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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Disclosure Earnings Per Share E P S And Dividends Basic And Diluted Earnings Per Share Computation [Abstract]
Net Income	$ 390	$ 347	$ 1,043	$ 1,051
Weighted Average Common Shares Outstanding, Basic	505,858	505,914	505,900	505,942
Effect of Stock Based Compensation Awards, Basic	0	0	0	0
Total Shares, Basic	505,858	505,914	505,900	505,942
Net Income, Basic	$ 0.77	$ 0.69	$ 2.06	$ 2.08
Weighted Average Common Shares Outstanding, Diluted	505,858	505,914	505,900	505,942
Effect of Stock Based Compensation Awards, Diluted	1,836	1,197	1,533	1,095
Total Shares, Diluted	507,694	507,111	507,433	507,037
Net Income, Diluted	$ 0.77	$ 0.68	$ 2.06	$ 2.07