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) Income [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	471				471
Other comprehensive income	451					451
Preferred stock issued	500	500
Cash dividends declared:
Common stock	(92)				(92)
Common stock awards and options exercised, including related taxes, shares			1,931
Common stock awards and options exercised, including related taxes	73		2	71
Other, shares							(18)
Other	(10)			(11)			1
Balance at Mar. 31, 2011	19,180	500	504	9,416	9,013	(238)	(15)
Balance, shares at Mar. 31, 2011			503,995				402
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	427				427
Other comprehensive income	360					360
Cash dividends declared:
Common stock	(118)				(118)
Preferred stock	(7)				(7)
Common stock awards and options exercised, including related taxes, shares			(25)				(2,290)
Common stock awards and options exercised, including related taxes	99			(11)			110
Other, shares							(3)
Other
Balance at Mar. 31, 2012	$ 20,159	$ 500	$ 504	$ 9,546	$ 10,478	$ (299)	$ (570)
Balance, shares at Mar. 31, 2012			503,941				14,249