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
	Mar. 31, 2012		Mar. 31, 2011
Earnings Per Share [Abstract]
Net income	$ 427		$ 471
Less: Preferred stock dividends	(7)		0
Less: Dividends and undistributed earnings allocated to participating securities	(3)	[1]	(5)	[1]
Net income available to common stockholders, Basic	$ 417		$ 466
Basic average shares	484,942		497,471
Effect of dilutive securities: stock options and stock awards	5,512		3,509
Diluted average shares	490,454		500,980
Anti-dilutive securities	1,470	[2]	1,311	[2]
Earnings per share: Basic	$ 0.86		$ 0.94
Earnings per share: Diluted	$ 0.85	[3]	$ 0.93	[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.