Earnings Per Share (EPS) And Dividends (Basic And Diluted Earnings Per Share Computation) (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net Income	$ 320	$ 493
Weighted Average Common Shares Outstanding, Basic	505,942	506,010
Effect of Stock Based Compensation Awards, Basic	0	0
Total Shares, Basic	505,942	506,010
Continuing Operations, Basic	$ 0.63	$ 0.97
Net Income, Basic	$ 0.63	$ 0.97
Weighted Average Common Shares Outstanding, Diluted	505,942	506,010
Effect of Stock Based Compensation Awards, Diluted	1,278	1,019
Total Shares, Diluted	507,220	507,029
Continuing Operations, Diluted	$ 0.63	$ 0.97
Net Income, Diluted	$ 0.63	$ 0.97