EARNINGS PER SHARE (Tables)

9 Months Ended

Sep. 30, 2020

Earnings Per Share [Abstract]

Earnings Per Share Computation

The following table summarizes the computation of basic and diluted earnings per share:

	(In Millions, Except Per Share Amounts)
	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Income (loss) from continuing operations	$	2.2	$	91.8	$	(154.8)	$	231.1
Income from continuing operations attributable to noncontrolling interest	(11.9)		—		(31.2)		—
Net income (loss) from continuing operations attributable to Cliffs shareholders	(9.7)		91.8		(186.0)		231.1
Loss from discontinued operations, net of tax	(0.3)		(0.9)		—		(1.5)
Net income (loss) attributable to Cliffs shareholders	$	(10.0)	$	90.9	$	(186.0)	$	229.6
Weighted average number of shares:
Basic	399.4		270.0		365.2		278.4
Convertible senior notes	—		3.7		—		5.8
Employee stock plans	—		2.9		—		3.6
Diluted	399.4		276.6		365.2		287.8
Earnings (loss) per common share attributable to Cliffs shareholders - basic:
Continuing operations	$	(0.02)	$	0.34	$	(0.51)	$	0.83
Discontinued operations	—		—		—		(0.01)
	$	(0.02)	$	0.34	$	(0.51)	$	0.82
Earnings (loss) per common share attributable to Cliffs shareholders - diluted:
Continuing operations	$	(0.02)	$	0.33	$	(0.51)	$	0.80
Discontinued operations	—		—		—		—
	$	(0.02)	$	0.33	$	(0.51)	$	0.80

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

The following table summarizes the shares that have been excluded from the diluted earnings per share calculation as they were anti-dilutive:

	(In Millions)
	Three Months Ended September 30,		Nine Months Ended September 30,
	2020	2019	2020	2019
Shares related to employee stock plans	1.8	—	1.6	—