Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock	Paid-in Capital in Excess of Par Value	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest in Consolidated Subsidiaries
Beginning balance at Dec. 31, 2018	$ 9,544	$ 2,671	$ 211	$ (6,744)	$ 13,739	$ (355)	$ 22
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,129)	0	0	0	(1,131)	0	2
Other comprehensive income (loss)	(8)	0	0	0	0	(8)	0
Cash dividends	(630)	0	0	0	(630)	0
Cash dividends - Noncontrolling interest							0
Stock plans	348	(2)	(67)	417	0	0	0
Stock repurchase program	(100)	0	0	(100)	0	0	0
Other	0	0	1	0	(11)	(1)	(11)
Ending balance at Dec. 31, 2019	$ 8,025	2,669	143	(6,427)	11,989	(362)	13
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared	$ 0.72
Net income (loss)	$ (2,942)	0	0	0	(2,945)	0	3
Other comprehensive income (loss)	0
Cash dividends	(278)	0	0	0	(278)	0
Cash dividends - Noncontrolling interest							0
Stock plans	285	(3)	(143)	506	(75)	0	0
Stock repurchase program	(100)	0	0	(100)	0	0	0
Other	(7)	0	0	0	0	0	(7)
Ending balance at Dec. 31, 2020	$ 4,983	2,666	0	(6,021)	8,691	(362)	9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared	$ 0.315
Net income (loss)	$ 1,468	0	0	0	1,457	0	11
Other comprehensive income (loss)	179	0	0	0	0	179	0
Cash dividends	(161)	0	0	0	(161)	0
Cash dividends - Noncontrolling interest							0
Stock plans	264	(1)	32	510	(277)	0	0
Other	(5)	0	0	0		0	(5)
Ending balance at Dec. 31, 2021	$ 6,728	$ 2,665	$ 32	$ (5,511)	$ 9,710	$ (183)	$ 15
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared	$ 0.18