Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Detail) (USD $) In Millions, except Share data, 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 Schedule Of Basic And Diluted Earnings Per Share [Abstract]
Net income (loss)	$ 132		$ 7		$ 118		$ 598
Basic weighted average shares	192,711,608	[1]	193,879,994	[1]	193,440,078	[1]	193,760,654	[1]
Stock options and warrants	4,035,163		1,097,648		4,322,410		1,074,883
Diluted weighted average shares	196,746,771		194,977,642		197,762,488		194,835,537
Basic	$ 0.68		$ 0.04		$ 0.61		$ 3.09
Diluted	$ 0.67		$ 0.04		$ 0.60		$ 3.07
Unvested restricted stock and units that receive nonforfeitable dividends or dividend equivalents	4,349,481		5,524,396		4,981,970		5,442,143

[1] Includes 4,349,481 and 5,524,396 of unvested restricted stock and units that receive nonforfeitable dividends or dividend equivalents for the three months ended September 30, 2013 and 2012,respectively. Includes 4,981,970 and 5,442,143 of unvested restricted stock and units that receive nonforfeitable dividends or dividend equivalents for the nine months endedSeptember 30, 2013 and 2012, respectively.