Consolidated Statement of Changes In Shareholders' Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	PREFERRED STOCK	COMMON STOCK	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	TREASURY STOCK
Beginning balance at Dec. 31, 2012	$ 20,869	$ 489	$ 504	$ 9,667	$ 11,751	$ 360	$ (1,902)
Beginning balance (shares) at Dec. 31, 2012			503,900,000				45,238,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	464				464
Other comprehensive income (loss)	(109)					(109)
Cash dividends declared:
Common stock	(118)				(118)
Preferred stock	(7)				(7)
Common stock acquired	(360)						(360)
Common stock acquired (shares)							6,548,000
Common stock awards and options exercised, including related taxes	130			2			128
Common stock awards and options exercised, including related taxes (shares)			(4,000)				(3,475,000)
Other	0
Other (shares)							(7,000)
Ending balance at Mar. 31, 2013	20,869	489	504	9,669	12,090	251	(2,134)
Ending balance (shares) at Mar. 31, 2013			503,896,000				48,304,000
Beginning balance at Dec. 31, 2013	20,378	491	504	9,776	13,395	(95)	(3,693)
Beginning balance (shares) at Dec. 31, 2013			503,883,000				69,754,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	363				363
Other comprehensive income (loss)	283					283
Preferred stock issued	742	742
Cash dividends declared:
Common stock	(112)				(112)
Preferred stock	(6)				(6)
Common stock acquired	(420)						(420)
Common stock acquired (shares)							6,075,000
Common stock awards and options exercised, including related taxes	46			(39)			85
Common stock awards and options exercised, including related taxes (shares)			(2,000)				(2,403,000)
Other	(1)				(1)
Other (shares)							14,000
Ending balance at Mar. 31, 2014	$ 21,273	$ 1,233	$ 504	$ 9,737	$ 13,639	$ 188	$ (4,028)
Ending balance (shares) at Mar. 31, 2014			503,881,000				73,440,000