Consolidated Statements Of Stockholders' 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, 2014	$ 26,341	$ 41	$ 4,088	$ 16,631	$ 779		$ 4,802
Balance, shares, at Dec. 31, 2014		409
Net loss	(10,291)			(9,922)			(369)
Other comprehensive earnings (loss), net of tax	(458)				(458)
Restricted stock grants, net of cancellations, shares		2
Common stock repurchased	(23)					$ (23)
Common stock retired			(23)			23
Common stock dividends	(296)			(296)
Share-based compensation	129		129
Subsidiary equity transactions	704		577				127
Distributions to noncontrolling interests	(186)						(186)
Other	2		2
Balance, at Sep. 30, 2015	15,922	$ 41	4,773	6,413	321		4,374
Balance, shares, at Sep. 30, 2015		411
Balance, at Dec. 31, 2015	10,989	$ 42	4,996	1,781	230		3,940
Balance, shares, at Dec. 31, 2015		418
Net loss	(4,024)			(3,633)			(391)
Other comprehensive earnings (loss), net of tax	48				48
Restricted stock grants, net of cancellations, shares		3
Common stock repurchased	(23)					(23)
Common stock retired			(23)			$ 23
Common stock dividends	(190)		(65)	(125)
Common stock issued	2,127	$ 10	2,117
Common stock issued, shares		103
Share-based compensation	142		142
Subsidiary equity transactions	1,216		320				896
Distributions to noncontrolling interests	(224)						(224)
Balance, at Sep. 30, 2016	$ 10,061	$ 52	$ 7,487	$ (1,977)	$ 278		$ 4,221
Balance, shares, at Sep. 30, 2016		524