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		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Disclosure Earnings Per Share E P S And Dividends Basic And Diluted Earnings Per Share Computation [Abstract]
Net Income	$ 333	$ 211	$ 653	$ 704
Weighted Average Common Shares Outstanding, Basic	505,900	505,903	505,921	505,956
Effect of Stock Based Compensation Awards, Basic	0	0	0	0
Total Shares, Basic	505,900	505,903	505,921	505,956
Net Income, Basic	$ 0.66	$ 0.42	$ 1.29	$ 1.39
Weighted Average Common Shares Outstanding, Diluted	505,900	505,903	505,921	505,956
Effect of Stock Based Compensation Awards, Diluted	1,481	1,066	1,380	1,043
Total Shares, Diluted	507,381	506,969	507,301	506,999
Net Income, Diluted	$ 0.66	$ 0.42	$ 1.29	$ 1.39