Earnings Per Share (Schedule Of Basic And Diluted Earnings Per Share) (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Stock options outstanding, antidilutive	3,045,974		3,559,044
Net income (loss)	$ 164		$ 10
Basic weighted average shares	194,523,933	[1]	193,489,424	[1]
Effect of common stock equivalents: Stock options	1,108,027		1,105,550
Diluted weighted average shares	195,631,960		194,594,974
Basic	$ 0.84		$ 0.05
Diluted	$ 0.84		$ 0.05
Unvested restricted stock and units that receive nonforfeitable dividends or dividend equivalents	6,125,599		5,219,053

[1] Includes 6,125,599 and 5,219,053 of unvested restricted stock and units that receive nonforfeitable dividends or dividend equivalents for the three months ended March 31, 2013 and 2012, respectively.