CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions		Total		Common Stock	Preferred Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Common Stock in Treasury
Beginning balance (in shares) at Dec. 31, 2017				512,134,311	1,725,000				31,269
Beginning balance at Dec. 31, 2017		$ 1,979		$ 5		$ 4,698	$ (2,679)	$ (44)	$ (1)
Comprehensive income
Net income (loss)		537	[1]				537
Other comprehensive income		8						8
Comprehensive income (loss)	[1]	545
Stock-based compensation		21				21
Preferred stock dividend (in shares)				74,998,614	(1,725,000)
Preferred stock dividend		$ 0		$ 1		(1)
Issuance of restricted stock (in shares)				349,562
Cancellation of restricted stock (in shares)				(1,804,122)
Performance units vested (in shares)				214,866
Treasury stock (in shares)		39,061,268							39,061,268
Treasury stock		$ (180)							$ (180)
Tax withholding - stock compensation (in shares)				(486,124)
Tax withholding – stock compensation		(3)				(3)
Ending balance (in shares) at Dec. 31, 2018				585,407,107	0				39,092,537
Ending balance at Dec. 31, 2018		2,362		$ 6		4,715	(2,142)	(36)	$ (181)
Comprehensive income
Net income (loss)		891					891
Other comprehensive income		3						3
Comprehensive income (loss)		894
Stock-based compensation		$ 12				12
Issuance of restricted stock (in shares)				236,978
Cancellation of restricted stock (in shares)				(239,571)
Performance units vested (in shares)				535,802
Treasury stock (in shares)		5,260,687							5,260,687
Treasury stock		$ (21)							$ (21)
Tax withholding - stock compensation (in shares)				(384,393)
Tax withholding – stock compensation		(1)				(1)
Ending balance (in shares) at Dec. 31, 2019				585,555,923	0				44,353,224
Ending balance at Dec. 31, 2019		3,246		$ 6		4,726	(1,251)	(33)	$ (202)
Comprehensive income
Net income (loss)		(3,112)					(3,112)
Other comprehensive income		(5)						(5)
Comprehensive income (loss)		(3,117)
Stock-based compensation		4				4
Issuance of common stock (in shares)				63,250,000
Issuance of common stock		152				152
Issuance of restricted stock (in shares)				311,446
Cancellation of restricted stock (in shares)				(1,274,802)
Restricted units granted (in shares)				2,697,170
Restricted units granted		3				3
Montage acquisition exchange (in shares)				69,740,848
Montage merger exchange		213		$ 1		212
Tax withholding - stock compensation (in shares)				(1,484,885)
Tax withholding – stock compensation		(4)				(4)
Ending balance (in shares) at Dec. 31, 2020				718,795,700	0				44,353,224
Ending balance at Dec. 31, 2020		$ 497		$ 7		$ 5,093	$ (4,363)	$ (38)	$ (202)

[1] In 2018, deferred tax activity incurred in other comprehensive income was offset by a valuation allowance.