Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions		Total	Common Stock	Additional Paid-in Capital	Retained Earnings / (Deficit)	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance at Dec. 31, 2018		$ 13,687	$ 0	$ 11,671	$ 10,039	$ (7,825)	$ (198)
Beginning balance (shares) at Dec. 31, 2018			688				8
Consolidated Statements of Stockholders' Equity
Net income/(loss)		4,767			4,767
Dividends declared		(981)			(981)
Other comprehensive income (loss)		(164)				(164)
Common stock issued for employee equity awards and other	[1]	76		114			$ (38)
Common stock issued for employee equity awards and other (shares)	[1]		2				1
Stock purchased and retired		(2,027)		(656)	(1,371)
Stock purchased and retired (shares)			(38)
Ending balance at Dec. 31, 2019		15,358	$ 0	11,129	12,454	(7,989)	$ (236)
Ending balance (shares) at Dec. 31, 2019			652				9
Consolidated Statements of Stockholders' Equity
Net income/(loss)		(12,385)			(12,385)
Dividends declared		(257)			(257)
Other comprehensive income (loss)		(1,049)				(1,049)
Common stock issued for employee equity awards and other	[1]	97		120			$ (23)
Common stock issued for employee equity awards and other (shares)	[1]		1				0
Stock purchased and retired		(344)		(104)	(240)
Stock purchased and retired (shares)			(6)
Government grant warrant issuance		114		114
Ending balance at Dec. 31, 2020		1,534	$ 0	11,259	(428)	(9,038)	$ (259)
Ending balance (shares) at Dec. 31, 2020			647				9
Consolidated Statements of Stockholders' Equity
Net income/(loss)		280			280
Other comprehensive income (loss)		1,908				1,908
Common stock issued for employee equity awards and other	[1]	79		102			$ (23)
Common stock issued for employee equity awards and other (shares)	[1]		3				1
Government grant warrant issuance		86		86
Ending balance at Dec. 31, 2021		$ 3,887	$ 0	$ 11,447	$ (148)	$ (7,130)	$ (282)
Ending balance (shares) at Dec. 31, 2021			650				10

[1] Treasury shares were withheld for payment of taxes, at a weighted average price per share of $38.87, $52.17 and $50.20 in 2021, 2020 and 2019, respectively.