Statement of Changes in Consolidated Equity - USD ($) $ in Millions	Total	Preferred Class A [Member]	Preferred Class B [Member]	Preferred Stock [Member]	Mandatory Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Preferred Class A [Member]	Retained Earnings [Member] Preferred Class B [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2012	$ 16,523			$ 55		$ 1,178	$ 7,560	$ 11,689			$ (3,881)	$ (3,402)	$ 3,324
Net (loss) income	(2,244)							(2,285)					41
Other comprehensive loss (B)	(595)											(257)	(338)
Cash dividends declared:
Preferred share, value	(2)							(2)
Common share, value	(130)							(130)
Stock-based compensation (R)	71						71
Common stock issued: compensation plans (R)	(3)						(122)				119
Distributions	(109)												(109)
Contributions (M)	12												12
Other	(1)												(1)
Balance at Dec. 31, 2013	13,522			55		1,178	7,509	9,272			(3,762)	(3,659)	2,929
Net (loss) income	177							268					(91)
Other comprehensive loss (B)	(1,272)											(1,018)	(254)
Cash dividends declared:
Preferred share, value		$ (2)	$ (19)						$ (2)	$ (19)
Common share, value	(140)							(140)
Stock-based compensation (R)	87						87
Common stock issued: compensation plans (R)	136						(584)				720
Issuance of mandatory convertible preferred stock (R)	1,213				$ 3		1,210
Issuance of common stock (F, K, & R)	1,185					126	1,059
Distributions	(120)												(120)
Contributions (M)	53												53
Purchase of equity from noncontrolling interest (F)	(28)						3						(31)
Other	2												2
Balance at Dec. 31, 2014	14,794			55	3	1,304	9,284	9,379			(3,042)	(4,677)	2,488
Net (loss) income	(197)							(322)					125
Other comprehensive loss (B)	(1,176)											(754)	(422)
Cash dividends declared:
Preferred share, value		$ (2)	$ (67)						$ (2)	$ (67)
Common share, value	(154)							(154)
Equity option on convertible notes (F)	55						55
Stock-based compensation (R)	92						92
Common stock issued: compensation plans (R)	22						(195)				217
Issuance of common stock (F, K, & R)	870					87	783
Distributions	(106)												(106)
Contributions (M)	2												2
Other	(2)												(2)
Balance at Dec. 31, 2015	$ 14,131			$ 55	$ 3	$ 1,391	$ 10,019	$ 8,834			$ (2,825)	$ (5,431)	$ 2,085