Consolidated Statement Of Changes In Shareholders' Equity (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2010	$ 17,787		$ 502	$ 9,356	$ 8,634	$ (689)	$ (16)
Balance, shares at Dec. 31, 2010			502,064				420
Net income	984				984
Other comprehensive income	849					849
Preferred stock issued	500	500
Cash dividends declared:
Common stock	(181)				(181)
Preferred stock	(7)				(7)
Common stock acquired, shares							4,872
Common stock acquired	(225)						(225)
Common stock awards and options exercised, including related taxes, shares			1,988				(127)
Common stock awards and options exercised, including related taxes	137		2	129			6
Other, shares							(7)
Other	(10)			(11)			1
Balance at Jun. 30, 2011	19,834	500	504	9,474	9,430	160	(234)
Balance, shares at Jun. 30, 2011			504,052				5,158
Balance at Dec. 31, 2011	19,398	500	504	9,557	10,176	(659)	(680)
Balance, shares at Dec. 31, 2011			503,966				16,542
Net income	917				917
Other comprehensive income	122					122
Cash dividends declared:
Common stock	(233)				(233)
Preferred stock	(14)				(14)
Common stock acquired, shares	(11,100)						11,098
Common stock acquired	(480)						(480)
Common stock awards and options exercised, including related taxes, shares			(35)				(2,534)
Common stock awards and options exercised, including related taxes	186		0	65			121
Other, shares							3
Other	1			1			0
Balance at Jun. 30, 2012	$ 19,897	$ 500	$ 504	$ 9,623	$ 10,846	$ (537)	$ (1,039)
Balance, shares at Jun. 30, 2012			503,931				25,109