Statement of Changes in Consolidated Equity (USD $) In Millions, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Balance at Mar. 31, 2013	$ 16,774	$ 55	$ 1,178	$ 7,508	$ 11,805	$ (3,816)	$ (3,309)	$ 3,353
Net income (loss)	(148)				(119)			(29)
Other comprehensive income (loss)	(723)						(474)	(249)
Cash dividends declared:
Common share, value	(33)				(33)
Stock-based compensation	23			23
Common stock issued: compensation plans	(3)			(7)		4
Distributions	(28)							(28)
Contributions	(3)							(3)
Other	(1)							(1)
Balance at Jun. 30, 2013	15,858	55	1,178	7,524	11,653	(3,812)	(3,783)	3,043
Balance at Dec. 31, 2012	16,523	55	1,178	7,560	11,689	(3,881)	(3,402)	3,324
Net income (loss)	22				30			(8)
Other comprehensive income (loss)	(611)						(381)	(230)
Cash dividends declared:
Preferred share, value	(1)				(1)
Common share, value	(65)				(65)
Stock-based compensation	46			46
Common stock issued: compensation plans	(13)			(82)		69
Distributions	(53)							(53)
Contributions	12							12
Other	(2)							(2)
Balance at Jun. 30, 2013	15,858	55	1,178	7,524	11,653	(3,812)	(3,783)	3,043
Balance at Dec. 31, 2013	13,522	55	1,178	7,509	9,272	(3,762)	(3,659)	2,929
Net income (loss)	(68)				(40)			(28)
Other comprehensive income (loss)	632						491	141
Cash dividends declared:
Preferred share, value	(1)				(1)
Common share, value	(68)				(68)
Stock-based compensation	49			49
Common stock issued: compensation plans	78			(409)		487
Issuance of common stock (G)	575		89	486
Distributions	(55)							(55)
Contributions	44							44
Other	(2)							(2)
Balance at Jun. 30, 2014	14,706	55	1,267	7,635	9,163	(3,275)	(3,168)	3,029
Balance at Mar. 31, 2014	14,374	55	1,267	7,704	9,061	(3,395)	(3,301)	2,983
Net income (loss)	129				138			(9)
Other comprehensive income (loss)	185						133	52
Cash dividends declared:
Common share, value	(36)				(36)
Stock-based compensation	24			24
Common stock issued: compensation plans	27			(93)		120
Distributions	(20)							(20)
Contributions	24							24
Other	(1)							(1)
Balance at Jun. 30, 2014	$ 14,706	$ 55		$ 7,635	$ 9,163	$ (3,275)	$ (3,168)	$ 3,029