders	$ 304	$ 1,363	$ 1,741	$ 2,251