Consolidated Statements of Equity (USD $) In Millions, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Reinvested Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2009	$ 7,651	$ 237	$ 297	$ 8,469	$ 10,710	$ (5,771)	$ (6,727)	$ 436
Acquisition of a majority interest in a consolidated subsidiary	9							9
Net income	3,052				3,031			21
Other comphrehensive income (loss)	(17)					(19)		2
Common dividends	(1,503)				(1,500)			(3)
Preferred dividends	(10)				(10)
Common Stock
Issued - compensation plans	811		6	805
Repurchased	(250)						(250)
Retired	0		(2)	(47)	(201)		250
Balance at Dec. 31, 2010	9,743	237	301	9,227	12,030	(5,790)	(6,727)	465
Sale of a majority interest in a consolidated subsidiary	(3)							(3)
Net income	3,510				3,474			36
Other comphrehensive income (loss)	(2,978)					(2,960)		(18)
Common dividends	(1,542)				(1,531)			(11)
Preferred dividends	(10)				(10)
Common Stock
Issued - compensation plans	1,014		7	1,007
Repurchased	(672)						(672)
Retired	0		(4)	(127)	(541)		672
Balance at Dec. 31, 2011	9,062	237	304	10,107	13,422	(8,750)	(6,727)	469
Acquisitions of a noncontrolling interest in consolidated subsidiaries	(395)			(25)				(370)
Net income	2,813				2,788			25
Other comphrehensive income (loss)	132					104		28
Common dividends	(1,654)				(1,593)			(61)
Preferred dividends	(10)				(10)
Common Stock
Issued - compensation plans	631		4	627
Repurchased	(400)						(400)
Retired	0		(2)	(77)	(321)		400
Balance at Dec. 31, 2012	$ 10,179	$ 237	$ 306	$ 10,632	$ 14,286	$ (8,646)	$ (6,727)	$ 91