Statement of Changes in Consolidated Equity (Unaudited) - 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, 2014	$ 14,794			$ 55	$ 3	$ 1,304	$ 9,284	$ 9,379			$ (3,042)	$ (4,677)	$ 2,488
Net income	568							379					189
Other comprehensive (loss) income (C)	(1,361)											(855)	(506)
Cash dividends declared:
Preferred share, value		$ (2)	$ (50)						$ (2)	$ (50)
Common share, value	(153)							(153)
Stock-based compensation	78						78
Common stock issued: compensation plans	21						(191)				212
Issuance of common stock (E)	870					87	783
Distributions	(72)												(72)
Other	(2)												(2)
Balance at Sep. 30, 2015	14,691			55	3	1,391	9,954	9,553			(2,830)	(5,532)	2,097
Balance at Jun. 30, 2015	14,638			55	3	1,304	9,147	9,605			(2,834)	(4,966)	2,324
Net income	106							44					62
Other comprehensive (loss) income (C)	(855)											(566)	(289)
Cash dividends declared:
Preferred share, value		(1)	(16)						(1)	(16)
Common share, value	(79)							(79)
Stock-based compensation	23						23
Common stock issued: compensation plans	5						1				4
Issuance of common stock (E)	870					87	783
Distributions	(1)												(1)
Other	1												1
Balance at Sep. 30, 2015	14,691			55	3	1,391	9,954	9,553			(2,830)	(5,532)	2,097
Balance at Dec. 31, 2015	14,131			55	3	1,391	10,019	8,834			(2,825)	(5,431)	2,085
Net income	375							317					58
Other comprehensive (loss) income (C)	(237)											(427)	190
Cash dividends declared:
Preferred share, value		(2)	(50)						(2)	(50)
Common share, value	(159)							(159)
Stock-based compensation	73						73
Common stock issued: compensation plans	(23)						(209)				186
Retirement of Treasury stock (M)						(76)	(2,563)				2,639
Reverse stock split (A & M)						(877)	877
Distributions	(176)												(176)
Other	13												13
Balance at Sep. 30, 2016	13,945			55	3	438	8,197	8,940				(5,858)	2,170
Balance at Jun. 30, 2016	14,529			55	3	1,391	9,877	8,871			(2,647)	(5,215)	2,194
Net income	186							166					20
Other comprehensive (loss) income (C)	(609)											(643)	34
Cash dividends declared:
Preferred share, value		$ (1)	$ (16)						$ (1)	$ (16)
Common share, value	(80)							(80)
Stock-based compensation	18						18
Common stock issued: compensation plans	(4)						(12)				8
Retirement of Treasury stock (M)						(76)	(2,563)				$ 2,639
Reverse stock split (A & M)						(877)	877
Distributions	(92)												(92)
Other	14												14
Balance at Sep. 30, 2016	$ 13,945			$ 55	$ 3	$ 438	$ 8,197	$ 8,940				$ (5,858)	$ 2,170