Consolidated Statements Of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2016	$ 12,722	$ 52	$ 7,237	$ (69)	$ 1,054		$ 4,448
Balance, shares at Dec. 31, 2016		523
Net earnings (loss)	562			522			40
Other comprehensive earnings (loss), net of tax	45				45
Restricted stock grants, net of cancellations, value	1	$ 1
Restricted stock grants, net of cancellations, shares		2
Common stock repurchased	(41)					$ (41)
Common stock retired			(41)			41
Common stock dividends	(65)			(65)
Share-based compensation	69		69
Share-based compensation, shares		1
Subsidiary equity transactions	117		11				106
Distributions to noncontrolling interests	(163)						(163)
Balance at Jun. 30, 2017	13,247	$ 53	7,276	388	1,099		4,431
Balance, shares at Jun. 30, 2017		526
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)	(488)			(622)			134
Other comprehensive earnings (loss), net of tax	(75)				(75)
Restricted stock grants, net of cancellations, shares		3
Common stock repurchased	(556)	$ (1)				(555)
Common stock retired		$ (1)	(532)			533
Common stock retired, shares		(14)
Common stock dividends	(74)			(74)
Share-based compensation	89		89
Share-based compensation, shares		1
Subsidiary equity transactions	67		(2)				69
Distributions to noncontrolling interests	(219)						(219)
Balance at Jun. 30, 2018	$ 12,848	$ 51	$ 6,888	$ 6	$ 1,091	$ (22)	$ 4,834
Balance, shares at Jun. 30, 2018		515