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				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Earnings Per Common Share
Net income	$ 555		$ 546		$ 1,539		$ 1,473
Less: Preferred stock dividends	(6)				(13)
Less: Dividends and undistributed earnings allocated to participating securities	(6)	[1]	(6)	[1]	(15)	[1]	(14)	[1]
Net income available to common shareholders	$ 543		$ 540		$ 1,511		$ 1,459
Basic average shares	490,840		495,729		495,015		495,312
Effect of dilutive securities: stock options and stock awards	3,940		2,430		3,402		2,403
Diluted average shares	494,780		498,159		498,417		497,715
Anti-dilutive securities	3,636	[2]	12,386	[2]	2,589	[2]	10,590	[2]
Earnings per share: Basic	$ 1.11		$ 1.09		$ 3.05		$ 2.94
Earnings per share: Diluted	$ 1.10	[3]	$ 1.08	[3]	$ 3.03	[3]	$ 2.93	[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 stock options, restricted stock and other securities 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 was more dilutive than the calculation using the treasury stock method.