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	462							335					127
Other comprehensive (loss) income (C)	(506)											(289)	(217)
Cash dividends declared:
Common share, value	(74)							(74)
Preferred share, value		$ (1)	$ (34)						$ (1)	$ (34)
Stock-based compensation	55						55
Common stock issued: compensation plans	16						(192)				208
Distributions	(71)												(71)
Other	(3)												(3)
Balance at Jun. 30, 2015	14,638			55	3	1,304	9,147	9,605			(2,834)	(4,966)	2,324
Balance at Mar. 31, 2015	13,843			55	3	1,304	9,124	9,520			(2,841)	(5,591)	2,269
Net income	207							140					67
Other comprehensive (loss) income (C)	656											625	31
Cash dividends declared:
Common share, value	(38)							(38)
Preferred share, value			(17)							(17)
Stock-based compensation	29						29
Common stock issued: compensation plans	1						(6)				7
Distributions	(42)												(42)
Other	(1)												(1)
Balance at Jun. 30, 2015	14,638			55	3	1,304	9,147	9,605			(2,834)	(4,966)	2,324
Balance at Dec. 31, 2015	14,131			55	3	1,391	10,019	8,834			(2,825)	(5,431)	2,085
Net income	189							151					38
Other comprehensive (loss) income (C)	372											216	156
Cash dividends declared:
Common share, value	(79)							(79)
Preferred share, value		$ (1)	(34)						$ (1)	(34)
Stock-based compensation	55						55
Common stock issued: compensation plans	(19)						(197)				178
Distributions	(84)												(84)
Other	(1)												(1)
Balance at Jun. 30, 2016	14,529			55	3	1,391	9,877	8,871			(2,647)	(5,215)	2,194
Balance at Mar. 31, 2016	14,361			55	3	1,391	9,856	8,753			(2,657)	(5,175)	2,135
Net income	178							135					43
Other comprehensive (loss) income (C)	10											(40)	50
Cash dividends declared:
Preferred share, value			$ (17)							$ (17)
Stock-based compensation	29						29
Common stock issued: compensation plans	2						(8)				10
Distributions	(34)												(34)
Balance at Jun. 30, 2016	$ 14,529			$ 55	$ 3	$ 1,391	$ 9,877	$ 8,871			$ (2,647)	$ (5,215)	$ 2,194