Consolidated Statement Of Changes In Shareholders' Equity (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Total	Series A Preferred Stock	Series C Preferred Stock	Preferred Stock [Member]	Preferred Stock [Member] Series A Preferred Stock	Preferred Stock [Member] Series C Preferred Stock	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2009 (As Previously Reported [Member])	$ 14,491			$ 0			$ 495	$ 9,180	$ 7,071	$ (2,238)	$ (17)
Adjustment for effect of application of provisions of new accounting standard at Dec. 31, 2009	0								27	(27)
Beginning balance at Dec. 31, 2009	14,491			0			495	9,180	7,098	(2,265)	(17)
Beginning balance (shares) at Dec. 31, 2009 (As Previously Reported [Member])							495,366				432
Beginning balance (shares) at Dec. 31, 2009							495,366				432
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,556								1,556
Other comprehensive income	1,576									1,576
Cash dividends declared:
Common stock	(20)								(20)
Common stock awards and options exercised, including related taxes (shares)							6,698
Common stock awards and options exercised, including related taxes	183						7	176
Other (shares)											(12)
Other	1										1
Ending balance at Dec. 31, 2010	17,787						502	9,356	8,634	(689)	(16)
Ending balance (shares) at Dec. 31, 2010				0			502,064				420
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,920								1,920
Other comprehensive income	30									30
Preferred stock issued	500			500
Cash dividends declared:
Common stock	(358)								(358)
Preferred stock	(20)								(20)
Common stock acquired (shares)	16,300										16,313
Common stock acquired	(675)										(675)
Common stock awards and options exercised, including related taxes (shares)	1,028						1,902				(177)
Common stock awards and options exercised, including related taxes	235						2	223			10
Other (shares)											(14)
Other	(21)							(22)			1
Ending balance at Dec. 31, 2011	19,398			500			504	9,557	10,176	(659)	(680)
Ending balance (shares) at Dec. 31, 2011							503,966				16,542
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,061								2,061
Other comprehensive income	1,019									1,019
Redemption of preferred stock		(500)			(500)
Preferred stock issued			488			488
Preferred Stock, Accretion of Issuance Costs	0					1			(1)
Cash dividends declared:
Common stock	(456)								(456)
Preferred stock	(29)								(29)
Common stock acquired (shares)											33,408
Common stock acquired	(1,440)										(1,440)
Common stock awards and options exercised, including related taxes (shares)	1,459						(66)				(4,693)
Common stock awards and options exercised, including related taxes	327							110			217
Other (shares)											(19)
Other	1										1
Ending balance at Dec. 31, 2012	$ 20,869			$ 489			$ 504	$ 9,667	$ 11,751	$ 360	$ (1,902)
Ending balance (shares) at Dec. 31, 2012							503,900				45,238