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, 2013		Mar. 31, 2012
Earnings Per Share [Abstract]
Net income	$ 464		$ 427
Less: Preferred stock dividends	(7)		(7)
Less: Dividends and undistributed earnings allocated to participating securities	(2)	[1]	(3)	[1]
Net income available to common shareholders	$ 455		$ 417
Basic average common shares	454,315		484,942
Effect of dilutive securities: common stock options and common stock awards	8,436		5,512
Diluted average shares	462,751		490,454
Anti-dilutive securities	2,488	[2]	1,470	[2]
Earnings per Common Share:
Basic (per share)	$ 1.00		$ 0.86
Diluted (per share)	$ 0.98		$ 0.85

[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 awards, contain 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.