Consolidated Statements Of Equity - USD ($) shares in Millions, $ in Millions	Total	Effect of Adoption of Lease Accounting [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earning [Member]	Retained Earning [Member] Effect of Adoption of Lease Accounting [Member]	Other Comprehensive Earnings (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2017	$ 14,104		$ 53	$ 7,333	$ 702		$ 1,166		$ 4,850
Balance, shares at Dec. 31, 2017			525
Net earnings (loss)	3,224				3,064				160
Other comprehensive earnings (loss), net of tax	(108)						(108)
Restricted stock grants, net of cancellations, shares			3
Common stock repurchased	(3,017)							$ (3,017)
Common stock retired			$ (8)	(2,987)				2,995
Common stock retired, shares			(79)
Common stock dividends	(149)				(149)
Share-based compensation	140			140
Share-based compensation, shares			1
Divestment of subsidiary equity investment	(4,861)						2		(4,863)
Subsidiary equity transactions	72								72
Distributions to noncontrolling interests	(219)								(219)
Other					33		(33)
Balance at Dec. 31, 2018	9,186	$ (7)	$ 45	4,486	3,650	$ (7)	1,027	(22)
Balance, shares at Dec. 31, 2018			450
Net earnings (loss)	(353)				(355)				2
Other comprehensive earnings (loss), net of tax	(1,146)						(1,146)
Restricted stock grants, net of cancellations, shares			3
Common stock repurchased	(1,852)							(1,852)
Common stock retired			$ (7)	(1,867)				1,874
Common stock retired, shares			(71)
Common stock dividends	(140)				(140)
Share-based compensation	116			116
Contributions from noncontrolling interests	116								116
Balance at Dec. 31, 2019	5,920		$ 38	2,735	3,148		(119)		118
Balance, shares at Dec. 31, 2019			382
Net earnings (loss)	(2,671)				(2,680)				9
Other comprehensive earnings (loss), net of tax	(8)						(8)
Restricted stock grants, net of cancellations, shares			3
Common stock repurchased	(57)							(57)
Common stock retired				(57)				$ 57
Common stock retired, shares			(3)
Common stock dividends	(260)				(260)
Share-based compensation	88			88
Contributions from noncontrolling interests	21								21
Distributions to noncontrolling interests	(14)								(14)
Balance at Dec. 31, 2020	$ 3,019		$ 38	$ 2,766	$ 208		$ (127)		$ 134
Balance, shares at Dec. 31, 2020			382