Consolidated Statements Of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Other Comprehensive Earnings (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2018	$ 9,186	$ 45	$ 4,486	$ 3,650	$ 1,027	$ (22)
Balance, shares at Dec. 31, 2018		450
Effect of adoption of lease accounting at Dec. 31, 2018	(19)			(19)
Net earnings (loss)	(317)			(317)
Other comprehensive earnings, net of tax	37				37
Restricted stock grants, net of cancellations, shares		3
Common stock repurchased	(1,042)					(1,042)
Common stock retired		$ (3)	(1,014)			1,017
Common stock retired, shares		(36)
Common stock dividends	(34)			(34)
Share-based compensation	46		46
Balance at Mar. 31, 2019	7,857	$ 42	3,518	3,280	1,064	(47)
Balance, shares at Mar. 31, 2019		417
Balance at Dec. 31, 2019	5,920	$ 38	2,735	3,148	(119)		$ 118
Balance, shares at Dec. 31, 2019		382
Net earnings (loss)	(1,815)			(1,816)			1
Other comprehensive earnings, net of tax	1				1
Restricted stock grants, net of cancellations, shares		3
Common stock repurchased	(54)					(54)
Common stock retired			(54)			$ 54
Common stock retired, shares		(3)
Common stock dividends	(34)			(34)
Share-based compensation	20		20
Share-based compensation, shares		1
Contributions from noncontrolling interests	5						5
Distributions to noncontrolling interests	(3)						(3)
Balance at Mar. 31, 2020	$ 4,040	$ 38	$ 2,701	$ 1,298	$ (118)		$ 121
Balance, shares at Mar. 31, 2020		383