Consolidated Statement Of Changes In Shareholders' Equity (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Total	Series A Preferred Stock [Member]	Series C Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock [Member] Series A Preferred Stock [Member]	Preferred Stock [Member] Series C 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	1,539								1,539
Other comprehensive income	374									374
Preferred stock issued	500			500
Cash dividends declared:
Common stock	(271)								(271)
Preferred stock	(13)								(13)
Common stock acquired, shares											10,700
Common stock acquired	(450)										(450)
Common stock awards and options exercised, including related taxes, shares							1,937				(197)
Common stock awards and options exercised, including related taxes	195						2	183			10
Other, shares											(4)
Other	(10)							(11)			1
Balance at Sep. 30, 2011	19,651			500			504	9,528	9,889	(315)	(455)
Balance, shares at Sep. 30, 2011							504,001				10,919
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	1,591								1,591
Other comprehensive income	845									845
Commitment to redeem preferred stock		(500)			(500)
Preferred stock issued			488			488
Cash dividends declared:
Common stock	(346)								(346)
Preferred stock	(29)								(29)
Common stock acquired, shares	(22,500)										22,496
Common stock acquired	(960)										(960)
Common stock awards and options exercised, including related taxes, shares							(48)				(3,938)
Common stock awards and options exercised, including related taxes	260						0	75			185
Other, shares											(9)
Other	2							2			0
Balance at Sep. 30, 2012	$ 20,749			$ 488			$ 504	$ 9,634	$ 11,392	$ 186	$ (1,455)
Balance, shares at Sep. 30, 2012							503,918				35,091