Earnings Per Common Share (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Earnings Per Share [Abstract]
Net income	$ 490		$ 513		$ 917		$ 984
Less: Preferred stock dividends	(7)		(7)		(14)		(7)
Less: Dividends and undistributed earnings allocated to participating securities	(3)	[1]	(4)	[1]	(6)	[1]	(9)	[1]
Net income available to common shareholders	$ 480		$ 502		$ 897		$ 968
Basic average common shares	481,404		496,806		483,165		497,137
Effect of dilutive securities: common stock options and common stock awards	7,114		4,238		5,980		3,616
Diluted average shares	488,518		501,044		489,145		500,753
Anti-dilutive securities	5,525	[2]	1,434	[2]	5,678	[2]	1,155	[2]
Earnings per Common Share: Basic	$ 1.00		$ 1.01		$ 1.86		$ 1.95
Earnings per Common Share: Diluted	$ 0.98	[3]	$ 1.00	[3]	$ 1.83	[3]	$ 1.93	[3]

[1] Represented the portion of net income available to common equity allocated to participating securities; participating securities, composed of unvested restricted stock and director stock, have non-forfeitable rights to dividends during the vesting period on a basis equivalent to dividends paid to common shareholders.

[2] Represented common stock options and other equity-based awards outstanding but not included in the computation of diluted average shares because their effect was anti-dilutive.

[3] Calculations reflect the allocation of earnings to participating securities using the two-class method, as this computation is more dilutive than the calculation using the treasury stock method.