INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

Income (loss) from continuing operations before income taxes includes the following components:

	(In Millions)
	2020		2019		2018
United States	$	(201)	$	313	$	565
Foreign	8		—		—
	$	(193)	$	313	$	565

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

The components of the income tax provision (benefit) on continuing operations consist of the following:

	(In Millions)
	2020		2019		2018
Current provision (benefit):
United States federal	$	(2)	$	(1)	$	(1)
United States state & local	—		—		—
Foreign	(1)		—		1
	(3)		(1)		—
Deferred provision (benefit):
United States federal	(95)		19		(475)
United States state & local	(11)		—		—
Foreign	(2)		—		—
Total income tax provision (benefit) from continuing operations	$	(111)	$	18	$	(475)

The components of income taxes for other than continuing operations consisted of the following:

	(In Millions)
	2020		2019		2018
Other comprehensive income:
Postretirement benefit liability	$	(52)	$	11	$	4
Unrealized net loss on derivative financial instruments	(1)		—		1
Total	$	(53)	$	11	$	5

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Reconciliation of our income tax attributable to continuing operations computed at the U.S. federal statutory rate is as follows:

	(In Millions)
	2020				2019				2018
Tax at U.S. statutory rate	$	(41)	21	%	$	66	21	%	$	119	21	%
Increase (decrease) due to:
Percentage depletion in excess of cost depletion	(42)		22		(49)		(16)		(55)		(10)
Non-taxable income related to noncontrolling interests	(9)		4		—		—		—		—
Luxembourg legal entity reduction	—		—		846		271		162		29
Valuation allowance release:
Current year activity	—		—		—		—		(80)		(14)
Release of U.S. valuation allowance	—		—		—		—		(461)		(81)
Luxembourg legal entity reduction	—		—		(846)		(271)		(162)		(29)
State taxes, net	(11)		6		—		—		—		—
Other items, net	(8)		4		1		1		2		—
Provision for income tax expense (benefit) and effective income tax rate including discrete items	$	(111)	57	%	$	18	6	%	$	(475)	(84)	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

Significant components of our deferred tax assets and liabilities are as follows:

	(In Millions)
	2020		2019
Deferred tax assets:
Operating loss and other carryforwards	$	1,236	$	795
Pension and OPEB liabilities	228		114
Property, plant and equipment and mineral rights	—		1
State and local	132		71
Other liabilities	190		70
Total deferred tax assets before valuation allowance	1,786		1,051
Deferred tax asset valuation allowance	(836)		(441)
Net deferred tax assets	950		610
Deferred tax liabilities:
Investment in partnerships	(144)		(137)
Property, plant and equipment and mineral rights	(246)		—
Other assets	(68)		(14)
Total deferred tax liabilities	(458)		(151)
Net deferred tax assets	$	492	$	459

Summary of Valuation Allowance [Table Text Block]

The changes in the valuation allowance are presented below:

	(In Millions)
	2020		2019		2018
Balance at beginning of year	$	441	$	1,287	$	1,983
Change in valuation allowance:
Included in income tax expense (benefit)	(3)		(846)		(691)
Change in deferred assets in other comprehensive income	—		—		(5)
Increase from acquisitions	398		—		—
Balance at end of year	$	836	$	441	$	1,287

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:

	(In Millions)
	2020		2019		2018
Unrecognized tax benefits balance as of January 1	$	29	$	29	$	33
Increase for tax positions in current year	7		—		4
Decrease for tax positions of prior year	(4)		—		—
Lapses in statutes of limitations	—		—		(8)
Increases from acquisitions	75		—		—
Unrecognized tax benefits balance as of December 31	$	107	$	29	$	29