ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)

6 Months Ended

Jun. 30, 2021

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)

The following tables reflect the changes in Accumulated other comprehensive loss related to Cliffs shareholders’ equity:

	(In Millions)
	Postretirement Benefit Liability, net of tax		Foreign Currency Translation		Derivative Financial Instruments, net of tax		Accumulated Other Comprehensive Loss
December 31, 2020	$	(135)	$	3	$	(1)	$	(133)
Other comprehensive income (loss) before reclassifications	—		(1)		8		7
Net (income) loss reclassified from accumulated other comprehensive loss	7		—		(1)		6
March 31, 2021	$	(128)	$	2	$	6	$	(120)
Other comprehensive income before reclassifications	—		—		51		51
Net (income) loss reclassified from accumulated other comprehensive loss	7		—		(4)		3
June 30, 2021	$	(121)	$	2	$	53	$	(66)

	(In Millions)
	Postretirement Benefit Liability, net of tax		Foreign Currency Translation		Derivative Financial Instruments, net of tax		Accumulated Other Comprehensive Loss
December 31, 2019	$	(316)	$	—	$	(3)	$	(319)
Other comprehensive loss before reclassifications	—		(1)		(5)		(6)
Net loss reclassified from accumulated other comprehensive loss	6		—		2		8
March 31, 2020	$	(310)	$	(1)	$	(6)	$	(317)
Other comprehensive income before reclassifications	—		1		1		2
Net loss reclassified from accumulated other comprehensive loss	6		—		3		9
June 30, 2020	$	(304)	$	—	$	(2)	$	(306)

Details of Accumulated Other Comprehensive Income (Loss) Components

The following table reflects the details about Accumulated other comprehensive loss components reclassified from Cliffs shareholders’ equity:

	(In Millions)
Details about Accumulated Other Comprehensive Loss Components	Amount of (Income)/Loss Reclassified into Income, Net of Tax								Affected Line Item in the Statement of Unaudited Condensed Consolidated Operations
	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Changes in pension and OPEB:
Prior service credits	$	—	$	(1)	$	—	$	(1)	Net periodic benefit credits other than service cost component
Net actuarial loss	9		8		18		15		Net periodic benefit credits other than service cost component
	9		7		18		14		Total before taxes
Income tax benefit	(2)		(1)		(4)		(2)		Income tax benefit (expense)
Net of taxes	$	7	$	6	$	14	$	12
Changes in derivative financial instruments:
Commodity contracts	$	(5)	$	4	$	(6)	$	7	Cost of goods sold
Income tax (benefit) expense	1		(1)		1		(2)		Income tax benefit (expense)
Net of taxes	$	(4)	$	3	$	(5)	$	5
Total reclassifications for the period, net of tax	$	3	$	9	$	9	$	17